Calling local_bh_enable() will want to actually start processing
softirqs, which isn't a good idea since this can get called with IRQs
disabled.
Cure this by using _local_bh_enable() which doesn't start processing
softirqs, and use raw_local_irq_save() to avoid any softirqs from
happening without letting lockdep think IRQs are in fact disabled.
Reported-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
LKML-Reference: <20110203141548.039540914@chello.nl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix update_curr_rt()
sched, docs: Update schedstats documentation to version 15
Currently the syscall_meta structures for the syscall tracepoints are
placed in the __syscall_metadata section, and at link time, the linker
makes one large array of all these syscall metadata structures. On boot
up, this array is read (much like the initcall sections) and the syscall
data is processed.
The problem is that there is no guarantee that gcc will place complex
structures nicely together in an array format. Two structures in the
same file may be placed awkwardly, because gcc has no clue that they
are suppose to be in an array.
A hack was used previous to force the alignment to 4, to pack the
structures together. But this caused alignment issues with other
architectures (sparc).
Instead of packing the structures into an array, the structures' addresses
are now put into the __syscall_metadata section. As pointers are always the
natural alignment, gcc should always pack them tightly together
(otherwise initcall, extable, etc would also fail).
By having the pointers to the structures in the section, we can still
iterate the trace_events without causing unnecessary alignment problems
with other architectures, or depending on the current behaviour of
gcc that will likely change in the future just to tick us kernel developers
off a little more.
The __syscall_metadata section is also moved into the .init.data section
as it is now only needed at boot up.
Suggested-by: David Miller <davem@davemloft.net>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make the tracepoints more robust, making them solid enough to handle compiler
changes by not relying on anything based on compiler-specific behavior with
respect to structure alignment. Implement an approach proposed by David Miller:
use an array of const pointers to refer to the individual structures, and export
this pointer array through the linker script rather than the structures per se.
It will consume 32 extra bytes per tracepoint (24 for structure padding and 8
for the pointers), but are less likely to break due to compiler changes.
History:
commit 7e066fb8 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE()
added the aligned(32) type and variable attribute to the tracepoint structures
to deal with gcc happily aligning statically defined structures on 32-byte
multiples.
One attempt was to use a 8-byte alignment for tracepoint structures by applying
both the variable and type attribute to tracepoint structures definitions and
declarations. It worked fine with gcc 4.5.1, but broke with gcc 4.4.4 and 4.4.5.
The reason is that the "aligned" attribute only specify the _minimum_ alignment
for a structure, leaving both the compiler and the linker free to align on
larger multiples. Because tracepoint.c expects the structures to be placed as an
array within each section, up-alignment cause NULL-pointer exceptions due to the
extra unexpected padding.
(this patch applies on top of -tip)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: David S. Miller <davem@davemloft.net>
LKML-Reference: <20110126222622.GA10794@Krystal>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently only implemented for fair class tasks.
Add a yield_to_task method() to the fair scheduling class. allowing the
caller of yield_to() to accelerate another thread in it's thread group,
task group.
Implemented via a scheduler hint, using cfs_rq->next to encourage the
target being selected. We can rely on pick_next_entity to keep things
fair, so noone can accelerate a thread that has already used its fair
share of CPU time.
This also means callers should only call yield_to when they really
mean it. Calling it too often can result in the scheduler just
ignoring the hint.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110201095051.4ddb7738@annuminas.surriel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use the buddy mechanism to implement yield_task_fair. This
allows us to skip onto the next highest priority se at every
level in the CFS tree, unless doing so would introduce gross
unfairness in CPU time distribution.
We order the buddy selection in pick_next_entity to check
yield first, then last, then next. We need next to be able
to override yield, because it is possible for the "next" and
"yield" task to be different processen in the same sub-tree
of the CFS tree. When they are, we need to go into that
sub-tree regardless of the "yield" hint, and pick the correct
entity once we get to the right level.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110201095103.3a79e92a@annuminas.surriel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The clear_buddies function does not seem to play well with the concept
of hierarchical runqueues. In the following tree, task groups are
represented by 'G', tasks by 'T', next by 'n' and last by 'l'.
(nl)
/ \
G(nl) G
/ \ \
T(l) T(n) T
This situation can arise when a task is woken up T(n), and the previously
running task T(l) is marked last.
When clear_buddies is called from either T(l) or T(n), the next and last
buddies of the group G(nl) will be cleared. This is not the desired
result, since we would like to be able to find the other type of buddy
in many cases.
This especially a worry when implementing yield_task_fair through the
buddy system.
The fix is simple: only clear the buddy type that the task itself
is indicated to be. As an added bonus, we stop walking up the tree
when the buddy has already been cleared or pointed elsewhere.
Signed-off-by: Rik van Riel <riel@redhat.coM>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110201094837.6b0962a9@annuminas.surriel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
With CONFIG_FAIR_GROUP_SCHED, each task_group has its own cfs_rq.
Yielding to a task from another cfs_rq may be worthwhile, since
a process calling yield typically cannot use the CPU right now.
Therefor, we want to check the per-cpu nr_running, not the
cgroup local one.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110201094715.798c4f86@annuminas.surriel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
cpu_stopper_thread()
migration_cpu_stop()
__migrate_task()
deactivate_task()
dequeue_task()
dequeue_task_rq()
update_curr_rt()
Will call update_curr_rt() on rq->curr, which at that time is
rq->stop. The problem is that rq->stop.prio matches an RT prio and
thus falsely assumes its a rt_sched_class task.
Reported-Debuged-Tested-Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Cc: stable@kernel.org # .37
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It is quite possible for the event to have been disabled between
perf_event_read() sending the IPI and the CPU servicing the IPI and
calling __perf_event_read(), hence revalidate the state.
Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Oleg reported that on architectures with
__ARCH_WANT_INTERRUPTS_ON_CTXSW the IPI from
task_oncpu_function_call() can land before perf_event_task_sched_in()
and cause interesting situations for eg. perf_install_in_context().
This patch reworks the task_oncpu_function_call() interface to give a
more usable primitive as well as rework all its users to hopefully be
more obvious as well as remove the races.
While looking at the code I also found a number of races against
perf_event_task_sched_out() which can flip contexts between tasks so
plug those too.
Reported-and-reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently the trace_event structures are placed in the _ftrace_events
section, and at link time, the linker makes one large array of all
the trace_event structures. On boot up, this array is read (much like
the initcall sections) and the events are processed.
The problem is that there is no guarantee that gcc will place complex
structures nicely together in an array format. Two structures in the
same file may be placed awkwardly, because gcc has no clue that they
are suppose to be in an array.
A hack was used previous to force the alignment to 4, to pack the
structures together. But this caused alignment issues with other
architectures (sparc).
Instead of packing the structures into an array, the structures' addresses
are now put into the _ftrace_event section. As pointers are always the
natural alignment, gcc should always pack them tightly together
(otherwise initcall, extable, etc would also fail).
By having the pointers to the structures in the section, we can still
iterate the trace_events without causing unnecessary alignment problems
with other architectures, or depending on the current behaviour of
gcc that will likely change in the future just to tick us kernel developers
off a little more.
The _ftrace_event section is also moved into the .init.data section
as it is now only needed at boot up.
Suggested-by: David Miller <davem@davemloft.net>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
move_native_irq() masks and unmasks the interrupt line
unconditionally, but the interrupt line might be masked due to a
threaded oneshot handler in progress. Unmasking the line in that case
can lead to interrupt storms. Observed on PREEMPT_RT.
Originally-from: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
This patch adds support for adding and removing posix clocks. The
clock lifetime cycle is patterned after usb devices. Each clock is
represented by a standard character device. In addition, the driver
may optionally implement custom character device operations.
The posix clock and timer system calls listed below now work with
dynamic posix clocks, as well as the traditional static clocks.
The following system calls are affected:
- clock_adjtime (brand new syscall)
- clock_gettime
- clock_getres
- clock_settime
- timer_create
- timer_delete
- timer_gettime
- timer_settime
[ tglx: Adapted to the posix-timer cleanup. Moved clock_posix_dynamic
to posix-clock.c and made all referenced functions static ]
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <20110201134420.164172635@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Rename register_posix_clock() to posix_timers_register_clock(). That's
what the function really does. As a side effect this cleans up the
posix_clock namespace for the upcoming dynamic posix_clock
infrastructure.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
Cc: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <alpine.LFD.2.00.1102021222240.31804@localhost6.localdomain6>
Extend the negative clockids which are currently used by posix cpu
timers to encode the PID with a file descriptor based type which
encodes the fd in the upper bits.
Originally-from: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <20110201134420.062860200@linutronix.de>
A new syscall is introduced that allows tuning of a POSIX clock. The
new call, clock_adjtime, takes two parameters, the clock ID and a
pointer to a struct timex. Any ADJTIMEX(2) operation may be requested
via this system call, but various POSIX clocks may or may not support
tuning.
[ tglx: Adapted to the posix-timer cleanup series. Avoid copy_to_user
in the error case ]
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <20110201134419.869804645@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Split out the compat timex accessors into separate
functions. Preparatory patch for a new syscall.
[ tglx: Split that patch from Richards "posix-timers: Introduce a
syscall for clock tuning.". Keeps the changes strictly
separate ]
Originally-from: Richard Cochran <richardcochran@gmail.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20110201134419.772343089@linutronix.de>
This patch adds a new mode bit into the timex structure. When set, the bit
instructs the kernel to add the given time value to the current time.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <20110201134320.688829863@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This adds a kernel-internal timekeeping interface to add or subtract
a fixed amount from CLOCK_REALTIME. This makes it so kernel users or
interfaces trying to do so do not have to read the time, then add an
offset and then call settimeofday(), which adds some extra error in
comparision to just simply adding the offset in the kernel timekeeping
core.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134419.584311693@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pick the cleanup to the comment in posix-timers.c from Richards all in
one conversion patch.
Originally-from: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <20110201134419.487708516@linutronix.de>
All functions are accessed via clock_posix_cpu now. So make them static.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134419.389755466@linutronix.de>
All users gone. Remove the cruft.
Huge thanks to Richard Cochran who tackled that maze first.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134419.294620613@linutronix.de>
Set the common function for CLOCK_MONOTONIC and CLOCK_REALTIME kclocks
and use the new decoding function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134419.198999420@linutronix.de>
Set the common function for CLOCK_MONOTONIC and CLOCK_REALTIME kclocks
and use the new decoding function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134419.101243181@linutronix.de>
Set the common function for CLOCK_MONOTONIC and CLOCK_REALTIME kclocks
and use the new decoding function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134419.001863714@linutronix.de>
Setup timer_create for CLOCK_MONOTONIC and CLOCK_REALTIME kclocks and
remove the no_timer_create() implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134418.903604289@linutronix.de>
The res member of kclock is only used by mmtimer.c, but even there it
contains redundant information. Remove the field and fixup mmtimer.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134418.808714587@linutronix.de>
Use the new kclock decoding. Fixup the fallout in mmtimer.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134418.709802797@linutronix.de>
Richard said: "I would think that we can require k_clocks to provide
the read function. This could be checked and enforced in
register_posix_clock()."
Add checks for clock_getres and clock_get in the register function.
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Cc: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use the new kclock decoding mechanism and rename the misnomed
common_clock_get() to posix_clock_realtime_get().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134418.611097203@linutronix.de>
Use the new kclock decoding function in clock_settime and cleanup all
kclocks which use the default functions. Rename the misnomed
common_clock_set() to posix_clock_realtime_set().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134418.518851246@linutronix.de>
CLOCK_THREAD_CPUTIME_ID implements stub functions for nanosleep and
nanosleep_restart, which return -EINVAL. That return value is
wrong. The correct return value is -ENOTSUP.
Remove the stubs and let the new dispatch code return the correct
error code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134418.422446502@linutronix.de>
posix timers still use the legacy arg0-arg3 members of
restart_block. Use restart_block.nanosleep instead
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134418.232288779@linutronix.de>
Use the new kclock decoding function in clock_nanosleep_restart.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134418.131263211@linutronix.de>
Use the new kclock decoding function in clock_nanosleep and cleanup all
kclocks which use the default functions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134418.034175556@linutronix.de>
New function to find the kclock for a given clockid.
Returns a pointer to clock_posix_cpu if clockid < 0. If clockid >=
MAXCLOCK or if the clock_getres pointer is not set it returns
NULL. For valid clocks it returns a pointer to the matching
posix_clock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <johnstul@us.ibm.com>
Acked-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134417.938447839@linutronix.de>
The CLOCK_DISPATCH() macro is a horrible magic. We call common
functions if a function pointer is not set. That's just backwards.
To support dynamic file decriptor based clocks we need to cleanup that
dispatch logic.
Create a k_clock struct clock_posix_cpu which has all the
posix-cpu-timer functions filled in. After the cleanup the functions
can be made static.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134417.841974553@linutronix.de>
Cosmetic. No functional change
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134417.745627057@linutronix.de>
Define the conditional nanosleep not supported error value outside of
do_posix_clock_nonanosleep(). Preparatory patch for further cleanups.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134417.643486574@linutronix.de>
Both settimeofday() and clock_settime() promise with a 'const'
attribute not to alter the arguments passed in. This patch adds the
missing 'const' attribute into the various kernel functions
implementing these calls.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <20110201134417.545698637@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The only user for this hook was selinux. sysctl routes every call
through /proc/sys/. Selinux and other security modules use the file
system checks for sysctl too, so no need for this hook any more.
Signed-off-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
The xtime/dotimer cleanup broke architectures which do not implement
clockevents. Time to send out another __do_IRQ threat.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Ingo Molnar <mingo@elte.hu>
Cc: Torben Hohn <torbenh@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: johnstul@us.ibm.com
Cc: yong.zhang0@gmail.com
Cc: hch@infradead.org
LKML-Reference: <20110127145905.23248.30458.stgit@localhost>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
All callers of do_timer() are converted to xtime_update(). The only
users of xtime_lock are in kernel/time/. Make both local to
kernel/time/ and remove them from the global header files.
[ tglx: Reuse tick-internal.h instead of creating another local header
file. Massaged changelog ]
Signed-off-by: Torben Hohn <torbenh@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: johnstul@us.ibm.com
Cc: yong.zhang0@gmail.com
Cc: hch@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The hrtimer code accesses timekeeping variables under
xtime_lock. Provide a sensible accessor function and use it.
[ tglx: Removed the conditionals, unused variable, fixed codingstyle
and massaged changelog ]
Signed-off-by: Torben Hohn <torbenh@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: johnstul@us.ibm.com
Cc: yong.zhang0@gmail.com
Cc: hch@infradead.org
LKML-Reference: <20110127145905.23248.30458.stgit@localhost>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
do_timer() is primary timekeeping related. calc_global_load() is
called from do_timer() as well, but that's more for historical
reasons.
[ tglx: Fixed up the calc_global_load() reject andmassaged changelog ]
Signed-off-by: Torben Hohn <torbenh@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: johnstul@us.ibm.com
Cc: yong.zhang0@gmail.com
Cc: hch@infradead.org
LKML-Reference: <20110127145855.23248.56933.stgit@localhost>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If it was not possible to enable watchdog for any cpu, switch
watchdog_enabled back to 0, because it's visible via
kernel.watchdog sysctl.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: <stable@kernel.org>
LKML-Reference: <1296230433-6261-2-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Passing nowatchdog to kernel disables 2 things: creation of
watchdog threads AND initialization of percpu watchdog_hrtimer.
As hrtimers are initialized only at boot it's not possible to
enable watchdog later - for me all watchdog threads started to
eat 100% of CPU time, but they could just crash.
Additionally, even if these threads would start properly,
watchdog_disable_all_cpus was guarded by no_watchdog check, so
you couldn't disable watchdog.
To fix this, remove no_watchdog variable and use already
existing watchdog_enabled variable.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
[ removed another no_watchdog instance ]
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: <stable@kernel.org>
LKML-Reference: <1296230433-6261-1-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The new code of commit cd7eab44e(genirq: Add IRQ affinity notifiers)
references irq_desc.affinity which fails to compile with
CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED=y.
Use irq_desc.irq_data.affinity instead.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Since check_prlimit_permission always fails in the case of SUID/GUID
processes, such processes are not able to read or set their own limits.
This commit changes this by assuming that process can always read/change
its own limits.
Signed-off-by: Kacper Kornet <kornet@camk.edu.pl>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In current rtmutex, the pending owner may be boosted by the tasks
in the rtmutex's waitlist when the pending owner is deboosted
or a task in the waitlist is boosted. This boosting is unrelated,
because the pending owner does not really take the rtmutex.
It is not reasonable.
Example.
time1:
A(high prio) onwers the rtmutex.
B(mid prio) and C (low prio) in the waitlist.
time2
A release the lock, B becomes the pending owner
A(or other high prio task) continues to run. B's prio is lower
than A, so B is just queued at the runqueue.
time3
A or other high prio task sleeps, but we have passed some time
The B and C's prio are changed in the period (time2 ~ time3)
due to boosting or deboosting. Now C has the priority higher
than B. ***Is it reasonable that C has to boost B and help B to
get the rtmutex?
NO!! I think, it is unrelated/unneed boosting before B really
owns the rtmutex. We should give C a chance to beat B and
win the rtmutex.
This is the motivation of this patch. This patch *ensures*
only the top waiter or higher priority task can take the lock.
How?
1) we don't dequeue the top waiter when unlock, if the top waiter
is changed, the old top waiter will fail and go to sleep again.
2) when requiring lock, it will get the lock when the lock is not taken and:
there is no waiter OR higher priority than waiters OR it is top waiter.
3) In any time, the top waiter is changed, the top waiter will be woken up.
The algorithm is much simpler than before, no pending owner, no
boosting for pending owner.
Other advantage of this patch:
1) The states of a rtmutex are reduced a half, easier to read the code.
2) the codes become shorter.
3) top waiter is not dequeued until it really take the lock:
they will retain FIFO when it is stolen.
Not advantage nor disadvantage
1) Even we may wakeup multiple waiters(any time when top waiter changed),
we hardly cause "thundering herd",
the number of wokenup task is likely 1 or very little.
2) two APIs are changed.
rt_mutex_owner() will not return pending owner, it will return NULL when
the top waiter is going to take the lock.
rt_mutex_next_owner() always return the top waiter.
will not return NULL if we have waiters
because the top waiter is not dequeued.
I have fixed the code that use these APIs.
need updated after this patch is accepted
1) Document/*
2) the testcase scripts/rt-tester/t4-l2-pi-deboost.tst
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4D3012D5.4060709@cn.fujitsu.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Commit 927c7a9e92 ("perf: Fix race in callchains") introduced
a mismatch in the sizing of struct callchain_cpus_entries.
nr_cpu_ids must be used instead of num_possible_cpus(), or we
might get out of bound memory accesses on some machines.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Miller <davem@davemloft.net>
Cc: Stephane Eranian <eranian@google.com>
CC: stable@kernel.org
LKML-Reference: <1295980851.3588.351.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix the build on UP.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Turner <pjt@google.com>
LKML-Reference: <20110122044852.102126037@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The BKL is going away, no need to test it any more.
I left the definitions of the test case numbers
in, so that the other tests do not get renumbered.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1295993854-4971-19-git-send-email-arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When a task is taken out of the fair class we must ensure the vruntime
is properly normalized because when we put it back in it will assume
to be normalized.
The case that goes wrong is when changing away from the fair class
while sleeping. Sleeping tasks have non-normalized vruntime in order
to make sleeper-fairness work. So treat the switch away from fair as a
wakeup and preserve the relative vruntime.
Also update sysrq-n to call the ->switch_{to,from} methods.
Reported-by: Onkalo Samu <samu.p.onkalo@nokia.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since commit 48c5ccae88 (sched: Simplify cpu-hot-unplug task
migration) this should no longer happen, so remove the code.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
softirq time in ksoftirqd context is not accounted in ns granularity
per cpu softirq stats, as we want that to be a part of ksoftirqd
exec_runtime.
Accounting them as softirq on /proc/stat separately.
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-6-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
CONFIG_IRQ_TIME_ACCOUNTING adds ns granularity irq time on each CPU.
This info is already used in scheduler to do proper task chargeback
(earlier patches). This patch retro-fits this ns granularity
hardirq and softirq information to /proc/stat irq and softirq fields.
The update is still done on timer tick, where we look at accumulated
ns hardirq/softirq time and account the tick to user/system/irq/hardirq/guest
accordingly.
No new interface added.
Earlier versions looked at adding this as new fields in some /proc
files. This one seems to be the best in terms of impact to existing
apps, even though it has somewhat more kernel code than earlier versions.
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-5-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Refactor account_system_time, to separate out the logic of
identifying the update needed and code that does actual update.
This is used by following patch for IRQ_TIME_ACCOUNTING,
which has different identification logic and same update logic.
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-4-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add nsecs_to_cputime64 interface. This is used in following patches that
updates cpu irq stat based on ns granularity info in IRQ_TIME_ACCOUNTING.
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-3-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cleanup patch, freeing up PF_KSOFTIRQD and use per_cpu ksoftirqd pointer
instead, as suggested by Eric Dumazet.
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-2-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since cfs->{load_stamp,load_last} are zero-initalized the initial load update
will consider the delta to be 'since the beginning of time'.
This results in a lot of pointless divisions to bring this large period to be
within the sysctl_sched_shares_window.
Fix this by initializing load_stamp to be 1 at cfs_rq initialization, this
allows for an initial load_stamp > load_last which then lets standard idle
truncation proceed.
We avoid spinning (and slightly improve consistency) by fixing delta to be
[period - 1] in this path resulting in a slightly more predictable shares ramp.
(Previously the amount of idle time preserved by the overflow would range between
[period/2,period-1].)
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044852.102126037@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Re-visiting this: Since update_cfs_shares will now only ever re-weight an
entity that is a relative parent of the current entity in enqueue_entity; we
can safely issue the account_entity_enqueue relative to that cfs_rq and avoid
the requirement for special handling of the enqueue case in update_cfs_shares.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044851.915214637@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The delta in clock_task is a more fair attribution of how much time a tg has
been contributing load to the current cpu.
While not really important it also means we're more in sync (by magnitude)
with respect to periodic updates (since __update_curr deltas are clock_task
based).
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044852.007092349@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since updates are against an entity's queuing cfs_rq it's not possible to
enter update_cfs_{shares,load} with a NULL cfs_rq. (Indeed, update_cfs_load
would crash prior to the check if we did anyway since we load is examined
during the initializers).
Also, in the update_cfs_load case there's no point
in maintaining averages for rq->cfs_rq since we don't perform shares
distribution at that level -- NULL check is replaced accordingly.
Thanks to Dan Carpenter for pointing out the deference before NULL check.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044851.825284940@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
While care is taken around the zero-point in effective_load to not exceed
the instantaneous rq->weight, it's still possible (e.g. using wake_idx != 0)
for (load + effective_load) to underflow.
In this case the comparing the unsigned values can result in incorrect balanced
decisions.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044851.734245014@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: wacom - pass touch resolution to clients through input_absinfo
Input: wacom - add 2 Bamboo Pen and touch models
Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistent
Input: sparse-keymap - fix KEY_VSW handling in sparse_keymap_setup
Input: tegra-kbc - add tegra keyboard driver
Input: gpio_keys - switch to using request_any_context_irq
Input: serio - allow registered drivers to get status flag
Input: ct82710c - return proper error code for ct82c710_open
Input: bu21013_ts - added regulator support
Input: bu21013_ts - remove duplicate resolution parameters
Input: tnetv107x-ts - don't treat NULL clk as an error
Input: tnetv107x-keypad - don't treat NULL clk as an error
Fix up trivial conflicts in drivers/input/keyboard/Makefile due to
additions of tc3589x/Tegra drivers
The -rt patches change the console_semaphore to console_mutex. As a
result, a quite large chunk of the patches changes all
acquire/release_console_sem() to acquire/release_console_mutex()
This commit makes things use more neutral function names which dont make
implications about the underlying lock.
The only real change is the return value of console_trylock which is
inverted from try_acquire_console_sem()
This patch also paves the way to switching console_sem from a semaphore to
a mutex.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: make console_trylock return 1 on success, per Geert]
Signed-off-by: Torben Hohn <torbenh@gmx.de>
Cc: Thomas Gleixner <tglx@tglx.de>
Cc: Greg KH <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf tools: Fix time function double declaration with glibc
perf tools: Fix build by checking if extra warnings are supported
perf tools: Fix build when using gcc 3.4.6
perf tools: Add missing header, fixes build
perf tools: Fix 64 bit integer format strings
perf test: Fix build on older glibcs
perf: perf_event_exit_task_context: s/rcu_dereference/rcu_dereference_raw/
perf test: Use cpu_map->[cpu] when setting affinity
perf symbols: Fix annotation of thumb code
perf: Annotate cpuctx->ctx.mutex to avoid a lockdep splat
powerpc, perf: Fix frequency calculation for overflowing counters (FSL version)
perf: Fix perf_event_init_task()/perf_event_free_task() interaction
perf: Fix find_get_context() vs perf_event_exit_task() race
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix poor interactivity on UP systems due to group scheduler nice tune bug
Currently sysrq_enabled and __sysrq_enabled are initialised separately
and inconsistently, leading to sysrq being actually enabled by reported
as not enabled in sysfs. The first change to the sysfs configurable
synchronises these two:
static int __read_mostly sysrq_enabled = 1;
static int __sysrq_enabled;
Add a common define to carry the default for these preventing them becoming
out of sync again. Default this to 1 to mirror previous behaviour.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: stable@kernel.org
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Michael Witten and Christian Kujau reported that the autogroup
scheduling feature hurts interactivity on their UP systems.
It turns out that this is an older bug in the group scheduling code,
and the wider appeal provided by the autogroup feature exposed it
more prominently.
When on UP with FAIR_GROUP_SCHED enabled, tune shares
only affect tg->shares, but is not reflected in
tg->se->load. The reason is that update_cfs_shares()
does nothing on UP.
So introduce update_cfs_shares() for UP && FAIR_GROUP_SCHED.
This issue was found when enable autogroup scheduling was enabled,
but it is an older bug that also exists on cgroup.cpu on UP.
Reported-and-Tested-by: Michael Witten <mfwitten@gmail.com>
Reported-and-Tested-by: Christian Kujau <christian@nerdbynature.de>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110124073352.GA24186@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently only drivers that are built as modules have their versions
shown in /sys/module/<module_name>/version, but this information might
also be useful for built-in drivers as well. This especially important
for drivers that do not define any parameters - such drivers, if
built-in, are completely invisible from userspace.
This patch changes MODULE_VERSION() macro so that in case when we are
compiling built-in module, version information is stored in a separate
section. Kernel then uses this data to create 'version' sysfs attribute
in the same fashion it creates attributes for module parameters.
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When initiating I/O on a multiqueue and multi-IRQ device, we may want
to select a queue for which the response will be handled on the same
or a nearby CPU. This requires a reverse-map of IRQ affinity. Add a
notification mechanism to support this.
This is based closely on work by Thomas Gleixner <tglx@linutronix.de>.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Cc: linux-net-drivers@solarflare.com
Cc: Tom Herbert <therbert@google.com>
Cc: David Miller <davem@davemloft.net>
LKML-Reference: <1295470904.11126.84.camel@bwh-desktop>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: note the nested NOT_RUNNING test in worker_clr_flags() isn't a noop
workqueue: relax lockdep annotation on flush_work()
In theory, almost every user of task->child->perf_event_ctxp[]
is wrong. find_get_context() can install the new context at any
moment, we need read_barrier_depends().
dbe08d82ce "perf: Fix
find_get_context() vs perf_event_exit_task() race" added
rcu_dereference() into perf_event_exit_task_context() to make
the precedent, but this makes __rcu_dereference_check() unhappy.
Use rcu_dereference_raw() to shut up the warning.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: acme@redhat.com
Cc: paulus@samba.org
Cc: stern@rowland.harvard.edu
Cc: a.p.zijlstra@chello.nl
Cc: fweisbec@gmail.com
Cc: roland@redhat.com
Cc: prasad@linux.vnet.ibm.com
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
LKML-Reference: <20110121174547.GA8796@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Lockdep spotted:
loop_1b_instruc/1899 is trying to acquire lock:
(event_mutex){+.+.+.}, at: [<ffffffff810e1908>] perf_trace_init+0x3b/0x2f7
but task is already holding lock:
(&ctx->mutex){+.+.+.}, at: [<ffffffff810eb45b>] perf_event_init_context+0xc0/0x218
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&ctx->mutex){+.+.+.}:
-> #2 (cpu_hotplug.lock){+.+.+.}:
-> #1 (module_mutex){+.+...}:
-> #0 (event_mutex){+.+.+.}:
But because the deadlock would be cpuhotplug (cpu-event) vs fork
(task-event) it cannot, in fact, happen. We can annotate this by giving the
perf_event_context used for the cpuctx a different lock class from those
used by tasks.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
All architectures are finally converted. Remove the cruft.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Michal Simek <monstr@monstr.eu>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
smp: Allow on_each_cpu() to be called while early_boot_irqs_disabled status to init/main.c
lockdep: Move early boot local IRQ enable/disable status to init/main.c
* akpm:
kernel/smp.c: consolidate writes in smp_call_function_interrupt()
kernel/smp.c: fix smp_call_function_many() SMP race
memcg: correctly order reading PCG_USED and pc->mem_cgroup
backlight: fix 88pm860x_bl macro collision
drivers/leds/ledtrig-gpio.c: make output match input, tighten input checking
MAINTAINERS: update Atmel AT91 entry
mm: fix truncate_setsize() comment
memcg: fix rmdir, force_empty with THP
memcg: fix LRU accounting with THP
memcg: fix USED bit handling at uncharge in THP
memcg: modify accounting function for supporting THP better
fs/direct-io.c: don't try to allocate more than BIO_MAX_PAGES in a bio
mm: compaction: prevent division-by-zero during user-requested compaction
mm/vmscan.c: remove duplicate include of compaction.h
memblock: fix memblock_is_region_memory()
thp: keep highpte mapped until it is no longer needed
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT
We have to test the cpu mask in the interrupt handler before checking the
refs, otherwise we can start to follow an entry before its deleted and
find it partially initailzed for the next trip. Presently we also clear
the cpumask bit before executing the called function, which implies
getting write access to the line. After the function is called we then
decrement refs, and if they go to zero we then unlock the structure.
However, this implies getting write access to the call function data
before and after another the function is called. If we can assert that no
smp_call_function execution function is allowed to enable interrupts, then
we can move both writes to after the function is called, hopfully allowing
both writes with one cache line bounce.
On a 256 thread system with a kernel compiled for 1024 threads, the time
to execute testcase in the "smp_call_function_many race" changelog was
reduced by about 30-40ms out of about 545 ms.
I decided to keep this as WARN because its now a buggy function, even
though the stack trace is of no value -- a simple printk would give us the
information needed.
Raw data:
Without patch:
ipi_test startup took 1219366ns complete 539819014ns total 541038380ns
ipi_test startup took 1695754ns complete 543439872ns total 545135626ns
ipi_test startup took 7513568ns complete 539606362ns total 547119930ns
ipi_test startup took 13304064ns complete 533898562ns total 547202626ns
ipi_test startup took 8668192ns complete 544264074ns total 552932266ns
ipi_test startup took 4977626ns complete 548862684ns total 553840310ns
ipi_test startup took 2144486ns complete 541292318ns total 543436804ns
ipi_test startup took 21245824ns complete 530280180ns total 551526004ns
With patch:
ipi_test startup took 5961748ns complete 500859628ns total 506821376ns
ipi_test startup took 8975996ns complete 495098924ns total 504074920ns
ipi_test startup took 19797750ns complete 492204740ns total 512002490ns
ipi_test startup took 14824796ns complete 487495878ns total 502320674ns
ipi_test startup took 11514882ns complete 494439372ns total 505954254ns
ipi_test startup took 8288084ns complete 502570774ns total 510858858ns
ipi_test startup took 6789954ns complete 493388112ns total 500178066ns
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h> /* sched clock */
#define ITERATIONS 100
static void do_nothing_ipi(void *dummy)
{
}
static void do_ipis(struct work_struct *dummy)
{
int i;
for (i = 0; i < ITERATIONS; i++)
smp_call_function(do_nothing_ipi, NULL, 1);
printk(KERN_DEBUG "cpu %d finished\n", smp_processor_id());
}
static struct work_struct work[NR_CPUS];
static int __init testcase_init(void)
{
int cpu;
u64 start, started, done;
start = local_clock();
for_each_online_cpu(cpu) {
INIT_WORK(&work[cpu], do_ipis);
schedule_work_on(cpu, &work[cpu]);
}
started = local_clock();
for_each_online_cpu(cpu)
flush_work(&work[cpu]);
done = local_clock();
pr_info("ipi_test startup took %lldns complete %lldns total %lldns\n",
started-start, done-started, done-start);
return 0;
}
static void __exit testcase_exit(void)
{
}
module_init(testcase_init)
module_exit(testcase_exit)
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Anton Blanchard");
Signed-off-by: Milton Miller <miltonm@bga.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I noticed a failure where we hit the following WARN_ON in
generic_smp_call_function_interrupt:
if (!cpumask_test_and_clear_cpu(cpu, data->cpumask))
continue;
data->csd.func(data->csd.info);
refs = atomic_dec_return(&data->refs);
WARN_ON(refs < 0); <-------------------------
We atomically tested and cleared our bit in the cpumask, and yet the
number of cpus left (ie refs) was 0. How can this be?
It turns out commit 54fdade1c3
("generic-ipi: make struct call_function_data lockless") is at fault. It
removes locking from smp_call_function_many and in doing so creates a
rather complicated race.
The problem comes about because:
- The smp_call_function_many interrupt handler walks call_function.queue
without any locking.
- We reuse a percpu data structure in smp_call_function_many.
- We do not wait for any RCU grace period before starting the next
smp_call_function_many.
Imagine a scenario where CPU A does two smp_call_functions back to back,
and CPU B does an smp_call_function in between. We concentrate on how CPU
C handles the calls:
CPU A CPU B CPU C CPU D
smp_call_function
smp_call_function_interrupt
walks
call_function.queue sees
data from CPU A on list
smp_call_function
smp_call_function_interrupt
walks
call_function.queue sees
(stale) CPU A on list
smp_call_function int
clears last ref on A
list_del_rcu, unlock
smp_call_function reuses
percpu *data A
data->cpumask sees and
clears bit in cpumask
might be using old or new fn!
decrements refs below 0
set data->refs (too late!)
The important thing to note is since the interrupt handler walks a
potentially stale call_function.queue without any locking, then another
cpu can view the percpu *data structure at any time, even when the owner
is in the process of initialising it.
The following test case hits the WARN_ON 100% of the time on my PowerPC
box (having 128 threads does help :)
#include <linux/module.h>
#include <linux/init.h>
#define ITERATIONS 100
static void do_nothing_ipi(void *dummy)
{
}
static void do_ipis(struct work_struct *dummy)
{
int i;
for (i = 0; i < ITERATIONS; i++)
smp_call_function(do_nothing_ipi, NULL, 1);
printk(KERN_DEBUG "cpu %d finished\n", smp_processor_id());
}
static struct work_struct work[NR_CPUS];
static int __init testcase_init(void)
{
int cpu;
for_each_online_cpu(cpu) {
INIT_WORK(&work[cpu], do_ipis);
schedule_work_on(cpu, &work[cpu]);
}
return 0;
}
static void __exit testcase_exit(void)
{
}
module_init(testcase_init)
module_exit(testcase_exit)
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Anton Blanchard");
I tried to fix it by ordering the read and the write of ->cpumask and
->refs. In doing so I missed a critical case but Paul McKenney was able
to spot my bug thankfully :) To ensure we arent viewing previous
iterations the interrupt handler needs to read ->refs then ->cpumask then
->refs _again_.
Thanks to Milton Miller and Paul McKenney for helping to debug this issue.
[miltonm@bga.com: add WARN_ON and BUG_ON, remove extra read of refs before initial read of mask that doesn't help (also noted by Peter Zijlstra), adjust comments, hopefully clarify scenario ]
[miltonm@bga.com: remove excess tests]
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Milton Miller <miltonm@bga.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: <stable@kernel.org> [2.6.32+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched, cgroup: Use exit hook to avoid use-after-free crash
sched: Fix signed unsigned comparison in check_preempt_tick()
sched: Replace rq->bkl_count with rq->rq_sched_info.bkl_count
sched, autogroup: Fix CONFIG_RT_GROUP_SCHED sched_setscheduler() failure
sched: Display autogroup names in /proc/sched_debug
sched: Reinstate group names in /proc/sched_debug
sched: Update effective_load() to use global share weights
percpu may end up calling vfree() during early boot which in
turn may call on_each_cpu() for TLB flushes. The function of
on_each_cpu() can be done safely while IRQ is disabled during
early boot but it assumed that the function is always called
with local IRQ enabled which ended up enabling local IRQ
prematurely during boot and triggering a couple of warnings.
This patch updates on_each_cpu() and smp_call_function_many()
such on_each_cpu() can be used safely while
early_boot_irqs_disabled is set.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110120110713.GC6036@htj.dyndns.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Ingo Molnar <mingo@elte.hu>
During early boot, local IRQ is disabled until IRQ subsystem is
properly initialized. During this time, no one should enable
local IRQ and some operations which usually are not allowed with
IRQ disabled, e.g. operations which might sleep or require
communications with other processors, are allowed.
lockdep tracked this with early_boot_irqs_off/on() callbacks.
As other subsystems need this information too, move it to
init/main.c and make it generally available. While at it,
toggle the boolean to early_boot_irqs_disabled instead of
enabled so that it can be initialized with %false and %true
indicates the exceptional condition.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110120110635.GB6036@htj.dyndns.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When NOHZ=y and high res timers are disabled (via cmdline or
Kconfig) tick_nohz_switch_to_nohz() will notify the user about
switching into NOHZ mode. Nothing is printed for the case where
HIGH_RES_TIMERS=y. Fix this for the HIGH_RES_TIMERS=y case by
duplicating the printk from the low res NOHZ path in the high
res NOHZ path.
This confused me since I was thinking 'dmesg | grep -i NOHZ' would
tell me if NOHZ was enabled, but if I have hrtimers there is
nothing.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1295419594-13085-1-git-send-email-sboyd@codeaurora.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
perf_event_init_task() should clear child->perf_event_ctxp[]
before anything else. Otherwise, if
perf_event_init_context(perf_hw_context) fails,
perf_event_free_task() can free perf_event_ctxp[perf_sw_context]
copied from parent->perf_event_ctxp[] by dup_task_struct().
Also move the initialization of perf_event_mutex and
perf_event_list from perf_event_init_context() to
perf_event_init_context().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
LKML-Reference: <20110119182228.GC12183@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
find_get_context() must not install the new perf_event_context
if the task has already passed perf_event_exit_task().
If nothing else, this means the memory leak. Initially
ctx->refcount == 2, it is supposed that
perf_event_exit_task_context() should participate and do the
necessary put_ctx().
find_lively_task_by_vpid() checks PF_EXITING but this buys
nothing, by the time we call find_get_context() this task can be
already dead. To the point, cmpxchg() can succeed when the task
has already done the last schedule().
Change find_get_context() to populate task->perf_event_ctxp[]
under task->perf_event_mutex, this way we can trust PF_EXITING
because perf_event_exit_task() takes the same mutex.
Also, change perf_event_exit_task_context() to use
rcu_dereference(). Probably this is not strictly needed, but
with or without this change find_get_context() can race with
setup_new_exec()->perf_event_exit_task(), rcu_dereference()
looks better.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
LKML-Reference: <20110119182207.GB12183@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now if we enable blktrace, cfq has too many messages output to the
trace buffer. It is fine if we don't specify any action mask.
But if I do like this:
blktrace /dev/sdb -a issue -a complete -o - | blkparse -i -
I only want to see 'D' and 'C', while with the following command
dd if=/mnt/ocfs2/test of=/dev/null bs=4k count=1 iflag=direct
I will get(with a 2.6.37 vanilla kernel):
8,16 0 0 0.000000000 0 m N cfq3805 alloced
8,16 0 0 0.000004126 0 m N cfq3805 insert_request
8,16 0 0 0.000004884 0 m N cfq3805 add_to_rr
8,16 0 0 0.000008417 0 m N cfq workload slice:300
8,16 0 0 0.000009557 0 m N cfq3805 set_active wl_prio:0 wl_type:2
8,16 0 0 0.000010640 0 m N cfq3805 fifo= (null)
8,16 0 0 0.000011193 0 m N cfq3805 dispatch_insert
8,16 0 0 0.000012221 0 m N cfq3805 dispatched a request
8,16 0 0 0.000012802 0 m N cfq3805 activate rq, drv=1
8,16 0 1 0.000013181 3805 D R 114759 + 8 [dd]
8,16 0 2 0.000164244 0 C R 114759 + 8 [0]
8,16 0 0 0.000167997 0 m N cfq3805 complete rqnoidle 0
8,16 0 0 0.000168782 0 m N cfq3805 set_slice=100
8,16 0 0 0.000169874 0 m N cfq3805 arm_idle: 8 group_idle: 0
8,16 0 0 0.000170189 0 m N cfq schedule dispatch
8,16 0 0 0.000397938 0 m N cfq3805 slice expired t=0
8,16 0 0 0.000399763 0 m N cfq3805 sl_used=1 disp=1 charge=1 iops=0 sect=8
8,16 0 0 0.000400227 0 m N cfq3805 del_from_rr
8,16 0 0 0.000400882 0 m N cfq3805 put_queue
See, there are 19 lines while I only need 2. I don't think it is
appropriate for a user.
So this patch will disable any messages if the BLK_TC_NOTIFY isn't set.
Now the output for the same command will look like:
8,16 0 1 0.000000000 4908 D R 114759 + 8 [dd]
8,16 0 2 0.000146827 0 C R 114759 + 8 [0]
Yes, it is what I want to see.
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Fix a bunch of
warning: ‘inline’ is not at beginning of declaration
messages when building a 'make allyesconfig' kernel with -Wextra.
These warnings are trivial to kill, yet rather annoying when building with
-Wextra.
The more we can cut down on pointless crap like this the better (IMHO).
A previous patch to do this for a 'allnoconfig' build has already been
merged. This just takes the cleanup a little further.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
By not notifying the controller of the on-exit move back to
init_css_set, we fail to move the task out of the previous
cgroup's cfs_rq. This leads to an opportunity for a
cgroup-destroy to come in and free the cgroup (there are no
active tasks left in it after all) to which the not-quite dead
task is still enqueued.
Reported-by: Miklos Vajna <vmiklos@frugalware.org>
Fixed-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1293206353.29444.205.camel@laptop>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf: Validate cpu early in perf_event_alloc()
perf: Find_get_context: fix the per-cpu-counter check
perf: Fix contexted inheritance
Starting from perf_event_alloc()->perf_init_event(), the kernel
assumes that event->cpu is either -1 or the valid CPU number.
Change perf_event_alloc() to validate this argument early. This
also means we can remove the similar check in
find_get_context().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: gregkh@suse.de
Cc: stable@kernel.org
LKML-Reference: <20110118161032.GC693@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If task == NULL, find_get_context() should always check that cpu
is correct.
Afaics, the bug was introduced by 38a81da2 "perf events: Clean
up pid passing", but even before that commit "&& cpu != -1" was
not exactly right, -ESRCH from find_task_by_vpid() is not
accurate.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: gregkh@suse.de
Cc: stable@kernel.org
LKML-Reference: <20110118161008.GB693@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Linus reported that the RCU lockdep annotation bits triggered for this
rcu_dereference() because we're not holding rcu_read_lock().
Going over the code I cannot convince myself its correct:
- holding a ref on the parent_ctx, doesn't avoid it being uncloned
concurrently (as the comment says), so we can race with a free.
- holding parent_ctx->mutex doesn't avoid the above free from taking
place either, it would at best avoid parent_ctx from being freed.
I.e. the warning is correct. To fix the bug, serialize against the
unclone_ctx() call by extending the reach of the parent_ctx->lock.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed unsigned comparison may lead to superfluous resched if leftmost
is right of the current task, wasting a few cycles, and inadvertently
_lengthening_ the current task's slice.
Reported-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294202477.9384.5.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now rq->rq_sched_info.bkl_count is not used for rq, scroll
rq->bkl_count into it. Thus we can save some space for rq.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294991859-13246-1-git-send-email-yong.zhang0@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If CONFIG_RT_GROUP_SCHED is set, __sched_setscheduler() fails due to autogroup
not allocating rt_runtime. Free unused/unusable rt_se and rt_rq, redirect RT
tasks to the root task group, and tell __sched_setscheduler() that it's ok.
Reported-and-tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294890890.8089.39.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add autogroup name to cfs_rq and tasks information to /proc/sched_debug.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110111101257.GF4772@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Displaying of group names in /proc/sched_debug was dropped in autogroup
patches. Add group names while displaying cfs_rq and tasks information.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110111101153.GE4772@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Previously effective_load would approximate the global load weight present on
a group taking advantage of:
entity_weight = tg->shares ( lw / global_lw ), where entity_weight was provided
by tg_shares_up.
This worked (approximately) for an 'empty' (at tg level) cpu since we would
place boost load representative of what a newly woken task would receive.
However, now that load is instantaneously updated this assumption is no longer
true and the load calculation is rather incorrect in this case.
Fix this (and improve the general case) by re-writing effective_load to take
advantage of the new shares distribution code.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110115015817.069769529@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When xt_AUDIT is built as a module, modpost reports a problem.
MODPOST 322 modules
ERROR: "audit_enabled" [net/netfilter/x_tables.ko] undefined!
WARNING: modpost: Found 1 section mismatch(es).
Cc: Thomas Graf <tgraf@redhat.com>
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: avoid pointless blocked-task warnings
rcu: demote SRCU_SYNCHRONIZE_DELAY from kernel-parameter status
rtmutex: Fix comment about why new_owner can be NULL in wake_futex_pi()
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, olpc: Add missing Kconfig dependencies
x86, mrst: Set correct APB timer IRQ affinity for secondary cpu
x86: tsc: Fix calibration refinement conditionals to avoid divide by zero
x86, ia64, acpi: Clean up x86-ism in drivers/acpi/numa.c
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
timekeeping: Make local variables static
time: Rename misnamed minsec argument of clocks_calc_mult_shift()
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: Remove syscall_exit_fields
tracing: Only process module tracepoints once
perf record: Add "nodelay" mode, disabled by default
perf sched: Fix list of events, dropping unsupported ':r' modifier
Revert "perf tools: Emit clearer message for sys_perf_event_open ENOENT return"
perf top: Fix annotate segv
perf evsel: Fix order of event list deletion
There is no need for syscall_exit_fields as the syscall
exit event class can already host the fields in its structure,
like most other trace events do by default. Use that
default behavior instead.
Following this scheme, we don't need anymore to override the
get_fields() callback of the syscall exit event class either.
Hence both syscall_exit_fields and syscall_get_exit_fields() can
be removed.
Also changed some indentation to keep the following under 80
characters:
".fields = LIST_HEAD_INIT(event_class_syscall_exit.fields),"
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4D301C0E.8090408@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin:
kernel: fix hlist_bl again
cgroups: Fix a lockdep warning at cgroup removal
fs: namei fix ->put_link on wrong inode in do_filp_open
cgroup can't use simple_lookup(), since that'd override its desired ->d_op.
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the RCU callback-processing kthread has nothing to do, it parks in
a wait_event(). If RCU remains idle for more than two minutes, the
kernel complains about this. This commit changes from wait_event()
to wait_event_interruptible() to prevent the kernel from complaining
just because RCU is idle.
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Thomas Weber <weber@corscience.de>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Because the adaptive synchronize_srcu_expedited() approach has
worked very well in testing, remove the kernel parameter and
replace it by a C-preprocessor macro. If someone finds problems
with this approach, a more complex and aggressively adaptive
approach might be required.
Longer term, SRCU will be merged with the other RCU implementations,
at which point synchronize_srcu_expedited() will be event driven,
just as synchronize_sched_expedited() currently is. At that point,
there will be no need for this adaptive approach.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Commit 2fd6b7f5 ("fs: dcache scale subdirs") forgot to annotate a dentry
lock, which caused a lockdep warning.
Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (59 commits)
ACPI / PM: Fix build problems for !CONFIG_ACPI related to NVS rework
ACPI: fix resource check message
ACPI / Battery: Update information on info notification and resume
ACPI: Drop device flag wake_capable
ACPI: Always check if _PRW is present before trying to evaluate it
ACPI / PM: Check status of power resources under mutexes
ACPI / PM: Rename acpi_power_off_device()
ACPI / PM: Drop acpi_power_nocheck
ACPI / PM: Drop acpi_bus_get_power()
Platform / x86: Make fujitsu_laptop use acpi_bus_update_power()
ACPI / Fan: Rework the handling of power resources
ACPI / PM: Register power resource devices as soon as they are needed
ACPI / PM: Register acpi_power_driver early
ACPI / PM: Add function for updating device power state consistently
ACPI / PM: Add function for device power state initialization
ACPI / PM: Introduce __acpi_bus_get_power()
ACPI / PM: Introduce function for refcounting device power resources
ACPI / PM: Add functions for manipulating lists of power resources
ACPI / PM: Prevent acpi_power_get_inferred_state() from making changes
ACPICA: Update version to 20101209
...
Add khugepaged to relocate fragmented pages into hugepages if new
hugepages become available. (this is indipendent of the defrag logic that
will have to make new hugepages available)
The fundamental reason why khugepaged is unavoidable, is that some memory
can be fragmented and not everything can be relocated. So when a virtual
machine quits and releases gigabytes of hugepages, we want to use those
freely available hugepages to create huge-pmd in the other virtual
machines that may be running on fragmented memory, to maximize the CPU
efficiency at all times. The scan is slow, it takes nearly zero cpu time,
except when it copies data (in which case it means we definitely want to
pay for that cpu time) so it seems a good tradeoff.
In addition to the hugepages being released by other process releasing
memory, we have the strong suspicion that the performance impact of
potentially defragmenting hugepages during or before each page fault could
lead to more performance inconsistency than allocating small pages at
first and having them collapsed into large pages later... if they prove
themselfs to be long lived mappings (khugepaged scan is slow so short
lived mappings have low probability to run into khugepaged if compared to
long lived mappings).
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This increase the size of the mm struct a bit but it is needed to
preallocate one pte for each hugepage so that split_huge_page will not
require a fail path. Guarantee of success is a fundamental property of
split_huge_page to avoid decrasing swapping reliability and to avoid
adding -ENOMEM fail paths that would otherwise force the hugepage-unaware
VM code to learn rolling back in the middle of its pte mangling operations
(if something we need it to learn handling pmd_trans_huge natively rather
being capable of rollback). When split_huge_page runs a pte is needed to
succeed the split, to map the newly splitted regular pages with a regular
pte. This way all existing VM code remains backwards compatible by just
adding a split_huge_page* one liner. The memory waste of those
preallocated ptes is negligible and so it is worth it.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Futex code is smarter than most other gup_fast O_DIRECT code and knows
about the compound internals. However now doing a put_page(head_page)
will not release the pin on the tail page taken by gup-fast, leading to
all sort of refcounting bugchecks. Getting a stable head_page is a little
tricky.
page_head = page is there because if this is not a tail page it's also the
page_head. Only in case this is a tail page, compound_head is called,
otherwise it's guaranteed unnecessary. And if it's a tail page
compound_head has to run atomically inside irq disabled section
__get_user_pages_fast before returning. Otherwise ->first_page won't be a
stable pointer.
Disableing irq before __get_user_page_fast and releasing irq after running
compound_head is needed because if __get_user_page_fast returns == 1, it
means the huge pmd is established and cannot go away from under us.
pmdp_splitting_flush_notify in __split_huge_page_splitting will have to
wait for local_irq_enable before the IPI delivery can return. This means
__split_huge_page_refcount can't be running from under us, and in turn
when we run compound_head(page) we're not reading a dangling pointer from
tailpage->first_page. Then after we get to stable head page, we are
always safe to call compound_lock and after taking the compound lock on
head page we can finally re-check if the page returned by gup-fast is
still a tail page. in which case we're set and we didn't need to split
the hugepage in order to take a futex on it.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We'd like to be able to oom_score_adj a process up/down as it
enters/leaves the foreground. Currently, it is not possible to oom_adj
down without CAP_SYS_RESOURCE. This patch allows a task to decrease its
oom_score_adj back to the value that a CAP_SYS_RESOURCE thread set it to
or its inherited value at fork. Assuming the thread that has forked it
has oom_score_adj of 0, each process could decrease it back from 0 upon
activation unless a CAP_SYS_RESOURCE thread elevated it to something
higher.
Alternative considered:
* a setuid binary
* a daemon with CAP_SYS_RESOURCE
Since you don't wan't all processes to be able to reduce their oom_adj, a
setuid or daemon implementation would be complex. The alternatives also
have much higher overhead.
This patch updated from original patch based on feedback from David
Rientjes.
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This warning was added in commit bdff746a39 ("clone: prepare to recycle
CLONE_STOPPED") three years ago. 2.6.26 came and went. As far as I know,
no-one is actually using CLONE_STOPPED.
Signed-off-by: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use modern per_cpu API to increment {soft|hard}irq counters, and use
per_cpu allocation for (struct irq_desc)->kstats_irq instead of an array.
This gives better SMP/NUMA locality and saves few instructions per irq.
With small nr_cpuids values (8 for example), kstats_irq was a small array
(less than L1_CACHE_BYTES), potentially source of false sharing.
In the !CONFIG_SPARSE_IRQ case, remove the huge, NUMA/cache unfriendly
kstat_irqs_all[NR_IRQS][NR_CPUS] array.
Note: we still populate kstats_irq for all possible irqs in
early_irq_init(). We probably could use on-demand allocations. (Code
included in alloc_descs()). Problem is not all IRQS are used with a prior
alloc_descs() call.
kstat_irqs_this_cpu() is not used anymore, remove it.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits)
block: ensure that completion error gets properly traced
blktrace: add missing probe argument to block_bio_complete
block cfq: don't use atomic_t for cfq_group
block cfq: don't use atomic_t for cfq_queue
block: trace event block fix unassigned field
block: add internal hd part table references
block: fix accounting bug on cross partition merges
kref: add kref_test_and_get
bio-integrity: mark kintegrityd_wq highpri and CPU intensive
block: make kblockd_workqueue smarter
Revert "sd: implement sd_check_events()"
block: Clean up exit_io_context() source code.
Fix compile warnings due to missing removal of a 'ret' variable
fs/block: type signature of major_to_index(int) to major_to_index(unsigned)
block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p)
cfq-iosched: don't check cfqg in choose_service_tree()
fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors
cdrom: export cdrom_check_events()
sd: implement sd_check_events()
sr: implement sr_check_events()
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (41 commits)
fs: add documentation on fallocate hole punching
Gfs2: fail if we try to use hole punch
Btrfs: fail if we try to use hole punch
Ext4: fail if we try to use hole punch
Ocfs2: handle hole punching via fallocate properly
XFS: handle hole punching via fallocate properly
fs: add hole punching to fallocate
vfs: pass struct file to do_truncate on O_TRUNC opens (try #2)
fix signedness mess in rw_verify_area() on 64bit architectures
fs: fix kernel-doc for dcache::prepend_path
fs: fix kernel-doc for dcache::d_validate
sanitize ecryptfs ->mount()
switch afs
move internal-only parts of ncpfs headers to fs/ncpfs
switch ncpfs
switch 9p
pass default dentry_operations to mount_pseudo()
switch hostfs
switch affs
switch configfs
...
MONOTONIC_RAW clock timestamps are ideally suited for frequency
calculation and also fit well into the original NTP hardpps design. Now
phase and frequency can be adjusted separately: the former based on
REALTIME clock and the latter based on MONOTONIC_RAW clock.
A new function getnstime_raw_and_real is added to timekeeping subsystem to
capture both timestamps at the same time and atomically.
Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit adds hardpps() implementation based upon the original one from
the NTPv4 reference kernel code from David Mills. However, it is highly
optimized towards very fast syncronization and maximum stickness to PPS
signal. The typical error is less then a microsecond.
To make it sync faster I had to throw away exponential phase filter so
that the full phase offset is corrected immediately. Then I also had to
throw away median phase filter because it gives a bigger error itself if
used without exponential filter.
Maybe we will find an appropriate filtering scheme in the future but it's
not necessary if the signal quality is ok.
Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 4be2c95d ("taskstats: pad taskstats netlink response for aligment
issues on ia64") added a null field to align the taskstats structure but
the discussion centered around ia64. The issue exists on other platforms
with inefficient unaligned access and adding them piecemeal would be an
unmaintainable mess.
This patch uses Dave Miller's suggestion of using a combination of
CONFIG_64BIT && !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to determine
whether alignment is needed.
Note that this will cause breakage on those platforms with applications
like iotop which had hard-coded offsets into the packet to access the
taskstats structure.
The message seen on systems without the alignment fixes looks like: kernel
unaligned access to 0xe000023879dca9bc, ip=0xa000000100133d10
The addresses may vary but resolve to locations inside __delayacct_add_tsk.
iotop makes what I'd call unreasonable assumptions about the contents of a
netlink genetlink packet containing generic attributes. They're typed and
have headers that specify value lengths, so the client can (should)
identify and skip the ones the client doesn't understand.
The kernel, as of version 2.6.36, presented a packet like so:
+--------------------------------+
| genlmsghdr - 4 bytes |
+--------------------------------+
| NLA header - 4 bytes | /* Aggregate header */
+-+------------------------------+
| | NLA header - 4 bytes | /* PID header */
| +------------------------------+
| | pid/tgid - 4 bytes |
| +------------------------------+
| | NLA header - 4 bytes | /* stats header */
| + -----------------------------+ <- oops. aligned on 4 byte boundary
| | struct taskstats - 328 bytes |
+-+------------------------------+
The iotop code expects that the kernel will behave as it did then,
assuming that the packet format is set in stone. The format is set in
stone, but the packet offsets are not. There's nothing in the packet
format that guarantees that the packet will be sent in exactly the same
way. The attribute contents are set (or versioned) and the aggregate
contents are set but they can be anywhere in the packet.
The issue here isn't that an unaligned structure gets passed to userspace,
it's that the NLA infrastructure has something of a weakness: The 4 byte
attribute header may force the payload to be unaligned. The taskstats
structure is created at an unaligned location and then 64-bit values are
operated on inside the kernel, so the unaligned access warnings gets
spewed everywhere.
It's possible to use the unaligned access API to operate on the structure
in the kernel but it seems like a wasted effort to work around userspace
code that isn't following the packet format. Any new additions would also
need the be worked around. It's a maintenance nightmare.
The conclusion of the earlier discussion seemed to be "ok fine, if we have
to break it, don't break it on arches that don't have the problem." Dave
pointed out that the unaligned access problem doesn't only exist on ia64,
but also on other 64-bit arches that don't have efficient unaligned access
and it should be fixed there as well. The committed version of the patch
and this addition keep with the conclusion of that discussion not to break
it unnecessarily, which the pid padding and the packet padding fixes did
do. x86_64 and powerpc don't suffer this problem so they shouldn't suffer
the solution. Other 64-bit architectures do and will, though.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reported-by: David S. Miller <davem@davemloft.net>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Florian Mickler <florian@mickler.org>
Cc: Guillaume Chazarain <guichaz@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently on 64-bit arch the user_namespace is 2096 and when being
kmalloc-ed it resides on a 4k slab wasting 2003 bytes.
If we allocate a separate cache for it and reduce the hash size from 128
to 64 chains the packaging becomes *much* better - the struct is 1072
bytes and the hole between is 98 bytes.
[akpm@linux-foundation.org: s/__initcall/module_init/]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ctl_unnumbered.txt have been removed in Documentation directory so just
also remove this invalid comments
[akpm@linux-foundation.org: fix Documentation/sysctl/00-INDEX, per Dave]
Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Cc: Dave Young <hidave.darkstar@gmail.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use temporary lr for struct latency_record for improved readability and
fewer columns used. Removed trailing space from output.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Jiri Kosina <trivial@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dump_list_lock is used to protect dump_list in kmsg_dumper implementation,
kmsg_dump() uses it to traverse dump_list too. But if there is contention
on the lock, kmsg_dump() will fail, and the valuable kernel message may be
lost.
This patch solves this issue with RCU. Because kmsg_dump() only read the
list, no lock is needed in kmsg_dump(). So that kmsg_dump() will never
fail because of lock contention.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add the %pK printk format specifier and the /proc/sys/kernel/kptr_restrict
sysctl.
The %pK format specifier is designed to hide exposed kernel pointers,
specifically via /proc interfaces. Exposing these pointers provides an
easy target for kernel write vulnerabilities, since they reveal the
locations of writable structures containing easily triggerable function
pointers. The behavior of %pK depends on the kptr_restrict sysctl.
If kptr_restrict is set to 0, no deviation from the standard %p behavior
occurs. If kptr_restrict is set to 1, the default, if the current user
(intended to be a reader via seq_printf(), etc.) does not have CAP_SYSLOG
(currently in the LSM tree), kernel pointers using %pK are printed as 0's.
If kptr_restrict is set to 2, kernel pointers using %pK are printed as
0's regardless of privileges. Replacing with 0's was chosen over the
default "(null)", which cannot be parsed by userland %p, which expects
"(nil)".
[akpm@linux-foundation.org: check for IRQ context when !kptr_restrict, save an indent level, s/WARN/WARN_ONCE/]
[akpm@linux-foundation.org: coding-style fixup]
[randy.dunlap@oracle.com: fix kernel/sysctl.c warning]
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: James Morris <jmorris@namei.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Thomas Graf <tgraf@infradead.org>
Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David S. Miller <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For arch which needs USE_GENERIC_SMP_HELPERS, it has to select
USE_GENERIC_SMP_HELPERS, rather than leaving a choice to user, since they
don't provide their own implementions.
Also, move on_each_cpu() to kernel/smp.c, it is strange to put it in
kernel/softirq.c.
For arch which doesn't use USE_GENERIC_SMP_HELPERS, e.g. blackfin, only
on_each_cpu() is compiled.
Signed-off-by: Amerigo Wang <amwang@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need to know the reason why system rebooted in support service.
However, we can't inform our customers of the reason because final
messages are lost on current Linux kernel.
This patch improves the situation above because the final messages are
saved by adding kmsg_dump() to reboot, halt, poweroff and
emergency_restart path.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Marco Stornelli <marco.stornelli@gmail.com>
Reviewed-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <0D753D10438DA54287A00B027084269764CE0E54B7@AUSP01VMBX24.collaborationhost.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The minsec argument to clocks_calc_mult_shift() is misnamed. It is used
to clamp the magnitude of the mult factor so that a multiplication with
any value in the given range won't overflow a 64 bit result. Let's
rename it to match the actual usage.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <alpine.LFD.2.00.1101111207140.17086@xanadu.home>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Generic Hardware Error Source provides a way to report platform
hardware errors (such as that from chipset). It works in so called
"Firmware First" mode, that is, hardware errors are reported to
firmware firstly, then reported to Linux by firmware. This way, some
non-standard hardware error registers or non-standard hardware link
can be checked by firmware to produce more valuable hardware error
information for Linux.
This patch adds POLL/IRQ/NMI notification types support.
Because the memory area used to transfer hardware error information
from BIOS to Linux can be determined only in NMI, IRQ or timer
handler, but general ioremap can not be used in atomic context, so a
special version of atomic ioremap is implemented for that.
Known issue:
- Error information can not be printed for recoverable errors notified
via NMI, because printk is not NMI-safe. Will fix this via delay
printing to IRQ context via irq_work or make printk NMI-safe.
v2:
- adjust printk format per comments.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The nested NOT_RUNNING test in worker_clr_flags() is slightly
misleading in that if NOT_RUNNING were a single flag the nested test
would be always %true and thus noop. Add a comment noting that the
test isn't a noop.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Currently, the lockdep annotation in flush_work() requires exclusive
access on the workqueue the target work is queued on and triggers
warning if a work is trying to flush another work on the same
workqueue; however, this is no longer true as workqueues can now
execute multiple works concurrently.
This patch adds lock_map_acquire_read() and make process_one_work()
hold read access to the workqueue while executing a work and
start_flush_work() check for write access if concurrnecy level is one
or the workqueue has a rescuer (as only one execution resource - the
rescuer - is guaranteed to be available under memory pressure), and
read access if higher.
This better represents what's going on and removes spurious lockdep
warnings which are triggered by fake dependency chain created through
flush_work().
* Peter pointed out that flushing another work from a WQ_MEM_RECLAIM
wq breaks forward progress guarantee under memory pressure.
Condition check accordingly updated.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Tested-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@kernel.org
The comment about why rt_mutex_next_owner() can return NULL in
wake_futex_pi() is not the normal case.
Tracing the cause of why this occurs is more likely that waiter
simply timedout. But because it originally caused contention with
the futex, the owner will go into the kernel when it unlocks
the lock. Then it will hit this code path and
rt_mutex_next_owner() will return NULL.
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (30 commits)
MAINTAINERS: Add tomoyo-dev-en ML.
SELinux: define permissions for DCB netlink messages
encrypted-keys: style and other cleanup
encrypted-keys: verify datablob size before converting to binary
trusted-keys: kzalloc and other cleanup
trusted-keys: additional TSS return code and other error handling
syslog: check cap_syslog when dmesg_restrict
Smack: Transmute labels on specified directories
selinux: cache sidtab_context_to_sid results
SELinux: do not compute transition labels on mountpoint labeled filesystems
This patch adds a new security attribute to Smack called SMACK64EXEC. It defines label that is used while task is running.
SELinux: merge policydb_index_classes and policydb_index_others
selinux: convert part of the sym_val_to_name array to use flex_array
selinux: convert type_val_to_struct to flex_array
flex_array: fix flex_array_put_ptr macro to be valid C
SELinux: do not set automatic i_ino in selinuxfs
selinux: rework security_netlbl_secattr_to_sid
SELinux: standardize return code handling in selinuxfs.c
SELinux: standardize return code handling in selinuxfs.c
SELinux: standardize return code handling in policydb.c
...
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6:
mkuboot.sh: Fail if mkimage is missing
gen_init_cpio: checkpatch fixes
gen_init_cpio: Avoid race between call to stat() and call to open()
modpost: Fix address calculation in reloc_location()
Make fixdep error handling more explicit
checksyscalls: Fix stand-alone usage
modpost: Put .zdebug* section on white list
kbuild: fix interaction of CONFIG_IKCONFIG and KCONFIG_CONFIG
kbuild: export linux/{a.out,kvm,kvm_para}.h on headers_install_all
kbuild: introduce HDR_ARCH_LIST for headers_install_all
headers_install: check exit status of unifdef
gen_init_cpio: remove leading `/' from file names
scripts/genksyms: fix header usage
fixdep: use hash table instead of a single array
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
spi / PM: Support dev_pm_ops
PM: Prototype the pm_generic_ operations
PM / Runtime: Generic resume shouldn't set RPM_ACTIVE unconditionally
PM: Use dev_name() in core device suspend and resume routines
PM: Permit registration of parentless devices during system suspend
PM: Replace the device power.status field with a bit field
PM: Remove redundant checks from core device resume routines
PM: Use a different list of devices for each stage of device suspend
PM: Avoid compiler warning in pm_noirq_op()
PM: Use pm_wakeup_pending() in __device_suspend()
PM / Wakeup: Replace pm_check_wakeup_events() with pm_wakeup_pending()
PM: Prevent dpm_prepare() from returning errors unnecessarily
PM: Fix references to basic-pm-debugging.txt in drivers-testing.txt
PM / Runtime: Add synchronous runtime interface for interrupt handlers (v3)
PM / Hibernate: When failed, in_suspend should be reset
PM / Hibernate: hibernation_ops->leave should be checked too
Freezer: Fix a race during freezing of TASK_STOPPED tasks
PM: Use proper ccflag flag in kernel/power/Makefile
PM / Runtime: Fix comments to match runtime callback code
We normally just use the BIO_UPTODATE flag to signal 0/-EIO. If
we have more information available, we should pass that along to
the trace output.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Conflicts:
security/smack/smack_lsm.c
Verified and added fix by Stephen Rothwell <sfr@canb.auug.org.au>
Ok'd by Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
DEFINE_TRACE should also exist when CONFIG_EVENT_TRACING=n. Otherwise, setting
only TRACEPOINTS=y is broken.
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
LKML-Reference: <20101028153117.GA4051@Krystal>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
While running my ftrace stress test, this showed up:
BUG: sleeping function called from invalid context at mm/mmap.c:233
...
note: cat[3293] exited with preempt_count 1
The bug was introduced by commit 91e86e560d
("tracing: Fix recursive user stack trace")
Cc: <stable@kernel.org>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4D0089AC.1020802@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
gameport: use this_cpu_read instead of lookup
x86: udelay: Use this_cpu_read to avoid address calculation
x86: Use this_cpu_inc_return for nmi counter
x86: Replace uses of current_cpu_data with this_cpu ops
x86: Use this_cpu_ops to optimize code
vmstat: User per cpu atomics to avoid interrupt disable / enable
irq_work: Use per cpu atomics instead of regular atomics
cpuops: Use cmpxchg for xchg to avoid lock semantics
x86: this_cpu_cmpxchg and this_cpu_xchg operations
percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
percpu,x86: relocate this_cpu_add_return() and friends
connector: Use this_cpu operations
xen: Use this_cpu_inc_return
taskstats: Use this_cpu_ops
random: Use this_cpu_inc_return
fs: Use this_cpu_inc_return in buffer.c
highmem: Use this_cpu_xx_return() operations
vmstat: Use this_cpu_inc_return for vm statistics
x86: Support for this_cpu_add, sub, dec, inc_return
percpu: Generic support for this_cpu_add, sub, dec, inc_return
...
Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (33 commits)
usb: don't use flush_scheduled_work()
speedtch: don't abuse struct delayed_work
media/video: don't use flush_scheduled_work()
media/video: explicitly flush request_module work
ioc4: use static work_struct for ioc4_load_modules()
init: don't call flush_scheduled_work() from do_initcalls()
s390: don't use flush_scheduled_work()
rtc: don't use flush_scheduled_work()
mmc: update workqueue usages
mfd: update workqueue usages
dvb: don't use flush_scheduled_work()
leds-wm8350: don't use flush_scheduled_work()
mISDN: don't use flush_scheduled_work()
macintosh/ams: don't use flush_scheduled_work()
vmwgfx: don't use flush_scheduled_work()
tpm: don't use flush_scheduled_work()
sonypi: don't use flush_scheduled_work()
hvsi: don't use flush_scheduled_work()
xen: don't use flush_scheduled_work()
gdrom: don't use flush_scheduled_work()
...
Fixed up trivial conflict in drivers/media/video/bt8xx/bttv-input.c
as per Tejun.
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Constify function scope static struct sched_param usage
sched: Fix strncmp operation
sched: Move sched_autogroup_exit() to free_signal_struct()
sched: Fix struct autogroup memory leak
sched: Mark autogroup_init() __init
sched: Consolidate the name of root_task_group and init_task_group
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (36 commits)
serial: apbuart: Fixup apbuart_console_init()
TTY: Add tty ioctl to figure device node of the system console.
tty: add 'active' sysfs attribute to tty0 and console device
drivers: serial: apbuart: Handle OF failures gracefully
Serial: Avoid unbalanced IRQ wake disable during resume
tty: fix typos/errors in tty_driver.h comments
pch_uart : fix warnings for 64bit compile
8250: fix uninitialized FIFOs
ip2: fix compiler warning on ip2main_pci_tbl
specialix: fix compiler warning on specialix_pci_tbl
rocket: fix compiler warning on rocket_pci_ids
8250: add a UPIO_DWAPB32 for 32 bit accesses
8250: use container_of() instead of casting
serial: omap-serial: Add support for kernel debugger
serial: fix pch_uart kconfig & build
drivers: char: hvc: add arm JTAG DCC console support
RS485 documentation: add 16C950 UART description
serial: ifx6x60: fix memory leak
serial: ifx6x60: free IRQ on error
Serial: EG20T: add PCH_UART driver
...
Fixed up conflicts in drivers/serial/apbuart.c with evil merge that
makes the code look fairly sane (unlike either side).
Function-scope statics are discouraged because they are
easily overlooked and can cause subtle bugs/races due to
their global (non-SMP safe) nature.
Linus noticed that we did this for sched_param - at minimum
make the const.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: Message-ID: <AANLkTinotRxScOHEb0HgFgSpGPkq_6jKTv5CfvnQM=ee@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
One of the operands, buf, is incorrect, since it is stripped and the
correct address for subsequent string comparing could change if
leading white spaces, if any, are removed from buf.
It is fixed by replacing buf with cmp.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <AANLkTinOPuYsVovrZpbuCCmG5deEyc8WgA_A1RJx_YK7@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Seems I lost a change somewhere, leaking memory.
sched: fix struct autogroup memory leak
Add missing change to actually use autogroup_free().
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294222285.8369.2.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
autogroup_init() is only called at boot time.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294375425-31065-1-git-send-email-yong.zhang0@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
root_task_group is the leftover of USER_SCHED, now it's always
same to init_task_group.
But as Mike suggested, root_task_group is maybe the suitable name
to keep for a tree.
So in this patch:
init_task_group --> root_task_group
init_task_group_load --> root_task_group_load
INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD
Suggested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110107071736.GA32635@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Adds perf_event_time() to try and centralize access to event
timing and in particular ctx->time. Prepares for cgroup support.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4d22059c.122ae30a.5e0e.ffff8b8b@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Replace all occurrences of:
event->cpu != -1 && event->cpu == smp_processor_id()
by a call to:
event_filter_match(event)
This makes the code more consistent and will make the cgroup
patch smaller.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4d220593.2308e30a.48c5.ffff8ae9@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In particular this patch move perf_event_exit_task() before
cgroup_exit() to allow for cgroup support. The cgroup_exit()
function detaches the cgroups attached to a task.
Other movements include hoisting some definitions and inlines
at the top of perf_event.c
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4d22058b.cdace30a.4657.ffff95b1@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
blktrace.c block bio complete callback needs to gain a new argument to reflect
the newly added "error" tracepoint argument. This is needed to match the new
block_bio_complete TRACE_EVENT as of
commit de983a7bfcb7c020901ca6e2314cf55a4207ab5a.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Jeff Moyer <jmoyer@redhat.com>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.
Patched with:
git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
dget_locked was a shortcut to avoid the lazy lru manipulation when we already
held dcache_lock (lru manipulation was relatively cheap at that point).
However, how that the lru lock is an innermost one, we never hold it at any
caller, so the lock cost can now be avoided. We already have well working lazy
dcache LRU, so it should be fine to defer LRU manipulations to scan time.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Protect d_subdirs and d_child with d_lock, except in filesystems that aren't
using dcache_lock for these anyway (eg. using i_mutex).
Note: if we change the locking rule in future so that ->d_child protection is
provided only with ->d_parent->d_lock, it may allow us to reduce some locking.
But it would be an exception to an otherwise regular locking scheme, so we'd
have to see some good results. Probably not worthwhile.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Change d_delete from a dentry deletion notification to a dentry caching
advise, more like ->drop_inode. Require it to be constant and idempotent,
and not take d_lock. This is how all existing filesystems use the callback
anyway.
This makes fine grained dentry locking of dput and dentry lru scanning
much simpler.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Switching d_op on a live dentry is racy in general, so avoid it. In this case
it is a negative dentry, which is safer, but there are still concurrent ops
which may be called on d_op in that case (eg. d_revalidate). So in general
a filesystem may not do this. Fix cgroupfs so as not to do this.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
The saving of the ACPI NVS area during hibernation and suspend and
restoring it during the subsequent resume is entirely specific to
ACPI, so move it to drivers/acpi and drop the CONFIG_SUSPEND_NVS
configuration option which is redundant.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
When ioremap() fails (which might happen for some reason), we nicely
oops in suspend_nvs_save() due to NULL dereference by memcpy() in there.
Fail gracefully instead.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (416 commits)
ARM: DMA: add support for DMA debugging
ARM: PL011: add DMA burst threshold support for ST variants
ARM: PL011: Add support for transmit DMA
ARM: PL011: Ensure IRQs are disabled in UART interrupt handler
ARM: PL011: Separate hardware FIFO size from TTY FIFO size
ARM: PL011: Allow better handling of vendor data
ARM: PL011: Ensure error flags are clear at startup
ARM: PL011: include revision number in boot-time port printk
ARM: vexpress: add sched_clock() for Versatile Express
ARM i.MX53: Make MX53 EVK bootable
ARM i.MX53: Some bug fix about MX53 MSL code
ARM: 6607/1: sa1100: Update platform device registration
ARM: 6606/1: sa1100: Fix platform device registration
ARM i.MX51: rename IPU irqs
ARM i.MX51: Add ipu clock support
ARM: imx/mx27_3ds: Add PMIC support
ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn()
mx51: fix usb clock support
MX51: Add support for usb host 2
arch/arm/plat-mxc/ehci.c: fix errors/typos
...
* 'x86-alternatives-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, suspend: Avoid unnecessary smp alternatives switch during suspend/resume
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-64, asm: Use fxsaveq/fxrestorq in more places
* 'x86-hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, hwmon: Add core threshold notification to therm_throt.c
* 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, paravirt: Use native_halt on a halt, not native_safe_halt
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
locking, lockdep: Convert sprintf_symbol to %pS
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
irq: Better struct irqaction layout
* 'x86-security-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
module: Move RO/NX module protection to after ftrace module update
x86: Resume trampoline must be executable
x86: Add RO/NX protection for loadable kernel modules
x86: Add NX protection for kernel data
x86: Fix improper large page preservation
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
MAINTAINERS: Update timer related entries
timers: Use this_cpu_read
timerqueue: Make timerqueue_getnext() static inline
hrtimer: fix timerqueue conversion flub
hrtimers: Convert hrtimers to use timerlist infrastructure
timers: Fixup allmodconfig build issue
timers: Rename timerlist infrastructure to timerqueue
timers: Introduce timerlist infrastructure.
hrtimer: Remove stale comment on curr_timer
timer: Warn when del_timer_sync() is called in hardirq context
timer: Del_timer_sync() can be used in softirq context
timer: Make try_to_del_timer_sync() the same on SMP and UP
posix-timers: Annotate lock_timer()
timer: Permit statically-declared work with deferrable timers
time: Use ARRAY_SIZE macro in timecompare.c
timer: Initialize the field slack of timer_list
timer_list: Remove alignment padding on 64 bit when CONFIG_TIMER_STATS
time: Compensate for rounding on odd-frequency clocksources
Fix up trivial conflict in MAINTAINERS
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits)
sched: Change wait_for_completion_*_timeout() to return a signed long
sched, autogroup: Fix reference leak
sched, autogroup: Fix potential access to freed memory
sched: Remove redundant CONFIG_CGROUP_SCHED ifdef
sched: Fix interactivity bug by charging unaccounted run-time on entity re-weight
sched: Move periodic share updates to entity_tick()
printk: Use this_cpu_{read|write} api on printk_pending
sched: Make pushable_tasks CONFIG_SMP dependant
sched: Add 'autogroup' scheduling feature: automated per session task groups
sched: Fix unregister_fair_sched_group()
sched: Remove unused argument dest_cpu to migrate_task()
mutexes, sched: Introduce arch_mutex_cpu_relax()
sched: Add some clock info to sched_debug
cpu: Remove incorrect BUG_ON
cpu: Remove unused variable
sched: Fix UP build breakage
sched: Make task dump print all 15 chars of proc comm
sched: Update tg->shares after cpu.shares write
sched: Allow update_cfs_load() to update global load
sched: Implement demand based update_cfs_load()
...
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (146 commits)
tools, perf: Documentation for the power events API
perf: Add calls to suspend trace point
perf script: Make some lists static
perf script: Use the default lost event handler
perf session: Warn about errors when processing pipe events too
perf tools: Fix perf_event.h header usage
perf test: Clarify some error reports in the open syscall test
x86, NMI: Add touch_nmi_watchdog to io_check_error delay
x86: Avoid calling arch_trigger_all_cpu_backtrace() at the same time
x86: Only call smp_processor_id in non-preempt cases
perf timechart: Adjust perf timechart to the new power events
perf: Clean up power events by introducing new, more generic ones
perf: Do not export power_frequency, but power_start event
perf test: Add test for counting open syscalls
perf evsel: Auto allocate resources needed for some methods
perf evsel: Use {cpu,thread}_map to shorten list of parameters
perf tools: Refactor all_tids to hold nr and the map
perf tools: Refactor cpumap to hold nr and the map
perf evsel: Introduce per cpu and per thread open helpers
perf evsel: Steal the counter reading routines from stat
...
* 'core-futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: Add futex_q static initializer
futex: Replace fshared and clockrt with combined flags
futex: Cleanup stale fshared flag interfaces
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: remove unused __list_for_each_rcu() macro
rculist: fix borked __list_for_each_rcu() macro
rcu: reduce __call_rcu()-induced contention on rcu_node structures
rcu: limit rcu_node leaf-level fanout
rcu: fine-tune grace-period begin/end checks
rcu: Keep gpnum and completed fields synchronized
rcu: Stop chasing QS if another CPU did it for us
rcu: increase synchronize_sched_expedited() batching
rcu: Make synchronize_srcu_expedited() fast if running readers
rcu: fix race condition in synchronize_sched_expedited()
rcu: update documentation/comments for Lai's adoption patch
rcu,cleanup: simplify the code when cpu is dying
rcu,cleanup: move synchronize_sched_expedited() out of sched.c
rcu: get rid of obsolete "classic" names in TREE_RCU tracing
rcu: Distinguish between boosting and boosted
rcu: document TINY_RCU and TINY_PREEMPT_RCU tracing.
rcu: add tracing for TINY_RCU and TINY_PREEMPT_RCU
rcu: priority boosting for TINY_PREEMPT_RCU
rcu: move TINY_RCU from softirq to kthread
rcu: add priority-inversion testing to rcutorture
Uses the machine_suspend trace point, called from the
generic kernel suspend_devices_and_enter function.
Signed-off-by: Jean Pihet <j-pihet@ti.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Arjan van de Ven <arjan@linux.intel.com>
CC: Thomas Renninger <trenn@suse.de>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-pm@lists.linux-foundation.org
LKML-Reference: <1294253342-29056-2-git-send-email-j-pihet@ti.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
wait_for_completion_*_timeout() can return:
0: if the wait timed out
-ve: if the wait was interrupted
+ve: if the completion was completed.
As they currently return an 'unsigned long', the last two cases
are not easily distinguished which can easily result in buggy
code, as is the case for the recently added
wait_for_completion_interruptible_timeout() call in
net/sunrpc/cache.c
So change them both to return 'long'. As MAX_SCHEDULE_TIMEOUT
is LONG_MAX, a large +ve return value should never overflow.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110105125016.64ccab0e@notabene.brown>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The cgroup exit mess also uncovered a struct autogroup reference leak.
copy_process() was simply freeing vs putting the signal_struct,
stranding a reference.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
LKML-Reference: <1293784350.6839.2.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Oleg pointed out that the /proc interface kref_get() useage may race with
the final put during autogroup_move_group(). A signal->autogroup assignment
may be in flight when the /proc interface dereference, leaving them taking
a reference to an already dead group.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292508592.5940.28.camel@maggy.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add these new power trace events:
power:cpu_idle
power:cpu_frequency
power:machine_suspend
The old C-state/idle accounting events:
power:power_start
power:power_end
Have now a replacement (but we are still keeping the old
tracepoints for compatibility):
power:cpu_idle
and
power:power_frequency
is replaced with:
power:cpu_frequency
power:machine_suspend is newly introduced.
Jean Pihet has a patch integrated into the generic layer
(kernel/power/suspend.c) which will make use of it.
the type= field got removed from both, it was never
used and the type is differed by the event type itself.
perf timechart userspace tool gets adjusted in a separate patch.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: rjw@sisk.pl
LKML-Reference: <1294073445-14812-3-git-send-email-trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1290072314-31155-2-git-send-email-trenn@suse.de>
power_frequency moved to drivers/cpufreq/cpufreq.c which has
to be compiled in, no need to export it.
intel_idle can a be module though...
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Jean Pihet <j-pihet@ti.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: rjw@sisk.pl
LKML-Reference: <1294073445-14812-2-git-send-email-trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1290072314-31155-2-git-send-email-trenn@suse.de>
The error message 'NMI watchdog failed to create perf event...'
does not make it clear that this is a fatal error for the
watchdog. It also currently prints the error value as a
pointer, rather than extracting the error code with PTR_ERR().
Fix that.
Add a note to the description of the 'nowatchdog' kernel
parameter to associate it with this message.
Reported-by: Cesare Leonardi <celeonar@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: 599368@bugs.debian.org
Cc: 608138@bugs.debian.org
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: <stable@kernel.org> # .37.x and later
LKML-Reference: <1294009362.3167.126.camel@localhost>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When racing on adding into user cache, the new allocated from mm slab
is freed without putting user namespace.
Since the user namespace is already operated by getting, putting has
to be issued.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ring_buffer: Off-by-one and duplicate events in ring_buffer_read_page
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu: print out alloc information with KERN_DEBUG instead of KERN_INFO
kthread_work: make lockdep happy
To avoid confusion with the meaning and return value of
pm_check_wakeup_events() replace it with pm_wakeup_pending() that
will work the other way around (ie. return true when system-wide
power transition should be aborted).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
When hibernation failed due to an error in swsusp_write() called by
hibernate(), it skips calling "power_down()" and returns. When
hibernate() is called again (probably after fixing up so that
swsusp_write() wouldn't fail again), before "in_suspend = 1" of
create_image is called, in_suspend should be 0. However, because
hibernate() did not reset "in_suspend" after a failure, it's already 1.
This patch fixes such inconsistency of "in_suspend" value.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Because hibernate calls hibernation_ops->leave() without checking
whether hibernation_ops->leave is NULL or not, hiberantion_set_ops
should WARN_ON if hibernation_ops->leave is NULL.
This patch added one more condition to check hibernation_ops->leave.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
After calling freeze_task(), try_to_freeze_tasks() see whether the
task is stopped or traced and if so, considers it to be frozen;
however, nothing guarantees that either the task being frozen sees
TIF_FREEZE or the freezer sees TASK_STOPPED -> TASK_RUNNING
transition. The task being frozen may wake up and not see TIF_FREEZE
while the freezer fails to notice the transition and believes the task
is still stopped.
This patch fixes the race by making freeze_task() always go through
fake_signal_wake_up() for applicable tasks. The function goes through
the target task's scheduler lock and thus guarantees that either the
target sees TIF_FREEZE or try_to_freeze_task() sees TASK_RUNNING.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Use the ccflags-$ flag instead of EXTRA_CFLAGS because EXTRA_CFLAGS is
deprecated and should now be switched. According to
(documentation/kbuild/makefiles.txt).
Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Fix two related problems in the event-copying loop of
ring_buffer_read_page.
The loop condition for copying events is off-by-one.
"len" is the remaining space in the caller-supplied page.
"size" is the size of the next event (or two events).
If len == size, then there is just enough space for the next event.
size was set to rb_event_ts_length, which may include the size of two
events if the first event is a time-extend, in order to assure time-
extends are kept together with the event after it. However,
rb_advance_reader always advances by one event. This would result in the
event after any time-extend being duplicated. Instead, get the size of
a single event for the memcpy, but use rb_event_ts_length for the loop
condition.
Signed-off-by: David Sharp <dhsharp@google.com>
LKML-Reference: <1293064704-8101-1-git-send-email-dhsharp@google.com>
LKML-Reference: <AANLkTin7nLrRPc9qGjdjHbeVDDWiJjAiYyb-L=gH85bx@mail.gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The commit:
84e1c6bb38
x86: Add RO/NX protection for loadable kernel modules
Broke the function tracer with this output:
------------[ cut here ]------------
WARNING: at kernel/trace/ftrace.c:1014 ftrace_bug+0x114/0x171()
Hardware name: Precision WorkStation 470
Modules linked in: i2c_core(+)
Pid: 86, comm: modprobe Not tainted 2.6.37-rc2+ #68
Call Trace:
[<ffffffff8104e957>] warn_slowpath_common+0x85/0x9d
[<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core]
[<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core]
[<ffffffff8104e989>] warn_slowpath_null+0x1a/0x1c
[<ffffffff810a9dfe>] ftrace_bug+0x114/0x171
[<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core]
[<ffffffff810aa0db>] ftrace_process_locs+0x1ae/0x274
[<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core]
[<ffffffff810aa29e>] ftrace_module_notify+0x39/0x44
[<ffffffff814405cf>] notifier_call_chain+0x37/0x63
[<ffffffff8106e054>] __blocking_notifier_call_chain+0x46/0x5b
[<ffffffff8106e07d>] blocking_notifier_call_chain+0x14/0x16
[<ffffffff8107ffde>] sys_init_module+0x73/0x1f3
[<ffffffff8100acf2>] system_call_fastpath+0x16/0x1b
---[ end trace 2aff4f4ca53ec746 ]---
ftrace faulted on writing [<ffffffffa00026db>]
__process_new_adapter+0x7/0x34 [i2c_core]
The cause was that the module text was set to read only before ftrace
could convert the calls to mcount to nops. Thus, the conversions failed
due to not being able to write to the text locations.
The simple fix is to move setting the module to read only after the
module notifiers are called (where ftrace sets the module mcounts to nops).
Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The taskstats structure is internally aligned on 8 byte boundaries but the
layout of the aggregrate reply, with two NLA headers and the pid (each 4
bytes), actually force the entire structure to be unaligned. This causes
the kernel to issue unaligned access warnings on some architectures like
ia64. Unfortunately, some software out there doesn't properly unroll the
NLA packet and assumes that the start of the taskstats structure will
always be 20 bytes from the start of the netlink payload. Aligning the
start of the taskstats structure breaks this software, which we don't
want. So, for now the alignment only happens on architectures that
require it and those users will have to update to fixed versions of those
packages. Space is reserved in the packet only when needed. This ifdef
should be removed in several years e.g. 2012 once we can be confident
that fixed versions are installed on most systems. We add the padding
before the aggregate since the aggregate is already a defined type.
Commit 85893120 ("delayacct: align to 8 byte boundary on 64-bit systems")
previously addressed the alignment issues by padding out the pid field.
This was supposed to be a compatible change but the circumstances
described above mean that it wasn't. This patch backs out that change,
since it was a hack, and introduces a new NULL attribute type to provide
the padding. Padding the response with 4 bytes avoids allocating an
aligned taskstats structure and copying it back. Since the structure
weighs in at 328 bytes, it's too big to do it on the stack.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reported-by: Brian Rogers <brian@xyzw.org>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Guillaume Chazarain <guichaz@gmail.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Russell King reports:
| On the ARM dev boards, we have a 32-bit counter running at 24MHz. Calling
| clocks_calc_mult_shift(&mult, &shift, 24MHz, NSEC_PER_SEC, 60) gives
| us a multiplier of 2796202666 and a shift of 26.
|
| Over a large counter delta, this produces an error - lets take a count
| from 362976315 to 4280663372:
|
| (4280663372-362976315) * 2796202666 / 2^26 - (4280663372-362976315) * (1000/24)
| => -38.91872422891230269990
|
| Can we do better?
|
| (4280663372-362976315) * 2796202667 / 2^26 - (4280663372-362976315) * (1000/24)
| 19.45936211449532822051
|
| which is about twice as good as the 2796202666 multiplier.
|
| Looking at the equivalent divisions obtained, 2796202666 / 2^26 gives
| 41.66666665673255920410ns per tick, whereas 2796202667 / 2^26 gives
| 41.66666667163372039794ns. The actual value wanted is 1000/24 =
| 41.66666666666666666666ns.
Fix this by ensuring we round to nearest when calculating the
multiplier.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Eric Miao <eric.y.miao@gmail.com>
Tested-by: Olof Johansson <olof@lixom.net>
Tested-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Conflicts:
MAINTAINERS
arch/arm/mach-omap2/pm24xx.c
drivers/scsi/bfa/bfa_fcpim.c
Needed to update to apply fixes for which the old branch was too
outdated.
spinlock in kthread_worker and wait_queue_head in kthread_work both
should be lockdep sensible, so change the interface to make it
suiltable for CONFIG_LOCKDEP.
tj: comment update
Reported-by: Nicolas <nicolas.mailhot@laposte.net>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Tested-by: Andy Walls <awalls@md.metrocast.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently, destroy_workqueue() makes the workqueue deny all new
queueing by setting WQ_DYING and flushes the workqueue once before
proceeding with destruction; however, there are cases where work items
queue more related work items. Currently, such users need to
explicitly flush the workqueue multiple times depending on the
possible depth of such chained queueing.
This patch updates the queueing path such that a work item can queue
further work items on the same workqueue even when WQ_DYING is set.
The flush on destruction is automatically retried until the workqueue
is empty. This guarantees that the workqueue is empty on destruction
while allowing chained queueing.
The flush retry logic whines if it takes too many retries to drain the
workqueue.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Linus reported that the new warning introduced by commit f26f9aff6a
"Sched: fix skip_clock_update optimization" triggers. The need_resched
flag can be set by other CPUs asynchronously so this debug check is
bogus - remove it.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <AANLkTinJ8hAG1TpyC+CSYPR47p48+1=E7fiC45hMXT_1@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-32: Make sure we can map all of lowmem if we need to
x86, vt-d: Handle previous faults after enabling fault handling
x86: Enable the intr-remap fault handling after local APIC setup
x86, vt-d: Fix the vt-d fault handling irq migration in the x2apic mode
x86, vt-d: Quirk for masking vtd spec errors to platform error handling logic
x86, xsave: Use alloc_bootmem_align() instead of alloc_bootmem()
bootmem: Add alloc_bootmem_align()
x86, gcc-4.6: Use gcc -m options when building vdso
x86: HPET: Chose a paranoid safe value for the ETIME check
x86: io_apic: Avoid unused variable warning when CONFIG_GENERIC_PENDING_IRQ=n
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf: Fix off by one in perf_swevent_init()
perf: Fix duplicate events with multiple-pmu vs software events
ftrace: Have recordmcount honor endianness in fn_ELF_R_INFO
scripts/tags.sh: Add magic for trace-events
tracing: Fix panic when lseek() called on "trace" opened for writing
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix the irqtime code for 32bit
sched: Fix the irqtime code to deal with u64 wraps
nohz: Fix get_next_timer_interrupt() vs cpu hotplug
Sched: fix skip_clock_update optimization
sched: Cure more NO_HZ load average woes
Mike Galbraith reported poor interactivity[*] when the new shares distribution
code was combined with autogroups.
The root cause turns out to be a mis-ordering of accounting accrued execution
time and shares updates. Since update_curr() is issued hierarchically,
updating the parent entity weights to reflect child enqueue/dequeue results in
the parent's unaccounted execution time then being accrued (vs vruntime) at the
new weight as opposed to the weight present at accumulation.
While this doesn't have much effect on processes with timeslices that cross a
tick, it is particularly problematic for an interactive process (e.g. Xorg)
which incurs many (tiny) timeslices. In this scenario almost all updates are
at dequeue which can result in significant fairness perturbation (especially if
it is the only thread, resulting in potential {tg->shares, MIN_SHARES}
transitions).
Correct this by ensuring unaccounted time is accumulated prior to manipulating
an entity's weight.
[*] http://xkcd.com/619/ is perversely Nostradamian here.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20101216031038.159704378@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Long running entities that do not block (dequeue) require periodic updates to
maintain accurate share values. (Note: group entities with several threads are
quite likely to be non-blocking in many circumstances).
By virtue of being long-running however, we will see entity ticks (otherwise
the required update occurs in dequeue/put and we are done). Thus we can move
the detection (and associated work) for these updates into the periodic path.
This restores the 'atomicity' of update_curr() with respect to accounting.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101216031038.067028969@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
x86: avoid high BIOS area when allocating address space
x86: avoid E820 regions when allocating address space
x86: avoid low BIOS area when allocating address space
resources: add arch hook for preventing allocation in reserved areas
Revert "resources: support allocating space within a region from the top down"
Revert "PCI: allocate bus resources from the top down"
Revert "x86/PCI: allocate space from the end of a region, not the beginning"
Revert "x86: allocate space within a region top-down"
Revert "PCI: fix pci_bus_alloc_resource() hang, prefer positive decode"
PCI: Update MCP55 quirk to not affect non HyperTransport variants
The irq work queue is a per cpu object and it is sufficient for
synchronization if per cpu atomics are used. Doing so simplifies
the code and reduces the overhead of the code.
Before:
christoph@linux-2.6$ size kernel/irq_work.o
text data bss dec hex filename
451 8 1 460 1cc kernel/irq_work.o
After:
christoph@linux-2.6$ size kernel/irq_work.o
text data bss dec hex filename
438 8 1 447 1bf kernel/irq_work.o
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Christoph Lameter <cl@linux.com>
When the current __call_rcu() function was written, the expedited
APIs did not exist. The __call_rcu() implementation therefore went
to great lengths to detect the end of old grace periods and to start
new ones, all in the name of reducing grace-period latency. Now the
expedited APIs do exist, and the usage of __call_rcu() has increased
considerably. This commit therefore causes __call_rcu() to avoid
worrying about grace periods unless there are a large number of
RCU callbacks stacked up on the current CPU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Some recent benchmarks have indicated possible lock contention on the
leaf-level rcu_node locks. This commit therefore limits the number of
CPUs per leaf-level rcu_node structure to 16, in other words, there
can be at most 16 rcu_data structures fanning into a given rcu_node
structure. Prior to this, the limit was 32 on 32-bit systems and 64 on
64-bit systems.
Note that the fanout of non-leaf rcu_node structures is unchanged. The
organization of accesses to the rcu_node tree is such that references
to non-leaf rcu_node structures are much less frequent than to the
leaf structures.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Use the CPU's bit in rnp->qsmask to determine whether or not the CPU
should try to report a quiescent state. Handle overflow in the check
for rdp->gpnum having fallen behind.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
When a CPU that was in an extended quiescent state wakes
up and catches up with grace periods that remote CPUs
completed on its behalf, we update the completed field
but not the gpnum that keeps a stale value of a backward
grace period ID.
Later, note_new_gpnum() will interpret the shift between
the local CPU and the node grace period ID as some new grace
period to handle and will then start to hunt quiescent state.
But if every grace periods have already been completed, this
interpretation becomes broken. And we'll be stuck in clusters
of spurious softirqs because rcu_report_qs_rdp() will make
this broken state run into infinite loop.
The solution, as suggested by Lai Jiangshan, is to ensure that
the gpnum and completed fields are well synchronized when we catch
up with completed grace periods on their behalf by other cpus.
This way we won't start noting spurious new grace periods.
Suggested-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
When a CPU is idle and others CPUs handled its extended
quiescent state to complete grace periods on its behalf,
it will catch up with completed grace periods numbers
when it wakes up.
But at this point there might be no more grace period to
complete, but still the woken CPU always keeps its stale
qs_pending value and will then continue to chase quiescent
states even if its not needed anymore.
This results in clusters of spurious softirqs until a new
real grace period is started. Because if we continue to
chase quiescent states but we have completed every grace
periods, rcu_report_qs_rdp() is puzzled and makes that
state run into infinite loops.
As suggested by Lai Jiangshan, just reset qs_pending if
someone completed every grace periods on our behalf.
Suggested-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The fix in commit #6a0cc49 requires more than three concurrent instances
of synchronize_sched_expedited() before batching is possible. This
patch uses a ticket-counter-like approach that is also not unrelated to
Lai Jiangshan's Ring RCU to allow sharing of expedited grace periods even
when there are only two concurrent instances of synchronize_sched_expedited().
This commit builds on Tejun's original posting, which may be found at
http://lkml.org/lkml/2010/11/9/204, adding memory barriers, avoiding
overflow of signed integers (other than via atomic_t), and fixing the
detection of batching.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This adds arch_remove_reservations(), which an arch can implement if it
needs to protect part of the address space from allocation.
Sometimes that can be done by just putting a region in the resource tree,
but there are cases where that doesn't work well. For example, x86 BIOS
E820 reservations are not related to devices, so they may overlap part of,
all of, or more than a device resource, so they may not end up at the
correct spot in the resource tree.
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Use this_cpu_inc_return in one place and avoid ugly __raw_get_cpu in
another.
V3->V4:
- Fix off by one.
V4-V4f:
- Use &listener_array
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
__get_cpu_var() can be replaced with this_cpu_read and will then use a
single read instruction with implied address calculation to access the
correct per cpu instance.
However, the address of a per cpu variable passed to __this_cpu_read()
cannot be determined (since it's an implied address conversion through
segment prefixes). Therefore apply this only to uses of __get_cpu_var
where the address of the variable is not used.
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Hugh Dickins <hughd@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Use this_cpu ops in various places to optimize per cpu data access.
Cc: Jason Baron <jbaron@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
tty: add 'active' sysfs attribute to tty0 and console device
Userspace can query the actual virtual console, and the configured
console devices behind /dev/tt0 and /dev/console.
The last entry in the list of devices is the active device, analog
to the console= kernel command line option.
The attribute supports poll(), which is raised when the virtual
console is changed or /dev/console is reconfigured.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
index 0000000..b138b66
Commit 3624eb0 (PM / Hibernate: Modify signature used to mark swap)
attempted to modify hibernate signature used to mark swap partitions
containing hibernation images, so that old kernels don't try to
handle compressed images. However, this change broke resume from
hibernation on Fedora 14 that apparently doesn't pass the resume=
argument to the kernel and tries to trigger resume from early user
space. This doesn't work, because the signature is now different,
so the old signature has to be restored to avoid the problem.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=22732 .
Reported-by: Dr. David Alan Gilbert <linux@treblig.org>
Reported-by: Zhang Rui <rui.zhang@intel.com>
Reported-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The user-space hibernation sends a wrong notification after the image
restoration because of thinko for the file flag check. RDONLY
corresponds to hibernation and WRONLY to restoration, confusingly.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@kernel.org
Simple sysfs emumeration of the PMUs.
Use a "event_source" bus, and add PMU devices using their name.
Each PMU device has a type attribute which contrains the value needed
for perf_event_attr::type to identify this PMU.
This is the minimal stub needed to start using this interface,
we'll consider extending the sysfs usage later.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101117222056.316982569@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Extend the perf_pmu_register() interface to allow for named and
dynamic pmu types.
Because we need to support the existing static types we cannot use
dynamic types for everything, hence provide a type argument.
If we want to enumerate the PMUs they need a name, provide one.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101117222056.259707703@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently we call perf_event_init() from sched_init(). In order to
make it more obvious move it to the cannnonical location.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101117222056.093629821@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since the irqtime accounting is using non-atomic u64 and can be read
from remote cpus (writes are strictly cpu local, reads are not) we
have to deal with observing partial updates.
When we do observe partial updates the clock movement (in particular,
->clock_task movement) will go funny (in either direction), a
subsequent clock update (observing the full update) will make it go
funny in the oposite direction.
Since we rely on these clocks to be strictly monotonic we cannot
suffer backwards motion. One possible solution would be to simply
ignore all backwards deltas, but that will lead to accounting
artefacts, most notable: clock_task + irq_time != clock, this
inaccuracy would end up in user visible stats.
Therefore serialize the reads using a seqcount.
Reviewed-by: Venkatesh Pallipadi <venki@google.com>
Reported-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292242434.6803.200.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some ARM systems have a short sched_clock() [ which needs to be fixed
too ], but this exposed a bug in the irq_time code as well, it doesn't
deal with wraps at all.
Fix the irq_time code to deal with u64 wraps by re-writing the code to
only use delta increments, which avoids the whole issue.
Reviewed-by: Venkatesh Pallipadi <venki@google.com>
Reported-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292242433.6803.199.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The perf_swevent_enabled[] array has PERF_COUNT_SW_MAX elements.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101024195041.GT5985@bicker>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: It is likely that WORKER_NOT_RUNNING is true
MAINTAINERS: Add workqueue entry
workqueue: check the allocation of system_unbound_wq
If you try to build a kernel with KCONFIG_CONFIG set (to a value
not equal to .config) and that config sets CONFIG_IKCONFIG then the
build will fail with:
make[1]: *** No rule to make target `.config', needed by \
`kernel/config_data.gz'. Stop.
because the kernel/Makefile contains a direct reference to .config.
This issue has been present since the introduction of KCONFIG_CONFIG
in 14cdd3c402.
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
CC: Roman Zippel <zippel@linux-m68k.org>
CC: Michal Marek <mmarek@suse.cz>
Reviewed-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Running the annotate branch profiler on three boxes, including my
main box that runs firefox, evolution, xchat, and is part of the distcc farm,
showed this with the likelys in the workqueue code:
correct incorrect % Function File Line
------- --------- - -------- ---- ----
96 996253 99 wq_worker_sleeping workqueue.c 703
96 996247 99 wq_worker_waking_up workqueue.c 677
The likely()s in this case were assuming that WORKER_NOT_RUNNING will
most likely be false. But this is not the case. The reason is
(and shown by adding trace_printks and testing it) that most of the time
WORKER_PREP is set.
In worker_thread() we have:
worker_clr_flags(worker, WORKER_PREP);
[ do work stuff ]
worker_set_flags(worker, WORKER_PREP, false);
(that 'false' means not to wake up an idle worker)
The wq_worker_sleeping() is called from schedule when a worker thread
is putting itself to sleep. Which happens most of the time outside
of that [ do work stuff ].
The wq_worker_waking_up is called by the wakeup worker code, which
is also callod outside that [ do work stuff ].
Thus, the likely and unlikely used by those two functions are actually
backwards.
Remove the annotation and let gcc figure it out.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
During suspend, we disable all the non boot cpus. And during resume we bring
them all back again. So no need to do alternatives_smp_switch() in between.
On my core 2 based laptop, this speeds up the suspend path by 15msec and the
resume path by 5 msec (suspend/resume speed up differences can be attributed
to the different P-states that the cpu is in during suspend/resume).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1290557500.4946.8.camel@sbsiddha-MOBL3.sc.intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Eric asked for this.
[tglx: Because it generates faster code according to Erics ]
Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-mm@kvack.org
LKML-Reference: <alpine.DEB.2.00.1011301404490.4039@router.home>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In converting the hrtimers to timerqueue, I missed
a spot in hrtimer_run_queues where we loop running
timers. We end up not pulling the new next value out
and instead just use the last next value, causing
boot time hangs in some cases.
The proper fix is to pull timerqueue_getnext each iteration
instead of using a local next value.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Converts the hrtimer code to use the new timerlist infrastructure
Signed-off-by: John Stultz <john.stultz@linaro.org>
LKML Reference: <1290136329-18291-3-git-send-email-john.stultz@linaro.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Richard Cochran <richardcochran@gmail.com>
Originally adapted from Huang Ying's patch which moved the
unknown_nmi_panic to the traps.c file. Because the old nmi
watchdog was deleted before this change happened, the
unknown_nmi_panic sysctl was lost. This re-adds it.
Also, the nmi_watchdog sysctl was re-implemented and its
documentation updated accordingly.
Patch-inspired-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: fweisbec@gmail.com
LKML-Reference: <1291068437-5331-3-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Eric Paris pointed out that it doesn't make sense to require
both CAP_SYS_ADMIN and CAP_SYSLOG for certain syslog actions.
So require CAP_SYSLOG, not CAP_SYS_ADMIN, when dmesg_restrict
is set.
(I'm also consolidating the now common error path)
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Use the reboot notifier to detach all running counters on reboot, this
solves a problem with kexec where the new kernel doesn't expect
running counters (rightly so).
It will however decrease the coverage of the NMI watchdog. Making a
kexec specific reboot notifier callback would be best, however that
would require touching all notifier callback handlers as they are not
properly structured to deal with new state.
As a compromise, place the perf reboot notifier at the very last
position in the list.
Reported-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
__get_cpu_var() is a bit inefficient, lets use __this_cpu_read() and
__this_cpu_write() to manipulate printk_pending.
printk_needs_cpu(cpu) is called only for the current cpu :
Use faster __this_cpu_read().
Remove the redundant unlikely on (cpu_is_offline(cpu)) test:
# size kernel/printk.o*
text data bss dec hex filename
9942 756 263488 274186 42f0a kernel/printk.o.new
9990 756 263488 274234 42f3a kernel/printk.o.old
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290788536.2855.237.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
As noted by Peter Zijlstra at https://lkml.org/lkml/2010/11/10/391
(while reviewing other stuff, though), tracking pushable tasks
only makes sense on SMP systems.
Signed-off-by: Dario Faggioli <raistlin@linux.it>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1291143093.2697.298.camel@Palantir>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This fixes a bug as seen on 2.6.32 based kernels where timers got
enqueued on offline cpus.
If a cpu goes offline it might still have pending timers. These will
be migrated during CPU_DEAD handling after the cpu is offline.
However while the cpu is going offline it will schedule the idle task
which will then call tick_nohz_stop_sched_tick().
That function in turn will call get_next_timer_intterupt() to figure
out if the tick of the cpu can be stopped or not. If it turns out that
the next tick is just one jiffy off (delta_jiffies == 1)
tick_nohz_stop_sched_tick() incorrectly assumes that the tick should
not stop and takes an early exit and thus it won't update the load
balancer cpu.
Just afterwards the cpu will be killed and the load balancer cpu could
be the offline cpu.
On 2.6.32 based kernel get_nohz_load_balancer() gets called to decide
on which cpu a timer should be enqueued (see __mod_timer()). Which
leads to the possibility that timers get enqueued on an offline cpu.
These will never expire and can cause a system hang.
This has been observed 2.6.32 kernels. On current kernels
__mod_timer() uses get_nohz_timer_target() which doesn't have that
problem. However there might be other problems because of the too
early exit tick_nohz_stop_sched_tick() in case a cpu goes offline.
The easiest and probably safest fix seems to be to let
get_next_timer_interrupt() just lie and let it say there isn't any
pending timer if the current cpu is offline.
I also thought of moving migrate_[hr]timers() from CPU_DEAD to
CPU_DYING, but seeing that there already have been fixes at least in
the hrtimer code in this area I'm afraid that this could add new
subtle bugs.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101201091109.GA8984@osiris.boeblingen.de.ibm.com>
Cc: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
idle_balance() drops/retakes rq->lock, leaving the previous task
vulnerable to set_tsk_need_resched(). Clear it after we return
from balancing instead, and in setup_thread_stack() as well, so
no successfully descheduled or never scheduled task has it set.
Need resched confused the skip_clock_update logic, which assumes
that the next call to update_rq_clock() will come nearly immediately
after being set. Make the optimization robust against the waking
a sleeper before it sucessfully deschedules case by checking that
the current task has not been dequeued before setting the flag,
since it is that useless clock update we're trying to save, and
clear unconditionally in schedule() proper instead of conditionally
in put_prev_task().
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reported-by: Bjoern B. Brandenburg <bbb.lst@gmail.com>
Tested-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
LKML-Reference: <1291802742.1417.9.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There's a long-running regression that proved difficult to fix and
which is hitting certain people and is rather annoying in its effects.
Damien reported that after 74f5187ac8 (sched: Cure load average vs
NO_HZ woes) his load average is unnaturally high, he also noted that
even with that patch reverted the load avgerage numbers are not
correct.
The problem is that the previous patch only solved half the NO_HZ
problem, it addressed the part of going into NO_HZ mode, not of
comming out of NO_HZ mode. This patch implements that missing half.
When comming out of NO_HZ mode there are two important things to take
care of:
- Folding the pending idle delta into the global active count.
- Correctly aging the averages for the idle-duration.
So with this patch the NO_HZ interaction should be complete and
behaviour between CONFIG_NO_HZ=[yn] should be equivalent.
Furthermore, this patch slightly changes the load average computation
by adding a rounding term to the fixed point multiplication.
Reported-by: Damien Wyart <damien.wyart@free.fr>
Reported-by: Tim McGrath <tmhikaru@gmail.com>
Tested-by: Damien Wyart <damien.wyart@free.fr>
Tested-by: Orion Poplawski <orion@cora.nwra.com>
Tested-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
Cc: Chase Douglas <chase.douglas@canonical.com>
LKML-Reference: <1291129145.32004.874.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Because the multi-pmu bits can share contexts between struct pmu
instances we could get duplicate events by iterating the pmu list.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86/pvclock: Zero last_value on resume
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf record: Fix eternal wait for stillborn child
perf header: Don't assume there's no attr info if no sample ids is provided
perf symbols: Figure out start address of kernel map from kallsyms
perf symbols: Fix kallsyms kernel/module map splitting
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
nohz: Fix printk_needs_cpu() return value on offline cpus
printk: Fix wake_up_klogd() vs cpu hotplug
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
PM / Hibernate: Fix memory corruption related to swap
PM / Hibernate: Use async I/O when reading compressed hibernation image
There is a problem that swap pages allocated before the creation of
a hibernation image can be released and used for storing the contents
of different memory pages while the image is being saved. Since the
kernel stored in the image doesn't know of that, it causes memory
corruption to occur after resume from hibernation, especially on
systems with relatively small RAM that need to swap often.
This issue can be addressed by keeping the GFP_IOFS bits clear
in gfp_allowed_mask during the entire hibernation, including the
saving of the image, until the system is finally turned off or
the hibernation is aborted. Unfortunately, for this purpose
it's necessary to rework the way in which the hibernate and
suspend code manipulates gfp_allowed_mask.
This change is based on an earlier patch from Hugh Dickins.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Ondrej Zary <linux@rainbow-software.org>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: stable@kernel.org
This is a fix for reading LZO compressed image using async I/O.
Essentially, instead of having just one page into which we keep
reading blocks from swap, we allocate enough of them to cover the
largest compressed size and then let block I/O pick them all up. Once
we have them all (and here we wait), we decompress them, as usual.
Obviously, the very first block we still pick up synchronously,
because we need to know the size of the lot before we pick up the
rest.
Also fixed the copyright line, which I've forgotten before.
Signed-off-by: Bojan Smojver <bojan@rexursive.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Use text_poke_smp_batch() on unoptimization path for reducing
the number of stop_machine() issues. If the number of
unoptimizing probes is more than MAX_OPTIMIZE_PROBES(=256),
kprobes unoptimizes first MAX_OPTIMIZE_PROBES probes and kicks
optimizer for remaining probes.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20101203095434.2961.22657.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use text_poke_smp_batch() in optimization path for reducing
the number of stop_machine() issues. If the number of optimizing
probes is more than MAX_OPTIMIZE_PROBES(=256), kprobes optimizes
first MAX_OPTIMIZE_PROBES probes and kicks optimizer for
remaining probes.
Changes in v5:
- Use kick_kprobe_optimizer() instead of directly calling
schedule_delayed_work().
- Rescheduling optimizer outside of kprobe mutex lock.
Changes in v2:
- Allocate code buffer and parameters in arch_init_kprobes()
instead of using static arraies.
- Merge previous max optimization limit patch into this patch.
So, this patch introduces upper limit of optimization at
once.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20101203095428.2961.8994.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reuse unused (waiting for unoptimizing and no user handler)
kprobe on given address instead of returning -EBUSY for
registering a new kprobe.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101203095416.2961.39080.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Unoptimization occurs when a probe is unregistered or disabled,
and is heavy because it recovers instructions by using
stop_machine(). This patch delays unoptimization operations and
unoptimize several probes at once by using
text_poke_smp_batch(). This can avoid unexpected system slowdown
coming from stop_machine().
Changes in v5:
- Split this patch into several cleanup patches and this patch.
- Fix some text_mutex lock miss.
- Use bool instead of int for behavior flags.
- Add additional comment for (un)optimizing path.
Changes in v2:
- Use dynamic allocated buffers and params.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101203095409.2961.82733.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Separate kprobe optimizing code from optimizer, this
will make easy to introducing unoptimizing code in
optimizer.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101203095403.2961.91201.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merge disabling kprobe to unregistering kprobe function
and add comments for disabing/unregistring process.
Current unregistering code disables(disarms) kprobes after
checking target kprobe status. This patch changes it to
disabling kprobe first after that it changing the kprobe's
state. This allows to share probe disabling code between
disable_kprobe() and unregister_kprobe().
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101203095356.2961.30152.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Rename irrelevant uses of "old_p" to more appropriate names.
Originally, "old_p" just meant "the old kprobe on given address"
but current code uses that name as "just another kprobe" or
something like that. This patch renames those pointer names
to more appropriate one for maintainability.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101203095350.2961.48110.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If perf_event_attr.sample_id_all is set it will add the PERF_SAMPLE_ identity
info:
TID, TIME, ID, CPU, STREAM_ID
As a trailer, so that older perf tools can process new files, just ignoring the
extra payload.
With this its possible to do further analysis on problems in the event stream,
like detecting reordering of MMAP and FORK events, etc.
V2: Fixup header size in comm, mmap and task processing, as we have to take into
account different sample_types for each matching event, noticed by Thomas Gleixner.
Thomas also noticed a problem in v2 where if we didn't had space in the buffer we
wouldn't restore the header size.
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Those will be made available in sample like events like MMAP, EXEC, etc in a
followup patch. So precalculate the extra id header space and have a separate
routine to fill them up.
V2: Thomas noticed that the id header needs to be precalculated at
inherit_events too:
LKML-Reference: <alpine.LFD.2.00.1012031245220.2653@localhost6.localdomain6>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <1291318772-30880-2-git-send-email-acme@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The precalculated header size is not updated when an event is inherited. That
results in bogus sample entries for all child events. Bug introduced in c320c7b.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <alpine.LFD.2.00.1012031245220.2653@localhost6.localdomain6>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If a user manages to trigger an oops with fs set to KERNEL_DS, fs is not
otherwise reset before do_exit(). do_exit may later (via mm_release in
fork.c) do a put_user to a user-controlled address, potentially allowing
a user to leverage an oops into a controlled write into kernel memory.
This is only triggerable in the presence of another bug, but this
potentially turns a lot of DoS bugs into privilege escalations, so it's
worth fixing. I have proof-of-concept code which uses this bug along
with CVE-2010-3849 to write a zero to an arbitrary kernel address, so
I've tested that this is not theoretical.
A more logical place to put this fix might be when we know an oops has
occurred, before we call do_exit(), but that would involve changing
every architecture, in multiple places.
Let's just stick it in do_exit instead.
[akpm@linux-foundation.org: update code comment]
Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit a1afb637(switch /proc/irq/*/spurious to seq_file) all
/proc/irq/XX/spurious files show the information of irq 0.
Current irq_spurious_proc_open() passes on NULL as the 3rd argument,
which is used as an IRQ number in irq_spurious_proc_show(), to the
single_open(). Because of this, all the /proc/irq/XX/spurious file
shows IRQ 0 information regardless of the IRQ number.
To fix the problem, irq_spurious_proc_open() must pass on the
appropreate data (IRQ number) to single_open().
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
LKML-Reference: <4CF4B778.90604@jp.fujitsu.com>
Cc: stable@kernel.org [2.6.33+]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
PERF_SAMPLE_{CALLCHAIN,RAW} have variable lenghts per sample, but the others
can be precalculated, reducing a bit the per sample cost.
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The file_ops struct for the "trace" special file defined llseek as seq_lseek().
However, if the file was opened for writing only, seq_open() was not called,
and the seek would dereference a null pointer, file->private_data.
This patch introduces a new wrapper for seq_lseek() which checks if the file
descriptor is opened for reading first. If not, it does nothing.
Cc: <stable@kernel.org>
Signed-off-by: Slava Pestov <slavapestov@google.com>
LKML-Reference: <1290640396-24179-1-git-send-email-slavapestov@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
A recurring complaint from CFS users is that parallel kbuild has
a negative impact on desktop interactivity. This patch
implements an idea from Linus, to automatically create task
groups. Currently, only per session autogroups are implemented,
but the patch leaves the way open for enhancement.
Implementation: each task's signal struct contains an inherited
pointer to a refcounted autogroup struct containing a task group
pointer, the default for all tasks pointing to the
init_task_group. When a task calls setsid(), a new task group
is created, the process is moved into the new task group, and a
reference to the preveious task group is dropped. Child
processes inherit this task group thereafter, and increase it's
refcount. When the last thread of a process exits, the
process's reference is dropped, such that when the last process
referencing an autogroup exits, the autogroup is destroyed.
At runqueue selection time, IFF a task has no cgroup assignment,
its current autogroup is used.
Autogroup bandwidth is controllable via setting it's nice level
through the proc filesystem:
cat /proc/<pid>/autogroup
Displays the task's group and the group's nice level.
echo <nice level> > /proc/<pid>/autogroup
Sets the task group's shares to the weight of nice <level> task.
Setting nice level is rate limited for !admin users due to the
abuse risk of task group locking.
The feature is enabled from boot by default if
CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via
the boot option noautogroup, and can also be turned on/off on
the fly via:
echo [01] > /proc/sys/kernel/sched_autogroup_enabled
... which will automatically move tasks to/from the root task group.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Paul Turner <pjt@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
[ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In the flipping and flopping between calling
unregister_fair_sched_group() on a per-cpu versus per-group basis
we ended up in a bad state.
Remove from the list for the passed cpu as opposed to some
arbitrary index.
( This fixes explosions w/ autogroup as well as a group
creation/destruction stress test. )
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20101130005740.080828123@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The synchronize_srcu_expedited() function is currently quick if there
are no active readers, but will delay a full jiffy if there are any.
If these readers leave their SRCU read-side critical sections quickly,
this is way too long to wait. So this commit first waits ten microseconds,
and only then falls back to jiffy-at-a-time waiting.
Reported-by: Avi Kivity <avi@redhat.com>
Reported-by: Marcelo Tosatti <mtosatti@redhat.com>
Tested-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The new (early 2010) implementation of synchronize_sched_expedited() uses
try_stop_cpu() to force a context switch on every CPU. It also permits
concurrent calls to synchronize_sched_expedited() to share a single call
to try_stop_cpu() through use of an atomically incremented
synchronize_sched_expedited_count variable. Unfortunately, this is
subject to failure as follows:
o Task A invokes synchronize_sched_expedited(), try_stop_cpus()
succeeds, but Task A is preempted before getting to the atomic
increment of synchronize_sched_expedited_count.
o Task B also invokes synchronize_sched_expedited(), with exactly
the same outcome as Task A.
o Task C also invokes synchronize_sched_expedited(), again with
exactly the same outcome as Tasks A and B.
o Task D also invokes synchronize_sched_expedited(), but only
gets as far as acquiring the mutex within try_stop_cpus()
before being preempted, interrupted, or otherwise delayed.
o Task E also invokes synchronize_sched_expedited(), but only
gets to the snapshotting of synchronize_sched_expedited_count.
o Tasks A, B, and C all increment synchronize_sched_expedited_count.
o Task E fails to get the mutex, so checks the new value
of synchronize_sched_expedited_count. It finds that the
value has increased, so (wrongly) assumes that its work
has been done, returning despite there having been no
expedited grace period since it began.
The solution is to have the lowest-numbered CPU atomically increment
the synchronize_sched_expedited_count variable within the
synchronize_sched_expedited_cpu_stop() function, which is under
the protection of the mutex acquired by try_stop_cpus(). However, this
also requires that piggybacking tasks wait for three rather than two
instances of try_stop_cpu(), because we cannot control the order in
which the per-CPU callback function occur.
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Lai's RCU-callback immediate-adoption patch changes the RCU tracing
output, so update tracing.txt. Also update a few comments to clarify
the synchronization design.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
When we handle the CPU_DYING notifier, the whole system is stopped except
for the current CPU. We therefore need no synchronization with the other
CPUs. This allows us to move any orphaned RCU callbacks directly to the
list of any online CPU without needing to run them through the global
orphan lists. These global orphan lists can therefore be dispensed with.
This commit makes thes changes, though currently victimizes CPU 0 @@@.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The first version of synchronize_sched_expedited() used the migration
code in the scheduler, and was therefore implemented in kernel/sched.c.
However, the more recent version of this code no longer uses the
migration code, so this commit moves it to the main RCU source files.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The TREE_RCU tracing had obsolete rcuclassic_trace_init() and
rcuclassic_trace_cleanup() function names. This commit brings them
up to date: rcutree_trace_init() and rcutree_trace_cleanup(),
respectively.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
RCU priority boosting's tracing did not distinguish between ongoing
boosting and completion of boosting. This commit therefore adds this
capability.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Add tracing for the tiny RCU implementations, including statistics on
boosting in the case of TINY_PREEMPT_RCU and RCU_BOOST.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Add priority boosting, but only for TINY_PREEMPT_RCU. This is enabled
by the default-off RCU_BOOST kernel parameter. The priority to which to
boost preempted RCU readers is controlled by the RCU_BOOST_PRIO kernel
parameter (defaulting to real-time priority 1) and the time to wait
before boosting the readers blocking a given grace period is controlled
by the RCU_BOOST_DELAY kernel parameter (defaulting to 500 milliseconds).
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
These warnings are spewed during a build of a 'allnoconfig' kernel
(especially the ones from u64_stats_sync.h show up a lot) when building
with -Wextra (which I often do)..
They are
a) annoying
b) easy to get rid of.
This patch kills them off.
include/linux/u64_stats_sync.h:70:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:77:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:84:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:96:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:115:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:127:1: warning: ‘inline’ is not at beginning of declaration
kernel/time.c:241:1: warning: ‘inline’ is not at beginning of declaration
kernel/time.c:257:1: warning: ‘inline’ is not at beginning of declaration
kernel/perf_event.c:4513:1: warning: ‘inline’ is not at beginning of declaration
mm/page_alloc.c:4012:1: warning: ‘inline’ is not at beginning of declaration
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Privileged syslog operations currently require CAP_SYS_ADMIN. Split
this off into a new CAP_SYSLOG privilege which we can sanely take away
from a container through the capability bounding set.
With this patch, an lxc container can be prevented from messing with
the host's syslog (i.e. dmesg -c).
Changelog: mar 12 2010: add selinux capability2:cap_syslog perm
Changelog: nov 22 2010:
. port to new kernel
. add a WARN_ONCE if userspace isn't using CAP_SYSLOG
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Acked-By: Kees Cook <kees.cook@canonical.com>
Cc: James Morris <jmorris@namei.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: "Christopher J. PeBenito" <cpebenito@tresys.com>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: James Morris <jmorris@namei.org>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf symbols: Remove incorrect open-coded container_of()
perf record: Handle restrictive permissions in /proc/{kallsyms,modules}
x86/kprobes: Prevent kprobes to probe on save_args()
irq_work: Drop cmpxchg() result
perf: Fix owner-list vs exit
x86, hw_nmi: Move backtrace_mask declaration under ARCH_HAS_NMI_WATCHDOG
tracing: Fix recursive user stack trace
perf,hw_breakpoint: Initialize hardware api earlier
x86: Ignore trap bits on single step exceptions
tracing: Force arch_local_irq_* notrace for paravirt
tracing: Fix module use of trace_bprintk()
The perf hardware pmu got initialized at various points in the boot,
some before early_initcall() some after (notably arch_initcall).
The problem is that the NMI lockup detector is ran from early_initcall()
and expects the hardware pmu to be present.
Sanitize this by moving all architecture hardware pmu implementations to
initialize at early_initcall() and move the lockup detector to an explicit
initcall right after that.
Cc: paulus <paulus@samba.org>
Cc: davem <davem@davemloft.net>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290707759.2145.119.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
and use it when appropriate.
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290525705-6265-1-git-send-email-fbuihuu@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove unused argument, 'dest_cpu' of migrate_task(), and pass runqueue,
as it is always known at the call site.
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <201011261237.09187.knikanth@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The spinning mutex implementation uses cpu_relax() in busy loops as a
compiler barrier. Depending on the architecture, cpu_relax() may do more
than needed in this specific mutex spin loops. On System z we also give
up the time slice of the virtual cpu in cpu_relax(), which prevents
effective spinning on the mutex.
This patch replaces cpu_relax() in the spinning mutex code with
arch_mutex_cpu_relax(), which can be defined by each architecture that
selects HAVE_ARCH_MUTEX_CPU_RELAX. The default is still cpu_relax(), so
this patch should not affect other architectures than System z for now.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290437256.7455.4.camel@thinkpad>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch fixes a hang observed with 2.6.32 kernels where timers got enqueued
on offline cpus.
printk_needs_cpu() may return 1 if called on offline cpus. When a cpu gets
offlined it schedules the idle process which, before killing its own cpu, will
call tick_nohz_stop_sched_tick(). That function in turn will call
printk_needs_cpu() in order to check if the local tick can be disabled. On
offline cpus this function should naturally return 0 since regardless if the
tick gets disabled or not the cpu will be dead short after. That is besides the
fact that __cpu_disable() should already have made sure that no interrupts on
the offlined cpu will be delivered anyway.
In this case it prevents tick_nohz_stop_sched_tick() to call
select_nohz_load_balancer(). No idea if that really is a problem. However what
made me debug this is that on 2.6.32 the function get_nohz_load_balancer() is
used within __mod_timer() to select a cpu on which a timer gets enqueued. If
printk_needs_cpu() returns 1 then the nohz_load_balancer cpu doesn't get
updated when a cpu gets offlined. It may contain the cpu number of an offline
cpu. In turn timers get enqueued on an offline cpu and not very surprisingly
they never expire and cause system hangs.
This has been observed 2.6.32 kernels. On current kernels __mod_timer() uses
get_nohz_timer_target() which doesn't have that problem. However there might be
other problems because of the too early exit tick_nohz_stop_sched_tick() in
case a cpu goes offline.
Easiest way to fix this is just to test if the current cpu is offline and call
printk_tick() directly which clears the condition.
Alternatively I tried a cpu hotplug notifier which would clear the condition,
however between calling the notifier function and printk_needs_cpu() something
could have called printk() again and the problem is back again. This seems to
be the safest fix.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
LKML-Reference: <20101126120235.406766476@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
wake_up_klogd() may get called from preemptible context but uses
__raw_get_cpu_var() to write to a per cpu variable. If it gets preempted
between getting the address and writing to it, the cpu in question could be
offline if the process gets scheduled back and hence writes to the per cpu data
of an offline cpu.
This buggy behaviour was introduced with fa33507a "printk: robustify
printk, fix#2" which was supposed to fix a "using smp_processor_id() in
preemptible" warning.
Let's use this_cpu_write() instead which disables preemption and makes sure
that the outlined scenario cannot happen.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101126124247.GC7023@osiris.boeblingen.de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Stephane noticed that because the perf_sw_event() call is inside the
perf_event_task_sched_out() call it won't get called unless we
have a per-task counter.
Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It was found that sometimes children of tasks with inherited events had
one extra event. Eventually it turned out to be due to the list rotation
no being exclusive with the list iteration in the inheritance code.
Cure this by temporarily disabling the rotation while we inherit the events.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
I found a trivial bug on initialization of workqueue.
Current init_workqueues doesn't check the result of
allocation of system_unbound_wq, this should be checked
like other queues.
Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add more clock information to /proc/sched_debug, Thomas wanted to see
the sched_clock_stable state.
Requested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Oleg mentioned that there is no actual guarantee the dying cpu's
migration thread is actually finished running when we get there, so
replace the BUG_ON() with a spinloop waiting for it.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
GCC warns us about:
kernel/cpu.c: In function ‘take_cpu_down’:
kernel/cpu.c:200:15: warning: unused variable ‘cpu’
This variable is unused since param->hcpu is directly
used later on in cpu_notify.
Signed-off-by: Dhaval Giani <dhaval_giani@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290091494.1145.5.camel@gondor.retis>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The recent cgroup-scheduling rework caused a UP build problem.
Cc: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This reverts commit 59365d136d.
It turns out that this can break certain existing user land setups.
Quoth Sarah Sharp:
"On Wednesday, I updated my branch to commit 460781b from linus' tree,
and my box would not boot. klogd segfaulted, which stalled the whole
system.
At first I thought it actually hung the box, but it continued booting
after 5 minutes, and I was able to log in. It dropped back to the
text console instead of the graphical bootup display for that period
of time. dmesg surprisingly still works. I've bisected the problem
down to this commit (commit 59365d136d)
The box is running klogd 1.5.5ubuntu3 (from Jaunty). Yes, I know
that's old. I read the bit in the commit about changing the
permissions of kallsyms after boot, but if I can't boot that doesn't
help."
So let's just keep the old default, and encourage distributions to do
the "chmod -r /proc/kallsyms" in their bootup scripts. This is not
worth a kernel option to change default behavior, since it's so easily
done in user space.
Reported-and-bisected-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Marcus Meissner <meissner@suse.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we have in something like the sched_switch event:
field:char prev_comm[TASK_COMM_LEN]; offset:12; size:16; signed:1;
When a userspace tool such as perf tries to parse this, the
TASK_COMM_LEN is meaningless. This is done because the TRACE_EVENT() macro
simply uses a #len to show the string of the length. When the length is
an enum, we get a string that means nothing for tools.
By adding a static buffer and a mutex to protect it, we can store the
string into that buffer with snprintf and show the actual number.
Now we get:
field:char prev_comm[16]; offset:12; size:16; signed:1;
Something much more useful.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
kgdb,ppc: Fix regression in evr register handling
kgdb,x86: fix regression in detach handling
kdb: fix crash when KDB_BASE_CMD_MAX is exceeded
kdb: fix memory leak in kdb_main.c
This adds a new trace event internal flag that allows them to be
used in perf by non privileged users in case of task bound tracing.
This is desired for syscalls tracepoint because they don't leak
global system informations, like some other tracepoints.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jason Baron <jbaron@redhat.com>
This patch is a logical extension of the protection provided by
CONFIG_DEBUG_RODATA to LKMs. The protection is provided by
splitting module_core and module_init into three logical parts
each and setting appropriate page access permissions for each
individual section:
1. Code: RO+X
2. RO data: RO+NX
3. RW data: RW+NX
In order to achieve proper protection, layout_sections() have
been modified to align each of the three parts mentioned above
onto page boundary. Next, the corresponding page access
permissions are set right before successful exit from
load_module(). Further, free_module() and sys_init_module have
been modified to set module_core and module_init as RW+NX right
before calling module_free().
By default, the original section layout and access flags are
preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y,
the patch will page-align each group of sections to ensure that
each page contains only one type of content and will enforce
RO/NX for each group of pages.
-v1: Initial proof-of-concept patch.
-v2: The patch have been re-written to reduce the number of #ifdefs
and to make it architecture-agnostic. Code formatting has also
been corrected.
-v3: Opportunistic RO/NX protection is now unconditional. Section
page-alignment is enabled when CONFIG_DEBUG_RODATA=y.
-v4: Removed most macros and improved coding style.
-v5: Changed page-alignment and RO/NX section size calculation
-v6: Fixed comments. Restricted RO/NX enforcement to x86 only
-v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added
calls to set_all_modules_text_rw() and set_all_modules_text_ro()
in ftrace
-v8: updated for compatibility with linux 2.6.33-rc5
-v9: coding style fixes
-v10: more coding style fixes
-v11: minor adjustments for -tip
-v12: minor adjustments for v2.6.35-rc2-tip
-v13: minor adjustments for v2.6.37-rc1-tip
Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com>
Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Reviewed-by: James Morris <jmorris@namei.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dave Jones <davej@redhat.com>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4CE2F914.9070106@free.fr>
[ minor cleanliness edits, -v14: build failure fix ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Formerly sched_group_set_shares would force a rebalance by overflowing domain
share sums. Now that per-cpu averages are maintained we can set the true value
by issuing an update_cfs_shares() following a tg->shares update.
Also initialize tg se->load to 0 for consistency since we'll now set correct
weights on enqueue.
Signed-off-by: Paul Turner <pjt@google.com?>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234938.465521344@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Refactor the global load updates from update_shares_cpu() so that
update_cfs_load() can update global load when it is more than ~10%
out of sync.
The new global_load parameter allows us to force an update, regardless of
the error factor so that we can synchronize w/ update_shares().
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234938.377473595@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When the system is busy, dilation of rq->next_balance makes lb->update_shares()
insufficiently frequent for threads which don't sleep (no dequeue/enqueue
updates). Adjust for this by making demand based updates based on the
accumulation of execution time sufficient to wrap our averaging window.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234938.291159744@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since shares updates are no longer expensive and effectively local, update them
at idle_balance(). This allows us to more quickly redistribute shares to
another cpu when our load becomes idle.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234938.204191702@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Introduce a new sysctl for the shares window and disambiguate it from
sched_time_avg.
A 10ms window appears to be a good compromise between accuracy and performance.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234938.112173964@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Avoid duplicate shares update calls by ensuring children always appear before
parents in rq->leaf_cfs_rq_list.
This allows us to do a single in-order traversal for update_shares().
Since we always enqueue in bottom-up order this reduces to 2 cases:
1) Our parent is already in the list, e.g.
root
\
b
/\
c d* (root->b->c already enqueued)
Since d's parent is enqueued we push it to the head of the list, implicitly ahead of b.
2) Our parent does not appear in the list (or we have no parent)
In this case we enqueue to the tail of the list, if our parent is subsequently enqueued
(bottom-up) it will appear to our right by the same rule.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234938.022488865@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Using cfs_rq->nr_running is not sufficient to synchronize update_cfs_load with
the put path since nr_running accounting occurs at deactivation.
It's also not safe to make the removal decision based on load_avg as this fails
with both high periods and low shares. Resolve this by clipping history after
4 periods without activity.
Note: the above will always occur from update_shares() since in the
last-task-sleep-case that task will still be cfs_rq->curr when update_cfs_load
is called.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234937.933428187@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
As part of enqueue_entity both a new entity weight and its contribution to the
queuing cfs_rq / rq are updated. Since update_cfs_shares will only update the
queueing weights when the entity is on_rq (which in this case it is not yet),
there's a dependency loop here:
update_cfs_shares needs account_entity_enqueue to update cfs_rq->load.weight
account_entity_enqueue needs the updated weight for the queuing cfs_rq load[*]
Fix this and avoid spurious dequeue/enqueues by issuing update_cfs_shares as
if we had accounted the enqueue already.
This was also resulting in rq->load corruption previously.
[*]: this dependency also exists when using the group cfs_rq w/
update_cfs_shares as the weight of the enqueued entity changes
without the load being updated.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234937.844900206@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make tg_shares_up() use the active cgroup list, this means we cannot
do a strict bottom-up walk of the hierarchy, but assuming its a very
wide tree with a small number of active groups it should be a win.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234937.754159484@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make certain load-balance actions scale per number of active cgroups
instead of the number of existing cgroups.
This makes wakeup/sleep paths more expensive, but is a win for systems
where the vast majority of existing cgroups are idle.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234937.666535048@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
By tracking a per-cpu load-avg for each cfs_rq and folding it into a
global task_group load on each tick we can rework tg_shares_up to be
strictly per-cpu.
This should improve cpu-cgroup performance for smp systems
significantly.
[ Paul: changed to use queueing cfs_rq + bug fixes ]
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234937.580480400@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
While discussing the need for sched_idle_next(), Oleg remarked that
since try_to_wake_up() ensures sleeping tasks will end up running on a
sane cpu, we can do away with migrate_live_tasks().
If we then extend the existing hack of migrating current from
CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the
need for the sched_idle_next() abomination disappears as well, since
idle will be the only possible thread left after the migration thread
stops.
This greatly simplifies the hot-unplug task migration path, as can be
seen from the resulting code reduction (and about half the new lines
are comments).
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1289851597.2109.547.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The compiler warned us about:
kernel/irq_work.c: In function 'irq_work_run':
kernel/irq_work.c:148: warning: value computed is not used
Dropping the cmpxchg() result is indeed weird, but correct -
so annotate away the warning.
Signed-off-by: Sergio Aguirre <saaguirre@ti.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1289930567-17828-1-git-send-email-saaguirre@ti.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Oleg noticed that a perf-fd keeping a reference on the creating task
leads to a few funny side effects.
There's two different aspects to this:
- kernel based perf-events, these should not take out
a reference on the creating task and appear on the task's
event list since they're not bound to fds nor visible
to userspace.
- fork() and pthread_create(), these can lead to the creating
task dying (and thus the task's event-list becomming useless)
but keeping the list and ref alive until the event is closed.
Combined they lead to malfunction of the ptrace hw_tracepoints.
Cure this by not considering kernel based perf_events for the
owner-list and destroying the owner-list when the owner dies.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Oleg Nesterov <oleg@redhat.com>
LKML-Reference: <1289576883.2084.286.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
An earlier commit reverts idle balancing throttling reset to fix a 30%
regression in volanomark throughput. We still need to reset idle_stamp
when we pull a task in newidle balance.
Reported-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Nikhil Rao <ncrao@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290022924-3548-1-git-send-email-ncrao@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now that we have a new nmi_watchdog that is more generic and
sits on top of the perf subsystem, we really do not need the old
nmi_watchdog any more.
In addition, the old nmi_watchdog doesn't really work if you are
using the default clocksource, hpet. The old nmi_watchdog code
relied on local apic interrupts to determine if the cpu is still
alive. With hpet as the clocksource, these interrupts don't
increment any more and the old nmi_watchdog triggers false
postives.
This piece removes the old nmi_watchdog code and stubs out any
variables and functions calls. The stubs are the same ones used
by the new nmi_watchdog code, so it should be well tested.
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: fweisbec@gmail.com
Cc: gorcunov@openvz.org
LKML-Reference: <1289578944-28564-2-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If RCU priority boosting is to be meaningful, callback invocation must
be boosted in addition to preempted RCU readers. Otherwise, in presence
of CPU real-time threads, the grace period ends, but the callbacks don't
get invoked. If the callbacks don't get invoked, the associated memory
doesn't get freed, so the system is still subject to OOM.
But it is not reasonable to priority-boost RCU_SOFTIRQ, so this commit
moves the callback invocations to a kthread, which can be boosted easily.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
When the number of dyanmic kdb commands exceeds KDB_BASE_CMD_MAX, the
kernel will fault.
Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Call kfree in the error path as well as the success path in kdb_ll().
Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Making /proc/kallsyms readable only for root by default makes it
slightly harder for attackers to write generic kernel exploits by
removing one source of knowledge where things are in the kernel.
This is the second submit, discussion happened on this on first submit
and mostly concerned that this is just one hole of the sieve ... but
one of the bigger ones.
Changing the permissions of at least System.map and vmlinux is also
required to fix the same set, but a packaging issue.
Target of this starter patch and follow ups is removing any kind of
kernel space address information leak from the kernel.
[ Side note: the default of root-only reading is the "safe" value, and
it's easy enough to then override at any time after boot. The /proc
filesystem allows root to change the permissions with a regular
chmod, so you can "revert" this at run-time by simply doing
chmod og+r /proc/kallsyms
as root if you really want regular users to see the kernel symbols.
It does help some tools like "perf" figure them out without any
setup, so it may well make sense in some situations. - Linus ]
Signed-off-by: Marcus Meissner <meissner@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Eugene Teo <eugeneteo@kernel.org>
Reviewed-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix cross-sched-class wakeup preemption
sched: Fix runnable condition for stoptask
sched: Use group weight, idle cpu metrics to fix imbalances during idle
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
PM / PM QoS: Fix reversed min and max
PM / OPP: Hide OPP configuration when SoCs do not provide an implementation
PM: Allow devices to be removed during late suspend and early resume
Move it out of printk.c so that we can use it all over the code. There
are some potential users which will be converted to that macro in next
patches.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
[S390] kprobes: Fix the return address of multiple kretprobes
[S390] kprobes: disable interrupts throughout
[S390] ftrace: build without frame pointers on s390
[S390] mm: add devmem_is_allowed() for STRICT_DEVMEM checking
[S390] vmlogrdr: purge after recording is switched off
[S390] cio: fix incorrect ccw_device_init_count
[S390] tape: add medium state notifications
[S390] fix get_user_pages_fast
Sigh...
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While at it, fix two checkpatch errors.
Several non-const struct instances constified by this patch were added after
the introduction of platform_suspend_ops in checkpatch.pl's list of "should
be const" structs (79404849e9).
Patch against mainline.
Inspired by hunks of the grsecurity patch, updated for newer kernels.
Signed-off-by: Lionel Debroux <lionel_debroux@yahoo.fr>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Patch against mainline.
Changes since v1: added one hunk; no longer adding "const" qualifier to
pointers in platform_hibernation_ops after seeing
b4144e4f6e.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The addition of CONFIG_SECURITY_DMESG_RESTRICT resulted in a build
failure when CONFIG_PRINTK=n. This is because the capabilities code
which used the new option was built even though the variable in question
didn't exist.
The patch here fixes this by moving the capabilities checks out of the
LSM and into the caller. All (known) LSMs should have been calling the
capabilities hook already so it actually makes the code organization
better to eliminate the hook altogether.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pm_qos_get_value had min and max reversed, causing all pm_qos
requests to have no effect.
Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: mark <markgross@thegnar.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@kernel.org
After recent blkdev_get() modifications, open_by_devnum() and
open_bdev_exclusive() are simple wrappers around blkdev_get().
Replace them with blkdev_get_by_dev() and blkdev_get_by_path().
blkdev_get_by_dev() is identical to open_by_devnum().
blkdev_get_by_path() is slightly different in that it doesn't
automatically add %FMODE_EXCL to @mode.
All users are converted. Most conversions are mechanical and don't
introduce any behavior difference. There are several exceptions.
* btrfs now sets FMODE_EXCL in btrfs_device->mode, so there's no
reason to OR it explicitly on blkdev_put().
* gfs2, nilfs2 and the generic mount_bdev() now set FMODE_EXCL in
sb->s_mode.
* With the above changes, sb->s_mode now always should contain
FMODE_EXCL. WARN_ON_ONCE() added to kill_block_super() to detect
errors.
The new blkdev_get_*() functions are with proper docbook comments.
While at it, add function description to blkdev_get() too.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Joern Engel <joern@lazybastard.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: reiserfs-devel@vger.kernel.org
Cc: xfs-masters@oss.sgi.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.
* blkdev_get/put() are the primary open and close functions.
* bd_claim/release() deal with exclusive open.
* open/close_bdev_exclusive() are combination of open and claim and
the other way around, respectively.
* bd_link/unlink_disk_holder() to create and remove holder/slave
symlinks.
* open_by_devnum() wraps bdget() + blkdev_get().
The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access. Reorganize the interface such that,
* blkdev_get() is extended to include exclusive access management.
@holder argument is added and, if is @FMODE_EXCL specified, it will
gain exclusive access atomically w.r.t. other exclusive accesses.
* blkdev_put() is similarly extended. It now takes @mode argument and
if @FMODE_EXCL is set, it releases an exclusive access. Also, when
the last exclusive claim is released, the holder/slave symlinks are
removed automatically.
* bd_claim/release() and close_bdev_exclusive() are no longer
necessary and either made static or removed.
* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
is no longer necessary and removed.
* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
and blkdev_get(). It also has an unexpected extra bdev_read_only()
test which probably should be moved into blkdev_get().
* open_by_devnum() is modified to take @holder argument and pass it to
blkdev_get().
Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should). This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.
open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features. Well, let's leave them for another day.
Most conversions are straight-forward. drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
The user stack trace can fault when examining the trace. Which
would call the do_page_fault handler, which would trace again,
which would do the user stack trace, which would fault and call
do_page_fault again ...
Thus this is causing a recursive bug. We need to have a recursion
detector here.
[ Resubmitted by Jiri Olsa ]
[ Eric Dumazet recommended using __this_cpu_* instead of __get_cpu_* ]
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <1289390172-9730-3-git-send-email-jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (27 commits)
block: remove unused copy_io_context()
Documentation: remove anticipatory scheduler info
block: remove REQ_HARDBARRIER
ioprio: rcu_read_lock/unlock protect find_task_by_vpid call (V2)
ioprio: fix RCU locking around task dereference
block: ioctl: fix information leak to userland
block: read i_size with i_size_read()
cciss: fix proc warning on attempt to remove non-existant directory
bio: take care not overflow page count when mapping/copying user data
block: limit vec count in bio_kmalloc() and bio_alloc_map_data()
block: take care not to overflow when calculating total iov length
block: check for proper length of iov entries in blk_rq_map_user_iov()
cciss: remove controllers supported by hpsa
cciss: use usleep_range not msleep for small sleeps
cciss: limit commands allocated on reset_devices
cciss: Use kernel provided PCI state save and restore functions
cciss: fix board status waiting code
drbd: Removed checks for REQ_HARDBARRIER on incomming BIOs
drbd: REQ_HARDBARRIER -> REQ_FUA transition for meta data accesses
drbd: Removed the BIO_RW_BARRIER support form the receiver/epoch code
...
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf, amd: Use kmalloc_node(,__GFP_ZERO) for northbridge structure allocation
perf_events: Fix time tracking in samples
perf trace: update usage
perf trace: update Documentation with new perf trace variants
perf trace: live-mode command-line cleanup
perf trace record: handle commands correctly
perf record: make the record options available outside perf record
perf trace scripting: remove system-wide param from shell scripts
perf trace scripting: fix some small memory leaks and missing error checks
perf: Fix usages of profile_cpu in builtin-top.c to use cpu_list
perf, ui: Eliminate stack-smashing protection compiler complaint
The kernel syslog contains debugging information that is often useful
during exploitation of other vulnerabilities, such as kernel heap
addresses. Rather than futilely attempt to sanitize hundreds (or
thousands) of printk statements and simultaneously cripple useful
debugging functionality, it is far simpler to create an option that
prevents unprivileged users from reading the syslog.
This patch, loosely based on grsecurity's GRKERNSEC_DMESG, creates the
dmesg_restrict sysctl. When set to "0", the default, no restrictions are
enforced. When set to "1", only users with CAP_SYS_ADMIN can read the
kernel syslog via dmesg(8) or other mechanisms.
[akpm@linux-foundation.org: explain the config option in kernel.txt]
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Eugene Teo <eugeneteo@kernel.org>
Acked-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Per task latencytop accumulator prematurely terminates due to erroneous
placement of latency_record_count. It should be incremented whenever a
new record is allocated instead of increment on every latencytop event.
Also fix search iterator to only search known record events instead of
blindly searching all pre-allocated space.
Signed-off-by: Ken Chen <kenchen@google.com>
Reviewed-by: Arjan van de Ven <arjan@infradead.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
clean_sort_range() should return a number of nonempty elements of range
array, but if the array is full clean_sort_range() returns 0.
The problem is that the number of nonempty elements is evaluated by
finding the first empty element of the array. If there is no such element
it returns an initial value of local variable nr_range that is zero.
The fix is trivial: it changes initial value of nr_range to size of the
array.
The bug can lead to loss of information regarding all ranges, since
typically returned value of clean_sort_range() is considered as an actual
number of ranges in the array after a series of add/subtract operations.
Found by Analytical Verification project of Linux Verification Center
(linuxtesting.org), thanks to Alexander Kolosov.
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When using early debugging, the kernel does not initialize the
hw_breakpoint API early enough and causes the late initialization of
the kernel debugger to fail. The boot arguments are:
earlyprintk=vga ekgdboc=kbd kgdbwait
Then simply type "go" at the kdb prompt and boot. The kernel will
later emit the message:
kgdb: Could not allocate hwbreakpoints
And at that point the kernel debugger will cease to work correctly.
The solution is to initialize the hw_breakpoint at the same time that
all the other perf call backs are initialized instead of using a
core_initcall() initialization which happens well after the kernel
debugger can make use of hardware breakpoints.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4CD3396D.1090308@windriver.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Instead of dealing with sched classes inside each check_preempt_curr()
implementation, pull out this logic into the generic wakeup preemption
path.
This fixes a hang in KVM (and others) where we are waiting for the
stop machine thread to run ...
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Tested-by: Marcelo Tosatti <mtosatti@redhat.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1288891946.2039.31.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On use of trace_printk() there's a macro that determines if the format
is static or a variable. If it is static, it defaults to __trace_bprintk()
otherwise it uses __trace_printk().
A while ago, Lai Jiangshan added __trace_bprintk(). In that patch, we
discussed a way to allow modules to use it. The difference between
__trace_bprintk() and __trace_printk() is that for faster processing,
just the format and args are stored in the trace instead of running
it through a sprintf function. In order to do this, the format used
by the __trace_bprintk() had to be persistent.
See commit 1ba28e02a1
The problem comes with trace_bprintk() where the module is unloaded.
The pointer left in the buffer is still pointing to the format.
To solve this issue, the formats in the module were copied into kernel
core. If the same format was used, they would use the same copy (to prevent
memory leak). This all worked well until we tried to merge everything.
At the time this was written, Lai Jiangshan, Frederic Weisbecker,
Ingo Molnar and myself were all touching the same code. When this was
merged, we lost the part of it that was in module.c. This kept out the
copying of the formats and unloading the module could cause bad pointers
left in the ring buffer.
This patch adds back (with updates required for current kernel) the
module code that sets up the necessary pointers.
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Since the OPP API is only useful with an appropraite SoC-specific
implementation there is no point in offering the ability to enable
the API on general systems. Provide an ARCH_HAS OPP Kconfig symbol
which masks out the option unless selected by an implementation.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Nishanth Menon <nm@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Heiko reported that the TASK_RUNNING check is not sufficient for
CONFIG_PREEMPT=y since we can get preempted with !TASK_RUNNING.
He suggested adding a ->se.on_rq test to the existing TASK_RUNNING
one, however TASK_RUNNING will always have ->se.on_rq, so we might as
well reduce that to a single test.
[ stop tasks should never get preempted, but its good to handle
this case correctly should this ever happen ]
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently we consider a sched domain to be well balanced when the imbalance
is less than the domain's imablance_pct. As the number of cores and threads
are increasing, current values of imbalance_pct (for example 25% for a
NUMA domain) are not enough to detect imbalances like:
a) On a WSM-EP system (two sockets, each having 6 cores and 12 logical threads),
24 cpu-hogging tasks get scheduled as 13 on one socket and 11 on another
socket. Leading to an idle HT cpu.
b) On a hypothetial 2 socket NHM-EX system (each socket having 8 cores and
16 logical threads), 16 cpu-hogging tasks can get scheduled as 9 on one
socket and 7 on another socket. Leaving one core in a socket idle
whereas in another socket we have a core having both its HT siblings busy.
While this issue can be fixed by decreasing the domain's imbalance_pct
(by making it a function of number of logical cpus in the domain), it
can potentially cause more task migrations across sched groups in an
overloaded case.
Fix this by using imbalance_pct only during newly_idle and busy
load balancing. And during idle load balancing, check if there
is an imbalance in number of idle cpu's across the busiest and this
sched_group or if the busiest group has more tasks than its weight that
the idle cpu in this_group can pull.
Reported-by: Nikhil Rao <ncrao@google.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1284760952.2676.11.camel@sbsiddha-MOBL3.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch corrects time tracking in samples. Without this patch
both time_enabled and time_running are bogus when user asks for
PERF_SAMPLE_READ.
One uses PERF_SAMPLE_READ to sample the values of other counters
in each sample. Because of multiplexing, it is necessary to know
both time_enabled, time_running to be able to scale counts correctly.
In this second version of the patch, we maintain a shadow
copy of ctx->time which allows us to compute ctx->time without
calling update_context_time() from NMI context. We avoid the
issue that update_context_time() must always be called with
ctx->lock held.
We do not keep shadow copies of the other event timings
because if the lead event is overflowing then it is active
and thus it's been scheduled in via event_sched_in() in
which case neither tstamp_stopped, tstamp_running can be modified.
This timing logic only applies to samples when PERF_SAMPLE_READ
is used.
Note that this patch does not address timing issues related
to sampling inheritance between tasks. This will be addressed
in a future patch.
With this patch, the libpfm4 example task_smpl now reports
correct counts (shown on 2.4GHz Core 2):
$ task_smpl -p 2400000000 -e unhalted_core_cycles:u,instructions_retired:u,baclears noploop 5
noploop for 5 seconds
IIP:0x000000004006d6 PID:5596 TID:5596 TIME:466,210,211,430 STREAM_ID:33 PERIOD:2,400,000,000 ENA=1,010,157,814 RUN=1,010,157,814 NR=3
2,400,000,254 unhalted_core_cycles:u (33)
2,399,273,744 instructions_retired:u (34)
53,340 baclears (35)
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4cc6e14b.1e07e30a.256e.5190@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The futex_q struct has grown considerably over the last couple years. I
believe it now merits a static initializer to avoid uninitialized data
errors (having spent more time than I care to admit debugging an uninitialized
q.bitset in an experimental new op code).
With the key initializer built in, several of the FUTEX_KEY_INIT calls can
be removed.
V2: use a static variable instead of an init macro.
use a C99 initializer and don't rely on variable ordering in the struct.
V3: make futex_q_init const
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1289252428-18383-1-git-send-email-dvhart@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In the early days we passed the mmap sem around. That became the
"int fshared" with the fast gup improvements. Then we added
"int clockrt" in places. This patch unifies these options as "flags".
[ tglx: Split out the stale fshared cleanup ]
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1289250609-16304-1-git-send-email-dvhart@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The fast GUP changes stopped using the fshared flag in
put_futex_keys(), but we kept the interface the same.
Cleanup all stale users.
This patch is split out from Darren Harts combo patch which also
combines various flags. This way the changes are clearly separated.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Darren Hart <dvhart@linux.intel.com>
LKML-Reference: <1289250609-16304-1-git-send-email-dvhart@linux.intel.com>
REQ_HARDBARRIER is dead now, so remove the leftovers. What's left
at this point is:
- various checks inside the block layer.
- sanity checks in bio based drivers.
- now unused bio_empty_barrier helper.
- Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while,
but Xen really needs to sort out it's barrier situaton.
- setting of ordered tags in uas - dead code copied from old scsi
drivers.
- scsi different retry for barriers - it's dead and should have been
removed when flushes were converted to FS requests.
- blktrace handling of barriers - removed. Someone who knows blktrace
better should add support for REQ_FLUSH and REQ_FUA, though.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Since commit 1dcc41bb (futex: Change 3rd arg of fetch_robust_entry()
to unsigned int*) some gcc versions decided to emit the following
warning:
kernel/futex.c: In function ‘exit_robust_list’:
kernel/futex.c:2492: warning: ‘next_pi’ may be used uninitialized in this function
The commit did not introduce the warning as gcc should have warned
before that commit as well. It's just gcc being silly.
The code path really can't result in next_pi being unitialized (or
should not), but let's keep the build clean. Annotate next_pi as an
uninitialized_var.
[ tglx: Addressed the same issue in futex_compat.c and massaged the
changelog ]
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Tested-by: Matt Fleming <matt@console-pimps.org>
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1288897200-13008-1-git-send-email-dvhart@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Commit 4221a9918e "Add RCU check for
find_task_by_vpid()" introduced rcu_lockdep_assert to find_task_by_pid_ns.
Add rcu_read_lock/rcu_read_unlock to call find_task_by_vpid.
Tetsuo Handa wrote:
| Quoting from one of posts in that thead
| http://kerneltrap.org/mailarchive/linux-kernel/2010/2/8/4536388
|
|| Usually tasklist gives enough protection, but if copy_process() fails
|| it calls free_pid() lockless and does call_rcu(delayed_put_pid().
|| This means, without rcu lock find_pid_ns() can't scan the hash table
|| safely.
Thomas Gleixner wrote:
| We can remove the tasklist_lock while at it. rcu_read_lock is enough.
Patch also replaces thread_group_leader with has_group_leader_pid
in accordance to comment by Oleg Nesterov:
| ... thread_group_leader() check is not relaible without
| tasklist. If we race with de_thread() find_task_by_vpid() can find
| the new leader before it updates its ->group_leader.
|
| perhaps it makes sense to change posix_cpu_timer_create() to use
| has_group_leader_pid() instead, just to make this code not look racy
| and avoid adding new problems.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
LKML-Reference: <20101103165256.GD30053@swordfish.minsk.epam.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
s390 doesn't need FRAME_POINTERS in order to have a working function tracer.
We don't need frame pointers in order to get strack traces since we always
have valid backchains by using the -mkernel-backchain gcc option.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Commit d9ca07a05c ("watchdog: Avoid kernel crash when disabling
watchdog") introduces a section mismatch.
Now that we reference no_watchdog from non-__init code it can no longer
be __initdata.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
posix-cpu-timers.c correctly assumes that the dying process does
posix_cpu_timers_exit_group() and removes all !CPUCLOCK_PERTHREAD
timers from signal->cpu_timers list.
But, it also assumes that timer->it.cpu.task is always the group
leader, and thus the dead ->task means the dead thread group.
This is obviously not true after de_thread() changes the leader.
After that almost every posix_cpu_timer_ method has problems.
It is not simple to fix this bug correctly. First of all, I think
that timer->it.cpu should use struct pid instead of task_struct.
Also, the locking should be reworked completely. In particular,
tasklist_lock should not be used at all. This all needs a lot of
nontrivial and hard-to-test changes.
Change __exit_signal() to do posix_cpu_timers_exit_group() when
the old leader dies during exec. This is not the fix, just the
temporary hack to hide the problem for 2.6.37 and stable. IOW,
this is obviously wrong but this is what we currently have anyway:
cpu timers do not work after mt exec.
In theory this change adds another race. The exiting leader can
detach the timers which were attached to the new leader. However,
the window between de_thread() and release_task() is small, we
can pretend that sys_timer_create() was called before de_thread().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We can optimize kernel/relay.c::relay_alloc_page_array() slightly by
using vzalloc. The patch makes these changes:
- use vzalloc instead of vmalloc+memset.
- remove redundant local variable 'array'.
- declare local 'pa_size' as const.
Cuts down nicely on both source and object-code size.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes a typo in the error message raised by audit when auditd has died.
Signed-off-by: Ross Kirk <ross.kirk@nexor.com>
--
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
genirq: Fix up irq_node() for irq_data changes.
genirq: Add single IRQ reservation helper
genirq: Warn if enable_irq is called before irq is set up
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
semaphore: Remove mutex emulation
staging: Final semaphore cleanup
jbd2: Convert jbd2_slab_create_sem to mutex
hpfs: Convert sbi->hpfs_creation_de to mutex
Fix up trivial change/delete conflicts with deleted 'dream' drivers
(drivers/staging/dream/camera/{mt9d112.c,mt9p012_fox.c,mt9t013.c,s5k3e2fx.c})
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
jump label: Add work around to i386 gcc asm goto bug
x86, ftrace: Use safe noops, drop trap test
jump_label: Fix unaligned traps on sparc.
jump label: Make arch_jump_label_text_poke_early() optional
jump label: Fix error with preempt disable holding mutex
oprofile: Remove deprecated use of flush_scheduled_work()
oprofile: Fix the hang while taking the cpu offline
jump label: Fix deadlock b/w jump_label_mutex vs. text_mutex
jump label: Fix module __init section race
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Check irq_remapped instead of remapping_enabled in destroy_irq()
Normal syscall audit doesn't catch 5th argument of syscall. It also
doesn't catch the contents of userland structures pointed to be
syscall argument, so for both old and new mmap(2) ABI it doesn't
record the descriptor we are mapping. For old one it also misses
flags.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Protect the task lookups in audit_receive_msg() with rcu_read_lock()
instead of tasklist_lock and use lock/unlock_sighand to protect
against the exit race.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
audit_receive_msg() sends uninitialized data for AUDIT_TTY_GET when
the task was not found.
Send reply only when task was found.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
While auditing all tasklist_lock read_lock sites I stumbled over the
following call chain:
audit_prepare_user_tty()
read_lock(&tasklist_lock);
tty_audit_push_task();
mutex_lock(&buf->mutex);
--> buf->mutex is locked with preemption disabled.
Solve this by acquiring a reference to the task struct under
rcu_read_lock and call tty_audit_push_task outside of the preempt
disabled region.
Move all code which needs to be protected by sighand lock into
tty_audit_push_task() and use lock/unlock_sighand as we do not hold
tasklist_lock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
I was doing some namespace checks and found some simple stuff in
audit that could be cleaned up. Make some functions static, and
put const on make_reply payload arg.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add support for matching by security label (e.g. SELinux context) of
the sender of an user-space audit record.
The audit filter code already allows user space to configure such
filters, but they were ignored during evaluation. This patch implements
evaluation of these filters.
For example, after application of this patch, PAM authentication logs
caused by cron can be disabled using
auditctl -a user,never -F subj_type=crond_t
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The kgdb_disable_hw_debug() was an architecture specific function for
disabling all hardware breakpoints on a per cpu basis when entering
the debug core.
This patch will remove the weak function kdbg_disable_hw_debug() and
change it into a call back which lives with the rest of hw breakpoint
call backs in struct kgdb_arch.
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The kdb_current legally be equal to NULL in the early boot of the x86
arch. The problem pcan be observed by booting with the kernel arguments:
earlyprintk=vga ekgdboc=kbd kgdbwait
The kdb shell will oops on entry and recursively fault because it
cannot get past the final stage of shell initialization.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Rusty pointed out that the per_cpu command uses up lots of space on
the stack and the cpu supress mask is probably not needed.
This patch removes the need for the supress mask as well as fixing up
the following problems with the kdb per_cpu command:
* The per_cpu command should allow an address as an argument
* When you have more data than can be displayed on one screen allow
the user to break out of the print loop.
Reported-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Some archs do not need to do anything special for jump labels on
startup (like MIPS). This patch adds a weak function stub for
arch_jump_label_text_poke_early();
Cc: Jason Baron <jbaron@redhat.com>
Cc: David Miller <davem@davemloft.net>
Cc: David Daney <ddaney@caviumnetworks.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <1286218615-24011-2-git-send-email-ddaney@caviumnetworks.com>
LKML-Reference: <20101015201037.703989993@goodmis.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Kprobes and jump label were having a race between mutexes that
was fixed by reordering the jump label. But this reordering
moved the jump label mutex into a preempt disable location.
This patch does a little fiddling to move the grabbing of
the jump label mutex from inside the preempt disable section
and still keep the order correct between the mutex and the
kprobes lock.
Reported-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jason Baron <jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (27 commits)
x86: allocate space within a region top-down
x86: update iomem_resource end based on CPU physical address capabilities
x86/PCI: allocate space from the end of a region, not the beginning
PCI: allocate bus resources from the top down
resources: support allocating space within a region from the top down
resources: handle overflow when aligning start of available area
resources: ensure callback doesn't allocate outside available space
resources: factor out resource_clip() to simplify find_resource()
resources: add a default alignf to simplify find_resource()
x86/PCI: MMCONFIG: fix region end calculation
PCI: Add support for polling PME state on suspended legacy PCI devices
PCI: Export some PCI PM functionality
PCI: fix message typo
PCI: log vendor/device ID always
PCI: update Intel chipset names and defines
PCI: use new ccflags variable in Makefile
PCI: add PCI_MSIX_TABLE/PBA defines
PCI: add PCI vendor id for STmicroelectronics
x86/PCI: irq and pci_ids patch for Intel Patsburg DeviceIDs
PCI: OLPC: Only enable PCI configuration type override on XO-1
...
register_kprobe() downs the 'text_mutex' and then calls
jump_label_text_reserved(), which downs the 'jump_label_mutex'.
However, the jump label code takes those mutexes in the reverse
order.
Fix by requiring the caller of jump_label_text_reserved() to do
the jump label locking via the newly added: jump_label_lock(),
jump_label_unlock(). Currently, kprobes is the only user
of jump_label_text_reserved().
Reported-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <759032c48d5e30c27f0bba003d09bffa8e9f28bb.1285965957.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Jump label uses is_module_text_address() to ensure that the module
__init sections are valid before updating them. However, between the
check for a valid module __init section and the subsequent jump
label update, the module's __init section could be freed out from under
us.
We fix this potential race by adding a notifier callback to the
MODULE_STATE_LIVE state. This notifier is called *after* the __init
section has been run but before it is going to be freed. In the
callback, the jump label code zeros the key value for any __init jump
code within the module, and we add a check for a non-zero key value when
we update jump labels. In this way we require no additional data
structures.
Thanks to Mathieu Desnoyers for pointing out this race condition.
Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <c6f037b7598777668025ceedd9294212fd95fa34.1285965957.git.jbaron@redhat.com>
[ Renamed remove_module_init() to remove_jump_label_module_init()
as suggested by Masami Hiramatsu. ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-mn10300: (44 commits)
MN10300: Save frame pointer in thread_info struct rather than global var
MN10300: Change "Matsushita" to "Panasonic".
MN10300: Create a defconfig for the ASB2364 board
MN10300: Update the ASB2303 defconfig
MN10300: ASB2364: Add support for SMSC911X and SMC911X
MN10300: ASB2364: Handle the IRQ multiplexer in the FPGA
MN10300: Generic time support
MN10300: Specify an ELF HWCAP flag for MN10300 Atomic Operations Unit support
MN10300: Map userspace atomic op regs as a vmalloc page
MN10300: And Panasonic AM34 subarch and implement SMP
MN10300: Delete idle_timestamp from irq_cpustat_t
MN10300: Make various interrupt priority settings configurable
MN10300: Optimise do_csum()
MN10300: Implement atomic ops using atomic ops unit
MN10300: Make the FPU operate in non-lazy mode under SMP
MN10300: SMP TLB flushing
MN10300: Use the [ID]PTEL2 registers rather than [ID]PTEL for TLB control
MN10300: Make the use of PIDR to mark TLB entries controllable
MN10300: Rename __flush_tlb*() to local_flush_tlb*()
MN10300: AM34 erratum requires MMUCTR read and write on exception entry
...
* 'module' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
NULL-terminate all pci_device_id tables
(trivial) Fix compiler warning in kernel/modules.c
If the same resource is inserted to the resource tree (maybe not on
purpose), a dead loop will be created. In this situation, The kernel does
not report any warning or error :(
The command below will show a endless print.
#cat /proc/iomem
[akpm@linux-foundation.org: add WARN_ON()]
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The taskstats interface uses microsecond granularity for the user and
system time values. The conversion from cputime to the taskstats values
uses the cputime_to_msecs primitive which effectively limits the
granularity to milliseconds. Add the cputime_to_usecs primitive for
architectures that have better, more precise CPU time values. Remove
cputime_to_msecs primitive because there are no more users left.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Luck Tony <tony.luck@intel.com>
Cc: Shailabh Nagar <nagar1234@in.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shailabh Nagar <nagar@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Separate the finding of a task_struct by pid or tgid from filling the
taskstats data. This makes the code more readable.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move each taskstats command into a single function. This makes the code
more readable and makes it easier to add new commands.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
prepare_reply() sets up an skb for the response. The payload contains:
+--------------------------------+
| genlmsghdr - 4 bytes |
+--------------------------------+
| NLA header - 4 bytes | /* Aggregate header */
+-+------------------------------+
| | NLA header - 4 bytes | /* PID header */
| +------------------------------+
| | pid/tgid - 4 bytes |
| +------------------------------+
| | NLA header - 4 bytes | /* stats header */
| + -----------------------------+ <- oops. aligned on 4 byte boundary
| | struct taskstats - 328 bytes |
+-+------------------------------+
The start of the taskstats struct must be 8 byte aligned on IA64 (and
other systems with 8 byte alignment rules for 64-bit types) or runtime
alignment warnings will be issued.
This patch pads the pid/tgid field out to sizeof(long), which forces the
alignment of taskstats. The getdelays userspace code is ok with this
since it assumes 32-bit pid/tgid and then honors that header's length
field.
An array is used to avoid exposing kernel memory contents to userspace in
the response.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In /proc/stat, the number of per-IRQ event is shown by making a sum each
irq's events on all cpus. But we can make use of kstat_irqs().
kstat_irqs() do the same calculation, If !CONFIG_GENERIC_HARDIRQ,
it's not a big cost. (Both of the number of cpus and irqs are small.)
If a system is very big and CONFIG_GENERIC_HARDIRQ, it does
for_each_irq()
for_each_cpu()
- look up a radix tree
- read desc->irq_stat[cpu]
This seems not efficient. This patch adds kstat_irqs() for
CONFIG_GENRIC_HARDIRQ and change the calculation as
for_each_irq()
look up radix tree
for_each_cpu()
- read desc->irq_stat[cpu]
This reduces cost.
A test on (4096cpusp, 256 nodes, 4592 irqs) host (by Jack Steiner)
%time cat /proc/stat > /dev/null
Before Patch: 2.459 sec
After Patch : .561 sec
[akpm@linux-foundation.org: unexport kstat_irqs, coding-style tweaks]
[akpm@linux-foundation.org: fix unused variable 'per_irq_sum']
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Jack Steiner <steiner@sgi.com>
Acked-by: Jack Steiner <steiner@sgi.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
find_new_reaper() releases and regrabs tasklist_lock but was missing
proper annotations. Add it. This remove following sparse warning:
warning: context imbalance in 'find_new_reaper' - unexpected unlock
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov pointed out we have to prevent multiple-threads-inside-exec
itself and we can reuse ->cred_guard_mutex for it. Yes, concurrent
execve() has no worth.
Let's move ->cred_guard_mutex from task_struct to signal_struct. It
naturally prevent multiple-threads-inside-exec.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lock_task_sighand() grabs sighand->siglock in case of returning non-NULL
but unlock_task_sighand() releases it unconditionally. This leads sparse
to complain about the lock context imbalance. Rename and wrap
lock_task_sighand() using __cond_lock() macro to make sparse happy.
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use new 'datavp' and 'datalp' variables to remove unnecesary castings.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since userspace API of ptrace syscall defines @addr and @data as void
pointers, it would be more appropriate to define them as unsigned long in
kernel. Therefore related functions are changed also.
'unsigned long' is typically used in other places in kernel as an opaque
data type and that using this helps cleaning up a lot of warnings from
sparse.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ns_cgroup will be removed very soon. Let's warn, for this version,
ns_cgroup is deprecated.
Make ns_cgroup and clone_children exclusive. If the clone_children is set
and the ns_cgroup is mounted, let's fail with EINVAL when the ns_cgroup
subsys is created (a printk will help the user to understand why the
creation fails).
Update the feature remove schedule file with the deprecated ns_cgroup.
Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Function "strcpy" is used without check for maximum allowed source string
length and could cause destination string overflow. Check for string
length is added before using "strcpy". Function now is return error if
source string length is more than a maximum.
akpm: presently considered NotABug, but add the check for general
future-safeness and robustness.
Signed-off-by: Evgeny Kuznetsov <EXT-Eugeny.Kuznetsov@nokia.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Current behavior:
=================
(1) When we mount a cgroup, we can specify the 'all' option which
means to enable all the cgroup subsystems. This is the default option
when no option is specified.
(2) If we want to mount a cgroup with a subset of the supported cgroup
subsystems, we have to specify a subsystems name list for the mount
option.
(3) If we specify another option like 'noprefix' or 'release_agent',
the actual code wants the 'all' or a subsystem name option specified
also. Not critical but a bit not friendly as we should assume (1) in
this case.
(4) Logically, the 'all' option is mutually exclusive with a subsystem
name, but this is not detected.
In other words:
succeed : mount -t cgroup -o all,freezer cgroup /cgroup
=> is it 'all' or 'freezer' ?
fails : mount -t cgroup -o noprefix cgroup /cgroup
=> succeed if we do '-o noprefix,all'
The following patches consolidate a bit the mount options check.
New behavior:
=============
(1) untouched
(2) untouched
(3) the 'all' option will be by default when specifying other than
a subsystem name option
(4) raises an error
In other words:
fails : mount -t cgroup -o all,freezer cgroup /cgroup
succeed : mount -t cgroup -o noprefix cgroup /cgroup
For the sake of lisibility, the if ... then ... else ... if ...
indentation when parsing the options has been changed to:
if ... then
...
continue
fi
Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jamal Hadi Salim <hadi@cyberus.ca>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ns_cgroup is a control group interacting with the namespaces. When a
new namespace is created, a corresponding cgroup is automatically created
too. The cgroup name is the pid of the process who did 'unshare' or the
child of 'clone'.
This cgroup is tied with the namespace because it prevents a process to
escape the control group and use the post_clone callback, so the child
cgroup inherits the values of the parent cgroup.
Unfortunately, the more we use this cgroup and the more we are facing
problems with it:
(1) when a process unshares, the cgroup name may conflict with a
previous cgroup with the same pid, so unshare or clone return -EEXIST
(2) the cgroup creation is out of control because there may have an
application creating several namespaces where the system will
automatically create several cgroups in his back and let them on the
cgroupfs (eg. a vrf based on the network namespace).
(3) the mix of (1) and (2) force an administrator to regularly check
and clean these cgroups.
This patchset removes the ns_cgroup by adding a new flag to the cgroup and
the cgroupfs mount option. It enables the copy of the parent cgroup when
a child cgroup is created. We can then safely remove the ns_cgroup as
this flag brings a compatibility. We have now to manually create and add
the task to a cgroup, which is consistent with the cgroup framework.
This patch:
Sent as an answer to a previous thread around the ns_cgroup.
https://lists.linux-foundation.org/pipermail/containers/2009-June/018627.html
It adds a control file 'clone_children' for a cgroup. This control file
is a boolean specifying if the child cgroup should be a clone of the
parent cgroup or not. The default value is 'false'.
This flag makes the child cgroup to call the post_clone callback of all
the subsystem, if it is available.
At present, the cpuset is the only one which had implemented the
post_clone callback.
The option can be set at mount time by specifying the 'clone_children'
mount option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jamal Hadi Salim <hadi@cyberus.ca>
Cc: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are 4 state transitions possible for a freezer. Only FREEZING ->
FROZEN transaction is done lazily. This patch allows update_freezer_state
only to perform this transaction and renames the function to
update_if_frozen.
Moreover is_task_frozen_enough function is removed and its every occurence
is replaced with frozen(). Therefore for a group to become FROZEN every
task must be frozen.
The previous version could trigger a following bug: When cgroup is in the
process of freezing (but none of its tasks are frozen yet),
update_freezer_state() (called from freezer_read or freezer_write) would
incorrectly report that a group is 'THAWED' (because nfrozen = 0),
allowing the transaction FREEZING -> THAWED without writing anything to
'freezer.state'. This is incorrect according to the documentation. This
could result in a 'THAWED' cgroup with frozen tasks inside.
A code to reproduce this bug is available here:
http://pentium.hopto.org/~thinred/repos/linux-misc/freezer_bug2.c
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is possible to move a task from its cgroup even if this group is
'FREEZING'. This results in a nasty bug - the moved task will become
frozen OUTSIDE its original cgroup and will remain in a permanent 'D'
state.
This patch allows to migrate the task only between THAWED cgroups.
This behavior was observed and easily reproduced on a single core laptop.
Notice that reproducibility depends highly on the machine used. Program
and instructions how to reproduce the bug can be fetched from:
http://pentium.hopto.org/~thinred/repos/linux-misc/freezer_bug.c
Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The root freezer_state is always CGROUP_THAWED so we can remove the
special case from the code. The test itself can be handy and is extracted
to static function.
Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Typedef the pointer to the function to be called by smp_call_function() and
friends:
typedef void (*smp_call_func_t)(void *info);
as it is used in a fair number of places.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-arch@vger.kernel.org
Building with CONFIG_KALLSYMS=n gives following warning:
/mnt/src/linux-git/kernel/module.c: In function ‘post_relocation’:
/mnt/src/linux-git/kernel/module.c:2534:2: warning: passing argument 2 of ‘add_kallsyms’ discards qualifiers from pointer target type
/mnt/src/linux-git/kernel/module.c:2038:13: note: expected ‘struct load_info *’ but argument is of type ‘const struct load_info *’
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits)
split invalidate_inodes()
fs: skip I_FREEING inodes in writeback_sb_inodes
fs: fold invalidate_list into invalidate_inodes
fs: do not drop inode_lock in dispose_list
fs: inode split IO and LRU lists
fs: switch bdev inode bdi's correctly
fs: fix buffer invalidation in invalidate_list
fsnotify: use dget_parent
smbfs: use dget_parent
exportfs: use dget_parent
fs: use RCU read side protection in d_validate
fs: clean up dentry lru modification
fs: split __shrink_dcache_sb
fs: improve DCACHE_REFERENCED usage
fs: use percpu counter for nr_dentry and nr_dentry_unused
fs: simplify __d_free
fs: take dcache_lock inside __d_path
fs: do not assign default i_ino in new_inode
fs: introduce a per-cpu last_ino allocator
new helper: ihold()
...
Add more wait, wake, and completion interfaces to the device-drivers
docbook.
Fix kernel-doc notation in the added files.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adding declaration of printk_ratelimit_state in ratelimit.h removes
potential build breakage and following sparse warning:
kernel/printk.c:1426:1: warning: symbol 'printk_ratelimit_state' was not declared. Should it be static?
[akpm@linux-foundation.org: remove unneeded ifdef]
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
get_option() takes its 2nd arg as int * so passing boot_delay to it
caused following warnings from sparse:
kernel/printk.c:223:27: warning: incorrect type in argument 2 (different signedness)
kernel/printk.c:223:27: expected int *pint
kernel/printk.c:223:27: got unsigned int static [toplevel] *<noident>
Since boot_delay can't grow more than 10,000 changing it to 'int *'
will not produce any problem.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit e6bde73b07 ("cpu-hotplug: return
better errno on cpu hotplug failure"), the cpu notifier can return an
encapsulated errno value.
This converts the cpu notifier to return an encapsulated errno value for
stop_machine().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/stop_machine.c: In function `cpu_stopper_thread':
kernel/stop_machine.c:265: warning: unused variable `ksym_buf'
ksym_buf[] is unused if WARN_ON() is a no-op.
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robin Holt tried to boot a 16TB system and found af_unix was overflowing
a 32bit value :
<quote>
We were seeing a failure which prevented boot. The kernel was incapable
of creating either a named pipe or unix domain socket. This comes down
to a common kernel function called unix_create1() which does:
atomic_inc(&unix_nr_socks);
if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
goto out;
The function get_max_files() is a simple return of files_stat.max_files.
files_stat.max_files is a signed integer and is computed in
fs/file_table.c's files_init().
n = (mempages * (PAGE_SIZE / 1024)) / 10;
files_stat.max_files = n;
In our case, mempages (total_ram_pages) is approx 3,758,096,384
(0xe0000000). That leaves max_files at approximately 1,503,238,553.
This causes 2 * get_max_files() to integer overflow.
</quote>
Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
integers, and change af_unix to use an atomic_long_t instead of atomic_t.
get_max_files() is changed to return an unsigned long. get_nr_files() is
changed to return a long.
unix_nr_socks is changed from atomic_t to atomic_long_t, while not
strictly needed to address Robin problem.
Before patch (on a 64bit kernel) :
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
-18446744071562067968
After patch:
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
2147483648
# cat /proc/sys/fs/file-nr
704 0 2147483648
Reported-by: Robin Holt <holt@sgi.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Miller <davem@davemloft.net>
Reviewed-by: Robin Holt <holt@sgi.com>
Tested-by: Robin Holt <holt@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Silly though it is, completions and wait_queue_heads use foo_ONSTACK
(COMPLETION_INITIALIZER_ONSTACK, DECLARE_COMPLETION_ONSTACK,
__WAIT_QUEUE_HEAD_INIT_ONSTACK and DECLARE_WAIT_QUEUE_HEAD_ONSTACK) so I
guess workqueues should do the same thing.
s/INIT_WORK_ON_STACK/INIT_WORK_ONSTACK/
s/INIT_DELAYED_WORK_ON_STACK/INIT_DELAYED_WORK_ONSTACK/
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After all that's what they are intended for.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ensure kmap_atomic() usage is strictly nested
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's pointless to kill a task if another thread sharing its mm cannot be
killed to allow future memory freeing. A subsequent patch will prevent
kills in such cases, but first it's necessary to have a way to flag a task
that shares memory with an OOM_DISABLE task that doesn't incur an
additional tasklist scan, which would make select_bad_process() an O(n^2)
function.
This patch adds an atomic counter to struct mm_struct that follows how
many threads attached to it have an oom_score_adj of OOM_SCORE_ADJ_MIN.
They cannot be killed by the kernel, so their memory cannot be freed in
oom conditions.
This only requires task_lock() on the task that we're operating on, it
does not require mm->mmap_sem since task_lock() pins the mm and the
operation is atomic.
[rientjes@google.com: changelog and sys_unshare() code]
[rientjes@google.com: protect oom_disable_count with task_lock in fork]
[rientjes@google.com: use old_mm for oom_disable_count in exec]
Signed-off-by: Ying Han <yinghan@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allocate space from the top of a region first, then work downward,
if an architecture desires this.
When we allocate space from a resource, we look for gaps between children
of the resource. Previously, we always looked at gaps from the bottom up.
For example, given this:
[mem 0xbff00000-0xf7ffffff] PCI Bus 0000:00
[mem 0xbff00000-0xbfffffff] gap -- available
[mem 0xc0000000-0xdfffffff] PCI Bus 0000:02
[mem 0xe0000000-0xf7ffffff] gap -- available
we attempted to allocate from the [mem 0xbff00000-0xbfffffff] gap first,
then the [mem 0xe0000000-0xf7ffffff] gap.
With this patch an architecture can choose to allocate from the top gap
[mem 0xe0000000-0xf7ffffff] first.
We can't do this across the board because iomem_resource.end is initialized
to 0xffffffff_ffffffff on 64-bit architectures, and most machines can't
address the entire 64-bit physical address space. Therefore, we only
allocate top-down if the arch requests it by clearing
"resource_alloc_from_bottom".
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
If tmp.start is near ~0, ALIGN(tmp.start) may overflow, which would
make us think there's more available space than there really is. We
would likely return something that conflicts with a previous resource,
which would cause a failure when allocate_resource() requests the newly-
allocated region.
Reference: https://bugzilla.redhat.com/show_bug.cgi?id=646027
Reported-by: Fabrice Bellet <fabrice@bellet.info>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The alignment callback returns a proposed location, which may have been
adjusted to avoid ISA aliases or for other architecture-specific reasons.
We already had a check ("tmp.start < tmp.end") to make sure the callback
doesn't return an area that extends past the available area. This patch
reworks the check to make sure it doesn't return an area that extends
either below or above the available area.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This factors out the min/max clipping to simplify find_resource().
No functional change.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This removes a test from find_resource(), which is getting cluttered.
No functional change.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The nr_dentry stat is a globally touched cacheline and atomic operation
twice over the lifetime of a dentry. It is used for the benfit of userspace
only. Turn it into a per-cpu counter and always decrement it in d_free instead
of doing various batching operations to reduce lock hold times in the callers.
Based on an earlier patch from Nick Piggin <npiggin@suse.de>.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Instead of always assigning an increasing inode number in new_inode
move the call to assign it into those callers that actually need it.
For now callers that need it is estimated conservatively, that is
the call is added to all filesystems that do not assign an i_ino
by themselves. For a few more filesystems we can avoid assigning
any inode number given that they aren't user visible, and for others
it could be done lazily when an inode number is actually needed,
but that's left for later patches.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The number of inodes allocated does not need to be tied to the
addition or removal of an inode to/from a list. If we are not tied
to a list lock, we could update the counters when inodes are
initialised or destroyed, but to do that we need to convert the
counters to be per-cpu (i.e. independent of a lock). This means that
we have the freedom to change the list/locking implementation
without needing to care about the counters.
Based on a patch originally from Eric Dumazet.
[AV: cleaned up a bit, fixed build breakage on weird configs
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Andrew,
Could you please review this patch, you probably are the right guy to
take it, because it crosses fs and net trees.
Note : /proc/sys/fs/file-nr is a read-only file, so this patch doesnt
depend on previous patch (sysctl: fix min/max handling in
__do_proc_doulongvec_minmax())
Thanks !
[PATCH V4] fs: allow for more than 2^31 files
Robin Holt tried to boot a 16TB system and found af_unix was overflowing
a 32bit value :
<quote>
We were seeing a failure which prevented boot. The kernel was incapable
of creating either a named pipe or unix domain socket. This comes down
to a common kernel function called unix_create1() which does:
atomic_inc(&unix_nr_socks);
if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
goto out;
The function get_max_files() is a simple return of files_stat.max_files.
files_stat.max_files is a signed integer and is computed in
fs/file_table.c's files_init().
n = (mempages * (PAGE_SIZE / 1024)) / 10;
files_stat.max_files = n;
In our case, mempages (total_ram_pages) is approx 3,758,096,384
(0xe0000000). That leaves max_files at approximately 1,503,238,553.
This causes 2 * get_max_files() to integer overflow.
</quote>
Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
integers, and change af_unix to use an atomic_long_t instead of
atomic_t.
get_max_files() is changed to return an unsigned long.
get_nr_files() is changed to return a long.
unix_nr_socks is changed from atomic_t to atomic_long_t, while not
strictly needed to address Robin problem.
Before patch (on a 64bit kernel) :
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
-18446744071562067968
After patch:
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
2147483648
# cat /proc/sys/fs/file-nr
704 0 2147483648
Reported-by: Robin Holt <holt@sgi.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Miller <davem@davemloft.net>
Reviewed-by: Robin Holt <holt@sgi.com>
Tested-by: Robin Holt <holt@sgi.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In the MN10300 arch, we occasionally see an assertion being tripped in
alloc_cwqs() at the following line:
/* just in case, make sure it's actually aligned */
---> BUG_ON(!IS_ALIGNED(wq->cpu_wq.v, align));
return wq->cpu_wq.v ? 0 : -ENOMEM;
The values are:
wa->cpu_wq.v => 0x902776e0
align => 0x100
and align is calculated by the following:
const size_t align = max_t(size_t, 1 << WORK_STRUCT_FLAG_BITS,
__alignof__(unsigned long long));
This is because the pointer in question (wq->cpu_wq.v) loses some of its
lower bits to control flags, and so the object it points to must be
sufficiently aligned to avoid the need to use those bits for pointing to
things.
Currently, 4 control bits and 4 colour bits are used in normal
circumstances, plus a debugging bit if debugging is set. This requires
the cpu_workqueue_struct struct to be at least 256 bytes aligned (or 512
bytes aligned with debugging).
PERCPU() alignment on MN13000, however, is only 32 bytes as set in
vmlinux.lds.S. So we set this to PAGE_SIZE (4096) to match most other
arches and stick a comment in alloc_cwqs() for anyone else who triggers
the assertion.
Reported-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mark Salter <msalter@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove text_mutex locking in optimize_all_kprobes, because
this function doesn't modify text. It simply queues probes on
optimization list for kprobe_optimizer worker thread.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101025131801.19160.70939.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove some sched_info_queue(), sched_info_dequeue() code comment.
We no longer belongs to the era of O(1) and we don't use active or expired
array anymore.
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <AANLkTi=REu0WzOp5N=nVT1=ZJ=ZA+MZFV+4CHSJ3Q-Yv@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Andrew Morton pointed out almost all sched_setscheduler() callers are
using fixed parameters and can be converted to static. It reduces runtime
memory use a little.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: James Morris <jmorris@namei.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'softirq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
softirqs: Make wakeup_softirqd static
* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, asm: Restore parentheses around one pushl_cfi argument
x86, asm: Fix ancient-GAS workaround
x86, asm: Fix CFI macro invocations to deal with shortcomings in gas
* 'x86-numa-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, numa: Assign CPUs to nodes in round-robin manner on fake NUMA
* 'x86-quirks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: HPET force enable for CX700 / VIA Epia LT
* 'x86-setup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, setup: Use string copy operation to optimze copy in kernel compression
* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, UV: Use allocated buffer in tlb_uv.c:tunables_read()
* 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, vm86: Fix preemption bug for int1 debug and int3 breakpoint handlers.
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
kdb,debug_core: adjust master cpu switch logic against new debug_core locking
debug_core: refactor locking for master/slave cpus
x86,kgdb: remove unnecessary call to kgdb_correct_hw_break()
debug_core: disable hw_breakpoints on all cores in kgdb_cpu_enter()
kdb,kgdb: fix sparse fixups
kdb: Fix oops in kdb_unregister
kdb,ftdump: Remove reference to internal kdb include
kdb: Allow kernel loadable modules to add kdb shell functions
debug_core: stop rcu warnings on kernel resume
debug_core: move all watch dog syncs to a single function
x86,kgdb: fix debugger hw breakpoint test regression in 2.6.35
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: remove in_workqueue_context()
workqueue: Clarify that schedule_on_each_cpu is synchronous
memory_hotplug: drop spurious calls to flush_scheduled_work()
shpchp: update workqueue usage
pciehp: update workqueue usage
isdn/eicon: don't call flush_scheduled_work() from diva_os_remove_soft_isr()
workqueue: add and use WQ_MEM_RECLAIM flag
workqueue: fix HIGHPRI handling in keep_working()
workqueue: add queue_work and activate_work trace points
workqueue: prepare for more tracepoints
workqueue: implement flush[_delayed]_work_sync()
workqueue: factor out start_flush_work()
workqueue: cleanup flush/cancel functions
workqueue: implement alloc_ordered_workqueue()
Fix up trivial conflict in fs/gfs2/main.c as per Tejun
The kdb shell needs to enforce switching back to the original CPU that
took the exception before restoring normal kernel execution. Resuming
from a different CPU than what took the original exception will cause
problems with spin locks that are freed from the a different processor
than had taken the lock.
The special logic in dbg_cpu_switch() can go away entirely with
because the state of what cpus want to be masters or slaves will
remain unchanged between entry and exit of the debug_core exception
context.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
For quite some time there have been problems with memory barriers and
various races with NMI on multi processor systems using the kernel
debugger. The algorithm for entering the kernel debug core and
resuming kernel execution was racy and had several known edge case
problems with attempting to debug something on a heavily loaded system
using breakpoints that are hit repeatedly and quickly.
The prior "locking" design entry worked as follows:
* The atomic counter kgdb_active was used with atomic exchange in
order to elect a master cpu out of all the cpus that may have
taken a debug exception.
* The master cpu increments all elements of passive_cpu_wait[].
* The master cpu issues the round up cpus message.
* Each "slave cpu" that enters the debug core increments its own
element in cpu_in_kgdb[].
* Each "slave cpu" spins on passive_cpu_wait[] until it becomes 0.
* The master cpu debugs the system.
The new scheme removes the two arrays of atomic counters and replaces
them with 2 single counters. One counter is used to count the number
of cpus waiting to become a master cpu (because one or more hit an
exception). The second counter is use to indicate how many cpus have
entered as slave cpus.
The new entry logic works as follows:
* One or more cpus enters via kgdb_handle_exception() and increments
the masters_in_kgdb. Each cpu attempts to get the spin lock called
dbg_master_lock.
* The master cpu sets kgdb_active to the current cpu.
* The master cpu takes the spinlock dbg_slave_lock.
* The master cpu asks to round up all the other cpus.
* Each slave cpu that is not already in kgdb_handle_exception()
will enter and increment slaves_in_kgdb. Each slave will now spin
try_locking on dbg_slave_lock.
* The master cpu waits for the sum of masters_in_kgdb and slaves_in_kgdb
to be equal to the sum of the online cpus.
* The master cpu debugs the system.
In the new design the kgdb_active can only be changed while holding
dbg_master_lock. Stress testing has not turned up any further
entry/exit races that existed in the prior locking design. The prior
locking design suffered from atomic variables not being truly atomic
(in the capacity as used by kgdb) along with memory barrier races.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Dongdong Deng <dongdong.deng@windriver.com>
The slave cpus do not have the hw breakpoints disabled upon entry to
the debug_core and as a result could cause unrecoverable recursive
faults on badly placed breakpoints, or get out of sync with the arch
specific hw breakpoint operations.
This patch addresses the problem by invoking kgdb_disable_hw_debug()
earlier in kgdb_enter_cpu for each cpu that enters the debug core.
The hw breakpoint dis/enable flow should be:
master_debug_cpu slave_debug_cpu
\ /
kgdb_cpu_enter
|
kgdb_disable_hw_debug --> uninstall pre-enabled hw_breakpoint
|
do add/rm dis/enable operates to hw_breakpoints on master_debug_cpu..
|
correct_hw_break --> correct/install the enabled hw_breakpoint
|
leave_kgdb
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Fix the following sparse warnings:
kdb_main.c:328:5: warning: symbol 'kdbgetu64arg' was not declared. Should it be static?
kgdboc.c:246:12: warning: symbol 'kgdboc_early_init' was not declared. Should it be static?
kgdb.c:652:26: warning: incorrect type in argument 1 (different address spaces)
kgdb.c:652:26: expected void const *ptr
kgdb.c:652:26: got struct perf_event *[noderef] <asn:3>*pev
The one in kgdb.c required the (void * __force) because of the return
code from register_wide_hw_breakpoint looking like:
return (void __percpu __force *)ERR_PTR(err);
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Nothing should try to use kdb_commands directly as sometimes it is
null. Instead, use the for_each_kdbcmd() iterator.
This particular problem dates back to the initial kdb merge (2.6.35),
but at that point nothing was dynamically unregistering commands from
the kdb shell.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Now that include/linux/kdb.h properly exports all the functions
required to dynamically add a kdb shell command, the reference to the
private kdb header can be removed.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
In order to allow kernel modules to dynamically add a command to the
kdb shell the kdb_register, kdb_register_repeat, kdb_unregister, and
kdb_printf need to be exported as GPL symbols.
Any kernel module that adds a dynamic kdb shell function should only
need to include linux/kdb.h.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
When returning from the kernel debugger reset the rcu jiffies_stall
value to prevent the rcu stall detector from sending NMI events which
invoke a stack dump for each cpu in the system.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Move the various clock and watch dog syncs to a single function in
advance of adding another sync for the rcu stall detector.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
vfs: make no_llseek the default
vfs: don't use BKL in default_llseek
llseek: automatically add .llseek fop
libfs: use generic_file_llseek for simple_attr
mac80211: disallow seeks in minstrel debug code
lirc: make chardev nonseekable
viotape: use noop_llseek
raw: use explicit llseek file operations
ibmasmfs: use generic_file_llseek
spufs: use llseek in all file operations
arm/omap: use generic_file_llseek in iommu_debug
lkdtm: use generic_file_llseek in debugfs
net/wireless: use generic_file_llseek in debugfs
drm: use noop_llseek
* 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: (30 commits)
BKL: remove BKL from freevxfs
BKL: remove BKL from qnx4
autofs4: Only declare function when CONFIG_COMPAT is defined
autofs: Only declare function when CONFIG_COMPAT is defined
ncpfs: Lock socket in ncpfs while setting its callbacks
fs/locks.c: prepare for BKL removal
BKL: Remove BKL from ncpfs
BKL: Remove BKL from OCFS2
BKL: Remove BKL from squashfs
BKL: Remove BKL from jffs2
BKL: Remove BKL from ecryptfs
BKL: Remove BKL from afs
BKL: Remove BKL from USB gadgetfs
BKL: Remove BKL from autofs4
BKL: Remove BKL from isofs
BKL: Remove BKL from fat
BKL: Remove BKL from ext2 filesystem
BKL: Remove BKL from do_new_mount()
BKL: Remove BKL from cgroup
BKL: Remove BKL from NTFS
...
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
BKL: introduce CONFIG_BKL.
dabusb: remove the BKL
sunrpc: remove the big kernel lock
init/main.c: remove BKL notations
blktrace: remove the big kernel lock
rtmutex-tester: make it build without BKL
dvb-core: kill the big kernel lock
dvb/bt8xx: kill the big kernel lock
tlclk: remove big kernel lock
fix rawctl compat ioctls breakage on amd64 and itanic
uml: kill big kernel lock
parisc: remove big kernel lock
cris: autoconvert trivial BKL users
alpha: kill big kernel lock
isapnp: BKL removal
s390/block: kill the big kernel lock
hpet: kill BKL, add compat_ioctl
The recent changes in the genirq core unearthed a bug in arch/um which
called enable_irq() before the interrupt was set up.
Warn and return instead of crashing the machine with a NULL pointer
dereference.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Weinberger <richard@nod.at>
