Commit Graph

567 Commits

Author SHA1 Message Date
Paul E. McKenney
7cb9249900 rcu: Permit dyntick-idle with callbacks pending
The current implementation of RCU_FAST_NO_HZ prevents CPUs from entering
dyntick-idle state if they have RCU callbacks pending.  Unfortunately,
this has the side-effect of often preventing them from entering this
state, especially if at least one other CPU is not in dyntick-idle state.
However, the resulting per-tick wakeup is wasteful in many cases: if the
CPU has already fully responded to the current RCU grace period, there
will be nothing for it to do until this grace period ends, which will
frequently take several jiffies.

This commit therefore permits a CPU that has done everything that the
current grace period has asked of it (rcu_pending() == 0) even if it
still as RCU callbacks pending.  However, such a CPU posts a timer to
wake it up several jiffies later (6 jiffies, based on experience with
grace-period lengths).  This wakeup is required to handle situations
that can result in all CPUs being in dyntick-idle mode, thus failing
to ever complete the current grace period.  If a CPU wakes up before
the timer goes off, then it cancels that timer, thus avoiding spurious
wakeups.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-12-11 10:32:07 -08:00
Paul E. McKenney
f535a607c1 rcu: Eliminate RCU_FAST_NO_HZ grace-period hang
With the new implementation of RCU_FAST_NO_HZ, it was possible to hang
RCU grace periods as follows:

o	CPU 0 attempts to go idle, cycles several times through the
	rcu_prepare_for_idle() loop, then goes dyntick-idle when
	RCU needs nothing more from it, while still having at least
	on RCU callback pending.

o	CPU 1 goes idle with no callbacks.

Both CPUs can then stay in dyntick-idle mode indefinitely, preventing
the RCU grace period from ever completing, possibly hanging the system.

This commit therefore prevents CPUs that have RCU callbacks from entering
dyntick-idle mode.  This approach also eliminates the need for the
end-of-grace-period IPIs used previously.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-12-11 10:32:02 -08:00
Paul E. McKenney
433cdddcd9 rcu: Add tracing for RCU_FAST_NO_HZ
This commit adds trace_rcu_prep_idle(), which is invoked from
rcu_prepare_for_idle() and rcu_wake_cpu() to trace attempts on
the part of RCU to force CPUs into dyntick-idle mode.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-12-11 10:32:00 -08:00
Paul E. McKenney
045fb9315a rcu: Update trace_rcu_dyntick() header comment
This commit updates the trace_rcu_dyntick() header comment to reflect
events added by commit 4b4f421.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-12-11 10:31:59 -08:00
Paul E. McKenney
4145fa7fbe rcu: Deconfuse dynticks entry-exit tracing
The trace_rcu_dyntick() trace event did not print both the old and
the new value of the nesting level, and furthermore printed only
the low-order 32 bits of it.  This could result in some confusion
when interpreting trace-event dumps, so this commit prints both
the old and the new value, prints the full 64 bits, and also selects
the process-entry/exit increment to print nicely in hexadecimal.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-12-11 10:31:42 -08:00
Paul E. McKenney
91afaf3002 rcu: Add failure tracing to rcutorture
Trace the rcutorture RCU accesses and dump the trace buffer when the
first failure is detected.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-12-11 10:31:26 -08:00
Paul E. McKenney
9b2e4f1880 rcu: Track idleness independent of idle tasks
Earlier versions of RCU used the scheduling-clock tick to detect idleness
by checking for the idle task, but handled idleness differently for
CONFIG_NO_HZ=y.  But there are now a number of uses of RCU read-side
critical sections in the idle task, for example, for tracing.  A more
fine-grained detection of idleness is therefore required.

This commit presses the old dyntick-idle code into full-time service,
so that rcu_idle_enter(), previously known as rcu_enter_nohz(), is
always invoked at the beginning of an idle loop iteration.  Similarly,
rcu_idle_exit(), previously known as rcu_exit_nohz(), is always invoked
at the end of an idle-loop iteration.  This allows the idle task to
use RCU everywhere except between consecutive rcu_idle_enter() and
rcu_idle_exit() calls, in turn allowing architecture maintainers to
specify exactly where in the idle loop that RCU may be used.

Because some of the userspace upcall uses can result in what looks
to RCU like half of an interrupt, it is not possible to expect that
the irq_enter() and irq_exit() hooks will give exact counts.  This
patch therefore expands the ->dynticks_nesting counter to 64 bits
and uses two separate bitfields to count process/idle transitions
and interrupt entry/exit transitions.  It is presumed that userspace
upcalls do not happen in the idle loop or from usermode execution
(though usermode might do a system call that results in an upcall).
The counter is hard-reset on each process/idle transition, which
avoids the interrupt entry/exit error from accumulating.  Overflow
is avoided by the 64-bitness of the ->dyntick_nesting counter.

This commit also adds warnings if a non-idle task asks RCU to enter
idle state (and these checks will need some adjustment before applying
Frederic's OS-jitter patches (http://lkml.org/lkml/2011/10/7/246).
In addition, validation of ->dynticks and ->dynticks_nesting is added.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-12-11 10:31:24 -08:00
Andrew Vagin
b781a602ac events, sched: Add tracepoint for accounting blocked time
This tracepoint shows how long a task is sleeping in uninterruptible state.

E.g. it may show how long and where a mutex is waited for.

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1322471015-107825-8-git-send-email-avagin@openvz.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06 08:51:23 +01:00
Mark Brown
bc7ee55633 regmap: Add trace event for successful cache reads
Currently we only trace physical reads, there's no instrumentation if
the read is satisfied from cache.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-11-30 20:51:09 +00:00
Linus Torvalds
32aaeffbd4 Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include <linux/module.h>
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include <linux/module.h>
  net: sch_generic remove redundant use of <linux/module.h>
  net: inet_timewait_sock doesnt need <linux/module.h>
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h
2011-11-06 19:44:47 -08:00
Linus Torvalds
208bca0860 Merge branch 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux
* 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: Add a 'reason' to wb_writeback_work
  writeback: send work item to queue_io, move_expired_inodes
  writeback: trace event balance_dirty_pages
  writeback: trace event bdi_dirty_ratelimit
  writeback: fix ppc compile warnings on do_div(long long, unsigned long)
  writeback: per-bdi background threshold
  writeback: dirty position control - bdi reserve area
  writeback: control dirty pause time
  writeback: limit max dirty pause time
  writeback: IO-less balance_dirty_pages()
  writeback: per task dirty rate limit
  writeback: stabilize bdi->dirty_ratelimit
  writeback: dirty rate control
  writeback: add bg_threshold parameter to __bdi_update_bandwidth()
  writeback: dirty position control
  writeback: account per-bdi accumulated dirtied pages
2011-11-06 19:02:23 -08:00
Linus Torvalds
f1f8935a5c Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (97 commits)
  jbd2: Unify log messages in jbd2 code
  jbd/jbd2: validate sb->s_first in journal_get_superblock()
  ext4: let ext4_ext_rm_leaf work with EXT_DEBUG defined
  ext4: fix a syntax error in ext4_ext_insert_extent when debugging enabled
  ext4: fix a typo in struct ext4_allocation_context
  ext4: Don't normalize an falloc request if it can fit in 1 extent.
  ext4: remove comments about extent mount option in ext4_new_inode()
  ext4: let ext4_discard_partial_buffers handle unaligned range correctly
  ext4: return ENOMEM if find_or_create_pages fails
  ext4: move vars to local scope in ext4_discard_partial_page_buffers_no_lock()
  ext4: Create helper function for EXT4_IO_END_UNWRITTEN and i_aiodio_unwritten
  ext4: optimize locking for end_io extent conversion
  ext4: remove unnecessary call to waitqueue_active()
  ext4: Use correct locking for ext4_end_io_nolock()
  ext4: fix race in xattr block allocation path
  ext4: trace punch_hole correctly in ext4_ext_map_blocks
  ext4: clean up AGGRESSIVE_TEST code
  ext4: move variables to their scope
  ext4: fix quota accounting during migration
  ext4: migrate cleanup
  ...
2011-11-02 10:06:20 -07:00
Minchan Kim
4356f21d09 mm: change isolate mode from #define to bitwise type
Change ISOLATE_XXX macro with bitwise isolate_mode_t type.  Normally,
macro isn't recommended as it's type-unsafe and making debugging harder as
symbol cannot be passed throught to the debugger.

Quote from Johannes
" Hmm, it would probably be cleaner to fully convert the isolation mode
into independent flags.  INACTIVE, ACTIVE, BOTH is currently a
tri-state among flags, which is a bit ugly."

This patch moves isolate mode from swap.h to mmzone.h by memcontrol.h

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31 17:30:44 -07:00
Paul Gortmaker
67b84999b1 Revert "tracing: Include module.h in define_trace.h"
This reverts commit 3a9f987b31.

With all the files that are real modules now having module.h
explicitly called out for inclusion, and no reliance on any
implicit presence of module.h assumed, we should no longer
need this workaround.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:32:35 -04:00
Paul Gortmaker
de47725421 include: replace linux/module.h with "struct module" wherever possible
The <linux/module.h> pretty much brings in the kitchen sink along
with it, so it should be avoided wherever reasonably possible in
terms of being included from other commonly used <linux/something.h>
files, as it results in a measureable increase on compile times.

The worst culprit was probably device.h since it is used everywhere.
This file also had an implicit dependency/usage of mutex.h which was
masked by module.h, and is also fixed here at the same time.

There are over a dozen other headers that simply declare the
struct instead of pulling in the whole file, so follow their lead
and simply make it a few more.

Most of the implicit dependencies on module.h being present by
these headers pulling it in have been now weeded out, so we can
finally make this change with hopefully minimal breakage.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:32:32 -04:00
Curt Wohlgemuth
0e175a1835 writeback: Add a 'reason' to wb_writeback_work
This creates a new 'reason' field in a wb_writeback_work
structure, which unambiguously identifies who initiates
writeback activity.  A 'wb_reason' enumeration has been
added to writeback.h, to enumerate the possible reasons.

The 'writeback_work_class' and tracepoint event class and
'writeback_queue_io' tracepoints are updated to include the
symbolic 'reason' in all trace events.

And the 'writeback_inodes_sbXXX' family of routines has had
a wb_stats parameter added to them, so callers can specify
why writeback is being started.

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-31 00:33:36 +08:00
Curt Wohlgemuth
ad4e38dd6a writeback: send work item to queue_io, move_expired_inodes
Instead of sending ->older_than_this to queue_io() and
move_expired_inodes(), send the entire wb_writeback_work
structure.  There are other fields of a work item that are
useful in these routines and in tracepoints.

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-31 00:33:27 +08:00
Wu Fengguang
ece13ac31b writeback: trace event balance_dirty_pages
Useful for analyzing the dynamics of the throttling algorithms and
debugging user reported problems.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-31 00:29:38 +08:00
Wu Fengguang
b48c104d22 writeback: trace event bdi_dirty_ratelimit
It helps understand how various throttle bandwidths are updated.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-31 00:29:21 +08:00
Linus Torvalds
68d99b2c8e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (549 commits)
  ALSA: hda - Fix ADC input-amp handling for Cx20549 codec
  ALSA: hda - Keep EAPD turned on for old Conexant chips
  ALSA: hda/realtek - Fix missing volume controls with ALC260
  ASoC: wm8940: Properly set codec->dapm.bias_level
  ALSA: hda - Fix pin-config for ASUS W90V
  ALSA: hda - Fix surround/CLFE headphone and speaker pins order
  ALSA: hda - Fix typo
  ALSA: Update the sound git tree URL
  ALSA: HDA: Add new revision for ALC662
  ASoC: max98095: Convert codec->hw_write to snd_soc_write
  ASoC: keep pointer to resource so it can be freed
  ASoC: sgtl5000: Fix wrong mask in some snd_soc_update_bits calls
  ASoC: wm8996: Fix wrong mask for setting WM8996_AIF_CLOCKING_2
  ASoC: da7210: Add support for line out and DAC
  ASoC: da7210: Add support for DAPM
  ALSA: hda/realtek - Fix DAC assignments of multiple speakers
  ASoC: Use SGTL5000_LINREG_VDDD_MASK instead of hardcoded mask value
  ASoC: Set sgtl5000->ldo in ldo_regulator_register
  ASoC: wm8996: Use SND_SOC_DAPM_AIF_OUT for AIF2 Capture
  ASoC: wm8994: Use SND_SOC_DAPM_AIF_OUT for AIF3 Capture
  ...
2011-10-28 14:25:01 -07:00
Eric Gouriou
6f91bc5fda ext4: optimize ext4_ext_convert_to_initialized()
This patch introduces a fast path in ext4_ext_convert_to_initialized()
for the case when the conversion can be performed by transferring
the newly initialized blocks from the uninitialized extent into
an adjacent initialized extent. Doing so removes the expensive
invocations of memmove() which occur during extent insertion and
the subsequent merge.

In practice this should be the common case for clients performing
append writes into files pre-allocated via
fallocate(FALLOC_FL_KEEP_SIZE). In such a workload performed via
direct IO and when using a suboptimal implementation of memmove()
(x86_64 prior to the 2.6.39 rewrite), this patch reduces kernel CPU
consumption by 32%.

Two new trace points are added to ext4_ext_convert_to_initialized()
to offer visibility into its operations. No exit trace point has
been added due to the multiplicity of return points. This can be
revisited once the upstream cleanup is backported.

Signed-off-by: Eric Gouriou <egouriou@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-27 11:43:23 -04:00
Linus Torvalds
8a4a8918ed Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
  llist: Add back llist_add_batch() and llist_del_first() prototypes
  sched: Don't use tasklist_lock for debug prints
  sched: Warn on rt throttling
  sched: Unify the ->cpus_allowed mask copy
  sched: Wrap scheduler p->cpus_allowed access
  sched: Request for idle balance during nohz idle load balance
  sched: Use resched IPI to kick off the nohz idle balance
  sched: Fix idle_cpu()
  llist: Remove cpu_relax() usage in cmpxchg loops
  sched: Convert to struct llist
  llist: Add llist_next()
  irq_work: Use llist in the struct irq_work logic
  llist: Return whether list is empty before adding in llist_add()
  llist: Move cpu_relax() to after the cmpxchg()
  llist: Remove the platform-dependent NMI checks
  llist: Make some llist functions inline
  sched, tracing: Show PREEMPT_ACTIVE state in trace_sched_switch
  sched: Remove redundant test in check_preempt_tick()
  sched: Add documentation for bandwidth control
  sched: Return unused runtime on group dequeue
  ...
2011-10-26 17:08:43 +02:00
Linus Torvalds
7115e3fcf4 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (121 commits)
  perf symbols: Increase symbol KSYM_NAME_LEN size
  perf hists browser: Refuse 'a' hotkey on non symbolic views
  perf ui browser: Use libslang to read keys
  perf tools: Fix tracing info recording
  perf hists browser: Elide DSO column when it is set to just one DSO, ditto for threads
  perf hists: Don't consider filtered entries when calculating column widths
  perf hists: Don't decay total_period for filtered entries
  perf hists browser: Honour symbol_conf.show_{nr_samples,total_period}
  perf hists browser: Do not exit on tab key with single event
  perf annotate browser: Don't change selection line when returning from callq
  perf tools: handle endianness of feature bitmap
  perf tools: Add prelink suggestion to dso update message
  perf script: Fix unknown feature comment
  perf hists browser: Apply the dso and thread filters when merging new batches
  perf hists: Move the dso and thread filters from hist_browser
  perf ui browser: Honour the xterm colors
  perf top tui: Give color hints just on the percentage, like on --stdio
  perf ui browser: Make the colors configurable and change the defaults
  perf tui: Remove unneeded call to newtCls on startup
  perf hists: Don't format the percentage on hist_entry__snprintf
  ...

Fix up conflicts in arch/x86/kernel/kprobes.c manually.

Ingo's tree did the insane "add volatile to const array", which just
doesn't make sense ("volatile const"?).  But we could remove the const
*and* make the array volatile to make doubly sure that gcc doesn't
optimize it away..

Also fix up kernel/trace/ring_buffer.c non-data-conflicts manually: the
reader_lock has been turned into a raw lock by the core locking merge,
and there was a new user of it introduced in this perf core merge.  Make
sure that new use also uses the raw accessor functions.
2011-10-26 17:03:38 +02:00
Linus Torvalds
19b4a8d520 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
  rcu: Move propagation of ->completed from rcu_start_gp() to rcu_report_qs_rsp()
  rcu: Remove rcu_needs_cpu_flush() to avoid false quiescent states
  rcu: Wire up RCU_BOOST_PRIO for rcutree
  rcu: Make rcu_torture_boost() exit loops at end of test
  rcu: Make rcu_torture_fqs() exit loops at end of test
  rcu: Permit rt_mutex_unlock() with irqs disabled
  rcu: Avoid having just-onlined CPU resched itself when RCU is idle
  rcu: Suppress NMI backtraces when stall ends before dump
  rcu: Prohibit grace periods during early boot
  rcu: Simplify unboosting checks
  rcu: Prevent early boot set_need_resched() from __rcu_pending()
  rcu: Dump local stack if cannot dump all CPUs' stacks
  rcu: Move __rcu_read_unlock()'s barrier() within if-statement
  rcu: Improve rcu_assign_pointer() and RCU_INIT_POINTER() documentation
  rcu: Make rcu_assign_pointer() unconditionally insert a memory barrier
  rcu: Make rcu_implicit_dynticks_qs() locals be correct size
  rcu: Eliminate in_irq() checks in rcu_enter_nohz()
  nohz: Remove nohz_cpu_mask
  rcu: Document interpretation of RCU-lockdep splats
  rcu: Allow rcutorture's stat_interval parameter to be changed at runtime
  ...
2011-10-26 16:26:53 +02:00
Linus Torvalds
e33bae14fd Merge branch 'for-linus' of git://github.com/ericvh/linux
* 'for-linus' of git://github.com/ericvh/linux:
  9p: fix 9p.txt to advertise msize instead of maxdata
  net/9p: Convert net/9p protocol dumps to tracepoints
  fs/9p: change an int to unsigned int
  fs/9p: Cleanup option parsing in 9p
  9p: move dereference after NULL check
  fs/9p: inode file operation is properly initialized init_special_inode
  fs/9p: Update zero-copy implementation in 9p
2011-10-26 14:20:53 +02:00
Linus Torvalds
7e0bb71e75 Merge branch 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
* 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (63 commits)
  PM / Clocks: Remove redundant NULL checks before kfree()
  PM / Documentation: Update docs about suspend and CPU hotplug
  ACPI / PM: Add Sony VGN-FW21E to nonvs blacklist.
  ARM: mach-shmobile: sh7372 A4R support (v4)
  ARM: mach-shmobile: sh7372 A3SP support (v4)
  PM / Sleep: Mark devices involved in wakeup signaling during suspend
  PM / Hibernate: Improve performance of LZO/plain hibernation, checksum image
  PM / Hibernate: Do not initialize static and extern variables to 0
  PM / Freezer: Make fake_signal_wake_up() wake TASK_KILLABLE tasks too
  PM / Hibernate: Add resumedelay kernel param in addition to resumewait
  MAINTAINERS: Update linux-pm list address
  PM / ACPI: Blacklist Vaio VGN-FW520F machine known to require acpi_sleep=nonvs
  PM / ACPI: Blacklist Sony Vaio known to require acpi_sleep=nonvs
  PM / Hibernate: Add resumewait param to support MMC-like devices as resume file
  PM / Hibernate: Fix typo in a kerneldoc comment
  PM / Hibernate: Freeze kernel threads after preallocating memory
  PM: Update the policy on default wakeup settings
  PM / VT: Cleanup #if defined uglyness and fix compile error
  PM / Suspend: Off by one in pm_suspend()
  PM / Hibernate: Include storage keys in hibernation image on s390
  ...
2011-10-25 15:18:39 +02:00
Linus Torvalds
4e7e2a2008 Merge branch 'for-linus' of git://opensource.wolfsonmicro.com/regmap
* 'for-linus' of git://opensource.wolfsonmicro.com/regmap: (62 commits)
  mfd: Enable rbtree cache for wm831x devices
  regmap: Support some block operations on cached devices
  regmap: Allow caches for devices with no defaults
  regmap: Ensure rbtree syncs registers set to zero properly
  regmap: Allow rbtree to cache zero default values
  regmap: Warn on raw I/O as well as bulk reads that bypass cache
  regmap: Return a sensible error code if we fail to read the cache
  regmap: Use bsearch() to search the register defaults
  regmap: Fix doc comment
  regmap: Optimize the lookup path to use binary search
  regmap: Ensure we scream if we enable cache bypass/only at the same time
  regmap: Implement regcache_cache_bypass helper function
  regmap: Save/restore the bypass state upon syncing
  regmap: Lock the sync path, ensure we use the lockless _regmap_write()
  regmap: Fix apostrophe usage
  regmap: Make _regmap_write() global
  regmap: Fix lock used for regcache_cache_only()
  regmap: Grab the lock in regcache_cache_only()
  regmap: Modify map->cache_bypass directly
  regmap: Fix regcache_sync generic implementation
  ...
2011-10-25 13:57:45 +02:00
Aneesh Kumar K.V
348b59012e net/9p: Convert net/9p protocol dumps to tracepoints
This helps in more control over debugging.
root@qemu-img-64:~# ls /pass/123
ls: cannot access /pass/123: No such file or directory
root@qemu-img-64:~# cat /sys/kernel/debug/tracing/trace
# tracer: nop
#
#           TASK-PID    CPU#    TIMESTAMP  FUNCTION
#              | |       |          |         |
              ls-1536  [001]    70.928584: 9p_protocol_dump: clnt 18446612132784021504 P9_TWALK(tag = 1)
000: 16 00 00 00 6e 01 00 01 00 00 00 02 00 00 00 01
010: 00 03 00 31 32 33 00 00 00 ff ff ff ff 00 00 00

              ls-1536  [001]    70.928587: <stack trace>
 => trace_9p_protocol_dump
 => p9pdu_finalize
 => p9_client_rpc
 => p9_client_walk
 => v9fs_vfs_lookup
 => d_alloc_and_lookup
 => walk_component
 => path_lookupat
              ls-1536  [000]    70.929696: 9p_protocol_dump: clnt 18446612132784021504 P9_RLERROR(tag = 1)
000: 0b 00 00 00 07 01 00 02 00 00 00 4e 03 00 02 00
010: 00 00 00 00 03 00 02 00 00 00 00 00 ff 43 00 00

              ls-1536  [000]    70.929697: <stack trace>
 => trace_9p_protocol_dump
 => p9_client_rpc
 => p9_client_walk
 => v9fs_vfs_lookup
 => d_alloc_and_lookup
 => walk_component
 => path_lookupat
 => do_path_lookup

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-10-24 11:13:12 -05:00
Rafael J. Wysocki
d727b60659 Merge branch 'pm-runtime' into pm-for-linus
* pm-runtime:
  PM / Tracing: build rpm-traces.c only if CONFIG_PM_RUNTIME is set
  PM / Runtime: Replace dev_dbg() with trace_rpm_*()
  PM / Runtime: Introduce trace points for tracing rpm_* functions
  PM / Runtime: Don't run callbacks under lock for power.irq_safe set
  USB: Add wakeup info to debugging messages
  PM / Runtime: pm_runtime_idle() can be called in atomic context
  PM / Runtime: Add macro to test for runtime PM events
  PM / Runtime: Add might_sleep() to runtime PM functions
2011-10-07 23:16:55 +02:00
Ingo Molnar
9d01402023 Merge commit 'v3.1-rc9' into perf/core
Merge reason: pick up latest fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-06 12:49:21 +02:00
Ingo Molnar
22f92bacbe Merge branch 'linus' into sched/core
Merge reason: pick up the latest fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-04 11:09:08 +02:00
Andrew Vagin
92e51938f5 perf: Fix counter of ftrace events
Each event adds some points to its counters. By default it adds 1,
and a number of points may be transmited in event's parameters.

E.g. sched:sched_stat_runtime adds how long process has been running.

But this functionality was broken by v2.6.31-rc5-392-gf413cdb
and now the event's parameters doesn't affect on a number of points.

TP_perf_assign isn't defined, so __perf_count(c) isn't executed and
__count is always equal to 1.

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1317052535-1765247-2-git-send-email-avagin@openvz.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-04 11:07:54 +02:00
Wu Fengguang
143dfe8611 writeback: IO-less balance_dirty_pages()
As proposed by Chris, Dave and Jan, don't start foreground writeback IO
inside balance_dirty_pages(). Instead, simply let it idle sleep for some
time to throttle the dirtying task. In the mean while, kick off the
per-bdi flusher thread to do background writeback IO.

RATIONALS
=========

- disk seeks on concurrent writeback of multiple inodes (Dave Chinner)

  If every thread doing writes and being throttled start foreground
  writeback, it leads to N IO submitters from at least N different
  inodes at the same time, end up with N different sets of IO being
  issued with potentially zero locality to each other, resulting in
  much lower elevator sort/merge efficiency and hence we seek the disk
  all over the place to service the different sets of IO.
  OTOH, if there is only one submission thread, it doesn't jump between
  inodes in the same way when congestion clears - it keeps writing to
  the same inode, resulting in large related chunks of sequential IOs
  being issued to the disk. This is more efficient than the above
  foreground writeback because the elevator works better and the disk
  seeks less.

- lock contention and cache bouncing on concurrent IO submitters (Dave Chinner)

  With this patchset, the fs_mark benchmark on a 12-drive software RAID0 goes
  from CPU bound to IO bound, freeing "3-4 CPUs worth of spinlock contention".

  * "CPU usage has dropped by ~55%", "it certainly appears that most of
    the CPU time saving comes from the removal of contention on the
    inode_wb_list_lock" (IMHO at least 10% comes from the reduction of
    cacheline bouncing, because the new code is able to call much less
    frequently into balance_dirty_pages() and hence access the global
    page states)

  * the user space "App overhead" is reduced by 20%, by avoiding the
    cacheline pollution by the complex writeback code path

  * "for a ~5% throughput reduction", "the number of write IOs have
    dropped by ~25%", and the elapsed time reduced from 41:42.17 to
    40:53.23.

  * On a simple test of 100 dd, it reduces the CPU %system time from 30% to 3%,
    and improves IO throughput from 38MB/s to 42MB/s.

- IO size too small for fast arrays and too large for slow USB sticks

  The write_chunk used by current balance_dirty_pages() cannot be
  directly set to some large value (eg. 128MB) for better IO efficiency.
  Because it could lead to more than 1 second user perceivable stalls.
  Even the current 4MB write size may be too large for slow USB sticks.
  The fact that balance_dirty_pages() starts IO on itself couples the
  IO size to wait time, which makes it hard to do suitable IO size while
  keeping the wait time under control.

  Now it's possible to increase writeback chunk size proportional to the
  disk bandwidth. In a simple test of 50 dd's on XFS, 1-HDD, 3GB ram,
  the larger writeback size dramatically reduces the seek count to 1/10
  (far beyond my expectation) and improves the write throughput by 24%.

- long block time in balance_dirty_pages() hurts desktop responsiveness

  Many of us may have the experience: it often takes a couple of seconds
  or even long time to stop a heavy writing dd/cp/tar command with
  Ctrl-C or "kill -9".

- IO pipeline broken by bumpy write() progress

  There are a broad class of "loop {read(buf); write(buf);}" applications
  whose read() pipeline will be under-utilized or even come to a stop if
  the write()s have long latencies _or_ don't progress in a constant rate.
  The current threshold based throttling inherently transfers the large
  low level IO completion fluctuations to bumpy application write()s,
  and further deteriorates with increasing number of dirtiers and/or bdi's.

  For example, when doing 50 dd's + 1 remote rsync to an XFS partition,
  the rsync progresses very bumpy in legacy kernel, and throughput is
  improved by 67% by this patchset. (plus the larger write chunk size,
  it will be 93% speedup).

  The new rate based throttling can support 1000+ dd's with excellent
  smoothness, low latency and low overheads.

For the above reasons, it's much better to do IO-less and low latency
pauses in balance_dirty_pages().

Jan Kara, Dave Chinner and me explored the scheme to let
balance_dirty_pages() wait for enough writeback IO completions to
safeguard the dirty limit. However it's found to have two problems:

- in large NUMA systems, the per-cpu counters may have big accounting
  errors, leading to big throttle wait time and jitters.

- NFS may kill large amount of unstable pages with one single COMMIT.
  Because NFS server serves COMMIT with expensive fsync() IOs, it is
  desirable to delay and reduce the number of COMMITs. So it's not
  likely to optimize away such kind of bursty IO completions, and the
  resulted large (and tiny) stall times in IO completion based throttling.

So here is a pause time oriented approach, which tries to control the
pause time in each balance_dirty_pages() invocations, by controlling
the number of pages dirtied before calling balance_dirty_pages(), for
smooth and efficient dirty throttling:

- avoid useless (eg. zero pause time) balance_dirty_pages() calls
- avoid too small pause time (less than   4ms, which burns CPU power)
- avoid too large pause time (more than 200ms, which hurts responsiveness)
- avoid big fluctuations of pause times

It can control pause times at will. The default policy (in a followup
patch) will be to do ~10ms pauses in 1-dd case, and increase to ~100ms
in 1000-dd case.

BEHAVIOR CHANGE
===============

(1) dirty threshold

Users will notice that the applications will get throttled once crossing
the global (background + dirty)/2=15% threshold, and then balanced around
17.5%. Before patch, the behavior is to just throttle it at 20% dirtyable
memory in 1-dd case.

Since the task will be soft throttled earlier than before, it may be
perceived by end users as performance "slow down" if his application
happens to dirty more than 15% dirtyable memory.

(2) smoothness/responsiveness

Users will notice a more responsive system during heavy writeback.
"killall dd" will take effect instantly.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-03 21:08:57 +08:00
Ingo Molnar
048b718029 Merge branch 'rcu/next' of git://github.com/paulmckrcu/linux into core/rcu 2011-10-01 14:21:36 +02:00
Paul E. McKenney
d4c08f2ac3 rcu: Add grace-period, quiescent-state, and call_rcu trace events
Add trace events to record grace-period start and end, quiescent states,
CPUs noticing grace-period start and end, grace-period initialization,
call_rcu() invocation, tasks blocking in RCU read-side critical sections,
tasks exiting those same critical sections, force_quiescent_state()
detection of dyntick-idle and offline CPUs, CPUs entering and leaving
dyntick-idle mode (except from NMIs), CPUs coming online and going
offline, and CPUs being kicked for staying in dyntick-idle mode for too
long (as in many weeks, even on 32-bit systems).

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

rcu: Add the rcu flavor to callback trace events

The earlier trace events for registering RCU callbacks and for invoking
them did not include the RCU flavor (rcu_bh, rcu_preempt, or rcu_sched).
This commit adds the RCU flavor to those trace events.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28 21:38:21 -07:00
Paul E. McKenney
385680a948 rcu: Add event-trace markers to TREE_RCU kthreads
Add event-trace markers to TREE_RCU kthreads to allow including these
kthread's CPU time in the utilization calculations.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28 21:38:19 -07:00
Paul E. McKenney
72fe701b70 rcu: Add RCU type to callback-invocation tracing
Add a string to the rcu_batch_start() and rcu_batch_end() trace
messages that indicates the RCU type ("rcu_sched", "rcu_bh", or
"rcu_preempt").  The trace messages for the actual invocations
themselves are not marked, as it should be clear from the
rcu_batch_start() and rcu_batch_end() events before and after.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28 21:38:15 -07:00
Paul E. McKenney
300df91ca9 rcu: Event-trace markers for computing RCU CPU utilization
This commit adds the trace_rcu_utilization() marker that is to be
used to allow postprocessing scripts compute RCU's CPU utilization,
give or take event-trace overhead.  Note that we do not include RCU's
dyntick-idle interface because event tracing requires RCU protection,
which is not available in dyntick-idle mode.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28 21:38:13 -07:00
Paul E. McKenney
29c00b4a1d rcu: Add event-tracing for RCU callback invocation
There was recently some controversy about the overhead of invoking RCU
callbacks.  Add TRACE_EVENT()s to obtain fine-grained timings for the
start and stop of a batch of callbacks and also for each callback invoked.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28 21:38:12 -07:00
Ming Lei
53b615ccca PM / Runtime: Introduce trace points for tracing rpm_* functions
This patch introduces 3 trace points to prepare for tracing
rpm_idle/rpm_suspend/rpm_resume functions, so we can use these
trace points to replace the current dev_dbg().

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-09-27 22:53:27 +02:00
Peter Zijlstra
557ab42542 sched, tracing: Show PREEMPT_ACTIVE state in trace_sched_switch
We had need to see the difference between scheduling a runnable task and
a runnable task being involuntarily preempted.

No app should rely on the old string output (the binary
trace event record format is not changed).

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1316164603.10174.11.camel@twins
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-09-26 13:25:54 +02:00
Mark Brown
e56235e099 ASoC: Add another DAPM stat for neighbour checks
The number of times we look at a potentially connected neighbour is just
as important as the number of times we actually recurse into looking at
that neighbour so also collect that statistic.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-22 17:24:40 +01:00
Mark Brown
de02d0786d ASoC: Trace and collect statistics for DAPM graph walking
One of the longest standing areas for improvement in ASoC has been the
DAPM algorithm - it repeats the same checks many times whenever it is run
and makes no effort to limit the areas of the graph it checks meaning we
do an awful lot of walks over the full graph. This has never mattered too
much as the size of the graph has generally been small in relation to the
size of the devices supported and the speed of CPUs but it is annoying.

In preparation for work on improving this insert a trace point after the
graph walk has been done. This gives us specific timing information for
the walk, and in order to give quantifiable (non-benchmark) numbers also
count every time we check a link or check the power for a widget and report
those numbers. Substantial changes in the algorithm may require tweaks to
the stats but they should be useful for simpler things.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-21 14:53:44 +01:00
Dimitris Papastamos
5936008901 regmap: Add the regcache_sync trace event
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-19 19:06:34 +01:00
Aditya Kali
d8990240d8 ext4: add some tracepoints in ext4/extents.c
This patch adds some tracepoints in ext4/extents.c and updates a tracepoint in
ext4/inode.c.

Tested: Built and ran the kernel and verified that these tracepoints work.
Also ran xfstests.

Signed-off-by: Aditya Kali <adityakali@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-09 19:18:51 -04:00
Wu Fengguang
c8ad620638 writeback: show raw dirtied_when in trace writeback_single_inode
Save inode->dirtied_when in the raw trace output for reliable scripting,
and to also show in formatted output the relative age in seconds for
easy human reading.

CC: Jan Kara <jack@suse.cz>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-08-31 08:48:15 +08:00
Linus Torvalds
5ccc38740a Merge branch 'for-linus' of git://git.kernel.dk/linux-block
* 'for-linus' of git://git.kernel.dk/linux-block: (23 commits)
  Revert "cfq: Remove special treatment for metadata rqs."
  block: fix flush machinery for stacking drivers with differring flush flags
  block: improve rq_affinity placement
  blktrace: add FLUSH/FUA support
  Move some REQ flags to the common bio/request area
  allow blk_flush_policy to return REQ_FSEQ_DATA independent of *FLUSH
  xen/blkback: Make description more obvious.
  cfq-iosched: Add documentation about idling
  block: Make rq_affinity = 1 work as expected
  block: swim3: fix unterminated of_device_id table
  block/genhd.c: remove useless cast in diskstats_show()
  drivers/cdrom/cdrom.c: relax check on dvd manufacturer value
  drivers/block/drbd/drbd_nl.c: use bitmap_parse instead of __bitmap_parse
  bsg-lib: add module.h include
  cfq-iosched: Reduce linked group count upon group destruction
  blk-throttle: correctly determine sync bio
  loop: fix deadlock when sysfs and LOOP_CLR_FD race against each other
  loop: add BLK_DEV_LOOP_MIN_COUNT=%i to allow distros 0 pre-allocated loop devices
  loop: add management interface for on-demand device allocation
  loop: replace linked list of allocated devices with an idr index
  ...
2011-08-19 10:47:07 -07:00
Namhyung Kim
c09c47caed blktrace: add FLUSH/FUA support
Add FLUSH/FUA support to blktrace. As FLUSH precedes WRITE and/or
FUA follows WRITE, use the same 'F' flag for both cases and
distinguish them by their (relative) position. The end results
look like (other flags might be shown also):

 - WRITE:            W
 - WRITE_FLUSH:      FW
 - WRITE_FUA:        WF
 - WRITE_FLUSH_FUA:  FWF

Note that we reuse TC_BARRIER due to lack of bit space of act_mask
so that the older versions of blktrace tools will report flush
requests as barriers from now on.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-08-11 10:36:05 +02:00
Mark Brown
3d9ead7c06 regmap: Use int rather than size_t for lengths when logging blocks
x86_64 warns as size_t is not an int.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
2011-08-10 00:26:33 +09:00
Mark Brown
fb2736bbae regmap: Add basic tracepoints
Trace single register reads and writes, plus start/stop tracepoints for
the actual I/O to see where we're spending time. This makes it easy to
have always on logging without overwhelming the logs and also lets us take
advantage of all the context and time information that the trace subsystem
collects for us.

We don't currently trace register values for bulk operations as this would
add complexity and overhead parsing the cooked data that's being worked
with.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-08-08 15:56:16 +09:00
Linus Torvalds
60ad446682 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (60 commits)
  ext4: prevent memory leaks from ext4_mb_init_backend() on error path
  ext4: use EXT4_BAD_INO for buddy cache to avoid colliding with valid inode #
  ext4: use ext4_msg() instead of printk in mballoc
  ext4: use ext4_kvzalloc()/ext4_kvmalloc() for s_group_desc and s_group_info
  ext4: introduce ext4_kvmalloc(), ext4_kzalloc(), and ext4_kvfree()
  ext4: use the correct error exit path in ext4_init_inode_table()
  ext4: add missing kfree() on error return path in add_new_gdb()
  ext4: change umode_t in tracepoint headers to be an explicit __u16
  ext4: fix races in ext4_sync_parent()
  ext4: Fix overflow caused by missing cast in ext4_fallocate()
  ext4: add action of moving index in ext4_ext_rm_idx for Punch Hole
  ext4: simplify parameters of reserve_backup_gdb()
  ext4: simplify parameters of add_new_gdb()
  ext4: remove lock_buffer in bclean() and setup_new_group_blocks()
  ext4: simplify journal handling in setup_new_group_blocks()
  ext4: let setup_new_group_blocks() set multiple bits at a time
  ext4: fix a typo in ext4_group_extend()
  ext4: let ext4_group_add_blocks() handle 0 blocks quickly
  ext4: let ext4_group_add_blocks() return an error code
  ext4: rename ext4_add_groupblocks() to ext4_group_add_blocks()
  ...

Fix up conflict in fs/ext4/inode.c: commit aacfc19c62 ("fs: simplify
the blockdev_direct_IO prototype") had changed the ext4_ind_direct_IO()
function for the new simplified calling convention, while commit
dae1e52cb1 ("ext4: move ext4_ind_* functions from inode.c to
indirect.c") moved the function to another file.
2011-08-01 13:56:03 -10:00
Theodore Ts'o
59be8e7280 ext4: change umode_t in tracepoint headers to be an explicit __u16
As requested by Al Viro, since umode_t may be changing to a u32 for
some architectures.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
2011-07-30 12:38:46 -04:00
Linus Torvalds
b993fdbc7f Merge branch 'upstream/xen-tracing2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
* 'upstream/xen-tracing2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen/tracing: fix compile errors when tracing is disabled.
2011-07-29 23:33:40 -07:00
Linus Torvalds
2ac232f37f Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
  jbd: change the field "b_cow_tid" of struct journal_head from type unsigned to tid_t
  ext3.txt: update the links in the section "useful links" to the latest ones
  ext3: Fix data corruption in inodes with journalled data
  ext2: check xattr name_len before acquiring xattr_sem in ext2_xattr_get
  ext3: Fix compilation with -DDX_DEBUG
  quota: Remove unused declaration
  jbd: Use WRITE_SYNC in journal checkpoint.
  jbd: Fix oops in journal_remove_journal_head()
  ext3: Return -EINVAL when start is beyond the end of fs in ext3_trim_fs()
  ext3/ioctl.c: silence sparse warnings about different address spaces
  ext3/ext4 Documentation: remove bh/nobh since it has been deprecated
  ext3: Improve truncate error handling
  ext3: use proper little-endian bitops
  ext2: include fs.h into ext2_fs.h
  ext3: Fix oops in ext3_try_to_allocate_with_rsv()
  jbd: fix a bug of leaking jh->b_jcount
  jbd: remove dependency on __GFP_NOFAIL
  ext3: Convert ext3 to new truncate calling convention
  jbd: Add fixed tracepoints
  ext3: Add fixed tracepoints

Resolve conflicts in fs/ext3/fsync.c due to fsync locking push-down and
new fixed tracepoints.
2011-07-26 11:34:40 -07:00
Linus Torvalds
f01ef569cd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback: (27 commits)
  mm: properly reflect task dirty limits in dirty_exceeded logic
  writeback: don't busy retry writeback on new/freeing inodes
  writeback: scale IO chunk size up to half device bandwidth
  writeback: trace global_dirty_state
  writeback: introduce max-pause and pass-good dirty limits
  writeback: introduce smoothed global dirty limit
  writeback: consolidate variable names in balance_dirty_pages()
  writeback: show bdi write bandwidth in debugfs
  writeback: bdi write bandwidth estimation
  writeback: account per-bdi accumulated written pages
  writeback: make writeback_control.nr_to_write straight
  writeback: skip tmpfs early in balance_dirty_pages_ratelimited_nr()
  writeback: trace event writeback_queue_io
  writeback: trace event writeback_single_inode
  writeback: remove .nonblocking and .encountered_congestion
  writeback: remove writeback_control.more_io
  writeback: skip balance_dirty_pages() for in-memory fs
  writeback: add bdi_dirty_limit() kernel-doc
  writeback: avoid extra sync work at enqueue time
  writeback: elevate queue_io() into wb_writeback()
  ...

Fix up trivial conflicts in fs/fs-writeback.c and mm/filemap.c
2011-07-26 10:39:54 -07:00
Jeremy Fitzhardinge
b3c4b98250 xen/tracing: fix compile errors when tracing is disabled.
When CONFIG_FUNCTION_TRACER is disabled, compilation fails as follows:
  CC      arch/x86/xen/setup.o
In file included from arch/x86/include/asm/xen/hypercall.h:42,
                 from arch/x86/xen/setup.c:19:
include/trace/events/xen.h:31: warning: 'struct multicall_entry' declared inside parameter list
include/trace/events/xen.h:31: warning: its scope is only this definition or declaration, which is probably not what you want
include/trace/events/xen.h:31: warning: 'struct multicall_entry' declared inside parameter list
include/trace/events/xen.h:31: warning: 'struct multicall_entry' declared inside parameter list
include/trace/events/xen.h:31: warning: 'struct multicall_entry' declared inside parameter list
[...]
arch/x86/xen/trace.c:5: error: '__HYPERVISOR_set_trap_table' undeclared here (not in a function)
arch/x86/xen/trace.c:5: error: array index in initializer not of integer type
arch/x86/xen/trace.c:5: error: (near initialization for 'xen_hypercall_names')
arch/x86/xen/trace.c:6: error: '__HYPERVISOR_mmu_update' undeclared here (not in a function)
arch/x86/xen/trace.c:6: error: array index in initializer not of integer type
arch/x86/xen/trace.c:6: error: (near initialization for 'xen_hypercall_names')

Fix this by making sure struct multicall_entry has a declaration in
scope at all times, and don't bother compiling xen/trace.c when tracing
is disabled.

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-25 15:51:02 -07:00
Linus Torvalds
c61264f98c Merge branch 'upstream/xen-tracing2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
* 'upstream/xen-tracing2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen/trace: use class for multicall trace
  xen/trace: convert mmu events to use DECLARE_EVENT_CLASS()/DEFINE_EVENT()
  xen/multicall: move *idx fields to start of mc_buffer
  xen/multicall: special-case singleton hypercalls
  xen/multicalls: add unlikely around slowpath in __xen_mc_entry()
  xen/multicalls: disable MC_DEBUG
  xen/mmu: tune pgtable alloc/release
  xen/mmu: use extend_args for more mmuext updates
  xen/trace: add tlb flush tracepoints
  xen/trace: add segment desc tracing
  xen/trace: add xen_pgd_(un)pin tracepoints
  xen/trace: add ptpage alloc/release tracepoints
  xen/trace: add mmu tracepoints
  xen/trace: add multicall tracing
  xen/trace: set up tracepoint skeleton
  xen/multicalls: remove debugfs stats
  trace/xen: add skeleton for Xen trace events
2011-07-24 09:06:47 -07:00
Linus Torvalds
e498037105 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: (297 commits)
  ALSA: asihpi - Replace with snd_ctl_boolean_mono_info()
  ALSA: asihpi - HPI version 4.08
  ALSA: asihpi - Add volume mute controls
  ALSA: asihpi - Control name updates
  ALSA: asihpi - Use size_t for sizeof result
  ALSA: asihpi - Explicitly include mutex.h
  ALSA: asihpi - Add new node and message defines
  ALSA: asihpi - Make local function static
  ALSA: asihpi - Fix minor typos and spelling
  ALSA: asihpi - Remove unused structures, macros and functions
  ALSA: asihpi - Remove spurious adapter index check
  ALSA: asihpi - Revise snd_pcm_debug_name, get rid of DEBUG_NAME macro
  ALSA: asihpi - DSP code loader API now independent of OS
  ALSA: asihpi - Remove controlex structs and associated special data transfer code
  ALSA: asihpi - Increase request and response buffer sizes
  ALSA: asihpi - Give more meaningful name to hpi request message type
  ALSA: usb-audio - Add quirk for  Roland / BOSS BR-800
  ALSA: hda - Remove a superfluous argument of via_auto_init_output()
  ALSA: hda - Fix indep-HP path (de-)activation for VT1708* codecs
  ALSA: hda - Add documentation for codec-specific mixer controls
  ...
2011-07-23 10:59:37 -07:00
Linus Torvalds
bbd9d6f7fb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (107 commits)
  vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp
  isofs: Remove global fs lock
  jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory
  fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.
  mm/truncate.c: fix build for CONFIG_BLOCK not enabled
  fs:update the NOTE of the file_operations structure
  Remove dead code in dget_parent()
  AFS: Fix silly characters in a comment
  switch d_add_ci() to d_splice_alias() in "found negative" case as well
  simplify gfs2_lookup()
  jfs_lookup(): don't bother with . or ..
  get rid of useless dget_parent() in btrfs rename() and link()
  get rid of useless dget_parent() in fs/btrfs/ioctl.c
  fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
  drivers: fix up various ->llseek() implementations
  fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
  Ext4: handle SEEK_HOLE/SEEK_DATA generically
  Btrfs: implement our own ->llseek
  fs: add SEEK_HOLE and SEEK_DATA flags
  reiserfs: make reiserfs default to barrier=flush
  ...

Fix up trivial conflicts in fs/xfs/linux-2.6/xfs_super.c due to the new
shrinker callout for the inode cache, that clashed with the xfs code to
start the periodic workers later.
2011-07-22 19:02:39 -07:00
Takashi Iwai
13b137ef03 Merge branch 'topic/asoc' into for-linus 2011-07-22 08:43:19 +02:00
Dave Chinner
095760730c vmscan: add shrink_slab tracepoints
It is impossible to understand what the shrinkers are actually doing
without instrumenting the code, so add a some tracepoints to allow
insight to be gained.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:27 -04:00
Jeremy Fitzhardinge
bd9ddc875b xen/trace: use class for multicall trace
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-18 15:43:46 -07:00
Jeremy Fitzhardinge
c43ed60cbf xen/trace: convert mmu events to use DECLARE_EVENT_CLASS()/DEFINE_EVENT()
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-18 15:43:46 -07:00
Jeremy Fitzhardinge
c8eed1719a xen/trace: add tlb flush tracepoints
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-18 15:43:27 -07:00
Jeremy Fitzhardinge
ab78f7ad2c xen/trace: add segment desc tracing
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-18 15:43:27 -07:00
Jeremy Fitzhardinge
5f94fb5b8e xen/trace: add xen_pgd_(un)pin tracepoints
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-18 15:43:27 -07:00
Jeremy Fitzhardinge
c2ba050d2e xen/trace: add ptpage alloc/release tracepoints
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-18 15:43:27 -07:00
Jeremy Fitzhardinge
8470880791 xen/trace: add mmu tracepoints
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-18 15:43:27 -07:00
Jeremy Fitzhardinge
c796f213a6 xen/trace: add multicall tracing
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-18 15:43:26 -07:00
Jeremy Fitzhardinge
634355d42b trace/xen: add skeleton for Xen trace events
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-18 15:42:37 -07:00
Tao Ma
b3d4c2b10b ext4: Add new ext4 trim tracepoints
Add ext4_trim_extent and ext4_trim_all_free.

Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-11 00:01:52 -04:00
Theodore Ts'o
12706394bc ext4: add tracepoint for ext4_journal_start
This will help debug who is responsible for starting a jbd2 transaction.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-10 22:37:50 -04:00
Theodore Ts'o
4862fd6047 jbd2: remove jbd2_dev_to_name() from jbd2 tracepoints
Using function calls in TP_printk causes perf heartburn, so print the
MAJOR/MINOR device numbers instead.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-10 22:05:08 -04:00
Wu Fengguang
e1cbe23601 writeback: trace global_dirty_state
Add trace event balance_dirty_state for showing the global dirty page
counts and thresholds at each global_dirty_limits() invocation.  This
will cover the callers throttle_vm_writeout(), over_bground_thresh()
and each balance_dirty_pages() loop.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-07-09 22:09:03 -07:00
Wu Fengguang
d46db3d582 writeback: make writeback_control.nr_to_write straight
Pass struct wb_writeback_work all the way down to writeback_sb_inodes(),
and initialize the struct writeback_control there.

struct writeback_control is basically designed to control writeback of a
single file, but we keep abuse it for writing multiple files in
writeback_sb_inodes() and its callers.

It immediately clean things up, e.g. suddenly wbc.nr_to_write vs
work->nr_pages starts to make sense, and instead of saving and restoring
pages_skipped in writeback_sb_inodes it can always start with a clean
zero value.

It also makes a neat IO pattern change: large dirty files are now
written in the full 4MB writeback chunk size, rather than whatever
remained quota in wbc->nr_to_write.

Acked-by: Jan Kara <jack@suse.cz>
Proposed-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-07-09 22:09:01 -07:00
David S. Miller
e12fe68ce3 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-07-05 23:23:37 -07:00
Liam Girdwood
a82ce2ae0d ASoC: core - Add platform IO tracing
Trace platform IO just like CODEC IO.

Signed-off-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-07-05 11:08:10 -07:00
Lukas Czerner
99cb1a318c jbd: Add fixed tracepoints
This commit adds fixed tracepoint for jbd. It has been based on fixed
tracepoints for jbd2, however there are missing those for collecting
statistics, since I think that it will require more intrusive patch so I
should have its own commit, if someone decide that it is needed. Also
there are new tracepoints in __journal_drop_transaction() and
journal_update_superblock().

The list of jbd tracepoints:

jbd_checkpoint
jbd_start_commit
jbd_commit_locking
jbd_commit_flushing
jbd_commit_logging
jbd_drop_transaction
jbd_end_commit
jbd_do_submit_data
jbd_cleanup_journal_tail
jbd_update_superblock_end

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-06-25 17:29:51 +02:00
Lukas Czerner
785c4bcc0d ext3: Add fixed tracepoints
This commit adds fixed tracepoints to the ext3 code. It is based on ext4
tracepoints, however due to the differences of both file systems, there
are some tracepoints missing (those for delaloc and for multi-block
allocator) and there are some ext3 specific as well (for reservation
windows).

Here is a list:

ext3_free_inode
ext3_request_inode
ext3_allocate_inode
ext3_evict_inode
ext3_drop_inode
ext3_mark_inode_dirty
ext3_write_begin
ext3_ordered_write_end
ext3_writeback_write_end
ext3_journalled_write_end
ext3_ordered_writepage
ext3_writeback_writepage
ext3_journalled_writepage
ext3_readpage
ext3_releasepage
ext3_invalidatepage
ext3_discard_blocks
ext3_request_blocks
ext3_allocate_blocks
ext3_free_blocks
ext3_sync_file_enter
ext3_sync_file_exit
ext3_sync_fs
ext3_rsv_window_add
ext3_discard_reservation
ext3_alloc_new_reservation
ext3_reserved
ext3_forget
ext3_read_block_bitmap
ext3_direct_IO_enter
ext3_direct_IO_exit
ext3_unlink_enter
ext3_unlink_exit
ext3_truncate_enter
ext3_truncate_exit
ext3_get_blocks_enter
ext3_get_blocks_exit
ext3_load_inode

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-06-25 17:29:51 +02:00
Satoru Moriya
3847ce32ae core: add tracepoints for queueing skb to rcvbuf
This patch adds 2 tracepoints to get a status of a socket receive queue
and related parameter.

One tracepoint is added to sock_queue_rcv_skb. It records rcvbuf size
and its usage. The other tracepoint is added to __sk_mem_schedule and
it records limitations of memory for sockets and current usage.

By using these tracepoints we're able to know detailed reason why kernel
drop the packet.

Signed-off-by: Satoru Moriya <satoru.moriya@hds.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-21 16:06:10 -07:00
Satoru Moriya
296f7ea75b udp: add tracepoints for queueing skb to rcvbuf
This patch adds a tracepoint to __udp_queue_rcv_skb to get the
return value of ip_queue_rcv_skb. It indicates why kernel drops
a packet at this point.

ip_queue_rcv_skb returns following values in the packet drop case:

rcvbuf is full                 : -ENOMEM
sk_filter returns error        : -EINVAL, -EACCESS, -ENOMEM, etc.
__sk_mem_schedule returns error: -ENOBUF

Signed-off-by: Satoru Moriya <satoru.moriya@hds.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-21 16:06:10 -07:00
Linus Torvalds
890879cfa0 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  jbd2: Fix oops in jbd2_journal_remove_journal_head()
  jbd2: Remove obsolete parameters in the comments for some jbd2 functions
  ext4: fixed tracepoints cleanup
  ext4: use FIEMAP_EXTENT_LAST flag for last extent in fiemap
  ext4: Fix max file size and logical block counting of extent format file
  ext4: correct comments for ext4_free_blocks()
2011-06-21 10:22:35 -07:00
Linus Torvalds
357ed6b1a1 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: Move RCU_BOOST #ifdefs to header file
  rcu: use softirq instead of kthreads except when RCU_BOOST=y
  rcu: Use softirq to address performance regression
  rcu: Simplify curing of load woes
2011-06-19 08:56:56 -07:00
KOSAKI Motohiro
d7911ef30c vmscan: implement swap token priority aging
While testing for memcg aware swap token, I observed a swap token was
often grabbed an intermittent running process (eg init, auditd) and they
never release a token.

Why?

Some processes (eg init, auditd, audispd) wake up when a process exiting.
And swap token can be get first page-in process when a process exiting
makes no swap token owner.  Thus such above intermittent running process
often get a token.

And currently, swap token priority is only decreased at page fault path.
Then, if the process sleep immediately after to grab swap token, the swap
token priority never be decreased.  That's obviously undesirable.

This patch implement very poor (and lightweight) priority aging.  It only
be affect to the above corner case and doesn't change swap tendency
workload performance (eg multi process qsbench load)

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-15 20:03:59 -07:00
KOSAKI Motohiro
83cd81a343 vmscan: implement swap token trace
This is useful for observing swap token activity.

example output:

             zsh-1845  [000]   598.962716: update_swap_token_priority:
mm=ffff88015eaf7700 old_prio=1 new_prio=0
          memtoy-1830  [001]   602.033900: update_swap_token_priority:
mm=ffff880037a45880 old_prio=947 new_prio=949
          memtoy-1830  [000]   602.041509: update_swap_token_priority:
mm=ffff880037a45880 old_prio=949 new_prio=951
          memtoy-1830  [000]   602.051959: update_swap_token_priority:
mm=ffff880037a45880 old_prio=951 new_prio=953
          memtoy-1830  [000]   602.052188: update_swap_token_priority:
mm=ffff880037a45880 old_prio=953 new_prio=955
          memtoy-1830  [001]   602.427184: put_swap_token:
token_mm=ffff880037a45880
             zsh-1789  [000]   602.427281: replace_swap_token:
old_token_mm=          (null) old_prio=0 new_token_mm=ffff88015eaf7018
new_prio=2
             zsh-1789  [001]   602.433456: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=2 new_prio=4
             zsh-1789  [000]   602.437613: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=4 new_prio=6
             zsh-1789  [000]   602.443924: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=6 new_prio=8
             zsh-1789  [000]   602.451873: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=8 new_prio=10
             zsh-1789  [001]   602.462639: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=10 new_prio=12

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel<riel@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-15 20:03:59 -07:00
Shaohua Li
09223371de rcu: Use softirq to address performance regression
Commit a26ac2455ffcf3(rcu: move TREE_RCU from softirq to kthread)
introduced performance regression. In an AIM7 test, this commit degraded
performance by about 40%.

The commit runs rcu callbacks in a kthread instead of softirq. We observed
high rate of context switch which is caused by this. Out test system has
64 CPUs and HZ is 1000, so we saw more than 64k context switch per second
which is caused by RCU's per-CPU kthread.  A trace showed that most of
the time the RCU per-CPU kthread doesn't actually handle any callbacks,
but instead just does a very small amount of work handling grace periods.
This means that RCU's per-CPU kthreads are making the scheduler do quite
a bit of work in order to allow a very small amount of RCU-related
processing to be done.

Alex Shi's analysis determined that this slowdown is due to lock
contention within the scheduler.  Unfortunately, as Peter Zijlstra points
out, the scheduler's real-time semantics require global action, which
means that this contention is inherent in real-time scheduling.  (Yes,
perhaps someone will come up with a workaround -- otherwise, -rt is not
going to do well on large SMP systems -- but this patch will work around
this issue in the meantime.  And "the meantime" might well be forever.)

This patch therefore re-introduces softirq processing to RCU, but only
for core RCU work.  RCU callbacks are still executed in kthread context,
so that only a small amount of RCU work runs in softirq context in the
common case.  This should minimize ksoftirqd execution, allowing us to
skip boosting of ksoftirqd for CONFIG_RCU_BOOST=y kernels.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Tested-by: "Alex,Shi" <alex.shi@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-06-14 15:25:39 -07:00
Wu Fengguang
e84d0a4f8e writeback: trace event writeback_queue_io
Note that it adds a little overheads to account the moved/enqueued
inodes from b_dirty to b_io. The "moved" accounting may be later used to
limit the number of inodes that can be moved in one shot, in order to
keep spinlock hold time under control.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-08 08:25:23 +08:00
Wu Fengguang
251d6a471c writeback: trace event writeback_single_inode
It is valuable to know how the dirty inodes are iterated and their IO size.

"writeback_single_inode: bdi 8:0: ino=134246746 state=I_DIRTY_SYNC|I_SYNC age=414 index=0 to_write=1024 wrote=0"

- "state" reflects inode->i_state at the end of writeback_single_inode()
- "index" reflects mapping->writeback_index after the ->writepages() call
- "to_write" is the wbc->nr_to_write at entrance of writeback_single_inode()
- "wrote" is the number of pages actually written

v2: add trace event writeback_single_inode_requeue as proposed by Dave.

CC: Dave Chinner <david@fromorbit.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-08 08:25:23 +08:00
Wu Fengguang
846d5a091b writeback: remove .nonblocking and .encountered_congestion
Remove two unused struct writeback_control fields:

	.encountered_congestion	(completely unused)
	.nonblocking		(never set, checked/showed in XFS,NFS/btrfs)

The .for_background check in nfs_write_inode() is also removed btw,
as .for_background implies WB_SYNC_NONE.

Reviewed-by: Jan Kara <jack@suse.cz>
Proposed-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-08 08:25:23 +08:00
Wu Fengguang
b7a2441f99 writeback: remove writeback_control.more_io
When wbc.more_io was first introduced, it indicates whether there are
at least one superblock whose s_more_io contains more IO work. Now with
the per-bdi writeback, it can be replaced with a simple b_more_io test.

Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-08 08:25:23 +08:00
Lukas Czerner
a9c667f8f0 ext4: fixed tracepoints cleanup
While creating fixed tracepoints for ext3, basically by porting them
from ext4, I found a lot of useless retyping, wrong type usage, useless
variable passing and other inconsistencies in the ext4 fixed tracepoint
code.

This patch cleans the fixed tracepoint code for ext4 and also simplify
some of them.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-06 09:51:52 -04:00
Linus Torvalds
0e833d8cfc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (40 commits)
  tg3: Fix tg3_skb_error_unmap()
  net: tracepoint of net_dev_xmit sees freed skb and causes panic
  drivers/net/can/flexcan.c: add missing clk_put
  net: dm9000: Get the chip in a known good state before enabling interrupts
  drivers/net/davinci_emac.c: add missing clk_put
  af-packet: Add flag to distinguish VID 0 from no-vlan.
  caif: Fix race when conditionally taking rtnl lock
  usbnet/cdc_ncm: add missing .reset_resume hook
  vlan: fix typo in vlan_dev_hard_start_xmit()
  net/ipv4: Check for mistakenly passed in non-IPv4 address
  iwl4965: correctly validate temperature value
  bluetooth l2cap: fix locking in l2cap_global_chan_by_psm
  ath9k: fix two more bugs in tx power
  cfg80211: don't drop p2p probe responses
  Revert "net: fix section mismatches"
  drivers/net/usb/catc.c: Fix potential deadlock in catc_ctrl_run()
  sctp: stop pending timers and purge queues when peer restart asoc
  drivers/net: ks8842 Fix crash on received packet when in PIO mode.
  ip_options_compile: properly handle unaligned pointer
  iwlagn: fix incorrect PCI subsystem id for 6150 devices
  ...
2011-06-04 23:16:00 +09:00
Koki Sanagi
ec764bf083 net: tracepoint of net_dev_xmit sees freed skb and causes panic
Because there is a possibility that skb is kfree_skb()ed and zero cleared
after ndo_start_xmit, we should not see the contents of skb like skb->len and
skb->dev->name after ndo_start_xmit. But trace_net_dev_xmit does that
and causes panic by NULL pointer dereference.
This patch fixes trace_net_dev_xmit not to see the contents of skb directly.

If you want to reproduce this panic,

1. Get tracepoint of net_dev_xmit on
2. Create 2 guests on KVM
2. Make 2 guests use virtio_net
4. Execute netperf from one to another for a long time as a network burden
5. host will panic(It takes about 30 minutes)

Signed-off-by: Koki Sanagi <sanagi.koki@jp.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-02 14:06:31 -07:00
Linus Torvalds
c4a227d89f Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (25 commits)
  perf: Fix SIGIO handling
  perf top: Don't stop if no kernel symtab is found
  perf top: Handle kptr_restrict
  perf top: Remove unused macro
  perf events: initialize fd array to -1 instead of 0
  perf tools: Make sure kptr_restrict warnings fit 80 col terms
  perf tools: Fix build on older systems
  perf symbols: Handle /proc/sys/kernel/kptr_restrict
  perf: Remove duplicate headers
  ftrace: Add internal recursive checks
  tracing: Update btrfs's tracepoints to use u64 interface
  tracing: Add __print_symbolic_u64 to avoid warnings on 32bit machine
  ftrace: Set ops->flag to enabled even on static function tracing
  tracing: Have event with function tracer check error return
  ftrace: Have ftrace_startup() return failure code
  jump_label: Check entries limit in __jump_label_update
  ftrace/recordmcount: Avoid STT_FUNC symbols as base on ARM
  scripts/tags.sh: Add magic for trace-events for etags too
  scripts/tags.sh: Fix ctags for DEFINE_EVENT()
  x86/ftrace: Fix compiler warning in ftrace.c
  ...
2011-05-28 12:55:55 -07:00
Linus Torvalds
8b29336fe0 Merge branch 'gpio/next' of git://git.secretlab.ca/git/linux-2.6
* 'gpio/next' of git://git.secretlab.ca/git/linux-2.6:
  gpio/via: rename VIA local config struct
  basic_mmio_gpio: split into a gpio library and platform device
  gpio: remove some legacy comments in build files
  gpio: add trace events for setting direction and value
  gpio/pca953x: Use handle_simple_irq instead of handle_edge_irq
  gpiolib: export gpiochip_find
  gpio: remove redundant Kconfig depends on GPIOLIB
  basic_mmio_gpio: convert to non-__raw* accessors
  basic_mmio_gpio: support direction registers
  basic_mmio_gpio: support different input/output registers
  basic_mmio_gpio: detect output method at probe time
  basic_mmio_gpio: request register regions
  basic_mmio_gpio: allow overriding number of gpio
  basic_mmio_gpio: convert to platform_{get,set}_drvdata()
  basic_mmio_gpio: remove runtime width/endianness evaluation
2011-05-26 12:14:41 -07:00
liubo
7f34b746f7 tracing: Update btrfs's tracepoints to use u64 interface
To avoid 64->32 truncating WARNING, update btrfs's tracepoints.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/4DACE6E3.8080200@cn.fujitsu.com
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-25 22:13:47 -04:00
liubo
2fc1b6f0d0 tracing: Add __print_symbolic_u64 to avoid warnings on 32bit machine
Filesystem, like Btrfs, has some "ULL" macros, and when these macros are passed
to tracepoints'__print_symbolic(), there will be 64->32 truncate WARNINGS during
compiling on 32bit box.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/4DACE6E0.7000507@cn.fujitsu.com
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-25 22:13:44 -04:00
Uwe Kleine-König
3f397c2144 gpio: add trace events for setting direction and value
This patch allows to trace gpio operations using ftrace

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-20 00:40:19 -06:00
Linus Torvalds
eb04f2f04e Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (78 commits)
  Revert "rcu: Decrease memory-barrier usage based on semi-formal proof"
  net,rcu: convert call_rcu(prl_entry_destroy_rcu) to kfree
  batman,rcu: convert call_rcu(softif_neigh_free_rcu) to kfree_rcu
  batman,rcu: convert call_rcu(neigh_node_free_rcu) to kfree()
  batman,rcu: convert call_rcu(gw_node_free_rcu) to kfree_rcu
  net,rcu: convert call_rcu(kfree_tid_tx) to kfree_rcu()
  net,rcu: convert call_rcu(xt_osf_finger_free_rcu) to kfree_rcu()
  net/mac80211,rcu: convert call_rcu(work_free_rcu) to kfree_rcu()
  net,rcu: convert call_rcu(wq_free_rcu) to kfree_rcu()
  net,rcu: convert call_rcu(phonet_device_rcu_free) to kfree_rcu()
  perf,rcu: convert call_rcu(swevent_hlist_release_rcu) to kfree_rcu()
  perf,rcu: convert call_rcu(free_ctx) to kfree_rcu()
  net,rcu: convert call_rcu(__nf_ct_ext_free_rcu) to kfree_rcu()
  net,rcu: convert call_rcu(net_generic_release) to kfree_rcu()
  net,rcu: convert call_rcu(netlbl_unlhsh_free_addr6) to kfree_rcu()
  net,rcu: convert call_rcu(netlbl_unlhsh_free_addr4) to kfree_rcu()
  security,rcu: convert call_rcu(sel_netif_free) to kfree_rcu()
  net,rcu: convert call_rcu(xps_dev_maps_release) to kfree_rcu()
  net,rcu: convert call_rcu(xps_map_release) to kfree_rcu()
  net,rcu: convert call_rcu(rps_map_release) to kfree_rcu()
  ...
2011-05-19 18:14:34 -07:00
Mel Gorman
1d929b7a84 mm: tracing: add missing GFP flags to tracing
include/linux/gfp.h and include/trace/events/gfpflags.h are out of sync.
When tracing is enabled, certain flags are not recognised and the text
output is less useful as a result.  Add the missing flags.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-11 18:50:45 -07:00