In file included from include/asm/mmzone.h:18,
from include/linux/mmzone.h:439,
<snip>
include/asm/srat.h:31:2: error: #error CONFIG_ACPI_SRAT not defined, and srat.h header has been included
make[1]: *** [arch/i386/kernel/asm-offsets.s] Error 1
This can happen with CONFIG_NUMA && !CONFIG_ACPI && !CONFIG_X86_NUMAQ
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Kill host_set->next
Fix simplex support
Allow per platform setting of IDE legacy bases
Some of this can be tidied further later on, in particular all the
legacy port gunge belongs as a PCI quirk/PCI header decode to understand
the special legacy IDE rules in the PCI spec.
Longer term Jeff also wants to move the request_irq/free_irq out of core
which will make this even cleaner.
tj: folded in three followup patches - ata_piix-fix, broken-arch-fix
and fix-new-legacy-handling, and separated per-dev xfermask into
separate patch preceding this one. Folded in fixes are...
* ata_piix-fix: fix build failure due to host_set->next removal
* broken-arch-fix: add missing include/asm-*/libata-portmap.h
* fix-new-legacy-handling:
* In ata_pci_init_legacy_port(), probe_num was incorrectly
incremented during initialization of the secondary port and
probe_ent->n_ports was incorrectly fixed to 1.
* Both legacy ports ended up having the same hard_port_no.
* When printing port information, both legacy ports printed
the first irq.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Kprobe inserts breakpoint instruction in probepoint and then jumps to
instruction slot when breakpoint is hit, the instruction slot icache must
be consistent with dcache. Here is the patch which invalidates instruction
slot icache area.
Without this patch, in some machines there will be fault when executing
instruction slot where icache content is inconsistent with dcache.
Signed-off-by: bibo,mao <bibo.mao@intel.com>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Acked-by: Keshavamurthy Anil S <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
set_wmb should not be used in the kernel because it just confuses the
code more and has no benefit. Since it is not currently used in the
kernel this patch removes it so that new code does not include it.
All archs define set_wmb(var, value) to do { var = value; wmb(); }
while(0) except ia64 and sparc which use a mb() instead. But this is
still moot since it is not used anyway.
Hasn't been tested on any archs but x86 and x86_64 (and only compiled
tested)
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
include/asm-i386/system.h has trailing semicolons in some of the
macros that cause legitimate code to fail compilation, so remove
them. Also remove extra blank lines within one group of macros.
And put stts() and clts() back together; they got separated somehow.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use thread info flags to track use of debug registers and IO bitmaps.
- add TIF_DEBUG to track when debug registers are active
- add TIF_IO_BITMAP to track when I/O bitmap is used
- modify __switch_to() to use the new TIF flags
Performance tested on Pentium II, ten runs of LMbench context switch
benchmark (smaller is better:)
before after
avg 3.65 3.39
min 3.55 3.33
Signed-off-by: Stephane Eranian <eranian@hpl.hp.com>
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use "+m" rather than a combination of "=m" and "m" for improved clarity
and consistency.
This also fixes some inlines that incorrectly didn't tell the compiler
that they read the old value at all, potentially causing the compiler to
generate bogus code. It appear that all of those potential bugs were
hidden by the use of extra "volatile" specifiers on the data structures
in question, though.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use the lock validator framework to prove spinlock and rwlock locking
correctness.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use the lock validator framework to prove rwsem locking correctness.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Clean up the x86 irqflags.h file:
- macro => inline function transformation
- simplifications
- style fixes
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use the new IRQF_ constants and remove the SA_INTERRUPT define
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Hide the magic in alternative.h and provide some dummy inline functions
for the UP case (gcc should manage to optimize away these calls). No
changes in module.c.
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch implements an API whereby an application can determine the
label of its peer's Unix datagram sockets via the auxiliary data mechanism of
recvmsg.
Patch purpose:
This patch enables a security-aware application to retrieve the
security context of the peer of a Unix datagram socket. The application
can then use this security context to determine the security context for
processing on behalf of the peer who sent the packet.
Patch design and implementation:
The design and implementation is very similar to the UDP case for INET
sockets. Basically we build upon the existing Unix domain socket API for
retrieving user credentials. Linux offers the API for obtaining user
credentials via ancillary messages (i.e., out of band/control messages
that are bundled together with a normal message). To retrieve the security
context, the application first indicates to the kernel such desire by
setting the SO_PASSSEC option via getsockopt. Then the application
retrieves the security context using the auxiliary data mechanism.
An example server application for Unix datagram socket should look like this:
toggle = 1;
toggle_len = sizeof(toggle);
setsockopt(sockfd, SOL_SOCKET, SO_PASSSEC, &toggle, &toggle_len);
recvmsg(sockfd, &msg_hdr, 0);
if (msg_hdr.msg_controllen > sizeof(struct cmsghdr)) {
cmsg_hdr = CMSG_FIRSTHDR(&msg_hdr);
if (cmsg_hdr->cmsg_len <= CMSG_LEN(sizeof(scontext)) &&
cmsg_hdr->cmsg_level == SOL_SOCKET &&
cmsg_hdr->cmsg_type == SCM_SECURITY) {
memcpy(&scontext, CMSG_DATA(cmsg_hdr), sizeof(scontext));
}
}
sock_setsockopt is enhanced with a new socket option SOCK_PASSSEC to allow
a server socket to receive security context of the peer.
Testing:
We have tested the patch by setting up Unix datagram client and server
applications. We verified that the server can retrieve the security context
using the auxiliary data mechanism of recvmsg.
Signed-off-by: Catherine Zhang <cxzhang@watson.ibm.com>
Acked-by: Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add ->retrigger() irq op to consolidate hw_irq_resend() implementations.
(Most architectures had it defined to NOP anyway.)
NOTE: ia64 needs testing. i386 and x86_64 tested.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/built-in.o: In function `sgivwfb_set_par':
sgivwfb.c:(.text+0x88583): undefined reference to `sgivwfb_mem_phys'
sgivwfb.c:(.text+0x88596): undefined reference to `sgivwfb_mem_phys'
sgivwfb.c:(.text+0x885a8): undefined reference to `sgivwfb_mem_phys'
drivers/built-in.o: In function `sgivwfb_check_var':
sgivwfb.c:(.text+0x88ad0): undefined reference to `sgivwfb_mem_size'
drivers/built-in.o: In function `sgivwfb_mmap':
sgivwfb.c:(.text+0x88c75): undefined reference to `sgivwfb_mem_size'
sgivwfb.c:(.text+0x88c7f): undefined reference to `sgivwfb_mem_phys'
drivers/built-in.o: In function `sgivwfb_probe':
sgivwfb.c:(.init.text+0x4060): undefined reference to `sgivwfb_mem_size'
sgivwfb.c:(.init.text+0x4065): undefined reference to `sgivwfb_mem_phys'
sgivwfb.c:(.init.text+0x4076): undefined reference to `sgivwfb_mem_phys'
sgivwfb.c:(.init.text+0x409c): undefined reference to `sgivwfb_mem_size'
sgivwfb.c:(.init.text+0x410e): undefined reference to `sgivwfb_mem_size'
sgivwfb.c:(.init.text+0x4113): undefined reference to `sgivwfb_mem_phys'
sgivwfb.c:(.init.text+0x4162): undefined reference to `sgivwfb_mem_size'
sgivwfb.c:(.init.text+0x4168): undefined reference to `sgivwfb_mem_phys'
make: *** [.tmp_vmlinux1] Error 1
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in
/sys/devices/system/cpu/ control the MC/SMT power savings policy for the
scheduler.
Based on the values (1-enable, 0-disable) for these controls, sched groups
cpu power will be determined for different domains. When power savings
policy is enabled and under light load conditions, scheduler will minimize
the physical packages/cpu cores carrying the load and thus conserving
power(with a perf impact based on the workload characteristics... see OLS
2005 CMP kernel scheduler paper for more details..)
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Con Kolivas <kernel@kolivas.org>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Move the i386 VDSO down into a vma and thus randomize it.
Besides the security implications, this feature also helps debuggers, which
can COW a vma-backed VDSO just like a normal DSO and can thus do
single-stepping and other debugging features.
It's good for hypervisors (Xen, VMWare) too, which typically live in the same
high-mapped address space as the VDSO, hence whenever the VDSO is used, they
get lots of guest pagefaults and have to fix such guest accesses up - which
slows things down instead of speeding things up (the primary purpose of the
VDSO).
There's a new CONFIG_COMPAT_VDSO (default=y) option, which provides support
for older glibcs that still rely on a prelinked high-mapped VDSO. Newer
distributions (using glibc 2.3.3 or later) can turn this option off. Turning
it off is also recommended for security reasons: attackers cannot use the
predictable high-mapped VDSO page as syscall trampoline anymore.
There is a new vdso=[0|1] boot option as well, and a runtime
/proc/sys/vm/vdso_enabled sysctl switch, that allows the VDSO to be turned
on/off.
(This version of the VDSO-randomization patch also has working ELF
coredumping, the previous patch crashed in the coredumping code.)
This code is a combined work of the exec-shield VDSO randomization
code and Gerd Hoffmann's hypervisor-centric VDSO patch. Rusty Russell
started this patch and i completed it.
[akpm@osdl.org: cleanups]
[akpm@osdl.org: compile fix]
[akpm@osdl.org: compile fix 2]
[akpm@osdl.org: compile fix 3]
[akpm@osdl.org: revernt MAXMEM change]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Cc: Gerd Hoffmann <kraxel@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Using C code for current_thread_info() lets the compiler optimize it.
With gcc 4.0.2, kernel is smaller:
text data bss dec hex filename
3645212 555556 312024 4512792 44dc18 2.6.17-rc6-nb-post/vmlinux
3647276 555556 312024 4514856 44e428 2.6.17-rc6-nb/vmlinux
-------
-2064
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Move the phys_core_id and cpu_core_id to cpuinfo_x86 structure. Similar
patch for x86_64 is already accepted by Andi earlier this week.
[akpm@osdl.org: fix warning]
Signed-off-by: Rohit Seth <rohitseth@google.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When new node becomes enable by hot-add, new sysfs file must be created for
new node. So, if new node is enabled by add_memory(), register_one_node() is
called to create it. In addition, I386's arch_register_node() and a part of
register_nodes() of powerpc are consolidated to register_one_node() as a
generic_code().
This is tested by Tiger4(IPF) with node hot-plug emulation.
Signed-off-by: Keiichiro Tokunaga <tokuanga.keiich@jp.fujitsu.com>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial:
typo fixes
Clean up 'inline is not at beginning' warnings for usb storage
Storage class should be first
i386: Trivial typo fixes
ixj: make ixj_set_tone_off() static
spelling fixes
fix paniced->panicked typos
Spelling fixes for Documentation/atomic_ops.txt
move acknowledgment for Mark Adler to CREDITS
remove the bouncing email address of David Campbell
Intel now has support for Architectural Performance Monitoring Counters
( Refer to IA-32 Intel Architecture Software Developer's Manual
http://www.intel.com/design/pentium4/manuals/253669.htm ). This
feature is present starting from Intel Core Duo and Intel Core Solo processors.
What this means is, the performance monitoring counters and some performance
monitoring events are now defined in an architectural way (using cpuid).
And there will be no need to check for family/model etc for these architectural
events.
Below is the patch to use this performance counters in nmi watchdog driver.
Patch handles both i386 and x86-64 kernels.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
On some i386/x86_64 systems, sending an NMI IPI as a broadcast will
reset the system. This seems to be a BIOS bug which affects machines
where one or more cpus are not under OS control. It occurs on HT
systems with a version of the OS that is not compiled without HT
support. It also occurs when a system is booted with max_cpus=n where
2 <= n < cpus known to the BIOS. The fix is to always send NMI IPI as
a mask instead of as a broadcast.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
x86_64 and i386 behave inconsistently when sending an IPI on vector 2
(NMI_VECTOR). Make both behave the same, so IPI 2 is sent as NMI.
The crash code was abusing send_IPI_allbutself() by passing a code
instead of a vector, it only worked because crash knew about the
internal code of send_IPI_allbutself(). Change crash to use NMI_VECTOR
instead, and remove the comment about how crash was abusing the function.
This patch is a pre-requisite for fixing the problem where sending an
IPI as NMI would reboot some Dell Xeon systems. I cannot fix that
problem while crash continus to abuse send_IPI_allbutself().
It also removes the inconsistency between i386 and x86_64 for
NMI_VECTOR. That will simplify all the RAS code that needs to bring
all the cpus to a clean stop, even when one or more cpus are spinning
disabled.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When a process changes CPUs while doing the non atomic cpu_local_*
operations it might operate on the local_t of a different CPUs.
Fix that by disabling preemption.
Pointed out by Christopher Lameter
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
During some profiling I noticed that default_idle causes a lot of
memory traffic. I think that is caused by the atomic operations
to clear/set the polling flag in thread_info. There is actually
no reason to make this atomic - only the idle thread does it
to itself, other CPUs only read it. So I moved it into ti->status.
Converted i386/x86-64/ia64 for now because that was the easiest
way to fix ACPI which also manipulates these flags in its idle
function.
Cc: Nick Piggin <npiggin@novell.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If no unwinding is possible at all for a certain exception instance,
fall back to the old style call trace instead of not showing any trace
at all.
Also, allow setting the stack trace mode at the command line.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
To increase the usefulness of reliable stack unwinding, this adds CFI
unwind annotations to many low-level i386 routines.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
These are the i386-specific pieces to enable reliable stack traces. This is
going to be even more useful once CFI annotations get added to he assembly
code, namely to entry.S.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Factor out the duplicated access/cache code into a single file
* Shared between i386/x86-64.
- Share flush code between AGP and IOMMU
* Fix a bug: AGP didn't wait for end of flush before
- Drop 8 northbridges limit and allocate dynamically
- Add lock to serialize AGP and IOMMU GART flushes
- Add PCI ID for next AMD northbridge
- Random related cleanups
The old K8 NUMA discovery code is unchanged. New systems
should all use SRAT for this.
Cc: "Navin Boppuri" <navin.boppuri@newisys.com>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Changes are largely identical to the i386 version:
* alternative #define are moved to the new alternative.h file.
* one new elf section with pointers to the lock prefixes which can be
nop'ed out for non-smp.
* two new elf sections simliar to the "classic" alternatives to
replace SMP code with simpler UP code.
* fixup headers to use alternative.h instead of defining their own
LOCK / LOCK_PREFIX macros.
The patch reuses the i386 version of the alternatives code to avoid code
duplication. The code in alternatives.c was shuffled around a bit to
reduce the number of #ifdefs needed. It also got some tweaks needed for
x86_64 (vsyscall page handling) and new features (noreplacement option
which was x86_64 only up to now). Debug printk's are changed from
compile-time to runtime.
Loosely based on a early version from Bastian Blank <waldi@debian.org>
Signed-off-by: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Intel systems report the cache level data from CPUID 4 in sysfs.
Add a CPUID 4 emulation for AMD CPUs to report the same
information for them. This allows programs to read this
information in a uniform way.
The AMD way to report this is less flexible so some assumptions
are hardcoded (e.g. no L3)
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With this patch Kprobes now registers for page fault notifications only when
their is an active probe registered. Once all the active probes are
unregistered their is no need to be notified of page faults and kprobes
unregisters itself from the page fault notifications. Hence we will have ZERO
side effects when no probes are active.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Overloading of page fault notification with the notify_die() has performance
issues(since the only interested components for page fault is kprobes and/or
kdb) and hence this patch introduces the new notifier call chain exclusively
for page fault notifications their by avoiding notifying unnecessary
components in the do_page_fault() code path.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This converts the i386 arch to use the generic timeofday subsystem. It
enabled the GENERIC_TIME option, disables the timer_opts code and other arch
specific timekeeping code and reworks the delay code.
While this patch enables the generic timekeeping, please note that this patch
does not provide any i386 clocksource. Thus only the jiffies clocksource will
be available. To get full replacements for the code being disabled here, the
timeofday-clocks-i386 patch will needed.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As part of the i386 conversion to the generic timekeeping infrastructure, this
introduces a new tsc.c file. The code in this file replaces the TSC
initialization, management and access code currently in timer_tsc.c (which
will be removed) that we want to preserve.
The code also introduces the following functionality:
o tsc_khz: like cpu_khz but stores the TSC frequency on systems that do not
change TSC frequency w/ CPU frequency
o check/mark_tsc_unstable: accessor/modifier flag for TSC timekeeping
usability
o minor cleanups to calibration math.
This patch also includes a one line __cpuinitdata fix from Zwane Mwaikambo.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As described in a previous patch and documented in mm/filemap.h,
copy_from_user_inatomic* shouldn't zero out the tail of the buffer after an
incomplete copy.
This patch implements that change for i386.
For the _nocache version, a new __copy_user_intel_nocache is defined similar
to copy_user_zeroio_intel_nocache, and this is ultimately used for the copy.
For the regular version, __copy_from_user_ll_nozero is defined which uses
__copy_user and __copy_user_intel - the later needs casts to reposition the
__user annotations.
If copy_from_user_atomic is given a constant length of 1, 2, or 4, then we do
still zero the destintion on failure. This didn't seem worth the effort of
fixing as the places where it is used really don't care.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The problem is that when we write to a file, the copy from userspace to
pagecache is first done with preemption disabled, so if the source address is
not immediately available the copy fails *and* *zeros* *the* *destination*.
This is a problem because a concurrent read (which admittedly is an odd thing
to do) might see zeros rather that was there before the write, or what was
there after, or some mixture of the two (any of these being a reasonable thing
to see).
If the copy did fail, it will immediately be retried with preemption
re-enabled so any transient problem with accessing the source won't cause an
error.
The first copying does not need to zero any uncopied bytes, and doing so
causes the problem. It uses copy_from_user_atomic rather than copy_from_user
so the simple expedient is to change copy_from_user_atomic to *not* zero out
bytes on failure.
The first of these two patches prepares for the change by fixing two places
which assume copy_from_user_atomic does zero the tail. The two usages are
very similar pieces of code which copy from a userspace iovec into one or more
page-cache pages. These are changed to remove the assumption.
The second patch changes __copy_from_user_inatomic* to not zero the tail.
Once these are accepted, I will look at similar patches of other architectures
where this is important (ppc, mips and sparc being the ones I can find).
This patch:
There is a problem with __copy_from_user_inatomic zeroing the tail of the
buffer in the case of an error. As it is called in atomic context, the error
may be transient, so it results in zeros being written where maybe they
shouldn't be.
In the usage in filemap, this opens a window for a well timed read to see data
(zeros) which is not consistent with any ordering of reads and writes.
Most cases where __copy_from_user_inatomic is called, a failure results in
__copy_from_user being called immediately. As long as the latter zeros the
tail, the former doesn't need to. However in *copy_from_user_iovec
implementations (in both filemap and ntfs/file), it is assumed that
copy_from_user_inatomic will zero the tail.
This patch removes that assumption, so that after this patch it will
be safe for copy_from_user_inatomic to not zero the tail.
This patch also adds some commentary to filemap.h and asm-i386/uaccess.h.
After this patch, all architectures that might disable preempt when
kmap_atomic is called need to have their __copy_from_user_inatomic* "fixed".
This includes
- powerpc
- i386
- mips
- sparc
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The floppy driver is already calling add_disk_randomness as it should, so this
was redundant.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Clean up and refactor i386 sub-architecture setup.
This change moves all the code from the
asm-i386/mach-*/setup_arch_pre/post.h headers, into
arch/i386/mach-*/setup.c. mach-*/setup_arch_pre.h is renamed to
setup_arch.h, and contains only things which should be in header files. It
is purely code-motion; there should be no functional changes at all.
Several functions in arch/i386/kernel/setup.c needed to be made non-static
so that they're visible to the code in mach-*/setup.c. asm-i386/setup.h is
used to hold the prototypes for these functions.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Cc: Martin Bligh <mbligh@google.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Andrey Panin <pazke@donpac.ru>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (65 commits)
ACPI: suppress power button event on S3 resume
ACPI: resolve merge conflict between sem2mutex and processor_perflib.c
ACPI: use for_each_possible_cpu() instead of for_each_cpu()
ACPI: delete newly added debugging macros in processor_perflib.c
ACPI: UP build fix for bugzilla-5737
Enable P-state software coordination via _PDC
P-state software coordination for speedstep-centrino
P-state software coordination for acpi-cpufreq
P-state software coordination for ACPI core
ACPI: create acpi_thermal_resume()
ACPI: create acpi_fan_suspend()/acpi_fan_resume()
ACPI: pass pm_message_t from acpi_device_suspend() to root_suspend()
ACPI: create acpi_device_suspend()/acpi_device_resume()
ACPI: replace spin_lock_irq with mutex for ec poll mode
ACPI: Allow a WAN module enable/disable on a Thinkpad X60.
sem2mutex: acpi, acpi_link_lock
ACPI: delete unused acpi_bus_drivers_lock
sem2mutex: drivers/acpi/processor_perflib.c
ACPI add ia64 exports to build acpi_memhotplug as a module
ACPI: asus_acpi_init(): propagate correct return value
...
Manual resolve of conflicts in:
arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
include/acpi/processor.h
compile fix: <asm-i386/alternative.h> needs <asm/types.h> for 'u8' --
just look at struct alt_instr.
My module includes <asm/bitops.h> as the first header, and as of 2.6.17 this
leads to compilation errors.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
New CPU flags for next generation of crypto engine as found in VIA C7
processors.
Signed-off-by: Michal Ludvig <michal@logix.cz>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
An immediate operand can't be the destination of the cmpl instruction,
so exclude it.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Mattia Dongili <malattia@linux.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Only drm, framebuffer, mtrr parts + misc files here and there.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use the x86 cache-bypassing copy instructions for copy_from_user().
Some performance data are
Total of GLOBAL_POWER_EVENTS (CPU cycle samples)
2.6.12.4.orig 1921587
2.6.12.4.nt 1599424
1599424/1921587=83.23% (16.77% reduction)
BSQ_CACHE_REFERENCE (L3 cache miss)
2.6.12.4.orig 57427
2.6.12.4.nt 20858
20858/57427=36.32% (63.7% reduction)
L3 cache miss reduction of __copy_from_user_ll
samples %
37408 65.1412 vmlinux __copy_from_user_ll
23 0.1103 vmlinux __copy_user_zeroing_intel_nocache
23/37408=0.061% (99.94% reduction)
Top 5 of 2.6.12.4.nt
Counted GLOBAL_POWER_EVENTS events (time during which processor is not stopped) with a unit mask of 0x01 (mandatory) count 100000
samples % app name symbol name
128392 8.0274 vmlinux __copy_user_zeroing_intel_nocache
64206 4.0143 vmlinux journal_add_journal_head
59746 3.7355 vmlinux do_get_write_access
47674 2.9807 vmlinux journal_put_journal_head
46021 2.8774 vmlinux journal_dirty_metadata
pattern9-0-cpu4-0-09011728/summary.out
Counted BSQ_CACHE_REFERENCE events (cache references seen by the bus unit) with a unit mask of 0x3f (multiple flags) count 3000
samples % app name symbol name
69755 4.2861 vmlinux __copy_user_zeroing_intel_nocache
55685 3.4215 vmlinux journal_add_journal_head
52371 3.2179 vmlinux __find_get_block
45504 2.7960 vmlinux journal_put_journal_head
36005 2.2123 vmlinux journal_stop
pattern9-0-cpu4-0-09011744/summary.out
Counted BSQ_CACHE_REFERENCE events (cache references seen by the bus unit) with a unit mask of 0x200 (read 3rd level cache miss) count 3000
samples % app name symbol name
1147 5.4994 vmlinux journal_add_journal_head
881 4.2240 vmlinux journal_dirty_data
872 4.1809 vmlinux blk_rq_map_sg
734 3.5192 vmlinux journal_commit_transaction
617 2.9582 vmlinux radix_tree_delete
pattern9-0-cpu4-0-09011731/summary.out
iozone results are
original 2.6.12.4 CPU time = 207.768 sec
cache aware CPU time = 184.783 sec
(three times run)
184.783/207.768=88.94% (11.06% reduction)
original:
pattern9-0-cpu4-0-08191720/iozone.out: CPU Utilization: Wall time 45.997 CPU time 64.527 CPU utilization 140.28 %
pattern9-0-cpu4-0-08191741/iozone.out: CPU Utilization: Wall time 46.878 CPU time 71.933 CPU utilization 153.45 %
pattern9-0-cpu4-0-08191743/iozone.out: CPU Utilization: Wall time 45.152 CPU time 71.308 CPU utilization 157.93 %
cache awre:
pattern9-0-cpu4-0-09011728/iozone.out: CPU Utilization: Wall time 44.842 CPU time 62.465 CPU utilization 139.30 %
pattern9-0-cpu4-0-09011731/iozone.out: CPU Utilization: Wall time 44.718 CPU time 59.273 CPU utilization 132.55 %
pattern9-0-cpu4-0-09011744/iozone.out: CPU Utilization: Wall time 44.367 CPU time 63.045 CPU utilization 142.10 %
Signed-off-by: Hiro Yoshioka <hyoshiok@miraclelinux.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
sys_move_pages() support for 32bit (i386 plus x86_64 compat layer)
Add support for move_pages() on i386 and also add the compat functions
necessary to run 32 bit binaries on x86_64.
Add compat_sys_move_pages to the x86_64 32bit binary layer. Note that it is
not up to date so I added the missing pieces. Not sure if this is done the
right way.
[akpm@osdl.org: compile fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6: (27 commits)
[PATCH] PCI: nVidia quirk to make AER PCI-E extended capability visible
[PATCH] PCI: fix issues with extended conf space when MMCONFIG disabled because of e820
[PATCH] PCI: Bus Parity Status sysfs interface
[PATCH] PCI: fix memory leak in MMCONFIG error path
[PATCH] PCI: fix error with pci_get_device() call in the mpc85xx driver
[PATCH] PCI: MSI-K8T-Neo2-Fir: run only where needed
[PATCH] PCI: fix race with pci_walk_bus and pci_destroy_dev
[PATCH] PCI: clean up pci documentation to be more specific
[PATCH] PCI: remove unneeded msi code
[PATCH] PCI: don't move ioapics below PCI bridge
[PATCH] PCI: cleanup unused variable about msi driver
[PATCH] PCI: disable msi mode in pci_disable_device
[PATCH] PCI: Allow MSI to work on kexec kernel
[PATCH] PCI: AMD 8131 MSI quirk called too late, bus_flags not inherited ?
[PATCH] PCI: Move various PCI IDs to header file
[PATCH] PCI Bus Parity Status-broken hardware attribute, EDAC foundation
[PATCH] PCI: i386/x86_84: disable PCI resource decode on device disable
[PATCH] PCI ACPI: Rename the functions to avoid multiple instances.
[PATCH] PCI: don't enable device if already enabled
[PATCH] PCI: Add a "enable" sysfs attribute to the pci devices to allow userspace (Xorg) to enable devices without doing foul direct access
...
VGA_MAP_MEM translates to ioremap() on some architectures. It makes sense
to do this to vga_vram_base, because we're going to access memory between
vga_vram_base and vga_vram_end.
But it doesn't really make sense to map starting at vga_vram_end, because
we aren't going to access memory starting there. On ia64, which always has
to be different, ioremapping vga_vram_end gives you something completely
incompatible with ioremapped vga_vram_start, so vga_vram_size ends up being
nonsense.
As a bonus, we often know the size up front, so we can use ioremap()
correctly, rather than giving it a zero size.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In IA64 platform, msi driver does not use irq_vector variable, and in
x86 platform LAST_DEVICE_VECTOR should one before FIRST_SYSTEM_VECTOR,
this patch modify this.
Signed-off-by: bibo, mao <bibo.mao@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Abstract portions of the MSI core for platforms that do not use standard
APIC interrupt controllers. This is implemented through a new arch-specific
msi setup routine, and a set of msi ops which can be set on a per platform
basis.
Signed-off-by: Mark Maule <maule@sgi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The patch addresses a problem with ACPI SCI interrupt entry, which gets
re-used, and the IRQ is assigned to another unrelated device. The patch
corrects the code such that SCI IRQ is skipped and duplicate entry is
avoided. Second issue came up with VIA chipset, the problem was caused by
original patch assigning IRQs starting 16 and up. The VIA chipset uses
4-bit IRQ register for internal interrupt routing, and therefore cannot
handle IRQ numbers assigned to its devices. The patch corrects this
problem by allowing PCI IRQs below 16.
Cc: len.brown@intel.com
Signed-off by: Natalie Protasevich <Natalie.Protasevich@unisys.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The FXSAVE information leak patch introduced a bug in FP exception
handling: it clears FP exceptions only when there are already
none outstanding. Mikael Pettersson reported that causes problems
with the Erlang runtime and has tested this fix.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Acked-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
These aren't needed by glibc or klibc, and they're broken in some cases
anyway. The uClibc folks are apparently switching over to stop using
them too (now that we agreed that they should be dropped, at least).
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Proposed fix for ptep_get_and_clear_full PAE bug. Pte_clear had the same bug,
so use the same fix for both. Turns out pmd_clear had it as well, but pgds
are not affected.
The problem is rather intricate. Page table entries in PAE mode are 64-bits
wide, but the only atomic 8-byte write operation available in 32-bit mode is
cmpxchg8b, which is expensive (at least on P4), and thus avoided. But it can
happen that the processor may prefetch entries into the TLB in the middle of an
operation which clears a page table entry. So one must always clear the P-bit
in the low word of the page table entry first when clearing it.
Since the sequence *ptep = __pte(0) leaves the order of the write dependent on
the compiler, it must be coded explicitly as a clear of the low word followed
by a clear of the high word. Further, there must be a write memory barrier
here to enforce proper ordering by the compiler (and, in the future, by the
processor as well).
On > 4GB memory machines, the implementation of pte_clear for PAE was clearly
deficient, as it could leave virtual mappings of physical memory above 4GB
aliased to memory below 4GB in the TLB. The implementation of
ptep_get_and_clear_full has a similar bug, although not nearly as likely to
occur, since the mappings being cleared are in the process of being destroyed,
and should never be dereferenced again.
But, as luck would have it, it is possible to trigger bugs even without ever
dereferencing these bogus TLB mappings, even if the clear is followed fairly
soon after with a TLB flush or invalidation. The problem is that memory above
4GB may now be aliased into the first 4GB of memory, and in fact, may hit a
region of memory with non-memory semantics. These regions include AGP and PCI
space. As such, these memory regions are not cached by the processor. This
introduces the bug.
The processor can speculate memory operations, including memory writes, as long
as they are committed with the proper ordering. Speculating a memory write to
a linear address that has a bogus TLB mapping is possible. Normally, the
speculation is harmless. But for cached memory, it does leave the falsely
speculated cacheline unmodified, but in a dirty state. This cache line will be
eventually written back. If this cacheline happens to intersect a region of
memory that is not protected by the cache coherency protocol, it can corrupt
data in I/O memory, which is generally a very bad thing to do, and can cause
total system failure or just plain undefined behavior.
These bugs are extremely unlikely, but the severity is of such magnitude, and
the fix so simple that I think fixing them immediately is justified. Also,
they are nearly impossible to debug.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
sys_splice() moves data to/from pipes with a file input/output. sys_vmsplice()
moves data to a pipe, with the input being a user address range instead.
This uses an approach suggested by Linus, where we can hold partial ranges
inside the pages[] map. Hopefully this will be useful for network
receive support as well.
Signed-off-by: Jens Axboe <axboe@suse.de>
AMD K7/K8 CPUs only save/restore the FOP/FIP/FDP x87 registers in FXSAVE
when an exception is pending. This means the value leak through
context switches and allow processes to observe some x87 instruction
state of other processes.
This was actually documented by AMD, but nobody recognized it as
being different from Intel before.
The fix first adds an optimization: instead of unconditionally
calling FNCLEX after each FXSAVE test if ES is pending and skip
it when not needed. Then do a x87 load from a kernel variable to
clear FOP/FIP/FDP.
This means other processes always will only see a constant value
defined by the kernel in their FP state.
I took some pain to make sure to chose a variable that's already
in L1 during context switch to make the overhead of this low.
Also alternative() is used to patch away the new code on CPUs
who don't need it.
Patch for both i386/x86-64.
The problem was discovered originally by Jan Beulich. Richard
Brunner provided the basic code for the workarounds, with contribution
from Jan.
This is CVE-2006-1056
Cc: richard.brunner@amd.com
Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
atomic_add_return() if CONFIG_M386 can accidentally enable local interrupts.
Signed-off-by: Lepton Wu <ytht.net@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Basically an in-kernel implementation of tee, which uses splice and the
pipe buffers as an intelligent way to pass data around by reference.
Where the user space tee consumes the input and produces a stdout and
file output, this syscall merely duplicates the data inside a pipe to
another pipe. No data is copied, the output just grabs a reference to the
input pipe data.
Signed-off-by: Jens Axboe <axboe@suse.de>
* 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block:
[PATCH] vfs: add splice_write and splice_read to documentation
[PATCH] Remove sys_ prefix of new syscalls from __NR_sys_*
[PATCH] splice: warning fix
[PATCH] another round of fs/pipe.c cleanups
[PATCH] splice: comment styles
[PATCH] splice: add Ingo as addition copyright holder
[PATCH] splice: unlikely() optimizations
[PATCH] splice: speedups and optimizations
[PATCH] pipe.c/fifo.c code cleanups
[PATCH] get rid of the PIPE_*() macros
[PATCH] splice: speedup __generic_file_splice_read
[PATCH] splice: add direct fd <-> fd splicing support
[PATCH] splice: add optional input and output offsets
[PATCH] introduce a "kernel-internal pipe object" abstraction
[PATCH] splice: be smarter about calling do_page_cache_readahead()
[PATCH] splice: optimize the splice buffer mapping
[PATCH] splice: cleanup __generic_file_splice_read()
[PATCH] splice: only call wake_up_interruptible() when we really have to
[PATCH] splice: potential !page dereference
[PATCH] splice: mark the io page as accessed
__NR_sys_kexec_load should be __NR_kexec_load. Mainly affects users of the
_syscallN() macros, and glibc is already checking for __NR_kexec_load.
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Current implementations define NODES_SHIFT in include/asm-xxx/numnodes.h for
each arch. Its definition is sometimes configurable. Indeed, ia64 defines 5
NODES_SHIFT values in the current git tree. But it looks a bit messy.
SGI-SN2(ia64) system requires 1024 nodes, and the number of nodes already has
been changeable by config. Suitable node's number may be changed in the
future even if it is other architecture. So, I wrote configurable node's
number.
This patch set defines just default value for each arch which needs multi
nodes except ia64. But, it is easy to change to configurable if necessary.
On ia64 the number of nodes can be already configured in generic ia64 and SN2
config. But, NODES_SHIFT is defined for DIG64 and HP'S machine too. So, I
changed it so that all platforms can be configured via CONFIG_NODES_SHIFT. It
would be simpler.
See also: http://marc.theaimsgroup.com/?l=linux-kernel&m=114358010523896&w=2
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
On i386, we don't use sys_ prefix for __NR_*. This patch removes it
[FWIW, _syscall*() macros will generate foo() instead of sys_foo().]
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Jens Axboe <axboe@suse.de>
If the HPET timer is enabled, the clock can drift by ~3 seconds a day.
This is due to the HPET timer not being initialized with the correct
setting (still using PIT count).
If HZ changes, this drift can become even more pronounced.
HPET patch initializes tick_nsec with correct tick_nsec settings for
HPET timer.
Vojtech comments:
"It's not entirely correct (it assumes the HPET ticks totally
exactly), but it's significantly better than assuming the PIT error
there."
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
AMD systems have a modern APIC that supports 8 bit IDs, but
don't have a XAPIC version number. Add a new "modern_apic"
subfunction that handles this correctly and use it (nearly)
everywhere where XAPIC is tested for.
I removed one wart: the code specified that external APICs
would use an 8bit APIC ID. But I checked a real 82093 data sheet
and it says clearly that they only use 4bit. So I removed
this special case since it would a bit awkward to implement now.
I removed the valid APIC tests in mptable parsing completely. On any modern
system they only check against the full field width (8bit) anyways
and are no-ops. This also fixes them doing the wrong thing
on >8 core Opterons.
This makes i386 boot again on 16 core Opterons.
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce a e820_all_mapped() function which checks if the entire range
<start,end> is mapped with type.
This is done by moving the local start variable to the end of each
known-good region; if at the end of the function the start address is
still before end, there must be a part that's not of the correct type;
otherwise it's a good region.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
local_t's were defined to be unsigned. This increases confusion because
atomic_t's are signed. The patch goes through and changes all implementations
to use signed longs throughout.
Also, x86-64 was using 32-bit quantities for the value passed into local_add()
and local_sub(). Fixed.
All (actually, both) existing users have been audited.
(Also s/__inline__/inline/ in x86_64/local.h)
Cc: Andi Kleen <ak@muc.de>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove the recently-added LINUX_FADV_ASYNC_WRITE and LINUX_FADV_WRITE_WAIT
fadvise() additions, do it in a new sys_sync_file_range() syscall instead.
Reasons:
- It's more flexible. Things which would require two or three syscalls with
fadvise() can be done in a single syscall.
- Using fadvise() in this manner is something not covered by POSIX.
The patch wires up the syscall for x86.
The sycall is implemented in the new fs/sync.c. The intention is that we can
move sys_fsync(), sys_fdatasync() and perhaps sys_sync() into there later.
Documentation for the syscall is in fs/sync.c.
A test app (sync_file_range.c) is in
http://www.zip.com.au/~akpm/linux/patches/stuff/ext3-tools.tar.gz.
The available-to-GPL-modules do_sync_file_range() is for knfsd: "A COMMIT can
say NFS_DATA_SYNC or NFS_FILE_SYNC. I can skip the ->fsync call for
NFS_DATA_SYNC which is hopefully the more common."
Note: the `async' writeout mode SYNC_FILE_RANGE_WRITE will turn synchronous if
the queue is congested. This is trivial to fix: add a new flag bit, set
wbc->nonblocking. But I'm not sure that we want to expose implementation
details down to that level.
Note: it's notable that we can sync an fd which wasn't opened for writing.
Same with fsync() and fdatasync()).
Note: the code takes some care to handle attempts to sync file contents
outside the 16TB offset on 32-bit machines. It makes such attempts appear to
succeed, for best 32-bit/64-bit compatibility. Perhaps it should make such
requests fail...
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Porting the patch I posted for x86_64 to i386.
http://marc.theaimsgroup.com/?l=linux-kernel&m=114178139610707&w=2
o While using kdump, after a system crash when second kernel boots, timer
vector gets (0x31) locked and CPU does not see timer interrupts
travelling from IOAPIC to APIC. Currently it does not lead to boot
failure in second kernel as timer interrupts continues to come as ExtInt
through LAPIC directly, but fixing it is good in case some boards do not
support the other mode.
o After a system crash, it is not safe to service interrupts any more,
hence interrupts are disabled. This leads to pending interrupts at
LAPIC. LAPIC sends these interrupts to the CPU during early boot of
second kernel. Other pending interrupts are discarded saying unexpected
trap but timer interrupt is serviced and CPU does not issue an LAPIC EOI
because it think this interrupt came from i8259 and sends ack to 8259.
This leads to vector 0x31 locking as LAPIC does not clear respective ISR
and keeps on waiting for EOI.
o This patch issues extra EOI for the pending interrupts who have ISR set.
o Though today only timer seems to be the special case because in early
boot it thinks interrupts are coming from i8259 and uses
mask_and_ack_8259A() as ack handler and does not issue LAPIC EOI. But
probably doing it in generic manner for all vectors makes sense.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It's been disabled since v2.1.88
Signed-off-by: Brian Gerst <bgerst@didntduck.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds support for the sys_splice system call. Using a pipe as a
transport, it can connect to files or sockets (latter as output only).
From the splice.c comments:
"splice": joining two ropes together by interweaving their strands.
This is the "extended pipe" functionality, where a pipe is used as
an arbitrary in-memory buffer. Think of a pipe as a small kernel
buffer that you can use to transfer data from one end to the other.
The traditional unix read/write is extended with a "splice()" operation
that transfers data buffers to or from a pipe buffer.
Named by Larry McVoy, original implementation from Linus, extended by
Jens to support splicing to files and fixing the initial implementation
bugs.
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Nowadays, even Debian stable ships a microcode_ctl utility recent enough to no
longer use this ioctl.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Tigran Aivazian <tigran_aivazian@symantec.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix up some RTC whitespace and style
Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Reading the CMOS clock on x86 and some other arches currently takes up to one
second because it synchronizes with the CMOS second tick-over. This delay
shows up at boot time as well a resume time.
This is the currently the most substantial boot time delay for machines that
are working towards instant-on capability. Also, a quick back of the envelope
calculation (.5sec * 2M users * 1 boot a day * 10 years) suggests it has cost
Linux users in the neighborhood of a million man-hours.
An earlier thread on this topic is here:
http://groups.google.com/group/linux.kernel/browse_frm/thread/8a24255215ff6151/2aa97e66a977653d?hl=en&lr=&ie=UTF-8&rnum=1&prev=/groups%3Fhl%3Den%26lr%3D%26ie%3DUTF-8%26selm%3D1To2R-2S7-11%40gated-at.bofh.it#2aa97e66a977653d
..from which the consensus seems to be that it's no longer desirable.
In my view, there are basically four cases to consider:
1) networked, need precise walltime: use NTP
2) networked, don't need precise walltime: use NTP anyway
3) not networked, don't need sub-second precision walltime: don't care
4) not networked, need sub-second precision walltime:
get a network or a radio time source because RTC isn't good enough anyway
So this patch series simply removes the synchronization in favor of a simple
seqlock-like approach using the seconds value.
Note that for purposes of timer accuracy on wakeup, this patch will cause us
to fire timers up to one second late. But as the current timer resume code
will already sync once (or more!), it's no worse for short timers.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The kernel's implementation of notifier chains is unsafe. There is no
protection against entries being added to or removed from a chain while the
chain is in use. The issues were discussed in this thread:
http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2
We noticed that notifier chains in the kernel fall into two basic usage
classes:
"Blocking" chains are always called from a process context
and the callout routines are allowed to sleep;
"Atomic" chains can be called from an atomic context and
the callout routines are not allowed to sleep.
We decided to codify this distinction and make it part of the API. Therefore
this set of patches introduces three new, parallel APIs: one for blocking
notifiers, one for atomic notifiers, and one for "raw" notifiers (which is
really just the old API under a new name). New kinds of data structures are
used for the heads of the chains, and new routines are defined for
registration, unregistration, and calling a chain. The three APIs are
explained in include/linux/notifier.h and their implementation is in
kernel/sys.c.
With atomic and blocking chains, the implementation guarantees that the chain
links will not be corrupted and that chain callers will not get messed up by
entries being added or removed. For raw chains the implementation provides no
guarantees at all; users of this API must provide their own protections. (The
idea was that situations may come up where the assumptions of the atomic and
blocking APIs are not appropriate, so it should be possible for users to
handle these things in their own way.)
There are some limitations, which should not be too hard to live with. For
atomic/blocking chains, registration and unregistration must always be done in
a process context since the chain is protected by a mutex/rwsem. Also, a
callout routine for a non-raw chain must not try to register or unregister
entries on its own chain. (This did happen in a couple of places and the code
had to be changed to avoid it.)
Since atomic chains may be called from within an NMI handler, they cannot use
spinlocks for synchronization. Instead we use RCU. The overhead falls almost
entirely in the unregister routine, which is okay since unregistration is much
less frequent that calling a chain.
Here is the list of chains that we adjusted and their classifications. None
of them use the raw API, so for the moment it is only a placeholder.
ATOMIC CHAINS
-------------
arch/i386/kernel/traps.c: i386die_chain
arch/ia64/kernel/traps.c: ia64die_chain
arch/powerpc/kernel/traps.c: powerpc_die_chain
arch/sparc64/kernel/traps.c: sparc64die_chain
arch/x86_64/kernel/traps.c: die_chain
drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list
kernel/panic.c: panic_notifier_list
kernel/profile.c: task_free_notifier
net/bluetooth/hci_core.c: hci_notifier
net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain
net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain
net/ipv6/addrconf.c: inet6addr_chain
net/netfilter/nf_conntrack_core.c: nf_conntrack_chain
net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain
net/netlink/af_netlink.c: netlink_chain
BLOCKING CHAINS
---------------
arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain
arch/s390/kernel/process.c: idle_chain
arch/x86_64/kernel/process.c idle_notifier
drivers/base/memory.c: memory_chain
drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list
drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list
drivers/macintosh/adb.c: adb_client_list
drivers/macintosh/via-pmu.c sleep_notifier_list
drivers/macintosh/via-pmu68k.c sleep_notifier_list
drivers/macintosh/windfarm_core.c wf_client_list
drivers/usb/core/notify.c usb_notifier_list
drivers/video/fbmem.c fb_notifier_list
kernel/cpu.c cpu_chain
kernel/module.c module_notify_list
kernel/profile.c munmap_notifier
kernel/profile.c task_exit_notifier
kernel/sys.c reboot_notifier_list
net/core/dev.c netdev_chain
net/decnet/dn_dev.c: dnaddr_chain
net/ipv4/devinet.c: inetaddr_chain
It's possible that some of these classifications are wrong. If they are,
please let us know or submit a patch to fix them. Note that any chain that
gets called very frequently should be atomic, because the rwsem read-locking
used for blocking chains is very likely to incur cache misses on SMP systems.
(However, if the chain's callout routines may sleep then the chain cannot be
atomic.)
The patch set was written by Alan Stern and Chandra Seetharaman, incorporating
material written by Keith Owens and suggestions from Paul McKenney and Andrew
Morton.
[jes@sgi.com: restructure the notifier chain initialization macros]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- fix: initialize the robust list(s) to NULL in copy_process.
- doc update
- cleanup: rename _inuser to _inatomic
- __user cleanups and other small cleanups
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
i386: add the futex_atomic_cmpxchg_inuser() assembly implementation, and wire
up the new syscalls.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Acked-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patchset provides a new (written from scratch) implementation of robust
futexes, called "lightweight robust futexes". We believe this new
implementation is faster and simpler than the vma-based robust futex solutions
presented before, and we'd like this patchset to be adopted in the upstream
kernel. This is version 1 of the patchset.
Background
----------
What are robust futexes? To answer that, we first need to understand what
futexes are: normal futexes are special types of locks that in the
noncontended case can be acquired/released from userspace without having to
enter the kernel.
A futex is in essence a user-space address, e.g. a 32-bit lock variable
field. If userspace notices contention (the lock is already owned and someone
else wants to grab it too) then the lock is marked with a value that says
"there's a waiter pending", and the sys_futex(FUTEX_WAIT) syscall is used to
wait for the other guy to release it. The kernel creates a 'futex queue'
internally, so that it can later on match up the waiter with the waker -
without them having to know about each other. When the owner thread releases
the futex, it notices (via the variable value) that there were waiter(s)
pending, and does the sys_futex(FUTEX_WAKE) syscall to wake them up. Once all
waiters have taken and released the lock, the futex is again back to
'uncontended' state, and there's no in-kernel state associated with it. The
kernel completely forgets that there ever was a futex at that address. This
method makes futexes very lightweight and scalable.
"Robustness" is about dealing with crashes while holding a lock: if a process
exits prematurely while holding a pthread_mutex_t lock that is also shared
with some other process (e.g. yum segfaults while holding a pthread_mutex_t,
or yum is kill -9-ed), then waiters for that lock need to be notified that the
last owner of the lock exited in some irregular way.
To solve such types of problems, "robust mutex" userspace APIs were created:
pthread_mutex_lock() returns an error value if the owner exits prematurely -
and the new owner can decide whether the data protected by the lock can be
recovered safely.
There is a big conceptual problem with futex based mutexes though: it is the
kernel that destroys the owner task (e.g. due to a SEGFAULT), but the kernel
cannot help with the cleanup: if there is no 'futex queue' (and in most cases
there is none, futexes being fast lightweight locks) then the kernel has no
information to clean up after the held lock! Userspace has no chance to clean
up after the lock either - userspace is the one that crashes, so it has no
opportunity to clean up. Catch-22.
In practice, when e.g. yum is kill -9-ed (or segfaults), a system reboot is
needed to release that futex based lock. This is one of the leading
bugreports against yum.
To solve this problem, 'Robust Futex' patches were created and presented on
lkml: the one written by Todd Kneisel and David Singleton is the most advanced
at the moment. These patches all tried to extend the futex abstraction by
registering futex-based locks in the kernel - and thus give the kernel a
chance to clean up.
E.g. in David Singleton's robust-futex-6.patch, there are 3 new syscall
variants to sys_futex(): FUTEX_REGISTER, FUTEX_DEREGISTER and FUTEX_RECOVER.
The kernel attaches such robust futexes to vmas (via
vma->vm_file->f_mapping->robust_head), and at do_exit() time, all vmas are
searched to see whether they have a robust_head set.
Lots of work went into the vma-based robust-futex patch, and recently it has
improved significantly, but unfortunately it still has two fundamental
problems left:
- they have quite complex locking and race scenarios. The vma-based
patches had been pending for years, but they are still not completely
reliable.
- they have to scan _every_ vma at sys_exit() time, per thread!
The second disadvantage is a real killer: pthread_exit() takes around 1
microsecond on Linux, but with thousands (or tens of thousands) of vmas every
pthread_exit() takes a millisecond or more, also totally destroying the CPU's
L1 and L2 caches!
This is very much noticeable even for normal process sys_exit_group() calls:
the kernel has to do the vma scanning unconditionally! (this is because the
kernel has no knowledge about how many robust futexes there are to be cleaned
up, because a robust futex might have been registered in another task, and the
futex variable might have been simply mmap()-ed into this process's address
space).
This huge overhead forced the creation of CONFIG_FUTEX_ROBUST, but worse than
that: the overhead makes robust futexes impractical for any type of generic
Linux distribution.
So it became clear to us, something had to be done. Last week, when Thomas
Gleixner tried to fix up the vma-based robust futex patch in the -rt tree, he
found a handful of new races and we were talking about it and were analyzing
the situation. At that point a fundamentally different solution occured to
me. This patchset (written in the past couple of days) implements that new
solution. Be warned though - the patchset does things we normally dont do in
Linux, so some might find the approach disturbing. Parental advice
recommended ;-)
New approach to robust futexes
------------------------------
At the heart of this new approach there is a per-thread private list of robust
locks that userspace is holding (maintained by glibc) - which userspace list
is registered with the kernel via a new syscall [this registration happens at
most once per thread lifetime]. At do_exit() time, the kernel checks this
user-space list: are there any robust futex locks to be cleaned up?
In the common case, at do_exit() time, there is no list registered, so the
cost of robust futexes is just a simple current->robust_list != NULL
comparison. If the thread has registered a list, then normally the list is
empty. If the thread/process crashed or terminated in some incorrect way then
the list might be non-empty: in this case the kernel carefully walks the list
[not trusting it], and marks all locks that are owned by this thread with the
FUTEX_OWNER_DEAD bit, and wakes up one waiter (if any).
The list is guaranteed to be private and per-thread, so it's lockless. There
is one race possible though: since adding to and removing from the list is
done after the futex is acquired by glibc, there is a few instructions window
for the thread (or process) to die there, leaving the futex hung. To protect
against this possibility, userspace (glibc) also maintains a simple per-thread
'list_op_pending' field, to allow the kernel to clean up if the thread dies
after acquiring the lock, but just before it could have added itself to the
list. Glibc sets this list_op_pending field before it tries to acquire the
futex, and clears it after the list-add (or list-remove) has finished.
That's all that is needed - all the rest of robust-futex cleanup is done in
userspace [just like with the previous patches].
Ulrich Drepper has implemented the necessary glibc support for this new
mechanism, which fully enables robust mutexes. (Ulrich plans to commit these
changes to glibc-HEAD later today.)
Key differences of this userspace-list based approach, compared to the vma
based method:
- it's much, much faster: at thread exit time, there's no need to loop
over every vma (!), which the VM-based method has to do. Only a very
simple 'is the list empty' op is done.
- no VM changes are needed - 'struct address_space' is left alone.
- no registration of individual locks is needed: robust mutexes dont need
any extra per-lock syscalls. Robust mutexes thus become a very lightweight
primitive - so they dont force the application designer to do a hard choice
between performance and robustness - robust mutexes are just as fast.
- no per-lock kernel allocation happens.
- no resource limits are needed.
- no kernel-space recovery call (FUTEX_RECOVER) is needed.
- the implementation and the locking is "obvious", and there are no
interactions with the VM.
Performance
-----------
I have benchmarked the time needed for the kernel to process a list of 1
million (!) held locks, using the new method [on a 2GHz CPU]:
- with FUTEX_WAIT set [contended mutex]: 130 msecs
- without FUTEX_WAIT set [uncontended mutex]: 30 msecs
I have also measured an approach where glibc does the lock notification [which
it currently does for !pshared robust mutexes], and that took 256 msecs -
clearly slower, due to the 1 million FUTEX_WAKE syscalls userspace had to do.
(1 million held locks are unheard of - we expect at most a handful of locks to
be held at a time. Nevertheless it's nice to know that this approach scales
nicely.)
Implementation details
----------------------
The patch adds two new syscalls: one to register the userspace list, and one
to query the registered list pointer:
asmlinkage long
sys_set_robust_list(struct robust_list_head __user *head,
size_t len);
asmlinkage long
sys_get_robust_list(int pid, struct robust_list_head __user **head_ptr,
size_t __user *len_ptr);
List registration is very fast: the pointer is simply stored in
current->robust_list. [Note that in the future, if robust futexes become
widespread, we could extend sys_clone() to register a robust-list head for new
threads, without the need of another syscall.]
So there is virtually zero overhead for tasks not using robust futexes, and
even for robust futex users, there is only one extra syscall per thread
lifetime, and the cleanup operation, if it happens, is fast and
straightforward. The kernel doesnt have any internal distinction between
robust and normal futexes.
If a futex is found to be held at exit time, the kernel sets the highest bit
of the futex word:
#define FUTEX_OWNER_DIED 0x40000000
and wakes up the next futex waiter (if any). User-space does the rest of
the cleanup.
Otherwise, robust futexes are acquired by glibc by putting the TID into the
futex field atomically. Waiters set the FUTEX_WAITERS bit:
#define FUTEX_WAITERS 0x80000000
and the remaining bits are for the TID.
Testing, architecture support
-----------------------------
I've tested the new syscalls on x86 and x86_64, and have made sure the parsing
of the userspace list is robust [ ;-) ] even if the list is deliberately
corrupted.
i386 and x86_64 syscalls are wired up at the moment, and Ulrich has tested the
new glibc code (on x86_64 and i386), and it works for his robust-mutex
testcases.
All other architectures should build just fine too - but they wont have the
new syscalls yet.
Architectures need to implement the new futex_atomic_cmpxchg_inuser() inline
function before writing up the syscalls (that function returns -ENOSYS right
now).
This patch:
Add placeholder futex_atomic_cmpxchg_inuser() implementations to every
architecture that supports futexes. It returns -ENOSYS.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Acked-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Just about every architecture defines some macros to do operations on pfns.
They're all virtually identical. This patch consolidates all of them.
One minor glitch is that at least i386 uses them in a very skeletal header
file. To keep away from #include dependency hell, I stuck the new
definitions in a new, isolated header.
Of all of the implementations, sh64 is the only one that varied by a bit.
It used some masks to ensure that any sign-extension got ripped away before
the arithmetic is done. This has been posted to that sh64 maintainers and
the development list.
Compiles on x86, x86_64, ia64 and ppc64.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add a new sched domain for representing multi-core with shared caches
between cores. Consider a dual package system, each package containing two
cores and with last level cache shared between cores with in a package. If
there are two runnable processes, with this appended patch those two
processes will be scheduled on different packages.
On such systems, with this patch we have observed 8% perf improvement with
specJBB(2 warehouse) benchmark and 35% improvement with CFP2000 rate(with 2
users).
This new domain will come into play only on multi-core systems with shared
caches. On other systems, this sched domain will be removed by domain
degeneration code. This new domain can be also used for implementing power
savings policy (see OLS 2005 CMP kernel scheduler paper for more details..
I will post another patch for power savings policy soon)
Most of the arch/* file changes are for cpu_coregroup_map() implementation.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
