linux-toradex.git/kernel/mutex.c, branch tegra-10.9.9

Merge branch 'linus' into perfcounters/core

2009-06-11T15:55:42+00:00

Conflicts:
	arch/x86/kernel/irqinit.c
	arch/x86/kernel/irqinit_64.c
	arch/x86/kernel/traps.c
	arch/x86/mm/fault.c
	include/linux/sched.h
	kernel/exit.c

Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-06-10T23:19:40+00:00

* 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  spinlock: Add missing __raw_spin_lock_flags() stub for UP
  mutex: add atomic_dec_and_mutex_lock(), fix
  locking, rtmutex.c: Documentation cleanup
  mutex: add atomic_dec_and_mutex_lock()

Merge commit 'v2.6.30-rc5' into sched/core

2009-05-11T10:59:37+00:00

Merge reason: sched/core was on .30-rc1 before, update to latest fixes

Signed-off-by: Ingo Molnar

Merge branch 'core/locking' into perfcounters/core

2009-05-06T06:47:26+00:00

Merge reason: we moved a mutex.h commit that originated from the
              perfcounters tree into core/locking - but now merge
	      back that branch to solve a merge artifact and to
	      pick up cleanups of this commit that happened in
	      core/locking.

Signed-off-by: Ingo Molnar

mutex: add atomic_dec_and_mutex_lock(), fix

2009-04-30T07:01:34+00:00

include/linux/mutex.h:136: warning: 'mutex_lock' declared inline after being called
 include/linux/mutex.h:136: warning: previous declaration of 'mutex_lock' was here

uninline it.

[ Impact: clean up and uninline, address compiler warning ]

Signed-off-by: Andrew Morton 
Cc: Al Viro 
Cc: Christoph Hellwig 
Cc: Eric Paris 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
LKML-Reference: <200904292318.n3TNIsi6028340@imap1.linux-foundation.org>
Signed-off-by: Ingo Molnar

Merge branch 'linus' into perfcounters/core

2009-04-29T12:47:05+00:00

Merge reason: This brach was on -rc1, refresh it to almost-rc4 to pick up
              the latest upstream fixes.

Signed-off-by: Ingo Molnar

sched: remove extra call overhead for schedule()

2009-04-20T18:49:53+00:00

Lai Jiangshan's patch reminded me that I promised Nick to remove
that extra call overhead in schedule().

Signed-off-by: Peter Zijlstra 
LKML-Reference: <20090313112300.927414207@chello.nl>
Signed-off-by: Ingo Molnar

mutex: have non-spinning mutexes on s390 by default

2009-04-09T17:28:24+00:00

Impact: performance regression fix for s390

The adaptive spinning mutexes will not always do what one would expect on
virtualized architectures like s390. Especially the cpu_relax() loop in
mutex_spin_on_owner might hurt if the mutex holding cpu has been scheduled
away by the hypervisor.

We would end up in a cpu_relax() loop when there is no chance that the
state of the mutex changes until the target cpu has been scheduled again by
the hypervisor.

For that reason we should change the default behaviour to no-spin on s390.

We do have an instruction which allows to yield the current cpu in favour of
a different target cpu. Also we have an instruction which allows us to figure
out if the target cpu is physically backed.

However we need to do some performance tests until we can come up with
a solution that will do the right thing on s390.

Signed-off-by: Heiko Carstens 
Acked-by: Peter Zijlstra 
Cc: Martin Schwidefsky 
Cc: Christian Borntraeger 
LKML-Reference: <20090409184834.7a0df7b2@osiris.boeblingen.de.ibm.com>
Signed-off-by: Ingo Molnar

mutex: drop "inline" from mutex_lock() inside kernel/mutex.c

2009-04-06T07:30:27+00:00

Impact: build fix

mutex_lock() is was defined inline in kernel/mutex.c, but wasn't
declared so not in .  This didn't cause a problem until
checkin 3a2d367d9aabac486ac4444c6c7ec7a1dab16267 added the
atomic_dec_and_mutex_lock() inline in between declaration and
definion.

This broke building with CONFIG_ALLOW_WARNINGS=n, e.g. make
allnoconfig.

Either from the source code nor the allnoconfig binary output I cannot
find any internal references to mutex_lock() in kernel/mutex.c, so
presumably this "inline" is now-useless legacy.

Cc: Eric Paris 
Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Orig-LKML-Reference: 
Signed-off-by: H. Peter Anvin

mutex: adaptive spinnning, performance tweaks

2009-01-14T18:03:54+00:00

Spin more agressively. This is less fair but also markedly faster.

The numbers:

 * dbench 50 (higher is better):
  spin        1282MB/s
  v10         548MB/s
  v10 no wait 1868MB/s

 * 4k creates (numbers in files/second higher is better):
  spin        avg 200.60 median 193.20 std 19.71 high 305.93 low 186.82
  v10         avg 180.94 median 175.28 std 13.91 high 229.31 low 168.73
  v10 no wait avg 232.18 median 222.38 std 22.91 high 314.66 low 209.12

 * File stats (numbers in seconds, lower is better):
  spin        2.27s
  v10         5.1s
  v10 no wait 1.6s

( The source changes are smaller than they look, I just moved the
  need_resched checks in __mutex_lock_common after the cmpxchg. )

Signed-off-by: Chris Mason 
Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar