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| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-24 12:21:02 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-24 12:21:02 -0700 |
| commit | 3b6c5507a69861e80c26f21d04601c674cbeec3d (patch) | |
| tree | 339c0761121f5a20d0573c3af3177af87e00e09f | |
| parent | guard page for stacks that grow upwards (diff) | |
| parent | mutex: Improve the scalability of optimistic spinning (diff) | |
| download | linux-dev-3b6c5507a69861e80c26f21d04601c674cbeec3d.tar.xz linux-dev-3b6c5507a69861e80c26f21d04601c674cbeec3d.zip | |
Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
mutex: Improve the scalability of optimistic spinning
| -rw-r--r-- | kernel/sched.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 41541d79e3c8..09b574e7f4df 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3865,8 +3865,16 @@ int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) /* * Owner changed, break to re-assess state. */ - if (lock->owner != owner) + if (lock->owner != owner) { + /* + * If the lock has switched to a different owner, + * we likely have heavy contention. Return 0 to quit + * optimistic spinning and not contend further: + */ + if (lock->owner) + return 0; break; + } /* * Is that owner really running on that cpu? |