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authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-24 15:21:02 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-24 15:21:02 -0400
commit3b6c5507a69861e80c26f21d04601c674cbeec3d (patch)
tree339c0761121f5a20d0573c3af3177af87e00e09f /kernel
parent8ca3eb08097f6839b2206e2242db4179aee3cfb3 (diff)
parent9d0f4dcc5c4d1c5dd01172172684a45b5f49d740 (diff)
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
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched.c10
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)
3865 /* 3865 /*
3866 * Owner changed, break to re-assess state. 3866 * Owner changed, break to re-assess state.
3867 */ 3867 */
3868 if (lock->owner != owner) 3868 if (lock->owner != owner) {
3869 /*
3870 * If the lock has switched to a different owner,
3871 * we likely have heavy contention. Return 0 to quit
3872 * optimistic spinning and not contend further:
3873 */
3874 if (lock->owner)
3875 return 0;
3869 break; 3876 break;
3877 }
3870 3878
3871 /* 3879 /*
3872 * Is that owner really running on that cpu? 3880 * Is that owner really running on that cpu?