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authorJason Low <jason.low2@hp.com>2014-01-28 20:13:12 +0100
committerIngo Molnar <mingo@kernel.org>2014-03-11 12:14:52 +0100
commit46af29e479cc0c1c63633007993af5292c2c3e75 (patch)
tree2d229487a929757e062cd9765263023ef762f1f9 /kernel/locking
parentlocking: Move mcs_spinlock.h into kernel/locking/ (diff)
downloadlinux-46af29e479cc0c1c63633007993af5292c2c3e75.tar.xz
linux-46af29e479cc0c1c63633007993af5292c2c3e75.zip
locking/mutexes: Return false if task need_resched() in mutex_can_spin_on_owner()
The mutex_can_spin_on_owner() function should also return false if the task needs to be rescheduled to avoid entering the MCS queue when it needs to reschedule. Signed-off-by: Jason Low <jason.low2@hp.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Waiman.Long@hp.com Cc: torvalds@linux-foundation.org Cc: tglx@linutronix.de Cc: riel@redhat.com Cc: akpm@linux-foundation.org Cc: davidlohr@hp.com Cc: hpa@zytor.com Cc: andi@firstfloor.org Cc: aswin@hp.com Cc: scott.norton@hp.com Cc: chegu_vinod@hp.com Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1390936396-3962-2-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/mutex.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 4f408be39a07..e6d646b18d6c 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -166,6 +166,9 @@ static inline int mutex_can_spin_on_owner(struct mutex *lock)
struct task_struct *owner;
int retval = 1;
+ if (need_resched())
+ return 0;
+
rcu_read_lock();
owner = ACCESS_ONCE(lock->owner);
if (owner)