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. Cc: chegu_vinod@hp.com Cc: paulmck@linux.vnet.ibm.com 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: mingo@kernel.org Cc: scott.norton@hp.com Signed-off-by: Jason Low Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1390936396-3962-2-git-send-email-jason.low2@hp.com --- kernel/locking/mutex.c | 3 +++ 1 file changed, 3 insertions(+) --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -166,6 +166,9 @@ static inline int mutex_can_spin_on_owne struct task_struct *owner; int retval = 1; + if (need_resched()) + return 0; + rcu_read_lock(); owner = ACCESS_ONCE(lock->owner); if (owner) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/