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From: Jason Low <jason.low2@hp.com>
To: mingo@redhat.com, peterz@infradead.org,
	paulmck@linux.vnet.ibm.com, Waiman.Long@hp.com,
	torvalds@linux-foundation.org, tglx@linutronix.de,
	jason.low2@hp.com
Cc: linux-kernel@vger.kernel.org, riel@redhat.com,
	akpm@linux-foundation.org, davidlohr@hp.com, hpa@zytor.com,
	aswin@hp.com, scott.norton@hp.com
Subject: [RFC 1/3] mutex: In mutex_can_spin_on_owner(), return false if task need_resched()
Date: Tue, 14 Jan 2014 16:33:08 -0800	[thread overview]
Message-ID: <1389745990-7069-2-git-send-email-jason.low2@hp.com> (raw)
In-Reply-To: <1389745990-7069-1-git-send-email-jason.low2@hp.com>

The mutex_can_spin_on_owner() function should also return false if the
task needs to be rescheduled.

Signed-off-by: Jason Low <jason.low2@hp.com>
---
 kernel/locking/mutex.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 4dd6e4c..85c6be1 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -212,6 +212,9 @@ 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)
-- 
1.7.1


  reply	other threads:[~2014-01-15  0:33 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-15  0:33 [RFC 0/3] mutex: Reduce spinning contention when there is no lock owner Jason Low
2014-01-15  0:33 ` Jason Low [this message]
2014-01-15  7:44   ` [RFC 1/3] mutex: In mutex_can_spin_on_owner(), return false if task need_resched() Peter Zijlstra
2014-01-15  7:48     ` Peter Zijlstra
2014-01-15 20:37       ` Paul E. McKenney
2014-01-15  0:33 ` [RFC 2/3] mutex: Modify the way optimistic spinners are queued Jason Low
2014-01-15 15:10   ` Waiman Long
2014-01-15 19:23     ` Jason Low
2014-01-15  0:33 ` [RFC 3/3] mutex: When there is no owner, stop spinning after too many tries Jason Low
2014-01-15  1:00   ` Andrew Morton
2014-01-15  7:04     ` Jason Low
2014-01-15  1:06   ` Davidlohr Bueso
2014-01-15  7:34     ` Jason Low
2014-01-15 15:19   ` Waiman Long
2014-01-16  2:45   ` Jason Low
2014-01-16  3:14     ` Linus Torvalds
2014-01-16  6:46       ` Jason Low
2014-01-16 12:05         ` Peter Zijlstra
2014-01-16 20:48           ` Jason Low

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