Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932179AbaA1TN0 (ORCPT ); Tue, 28 Jan 2014 14:13:26 -0500 Received: from g4t0014.houston.hp.com ([15.201.24.17]:32439 "EHLO g4t0014.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755461AbaA1TNY (ORCPT ); Tue, 28 Jan 2014 14:13:24 -0500 From: Jason Low 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, andi@firstfloor.org, aswin@hp.com, scott.norton@hp.com, chegu_vinod@hp.com Subject: [PATCH v2 1/5] mutex: In mutex_can_spin_on_owner(), return false if task need_resched() Date: Tue, 28 Jan 2014 11:13:12 -0800 Message-Id: <1390936396-3962-2-git-send-email-jason.low2@hp.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1390936396-3962-1-git-send-email-jason.low2@hp.com> References: <1390936396-3962-1-git-send-email-jason.low2@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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 -- 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/