From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752767AbbBRRLK (ORCPT ); Wed, 18 Feb 2015 12:11:10 -0500 Received: from terminus.zytor.com ([198.137.202.10]:39152 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753478AbbBRRLD (ORCPT ); Wed, 18 Feb 2015 12:11:03 -0500 Date: Wed, 18 Feb 2015 09:10:29 -0800 From: tip-bot for Jan Beulich Message-ID: Cc: mingo@kernel.org, JBeulich@suse.com, jbeulich@suse.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, tglx@linutronix.de, hpa@zytor.com Reply-To: jbeulich@suse.com, JBeulich@suse.com, mingo@kernel.org, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, hpa@zytor.com, peterz@infradead.org, tglx@linutronix.de In-Reply-To: <20150209113727.GS5029@twins.programming.kicks-ass.net> References: <20150209113727.GS5029@twins.programming.kicks-ass.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/numa: Avoid some pointless iterations Git-Commit-ID: 890a5409f9d0c84d75a1e16eebdfe91d8a57ef1e X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 890a5409f9d0c84d75a1e16eebdfe91d8a57ef1e Gitweb: http://git.kernel.org/tip/890a5409f9d0c84d75a1e16eebdfe91d8a57ef1e Author: Jan Beulich AuthorDate: Mon, 9 Feb 2015 12:30:00 +0100 Committer: Ingo Molnar CommitDate: Wed, 18 Feb 2015 16:18:02 +0100 sched/numa: Avoid some pointless iterations Commit 81907478c431 ("sched/fair: Avoid using uninitialized variable in preferred_group_nid()") unconditionally initializes max_group with NODE_MASK_NONE, this means that when !max_faults (max_group didn't get set), we'll now continue the iteration with an empty mask. Which in turn makes the actual body of the loop go away, so we'll just iterate until completion; short circuit this by breaking out of the loop as soon as this would happen. Signed-off-by: Jan Beulich Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20150209113727.GS5029@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 28cbaca..ee595ef 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1774,6 +1774,8 @@ static int preferred_group_nid(struct task_struct *p, int nid) } } /* Next round, evaluate the nodes within max_group. */ + if (!max_faults) + break; nodes = max_group; } return nid;