From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422637Ab3AXUQX (ORCPT ); Thu, 24 Jan 2013 15:16:23 -0500 Received: from terminus.zytor.com ([198.137.202.10]:34435 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161002Ab3AXUQK (ORCPT ); Thu, 24 Jan 2013 15:16:10 -0500 Date: Thu, 24 Jan 2013 12:15:35 -0800 From: tip-bot for Zhu Yanhai Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, pjt@google.com, peterz@infradead.org, rostedt@goodmis.org, akpm@linux-foundation.org, tglx@linutronix.de, gaoyang.zyh@taobao.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, pjt@google.com, rostedt@goodmis.org, akpm@linux-foundation.org, tglx@linutronix.de, gaoyang.zyh@taobao.com In-Reply-To: <1357621012-15039-1-git-send-email-gaoyang.zyh@taobao.com> References: <1357621012-15039-1-git-send-email-gaoyang.zyh@taobao.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched: Fix the broken sched_rr_get_interval() Git-Commit-ID: a59f4e079d19464eebb9b06513a1d4f55fdae5ba 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 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (terminus.zytor.com [127.0.0.1]); Thu, 24 Jan 2013 12:15:42 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: a59f4e079d19464eebb9b06513a1d4f55fdae5ba Gitweb: http://git.kernel.org/tip/a59f4e079d19464eebb9b06513a1d4f55fdae5ba Author: Zhu Yanhai AuthorDate: Tue, 8 Jan 2013 12:56:52 +0800 Committer: Ingo Molnar CommitDate: Thu, 24 Jan 2013 14:41:00 +0100 sched: Fix the broken sched_rr_get_interval() The caller of sched_sliced() should pass se.cfs_rq and se as the arguments, however in sched_rr_get_interval() we gave it rq.cfs_rq and se, which made the following computation obviously wrong. The change was introduced by commit: 77034937dc45 sched: fix crash in sys_sched_rr_get_interval() ... 5 years ago, while it had been the correct 'cfs_rq_of' before the commit. The change seems to be irrelevant to the commit msg, which was to return a 0 timeslice for tasks that are on an idle runqueue. So I believe that was just a plain typo. Signed-off-by: Zhu Yanhai Cc: Peter Zijlstra Cc: Paul Turner Cc: Thomas Gleixner Cc: Steven Rostedt Cc: Andrew Morton Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1357621012-15039-1-git-send-email-gaoyang.zyh@taobao.com [ Since this is an ABI and an old bug, we'll test this via a slow upstream route, to hopefully discover any app breakage. ] Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 5eea870..a7a19ff 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6101,7 +6101,7 @@ static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task * idle runqueue: */ if (rq->cfs.load.weight) - rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); + rr_interval = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se)); return rr_interval; }