From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932502Ab2GFGWo (ORCPT ); Fri, 6 Jul 2012 02:22:44 -0400 Received: from terminus.zytor.com ([198.137.202.10]:49001 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932257Ab2GFGWm (ORCPT ); Fri, 6 Jul 2012 02:22:42 -0400 Date: Thu, 5 Jul 2012 23:22:27 -0700 From: tip-bot for Prashanth Nageshappa Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, a.p.zijlstra@chello.nl, tglx@linutronix.de, prashanth@linux.vnet.ibm.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, tglx@linutronix.de, prashanth@linux.vnet.ibm.com In-Reply-To: <4FE06EEF.2090709@linux.vnet.ibm.com> References: <4FE06EEF.2090709@linux.vnet.ibm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched: Reset loop counters if all tasks are pinned and we need to redo load balance Git-Commit-ID: 4d44f7090f8233f6994e7397679a32c81187506d 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-4.2.6 (terminus.zytor.com [127.0.0.1]); Thu, 05 Jul 2012 23:22:32 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 4d44f7090f8233f6994e7397679a32c81187506d Gitweb: http://git.kernel.org/tip/4d44f7090f8233f6994e7397679a32c81187506d Author: Prashanth Nageshappa AuthorDate: Tue, 19 Jun 2012 17:52:07 +0530 Committer: Ingo Molnar CommitDate: Thu, 5 Jul 2012 21:09:10 +0200 sched: Reset loop counters if all tasks are pinned and we need to redo load balance While load balancing, if all tasks on the source runqueue are pinned, we retry after excluding the corresponding source cpu. However, loop counters env.loop and env.loop_break are not reset before retrying, which can lead to failure in moving the tasks. In this patch we reset env.loop and env.loop_break to their inital values before we retry. Signed-off-by: Prashanth Nageshappa Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/4FE06EEF.2090709@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 39b5771..3f94840 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4497,8 +4497,11 @@ more_balance: /* All tasks on this runqueue were pinned by CPU affinity */ if (unlikely(env.flags & LBF_ALL_PINNED)) { cpumask_clear_cpu(cpu_of(busiest), cpus); - if (!cpumask_empty(cpus)) + if (!cpumask_empty(cpus)) { + env.loop = 0; + env.loop_break = sched_nr_migrate_break; goto redo; + } goto out_balanced; } }