From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752550AbbJJS4i (ORCPT ); Sat, 10 Oct 2015 14:56:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42473 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752440AbbJJS4g (ORCPT ); Sat, 10 Oct 2015 14:56:36 -0400 Date: Sat, 10 Oct 2015 20:53:15 +0200 From: Oleg Nesterov To: Peter Zijlstra Cc: heiko.carstens@de.ibm.com, Tejun Heo , Ingo Molnar , Rik van Riel , Thomas Gleixner , Vitaly Kuznetsov , linux-kernel@vger.kernel.org Subject: [PATCH 3/3] sched: don't scan all-offline ->cpus_allowed twice if !CONFIG_CPUSETS Message-ID: <20151010185315.GA24100@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151010185255.GA24075@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If CONFIG_CPUSETS=n then "case cpuset" changes the state and runs the already failed for_each_cpu() loop again for no reason. Signed-off-by: Oleg Nesterov --- kernel/sched/core.c | 12 +++++++----- 1 files changed, 7 insertions(+), 5 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e4fa6be..b421e24 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1335,13 +1335,15 @@ static int select_fallback_rq(int cpu, struct task_struct *p) goto out; } + /* No more Mr. Nice Guy. */ switch (state) { case cpuset: - /* No more Mr. Nice Guy. */ - cpuset_cpus_allowed_fallback(p); - state = possible; - break; - + if (IS_ENABLED(CONFIG_CPUSETS)) { + cpuset_cpus_allowed_fallback(p); + state = possible; + break; + } + /* fall-through */ case possible: do_set_cpus_allowed(p, cpu_possible_mask); state = fail; -- 1.5.5.1