From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754581AbYIFRXp (ORCPT ); Sat, 6 Sep 2008 13:23:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752576AbYIFRXg (ORCPT ); Sat, 6 Sep 2008 13:23:36 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:57703 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752566AbYIFRXg (ORCPT ); Sat, 6 Sep 2008 13:23:36 -0400 Date: Sat, 6 Sep 2008 19:23:16 +0200 From: Ingo Molnar To: Max Krasnyansky Cc: linux-kernel@vger.kernel.org, svaidy@linux.vnet.ibm.com, peterz@infradead.org Subject: Re: [PATCH] sched: arch_reinit_sched_domains() must destroy domains to force rebuild Message-ID: <20080906172316.GK4856@elte.hu> References: <1220040701-3139-1-git-send-email-maxk@qualcomm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1220040701-3139-1-git-send-email-maxk@qualcomm.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Max Krasnyansky wrote: > What I realized recently is that calling rebuild_sched_domains() in > arch_reinit_sched_domains() by itself is not enough when cpusets are enabled. > partition_sched_domains() code is trying to avoid unnecessary domain rebuilds > and will not actually rebuild anything if new domain masks match the old ones. > > What this means is that doing > echo 1 > /sys/devices/system/cpu/sched_mc_power_savings > on a system with cpusets enabled will not take affect untill something changes > in the cpuset setup (ie new sets created or deleted). > > This patch fixes restore correct behaviour where domains must be rebuilt in > order to enable MC powersaving flags. > > Test on quad-core Core2 box with both CONFIG_CPUSETS and !CONFIG_CPUSETS. > Also tested on dual-core Core2 laptop. Lockdep is happy and things are working > as expected. > > Ingo, please apply. applied to tip/sched/cpuset, thanks Max. > btw We also need to push my other cpuset patch into mainline. [...] will push it once this has been tested some more. Ingo