Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751753Ab3I0L5d (ORCPT ); Fri, 27 Sep 2013 07:57:33 -0400 Received: from merlin.infradead.org ([205.233.59.134]:49719 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751078Ab3I0L52 (ORCPT ); Fri, 27 Sep 2013 07:57:28 -0400 Date: Fri, 27 Sep 2013 13:57:22 +0200 From: Peter Zijlstra To: Yuanhan Liu Cc: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, linux-tip-commits@vger.kernel.org, Fengguang Wu , Huang Ying , lkp@linux.intel.com Subject: Re: [tip:sched/core] sched: Add NEED_RESCHED to the preempt_count Message-ID: <20130927115722.GM3657@laptop.programming.kicks-ass.net> References: <20130927091427.GE24743@yliu-dev.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130927091427.GE24743@yliu-dev.sh.intel.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1457 Lines: 31 On Fri, Sep 27, 2013 at 05:14:27PM +0800, Yuanhan Liu wrote: > On Wed, Sep 25, 2013 at 09:38:38AM -0700, tip-bot for Peter Zijlstra wrote: > > Commit-ID: f27dde8deef33c9e58027df11ceab2198601d6a6 > > Gitweb: http://git.kernel.org/tip/f27dde8deef33c9e58027df11ceab2198601d6a6 > > Author: Peter Zijlstra > > AuthorDate: Wed, 14 Aug 2013 14:55:31 +0200 > > Committer: Ingo Molnar > > CommitDate: Wed, 25 Sep 2013 14:07:49 +0200 > > > > sched: Add NEED_RESCHED to the preempt_count > > Hi Peter, > > FYI, here we found a pigz regression by this commit. I just can't help myself; but pigs aren't supposed to fly anyway! :-) > Here is a list all of changed stats by this commit and it's parent 4a2b4b222743bb07fedf985b884550f2ca067ea9: > > time.involuntary_context_switches [ 3184 - 4753 ] [ 5.536e+05 - 5.9042e+05 ] > time.voluntary_context_switches [ 84559 - 1.2223e+05 ] [ 1.1008e+07 - 1.1092e+07 ] Gah, that looks like it completely wrecked preemptions. What kind of PREEMPT Kconfig options do you use? Or rather; could you attach your .config? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/