From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754263Ab1GBK10 (ORCPT ); Sat, 2 Jul 2011 06:27:26 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:60345 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753993Ab1GBK1Z (ORCPT ); Sat, 2 Jul 2011 06:27:25 -0400 Date: Sat, 2 Jul 2011 12:27:21 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: Paul Turner , linux-kernel@vger.kernel.org, Mike Galbraith Subject: Re: [patch 1/1] sched: update_curr versus correct cfs_rq in check_preempt_wakeup Message-ID: <20110702102721.GE17482@elte.hu> References: <20110702005222.262883892@google.com> <20110702005228.481583467@google.com> <20110702090817.GB17482@elte.hu> <1309600625.10073.8.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1309600625.10073.8.camel@twins> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes 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 * Peter Zijlstra wrote: > On Sat, 2011-07-02 at 11:08 +0200, Ingo Molnar wrote: > > * Paul Turner wrote: > > > > > We update_curr() versus the current entity as the preemption > > > decision is based on the relative vruntime. However, update_curr() > > > is not hierarchical and in the group scheduling case > > > find_matching_se() will have us making the comparison on a cfs_rq > > > different to the one just updated. > > > > Would be nice to include more contextual information in the > > changelog: how did you find it, what effect (if any) did you see > > from this patch, what effect do you expect others to see (if > > any). > > Agreed that the Changelog can be improved. From talking to pjt on > IRC though, I think he spotted this by reading through the code. 'code review' is a perfect answer to the 'how did you find it' question: when people read the changelog they will know that no practical effect has been observed (yet). Thanks, Ingo