From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754105Ab3AJPba (ORCPT ); Thu, 10 Jan 2013 10:31:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:13029 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753679Ab3AJPb3 (ORCPT ); Thu, 10 Jan 2013 10:31:29 -0500 Message-ID: <50EEDEC1.9020708@redhat.com> Date: Thu, 10 Jan 2013 10:31:13 -0500 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Mike Galbraith CC: linux-kernel@vger.kernel.org, aquini@redhat.com, walken@google.com, eric.dumazet@gmail.com, lwoodman@redhat.com, jeremy@goop.org, Jan Beulich , knoel@redhat.com, chegu_vinod@hp.com, raghavendra.kt@linux.vnet.ibm.com, mingo@redhat.com Subject: Re: [PATCH 0/5] x86,smp: make ticket spinlock proportional backoff w/ auto tuning References: <20130108172632.1126898a@annuminas.surriel.com> <1357831182.5841.21.camel@marge.simpson.net> In-Reply-To: <1357831182.5841.21.camel@marge.simpson.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/10/2013 10:19 AM, Mike Galbraith wrote: > On Tue, 2013-01-08 at 17:26 -0500, Rik van Riel wrote: > >> Please let me know if you manage to break this code in any way, >> so I can fix it... > > I didn't break it, but did let it play with rq->lock contention. Using > cyclictest -Smp99 -i 100 -d 0, with 3 rt tasks for pull_rt_task() to > pull around appears to have been a ~dead heat. Good to hear that the code seems to be robust. It seems to help prevent performance degradation in some workloads, and nobody seems to have found regressions yet. Thank you for testing.