From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751257AbbFRAzs (ORCPT ); Wed, 17 Jun 2015 20:55:48 -0400 Received: from mail-wg0-f49.google.com ([74.125.82.49]:36226 "EHLO mail-wg0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751476AbbFRAzl (ORCPT ); Wed, 17 Jun 2015 20:55:41 -0400 Message-ID: <1434588939.3444.25.camel@gmail.com> Subject: Re: [PATCH RESEND] sched: prefer an idle cpu vs an idle sibling for BALANCE_WAKE From: Mike Galbraith To: Josef Bacik Cc: Peter Zijlstra , riel@redhat.com, mingo@redhat.com, linux-kernel@vger.kernel.org, morten.rasmussen@arm.com Date: Thu, 18 Jun 2015 02:55:39 +0200 In-Reply-To: <5581B70D.2000800@fb.com> References: <1432761736-22093-1-git-send-email-jbacik@fb.com> <20150528102127.GD3644@twins.programming.kicks-ass.net> <20150528110514.GR18673@twins.programming.kicks-ass.net> <1434087305.3674.26.camel@gmail.com> <5581B70D.2000800@fb.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.11 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2015-06-17 at 11:06 -0700, Josef Bacik wrote: > On 06/11/2015 10:35 PM, Mike Galbraith wrote: > > On Thu, 2015-05-28 at 13:05 +0200, Peter Zijlstra wrote: > > If sd == NULL, we fall through and try to pull wakee despite nacked-by > > tsk_cpus_allowed() or wake_affine(). > > > > So maybe add a check in the if (sd_flag & SD_BALANCE_WAKE) for something > like this > > if (tmp >= 0) { > new_cpu = tmp; > goto unlock; > } else if (!want_affine) { > new_cpu = prev_cpu; > } > > so we can make sure we're not being pushed onto a cpu that we aren't > allowed on? Thanks, The buglet is a messenger methinks. You saying the patch helped without SD_BALANCE_WAKE being set is why I looked. The buglet would seem to say that preferring cache is not harming your load after all. It now sounds as though wake_wide() may be what you're squabbling with. Things aren't adding up all that well. -Mike