From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932729AbcFOQDg (ORCPT ); Wed, 15 Jun 2016 12:03:36 -0400 Received: from mail-lf0-f42.google.com ([209.85.215.42]:34948 "EHLO mail-lf0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751737AbcFOQDd (ORCPT ); Wed, 15 Jun 2016 12:03:33 -0400 Message-ID: <1466006609.4219.40.camel@gmail.com> Subject: Re: [rfc patch] sched/fair: Use instantaneous load for fork/exec balancing From: Mike Galbraith To: Dietmar Eggemann , Peter Zijlstra Cc: Yuyang Du , LKML Date: Wed, 15 Jun 2016 18:03:29 +0200 In-Reply-To: <5761752A.6000606@arm.com> References: <1465891111.1694.13.camel@gmail.com> <5760115C.7040306@arm.com> <1465922407.3626.21.camel@gmail.com> <5761752A.6000606@arm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5 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, 2016-06-15 at 16:32 +0100, Dietmar Eggemann wrote: > > In general, the fuzz helps us to not be so spastic. I'm not sure that > > we really really need to care all that much, because I strongly suspect > > that it's only gonna make any difference at all in corner cases, but > > there are real world cases that matter. I know for fact that schbench > > (facebook) which is at least based on a real world load fails early due > > to us stacking tasks due to that fuzzy view of reality. In that case, > > it's because the fuzz consists of a high amplitude aging sawtooth.. > > ... only for fork/exec? No. Identical workers had longish work/sleep cycle, aging resulted in weights that ranged from roughly 300-700(ish), depending on when you peeked at them. -Mike