Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932905AbdIFQO3 (ORCPT ); Wed, 6 Sep 2017 12:14:29 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:33817 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754626AbdIFQOZ (ORCPT ); Wed, 6 Sep 2017 12:14:25 -0400 Date: Wed, 6 Sep 2017 18:14:22 +0200 From: Peter Zijlstra To: Andy Lutomirski Cc: Andy Lutomirski , Ingo Molnar , "linux-kernel@vger.kernel.org" Subject: Re: Abysmal scheduler performance in Linus' tree? Message-ID: <20170906161422.kvqe5y6b3ng6ouyu@hirez.programming.kicks-ass.net> References: <20170906082520.xgvo3hewje7jvdyo@hirez.programming.kicks-ass.net> <877A43A3-AC8F-4D7C-88E4-8E3D36B1DAFA@amacapital.net> <20170906090333.7v627vdyvhe3x2cs@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170906090333.7v627vdyvhe3x2cs@hirez.programming.kicks-ass.net> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 711 Lines: 17 On Wed, Sep 06, 2017 at 11:03:33AM +0200, Peter Zijlstra wrote: > On Wed, Sep 06, 2017 at 01:59:14AM -0700, Andy Lutomirski wrote: > > > Any specifics on your setup? > > > > On further fiddling, I only see this after a suspend and resume cycle. > > Ah, ok. That's not something I otherwise test. Lets see if I can force > this brick of mine through a suspend-resume cycle :-) I'd be suspicious of these here commits: 77d1dfda0e79 ("sched/topology, cpuset: Avoid spurious/wrong domain rebuilds") 09e0dd8e0f2e ("sched/topology: Avoid pointless rebuild") bbdacdfed2f5 ("sched/debug: Optimize sched_domain sysctl generation") I tested them with regular hotplug, but suspend resume always is a tad funny.