From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964813AbeBMNaA (ORCPT ); Tue, 13 Feb 2018 08:30:00 -0500 Received: from outbound-smtp01.blacknight.com ([81.17.249.7]:43356 "EHLO outbound-smtp01.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935174AbeBMN37 (ORCPT ); Tue, 13 Feb 2018 08:29:59 -0500 Date: Tue, 13 Feb 2018 13:29:57 +0000 From: Mel Gorman To: Peter Zijlstra Cc: Mike Galbraith , Matt Fleming , LKML Subject: Re: [PATCH 1/2] sched/fair: Consider SD_NUMA when selecting the most idle group to schedule on Message-ID: <20180213132957.2c2lbsa5pd536oga@techsingularity.net> References: <20180212171131.26139-1-mgorman@techsingularity.net> <20180212171131.26139-2-mgorman@techsingularity.net> <20180213104541.GG25201@hirez.programming.kicks-ass.net> <20180213113548.tb7zxzly32oz3mfb@techsingularity.net> <20180213130445.GH25201@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20180213130445.GH25201@hirez.programming.kicks-ass.net> User-Agent: NeoMutt/20170912 (1.9.0) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 13, 2018 at 02:04:45PM +0100, Peter Zijlstra wrote: > On Tue, Feb 13, 2018 at 11:35:48AM +0000, Mel Gorman wrote: > > > However, if we have numa balancing enabled, that will counteract > > > the normal spreading across nodes, so in that regard it makes sense, but > > > the above code is not conditional on numa balancing. > > > > > > > It's not conditional on NUMA balancing because one case where it mattered > > was a fork-intensive workload driven by shell scripts. In that case, the > > workload benefits from preferring a local node without any involvement from > > NUMA balancing. I could make it conditional on it but it's not strictly > > related to automatic NUMA balancing, it's about being less eager about > > starting new children on remote nodes. > > Yeah, I suppose. And you're right, there's no real winning this. It's > all tea-leaves and entrails. > That is my new favourite description of this portion of the scheduler :D > In any case, I think I prefer the kill sync early variant and you were > going to ammend some comments. Can you respin and resend all these > patches (can do in a single series)? No problem. I had it prepared already and am just waiting for one result before I push send. Thanks. -- Mel Gorman SUSE Labs