From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932227AbeBLSLH (ORCPT ); Mon, 12 Feb 2018 13:11:07 -0500 Received: from outbound-smtp02.blacknight.com ([81.17.249.8]:51340 "EHLO outbound-smtp02.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751259AbeBLSLG (ORCPT ); Mon, 12 Feb 2018 13:11:06 -0500 Date: Mon, 12 Feb 2018 18:11:04 +0000 From: Mel Gorman To: Peter Zijlstra Cc: Mike Galbraith , Matt Fleming , LKML Subject: Re: [PATCH 2/2] sched/numa: Delay retrying placement for automatic NUMA balance after wake_affine Message-ID: <20180212181104.ynmpzlexuksn5oi6@techsingularity.net> References: <20180212171131.26139-1-mgorman@techsingularity.net> <20180212171131.26139-3-mgorman@techsingularity.net> <20180212173743.GB25201@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20180212173743.GB25201@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 Mon, Feb 12, 2018 at 06:37:43PM +0100, Peter Zijlstra wrote: > On Mon, Feb 12, 2018 at 05:11:31PM +0000, Mel Gorman wrote: > > +static void > > +update_wa_numa_placement(struct task_struct *p, int prev_cpu, int target) > > +{ > > + unsigned long interval; > > + > > + if (!static_branch_likely(&sched_numa_balancing)) > > + return; > > + > > + /* If balancing has no preference then accept the target */ > > + if (p->numa_preferred_nid == -1) > > + return; > > + > > + /* If the wakeup is not affecting locality then accept the target */ > > + if (cpus_share_cache(prev_cpu, target)) > > + return; > > Both the above comments speak of 'accepting' the target, but its a void > function, there's nothing they can do about it. It cannot not accept the > placement. > It's stale phrasing from an initial prototype that tried altering the placement which failed miserably. I'll fix it. -- Mel Gorman SUSE Labs