From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757099AbdLPS2O (ORCPT ); Sat, 16 Dec 2017 13:28:14 -0500 Received: from outbound-smtp14.blacknight.com ([46.22.139.231]:56012 "EHLO outbound-smtp14.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756846AbdLPS2K (ORCPT ); Sat, 16 Dec 2017 13:28:10 -0500 Date: Sat, 16 Dec 2017 18:28:08 +0000 From: Mel Gorman To: Mike Galbraith Cc: Peter Zijlstra , Ingo Molnar , linux-kernel@vger.kernel.org, Matt Fleming Subject: Re: [PATCH] sched: Only migrate tasks due to interrupts on an idle CPU if prev and target CPUs share cache Message-ID: <20171216182808.gc63wdzpxqw5p732@techsingularity.net> References: <20171215165241.ckrs7c6zobjj6rcx@techsingularity.net> <1513370286.11185.136.camel@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1513370286.11185.136.camel@gmx.de> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 15, 2017 at 09:38:06PM +0100, Mike Galbraith wrote: > On Fri, 2017-12-15 at 16:52 +0000, Mel Gorman wrote: > > > > It's a small improvement... > > From my log on corr.arch.suse.de (2x8 box) > > 4.15.0.g2db767d-default > Throughput 2665.88 MB/sec  8 clients  8 procs  max_latency=21.472 ms > 4.15.0.g2db767d-default NO_WA_IDLE > Throughput 3416.35 MB/sec  8 clients  8 procs  max_latency=9.825 ms > > Not so small improvement.  WA_IDLE ripped corr up pretty bad, turning > it off restored 4.4 performance. > Sounds plausible. I expect it depends on the remote access latency as well as whether the data gets prefetched fast enough. -- Mel Gorman SUSE Labs