From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754171AbbA0O4b (ORCPT ); Tue, 27 Jan 2015 09:56:31 -0500 Received: from smtprelay0251.hostedemail.com ([216.40.44.251]:55727 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751888AbbA0O43 (ORCPT ); Tue, 27 Jan 2015 09:56:29 -0500 X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1539:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:3138:3139:3140:3141:3142:3165:3352:3622:3865:3866:3870:3872:5007:6119:6261:7875:10004:10400:10848:10967:11026:11232:11658:11914:12043:12296:12438:12517:12519:12555:12663:12740:13069:13311:13357:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: grain59_5575d20935e31 X-Filterd-Recvd-Size: 1720 Date: Tue, 27 Jan 2015 09:56:26 -0500 From: Steven Rostedt To: Peter Zijlstra Cc: Xunlei Pang , linux-kernel@vger.kernel.org, Juri Lelli Subject: Re: [PATCH 5/5] sched/rt: Optimize find_lowest_rq() to select a cache hot cpu Message-ID: <20150127095626.707e434d@gandalf.local.home> In-Reply-To: <20150127142136.GE21418@twins.programming.kicks-ass.net> References: <1421642980-10045-1-git-send-email-pang.xunlei@linaro.org> <1421642980-10045-5-git-send-email-pang.xunlei@linaro.org> <20150127142136.GE21418@twins.programming.kicks-ass.net> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 27 Jan 2015 15:21:36 +0100 Peter Zijlstra wrote: > On Mon, Jan 19, 2015 at 04:49:40AM +0000, Xunlei Pang wrote: > > In find_lowest_rq(), if we can't find a wake_affine cpu from > > sched_domain, then we can actually determine a cache hot cpu > > instead of simply calling "cpumask_any(lowest_mask)" which > > always returns the first cpu in the mask. > > > > So, we can determine the cache hot cpu during the interation of > > sched_domain() in passing. > > Steve, I'm not getting this. Why are we using WAKE_AFFINE here? > It originated from Gregory Haskins topology patches. See 6e1254d2c41215da27025add8900ed187bca121d -- Steve