From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752011AbaAQJzK (ORCPT ); Fri, 17 Jan 2014 04:55:10 -0500 Received: from merlin.infradead.org ([205.233.59.134]:58618 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751701AbaAQJzH (ORCPT ); Fri, 17 Jan 2014 04:55:07 -0500 Date: Fri, 17 Jan 2014 10:54:59 +0100 From: Peter Zijlstra To: riel@redhat.com Cc: linux-kernel@vger.kernel.org, linux-mm@vger.kernel.org, mingo@redhat.com, chegu_vinod@hp.com, mgorman@suse.de, Rik van Riel Subject: Re: [PATCH 6/6] numa,sched: normalize faults_from stats and weigh by CPU use Message-ID: <20140117095459.GF11314@laptop.programming.kicks-ass.net> References: <1389939456-9541-1-git-send-email-riel@redhat.com> <1389939456-9541-7-git-send-email-riel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1389939456-9541-7-git-send-email-riel@redhat.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 17, 2014 at 01:17:36AM -0500, riel@redhat.com wrote: > + /* > + * Normalize the faults_from, so all tasks in a group > + * count according to CPU use, instead of by the raw > + * number of faults. This prevents the situation where > + * the garbage collector totally dominates the stats, > + * and the access patterns of the worker threads are > + * ignored. > + */ Instead of focusing on the one example (GC) here, I would suggest saying something along the lines of: Tasks with little runtime have little over-all impact on throughput and thus their faults are less important.