From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935188AbbGHP0m (ORCPT ); Wed, 8 Jul 2015 11:26:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39467 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758265AbbGHP0i (ORCPT ); Wed, 8 Jul 2015 11:26:38 -0400 Message-ID: <559D4128.2080606@redhat.com> Date: Wed, 08 Jul 2015 11:26:32 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Ingo Molnar , Srikar Dronamraju CC: Peter Zijlstra , linux-kernel@vger.kernel.org, Mel Gorman Subject: Re: [PATCH] sched/numa: Restore sched feature NUMA to its earlier avatar. References: <1436361633-4970-1-git-send-email-srikar@linux.vnet.ibm.com> <20150708135644.GC23380@gmail.com> In-Reply-To: <20150708135644.GC23380@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/08/2015 09:56 AM, Ingo Molnar wrote: > > * Srikar Dronamraju wrote: > >> In commit:8a9e62a "sched/numa: Prefer NUMA hotness over cache hotness" >> sched feature NUMA was always set to true. However this sched feature was >> suppose to be enabled on NUMA boxes only thro set_numabalancing_state(). >> >> To get back to the above behaviour, bring back NUMA_FAVOUR_HIGHER feature. > > Three typos and a non-standard commit ID reference. > >> /* >> + * NUMA_FAVOUR_HIGHER will favor moving tasks towards nodes where a >> + * higher number of hinting faults are recorded during active load >> + * balancing. It will resist moving tasks towards nodes where a lower >> + * number of hinting faults have been recorded. >> */ >> -SCHED_FEAT(NUMA, true) >> +SCHED_FEAT(NUMA_FAVOUR_HIGHER, true) >> #endif >> > > So the comment spells 'favor' American, the constant you introduce is British > spelling via 'FAVOUR'? Please use it consistently! > > Also, this name is totally non-intuitive. > > Make it something like NUMA_FAVOR_BUSY_NODES or so? It is not about relocating tasks to busier nodes. The scheduler still moves tasks from busier nodes to idler nodes. This code makes the scheduler more prone to move tasks from nodes where they have fewer NUMA faults, to nodes where they have more. Not sure what a good name would be to describe that... -- All rights reversed