From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753037AbbGUHv3 (ORCPT ); Tue, 21 Jul 2015 03:51:29 -0400 Received: from mail-wg0-f45.google.com ([74.125.82.45]:34740 "EHLO mail-wg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752293AbbGUHv2 (ORCPT ); Tue, 21 Jul 2015 03:51:28 -0400 Date: Tue, 21 Jul 2015 09:51:21 +0200 From: Ingo Molnar To: Srikar Dronamraju Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, Rik van Riel , Mel Gorman Subject: Re: [PATCH] sched/numa: Disable sched_numa_balancing on uma systems Message-ID: <20150721075120.GB25542@gmail.com> References: <1436978557-24935-1-git-send-email-srikar@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1436978557-24935-1-git-send-email-srikar@linux.vnet.ibm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Srikar Dronamraju wrote: > Commit 2a1ed24 ("sched/numa: Prefer NUMA hotness over cache hotness") > sets sched feature NUMA to true. However this can enable numa hinting > faults on a uma system. > > This commit ensures that numa hinting faults occur only on a numa system > by setting/resetting sched_numa_balancing. > > This commit > - Renames numabalancing_enabled to sched_numa_balancing > - Makes sched_numa_balancing common to CONFIG_SCHED_DEBUG and > !CONFIG_SCHED_DEBUG. Earlier it was only in !CONFIG_SCHED_DEBUG > - Checks for sched_numa_balancing instead of sched_feat(NUMA) > > Signed-off-by: Srikar Dronamraju > --- > kernel/sched/core.c | 16 ++++++---------- > kernel/sched/fair.c | 8 ++++---- > kernel/sched/sched.h | 10 ++-------- > 3 files changed, 12 insertions(+), 22 deletions(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 78b4bad10..4722f5c 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -2059,22 +2059,18 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p) > } > > #ifdef CONFIG_NUMA_BALANCING > -#ifdef CONFIG_SCHED_DEBUG > +__read_mostly bool sched_numa_balancing; > + > void set_numabalancing_state(bool enabled) > { > + sched_numa_balancing = enabled; > +#ifdef CONFIG_SCHED_DEBUG > if (enabled) > sched_feat_set("NUMA"); > else > sched_feat_set("NO_NUMA"); So why is the 'NUMA' sched_features option still twiddled? Your patch splits out a sched_numa_balancing flag - so the NUMA/NO_NUMA feature can go away, right? Thanks, Ingo