Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752506AbbDCRnK (ORCPT ); Fri, 3 Apr 2015 13:43:10 -0400 Received: from mail-wi0-f180.google.com ([209.85.212.180]:38876 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751617AbbDCRnH (ORCPT ); Fri, 3 Apr 2015 13:43:07 -0400 Date: Fri, 3 Apr 2015 19:42:59 +0200 From: Frederic Weisbecker To: cmetcalf@ezchip.com, Rik van Riel Cc: "Peter Zijlstra (Intel)" , "Paul E. McKenney" , "Rafael J. Wysocki" , Martin Schwidefsky , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] nohz: make nohz_full imply isolcpus Message-ID: <20150403174258.GC13598@lerouge> References: <1428078248-5425-1-git-send-email-cmetcalf@ezchip.com> <1428078248-5425-2-git-send-email-cmetcalf@ezchip.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1428078248-5425-2-git-send-email-cmetcalf@ezchip.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 Content-Length: 1440 Lines: 39 On Fri, Apr 03, 2015 at 12:24:08PM -0400, cmetcalf@ezchip.com wrote: > From: Chris Metcalf > > It's not clear that nohz_full is useful without isolcpus also > set, since otherwise the scheduler has to run periodically to > try to determine whether to steal work from other cores. > > Signed-off-by: Chris Metcalf I think Rick has a similar patch. > --- > I am puzzled why this has not been done before, so I suspect > there is some argument against it that I am missing, but I > wasn't able to turn anything up by searching LKML. > > kernel/sched/core.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index f0f831e8a345..275f12c608f2 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -6836,6 +6836,7 @@ static int init_sched_domains(const struct cpumask *cpu_map) > doms_cur = alloc_sched_domains(ndoms_cur); > if (!doms_cur) > doms_cur = &fallback_doms; > + tick_nohz_full_set_cpus(cpu_isolated_map); > cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); > err = build_sched_domains(doms_cur[0], NULL); > register_sched_domain_sysctl(); > -- > 2.1.2 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/