From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753680Ab3LJOC0 (ORCPT ); Tue, 10 Dec 2013 09:02:26 -0500 Received: from mail-wi0-f181.google.com ([209.85.212.181]:54128 "EHLO mail-wi0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753651Ab3LJOCX (ORCPT ); Tue, 10 Dec 2013 09:02:23 -0500 Date: Tue, 10 Dec 2013 15:02:19 +0100 From: Frederic Weisbecker To: Alex Shi Cc: mingo@redhat.com, peterz@infradead.org, morten.rasmussen@arm.com, vincent.guittot@linaro.org, daniel.lezcano@linaro.org, linux@arm.linux.org.uk, tony.luck@intel.com, fenghua.yu@intel.com, tglx@linutronix.de, akpm@linux-foundation.org, arjan@linux.intel.com, pjt@google.com, fengguang.wu@intel.com, james.hogan@imgtec.com, jason.low2@hp.com, viresh.kumar@linaro.org, hanjun.guo@linaro.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 3/3] nohz_full: update cpu load fix in nohz_full Message-ID: <20131210140217.GA10633@localhost.localdomain> References: <1386074112-30754-1-git-send-email-alex.shi@linaro.org> <1386074112-30754-4-git-send-email-alex.shi@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1386074112-30754-4-git-send-email-alex.shi@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 03, 2013 at 08:35:12PM +0800, Alex Shi wrote: > We are not always 0 when update nohz cpu load, after nohz_full enabled. > But current code still treat the cpu as idle. that is incorrect. > Fix it to use correct cpu_load. > > Signed-off-by: Alex Shi > --- > kernel/sched/proc.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/kernel/sched/proc.c b/kernel/sched/proc.c > index 16f5a30..f1441f0 100644 > --- a/kernel/sched/proc.c > +++ b/kernel/sched/proc.c > @@ -568,8 +568,14 @@ void update_cpu_load_nohz(void) > /* > * We were idle, this means load 0, the current load might be > * !0 due to remote wakeups and the sort. > + * or we may has only one task and in NO_HZ_FULL, then still use > + * normal cpu load. > */ > - __update_cpu_load(this_rq, 0, pending_updates); > + if (this_rq->cfs.h_nr_running) { > + unsigned load = get_rq_runnable_load(this_rq); > + __update_cpu_load(this_rq, load, pending_updates); > + } else > + __update_cpu_load(this_rq, 0, pending_updates); But decay_load_missed() doesnt handle non 0 loads, right? It probably make more sense to first fix __update_cpu_load() to make it handle this kind of thing before fixing the caller. Now you had patches that remove the cpu_load secondary idx I think? You should move this patch to that series. > } > raw_spin_unlock(&this_rq->lock); > } > -- > 1.8.1.2 >