From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756610AbbLGWrW (ORCPT ); Mon, 7 Dec 2015 17:47:22 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:48649 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755831AbbLGWrV (ORCPT ); Mon, 7 Dec 2015 17:47:21 -0500 From: "Rafael J. Wysocki" To: Viresh Kumar Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, ashwin.chaugule@linaro.org, "Rafael J. Wysocki" , LKML Subject: Re: [PATCH V2 5/6] cpufreq: governor: replace per-cpu delayed work with timers Date: Tue, 08 Dec 2015 00:17:18 +0100 Message-ID: <2389125.q3qMOpRs8O@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.1.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <3999637.u4UiK7zxOR@vostro.rjw.lan> References: <20151207075027.GC3294@ubuntu> <3999637.u4UiK7zxOR@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, December 07, 2015 11:43:50 PM Rafael J. Wysocki wrote: > On Monday, December 07, 2015 01:20:27 PM Viresh Kumar wrote: > > On 07-12-15, 02:28, Rafael J. Wysocki wrote: > > > What about if that happens in parallel with the decrementation in > > > dbs_work_handler()? > > > > > > Is there anything preventing that from happening? > > > > Hmmm, you are right. Following is required for that. > > > > diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c > > index c9e420bd0eec..d8a89e653933 100644 > > --- a/drivers/cpufreq/cpufreq_governor.c > > +++ b/drivers/cpufreq/cpufreq_governor.c > > @@ -230,6 +230,7 @@ static void dbs_work_handler(struct work_struct *work) > > struct dbs_data *dbs_data; > > unsigned int sampling_rate, delay; > > bool eval_load; > > + unsigned long flags; > > > > policy = shared->policy; > > dbs_data = policy->governor_data; > > @@ -257,7 +258,10 @@ static void dbs_work_handler(struct work_struct *work) > > delay = dbs_data->cdata->gov_dbs_timer(policy, eval_load); > > mutex_unlock(&shared->timer_mutex); > > > > + spin_lock_irqsave(&shared->timer_lock, flags); > > shared->skip_work--; > > + spin_unlock_irqrestore(&shared->timer_lock, flags); > > + > > gov_add_timers(policy, delay); > > } > > OK, so can you please send an updated patch with the above change folded in? In fact, I've already folded the above changes into the $subject patch (but this is an exception). I'll send the "atomic" changes separately. Thanks, Rafael