From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754134AbaIDMxJ (ORCPT ); Thu, 4 Sep 2014 08:53:09 -0400 Received: from mail-we0-f174.google.com ([74.125.82.174]:62913 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750990AbaIDMxG (ORCPT ); Thu, 4 Sep 2014 08:53:06 -0400 Message-ID: <540860AC.3030905@linaro.org> Date: Thu, 04 Sep 2014 14:53:00 +0200 From: Daniel Lezcano User-Agent: Mozilla/5.0 (X11; Linux i686; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: Chuansheng Liu , peterz@infradead.org, luto@amacapital.net, rjw@rjwysocki.net, mingo@redhat.com CC: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, changcheng.liu@intel.com, xiaoming.wang@intel.com, souvik.k.chakravarty@intel.com Subject: Re: [PATCH 1/3] sched: Add new API wake_up_if_idle() to wake up the idle cpu References: <1409815075-4180-1-git-send-email-chuansheng.liu@intel.com> In-Reply-To: <1409815075-4180-1-git-send-email-chuansheng.liu@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/04/2014 09:17 AM, Chuansheng Liu wrote: > Implementing one new API wake_up_if_idle(), which is used to > wake up the idle CPU. > > Suggested-by: Andy Lutomirski > Signed-off-by: Chuansheng Liu Hi Chuanseng, in the future, please prefix the patches with the version number and a changelog. Thanks -- Daniel Acked-by: Daniel Lezcano > --- > include/linux/sched.h | 1 + > kernel/sched/core.c | 19 +++++++++++++++++++ > 2 files changed, 20 insertions(+) > > diff --git a/include/linux/sched.h b/include/linux/sched.h > index 857ba40..3f89ac1 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -1024,6 +1024,7 @@ struct sched_domain_topology_level { > extern struct sched_domain_topology_level *sched_domain_topology; > > extern void set_sched_topology(struct sched_domain_topology_level *tl); > +extern void wake_up_if_idle(int cpu); > > #ifdef CONFIG_SCHED_DEBUG > # define SD_INIT_NAME(type) .name = #type > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 1211575..b818548 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -1620,6 +1620,25 @@ static void ttwu_queue_remote(struct task_struct *p, int cpu) > } > } > > +void wake_up_if_idle(int cpu) > +{ > + struct rq *rq = cpu_rq(cpu); > + unsigned long flags; > + > + if (!is_idle_task(rq->curr)) > + return; > + > + if (set_nr_if_polling(rq->idle)) { > + trace_sched_wake_idle_without_ipi(cpu); > + } else { > + raw_spin_lock_irqsave(&rq->lock, flags); > + if (is_idle_task(rq->curr)) > + smp_send_reschedule(cpu); > + /* Else cpu is not in idle, do nothing here */ > + raw_spin_unlock_irqrestore(&rq->lock, flags); > + } > +} > + > bool cpus_share_cache(int this_cpu, int that_cpu) > { > return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu); > -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog