From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753452AbbEGJ4x (ORCPT ); Thu, 7 May 2015 05:56:53 -0400 Received: from foss.arm.com ([217.140.101.70]:49512 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753402AbbEGJ4u (ORCPT ); Thu, 7 May 2015 05:56:50 -0400 Message-ID: <554B36DD.5080807@arm.com> Date: Thu, 07 May 2015 10:56:45 +0100 From: Sudeep Holla User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Preeti U Murthy CC: "peterz@infradead.org" , "tglx@linutronix.de" , "rafael.j.wysocki@intel.com" , "daniel.lezcano@linaro.org" , Sudeep Holla , "rlippert@google.com" , "linux-pm@vger.kernel.org" , "linus.walleij@linaro.org" , "linux-kernel@vger.kernel.org" , "mingo@redhat.com" , "linuxppc-dev@lists.ozlabs.org" Subject: Re: [PATCH] cpuidle: Handle tick_broadcast_enter() failure gracefully References: <20150507052600.20882.39542.stgit@preeti.in.ibm.com> In-Reply-To: <20150507052600.20882.39542.stgit@preeti.in.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Preeti, On 07/05/15 06:26, Preeti U Murthy wrote: > When a CPU has to enter an idle state where tick stops, it makes a call > to tick_broadcast_enter(). The call will fail if this CPU is the > broadcast CPU. Today, under such a circumstance, the arch cpuidle code > handles this CPU. This is not convincing because not only are we not > aware what the arch cpuidle code does, but we also do not account for > the idle state residency time and usage of such a CPU. > > This scenario can be handled better by simply asking the cpuidle > governor to choose an idle state where in ticks do not stop. To > accommodate this change move the setting of runqueue idle state from the > core to the cpuidle driver, else the rq->idle_state will be set wrong. > > Signed-off-by: Preeti U Murthy > --- > Based on linux-pm/bleeding-edge I am unable to apply this patch cleanly on linux-pm/bleeding-edge I think it conflicts with few patches that Rafael posted recently which are in the branch now. Regards, Sudeep