Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752805AbbEKWsy (ORCPT ); Mon, 11 May 2015 18:48:54 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:60761 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752617AbbEKWsw (ORCPT ); Mon, 11 May 2015 18:48:52 -0400 From: "Rafael J. Wysocki" To: Sudeep Holla Cc: Preeti U Murthy , "peterz@infradead.org" , "tglx@linutronix.de" , "rafael.j.wysocki@intel.com" , "daniel.lezcano@linaro.org" , "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 0/3] cpuidle: updates related to tick_broadcast_enter() failures Date: Tue, 12 May 2015 01:14:01 +0200 Message-ID: <3891627.8vhHP2jkbR@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.0.0+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <5550C721.2050906@arm.com> References: <20150508073418.28491.4150.stgit@preeti.in.ibm.com> <8965830.CMQzZzsqm0@vostro.rjw.lan> <5550C721.2050906@arm.com> 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 Content-Length: 2200 Lines: 57 On Monday, May 11, 2015 04:13:37 PM Sudeep Holla wrote: > > On 10/05/15 00:15, Rafael J. Wysocki wrote: > > On Saturday, May 09, 2015 10:33:05 PM Rafael J. Wysocki wrote: > >> On Saturday, May 09, 2015 10:11:41 PM Rafael J. Wysocki wrote: > >>> On Saturday, May 09, 2015 11:19:16 AM Preeti U Murthy wrote: > >>>> Hi Rafael, > >>>> > >>>> On 05/08/2015 07:48 PM, Rafael J. Wysocki wrote: > >>> > >>> [cut] > >>> > >>>>>> > >>>>>> + /* Take note of the planned idle state. */ > >>>>>> + idle_set_state(smp_processor_id(), target_state); > >>>>> > >>>>> And I wouldn't do this either. > >>>>> > >>>>> The behavior here is pretty much as though the driver demoted the state chosen > >>>>> by the governor and we don't call idle_set_state() again in those cases. > >>>> > >>>> Why is this wrong? > >>> > >>> It is not "wrong", but incomplete, because demotions done by the cpuidle driver > >>> should also be taken into account in the same way. > >>> > >>> But I'm seeing that the recent patch of mine that made cpuidle_enter_state() > >>> call default_idle_call() was a mistake, because it might confuse find_idlest_cpu() > >>> significantly as to what state the CPU is in. I'll drop that one for now. > >> > >> OK, done. > >> > >> So after I've dropped it I think we need to do three things: > >> (1) Move the idle_set_state() calls to cpuidle_enter_state(). > >> (2) Make cpuidle_enter_state() call default_idle_call() again, but this time > >> do that *before* it has called idle_set_state() for target_state. > >> (3) Introduce demotion as per my last patch. > >> > >> Let me cut patches for that. > > > > Done as per the above and the patches follow in replies to this messge. > > > > All on top of the current linux-next branch of the linux-pm.git tree. > > > > Tested on ARM Vexpress platforms with one of the CPU in broadcast mode > and also with broadcast timer. So, you can add: > > Tested-by: Sudeep Holla Thanks! -- 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/