From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e39.co.us.ibm.com (e39.co.us.ibm.com [32.97.110.160]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 64E4C1A0010 for ; Mon, 11 May 2015 13:49:08 +1000 (AEST) Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 10 May 2015 21:49:06 -0600 Received: from b03cxnp08026.gho.boulder.ibm.com (b03cxnp08026.gho.boulder.ibm.com [9.17.130.18]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id 0C9C63E40044 for ; Sun, 10 May 2015 21:49:04 -0600 (MDT) Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by b03cxnp08026.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t4B3mtP131195296 for ; Sun, 10 May 2015 20:48:55 -0700 Received: from d03av02.boulder.ibm.com (localhost [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t4B3n3SY024073 for ; Sun, 10 May 2015 21:49:03 -0600 Message-ID: <555026AA.20709@linux.vnet.ibm.com> Date: Mon, 11 May 2015 09:18:58 +0530 From: Preeti U Murthy MIME-Version: 1.0 To: "Rafael J. Wysocki" , peterz@infradead.org Subject: Re: [PATCH 0/3] cpuidle: updates related to tick_broadcast_enter() failures References: <20150508073418.28491.4150.stgit@preeti.in.ibm.com> <10239011.l6QLHlKIVm@vostro.rjw.lan> <3161640.llJtBoKCBr@vostro.rjw.lan> <8965830.CMQzZzsqm0@vostro.rjw.lan> In-Reply-To: <8965830.CMQzZzsqm0@vostro.rjw.lan> Content-Type: text/plain; charset=UTF-8 Cc: rlippert@google.com, daniel.lezcano@linaro.org, linux-pm@vger.kernel.org, linus.walleij@linaro.org, rafael.j.wysocki@intel.com, linux-kernel@vger.kernel.org, mingo@redhat.com, sudeep.holla@arm.com, tglx@linutronix.de, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 05/10/2015 04:45 AM, 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. I don't see the patches on linux-pm/linux-next. Regards Preeti U Murthy > >