From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753022AbaBXPQ6 (ORCPT ); Mon, 24 Feb 2014 10:16:58 -0500 Received: from merlin.infradead.org ([205.233.59.134]:40343 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752732AbaBXPQ4 (ORCPT ); Mon, 24 Feb 2014 10:16:56 -0500 Date: Mon, 24 Feb 2014 16:16:44 +0100 From: Peter Zijlstra To: Daniel Lezcano Cc: mingo@kernel.org, tglx@linutronix.de, rjw@rjwysocki.net, nicolas.pitre@linaro.org, preeti@linux.vnet.ibm.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2 1/5] idle/cpuidle: Split cpuidle_idle_call main function into smaller functions Message-ID: <20140224151644.GY27965@twins.programming.kicks-ass.net> References: <1393250151-6982-1-git-send-email-daniel.lezcano@linaro.org> <20140224150004.GX27965@twins.programming.kicks-ass.net> <530B6147.6010301@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <530B6147.6010301@linaro.org> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 24, 2014 at 04:12:07PM +0100, Daniel Lezcano wrote: > On 02/24/2014 04:00 PM, Peter Zijlstra wrote: > > > > > >None of this actually applies :/ I'm having major conflicts in > >driveres/cpuidle/cpuidle.c. > > Ok, except if I am missing something, the patchset is based on top of > tip/sched/core (commit 6990566). Ah! So the below commit from the timers/core branch is in the way. Thomas, Ingo, how do we go about solving this sched/core vs timers/core conflict? --- # git log 6990566..tip/master drivers/cpuidle/ commit 2f60b8ae0b2a006e4d3452e57ea98b59ce985d14 Merge: 9eaf844efc23 849401b66d30 Author: Ingo Molnar Date: Sat Feb 22 18:52:27 2014 +0100 Merge branch 'timers/core' commit ba8f20c2eb4158a443e9d6a909aee5010efa0c69 Author: Preeti U Murthy Date: Fri Feb 7 13:36:52 2014 +0530 cpuidle: Handle clockevents_notify(BROADCAST_ENTER) failure Some archs set the CPUIDLE_FLAG_TIMER_STOP flag for idle states in which the local timers stop. The cpuidle_idle_call() currently handles such idle states by calling into the broadcast framework so as to wakeup CPUs at their next wakeup event. With the hrtimer mode of broadcast, the BROADCAST_ENTER call into the broadcast frameowork can fail for archs that do not have an external clock device to handle wakeups and the CPU in question has thus to be made the stand by CPU. This patch handles such cases by failing the call into cpuidle so that the arch can take some default action. The arch will certainly not enter a similar idle state because a failed cpuidle call will also implicitly indicate that the broadcast framework has not registered this CPU to be woken up. Hence we are safe if we fail the cpuidle call. In the process move the functions that trace idle statistics just before and after the entry and exit into idle states respectively. In other scenarios where the call to cpuidle fails, we end up not tracing idle entry and exit since a decision on an idle state could not be taken. Similarly when the call to broadcast framework fails, we skip tracing idle statistics because we are in no further position to take a decision on an alternative idle state to enter into. Signed-off-by: Preeti U Murthy Cc: deepthi@linux.vnet.ibm.com Cc: paulmck@linux.vnet.ibm.com Cc: fweisbec@gmail.com Cc: paulus@samba.org Cc: srivatsa.bhat@linux.vnet.ibm.com Cc: svaidy@linux.vnet.ibm.com Cc: peterz@infradead.org Cc: benh@kernel.crashing.org Acked-by: Rafael J. Wysocki Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20140207080652.17187.66344.stgit@preeti.in.ibm.com Signed-off-by: Thomas Gleixner