From patchwork Wed Apr 20 17:27:15 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Hilman X-Patchwork-Id: 722541 Received: from smtp1.linux-foundation.org (smtp1.linux-foundation.org [140.211.169.13]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p3KHT59L023807 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL) for ; Wed, 20 Apr 2011 17:29:26 GMT Received: from daredevil.linux-foundation.org (localhost [127.0.0.1]) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with ESMTP id p3KHROpR005820; Wed, 20 Apr 2011 10:27:24 -0700 Received: from na3sys009aog108.obsmtp.com (na3sys009aog108.obsmtp.com [74.125.149.199]) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with SMTP id p3KHRJei005805 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 20 Apr 2011 10:27:22 -0700 Received: from mail-pz0-f52.google.com ([209.85.210.52]) (using TLSv1) by na3sys009aob108.postini.com ([74.125.148.12]) with SMTP ID DSNKTa8XdhXcoQT60/c3ajmOHwPh4huf5TDJ@postini.com; Wed, 20 Apr 2011 10:27:22 PDT Received: by mail-pz0-f52.google.com with SMTP id 12so1904076pzk.25 for ; Wed, 20 Apr 2011 10:27:18 -0700 (PDT) Received: by 10.143.20.3 with SMTP id x3mr4209316wfi.159.1303320438174; Wed, 20 Apr 2011 10:27:18 -0700 (PDT) Received: from localhost (c-24-18-179-55.hsd1.wa.comcast.net [24.18.179.55]) by mx.google.com with ESMTPS id m10sm1447113wfl.23.2011.04.20.10.27.16 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 20 Apr 2011 10:27:17 -0700 (PDT) From: Kevin Hilman To: Trinabh Gupta Organization: Texas Instruments, Inc. References: <20110420065445.332.13688.stgit@tringupt.in.ibm.com> <20110420065523.332.58678.stgit@tringupt.in.ibm.com> Date: Wed, 20 Apr 2011 10:27:15 -0700 In-Reply-To: <20110420065523.332.58678.stgit@tringupt.in.ibm.com> (Trinabh Gupta's message of "Wed, 20 Apr 2011 12:25:34 +0530") Message-ID: <87pqog6dfw.fsf@ti.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1.50 (gnu/linux) MIME-Version: 1.0 Received-SPF: pass (localhost is always allowed.) X-Spam-Status: No, hits=-104.532 required=5 tests=AWL, BAYES_00, OSDL_HEADER_SPF_PASS, OSDL_HEADER_SUBJECT_BRACKETED, USER_IN_WHITELIST X-Spam-Checker-Version: SpamAssassin 3.2.4-osdl_revision__1.47__ X-MIMEDefang-Filter: lf$Revision: 1.188 $ X-Scanned-By: MIMEDefang 2.63 on 140.211.169.21 Cc: venki@google.com, davinci-linux-open-source@linux.davincidsp.com, ak@linux.intel.com, len.brown@intel.com, peterz@infradead.org, linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-pm@lists.linux-foundation.org, linux-omap@vger.kernel.org, arjan@linux.intel.com, linux-arm-kernel@lists.infradead.org Subject: Re: [linux-pm] [RFC PATCH V3 1/4] cpuidle: Move dev->last_residency update to driver enter routine; remove dev->last_state X-BeenThere: linux-pm@lists.linux-foundation.org X-Mailman-Version: 2.1.9 Precedence: list List-Id: Linux power management List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Wed, 20 Apr 2011 17:29:26 +0000 (UTC) Trinabh Gupta writes: > Cpuidle subsystem only suggests the state to enter and does not > guarantee if the suggested state is entered. The actual entered state > may be different because of software or hardware demotion. Software > demotion is done by the back-end cpuidle driver and can be accounted > correctly. Current cpuidle code uses last_state field to capture the > actual state entered and based on that updates the statistics for the > state entered. > > Ideally the driver enter routine should update the counters, > and it should return the state actually entered rather than the time > spent there. OK, the return type was changed to return the state index instead of the time, but since the governors are still relying on dev->last_residency, drivers are required to update it. Because of that, why not keep the update of the time/usage counters in common code rather than duplicating it (9 times in this patch) into all the drivers? Something like the patch below should suffice. Kevin diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 845d3ef..875d241 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -91,6 +91,11 @@ static void cpuidle_idle_call(void) entered_state = target_state->enter(dev, drv, next_state); + /* Update cpuidle counters */ + dev->states_usage[entered_state].time += + (unsigned long long)dev->last_residency; + dev->states_usage[entered_state].usage++; + trace_power_end(dev->cpu); trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu);