From mboxrd@z Thu Jan 1 00:00:00 1970 From: Santosh Shilimkar Subject: Re: [PATCH 0/4] time: dynamic irq affinity Date: Sun, 10 Mar 2013 23:03:56 +0530 Message-ID: <513CC404.6000200@ti.com> References: <1361917047-29230-1-git-send-email-daniel.lezcano@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from bear.ext.ti.com ([192.94.94.41]:53461 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752711Ab3CJRck (ORCPT ); Sun, 10 Mar 2013 13:32:40 -0400 In-Reply-To: <1361917047-29230-1-git-send-email-daniel.lezcano@linaro.org> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Daniel Lezcano Cc: john.stultz@linaro.org, tglx@linutronix.de, viresh.kumar@linaro.org, jacob.jun.pan@linux.intel.com, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org, patches@linaro.org, linus.walleij@stericsson.com On Wednesday 27 February 2013 03:47 AM, Daniel Lezcano wrote: > When a cpu goes to a deep idle state where its local timer is shutdown, > it notifies the time framework to use the broadcast timer instead. > > Unfortunately, the broadcast device could wake up any CPU, including an > idle one which is not concerned by the wake up at all. > > This implies, in the worst case, an idle CPU will wake up to send an IPI > to another idle cpu. > > This patch solves this by setting the irq affinity to the cpu concerned > by the nearest timer event, by this way, the CPU which is wake up is > guarantee to be the one concerned by the next event and we are safe with > unnecessary wakeup for another idle CPU. > > As the irq affinity is not supported by all the archs, a flag is needed > to specify which clocksource can handle it. > > Daniel Lezcano (3): > time : pass broadcast parameter > time : set broadcast irq affinity > ARM: nomadik: add dynamic irq flag to the timer > > Viresh Kumar (1): > ARM: timer-sp: Set dynamic irq affinity > Thanks Daniel for addressing the comments from earlier version. This version looks good to me. Reviewed-by: Santosh Shilimkar Regards, Santosh P.S: As I mentioned 'CLOCK_EVT_FEAT_DYNIRQ' optimization on OMAP at least I found risky because you might end up missing the asynchronous IPI wakeups because of the current SGI's implementation. This must be true for other ARM platforms as well.