From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932917Ab3BSOKG (ORCPT ); Tue, 19 Feb 2013 09:10:06 -0500 Received: from mail-ee0-f45.google.com ([74.125.83.45]:64049 "EHLO mail-ee0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757062Ab3BSOKE (ORCPT ); Tue, 19 Feb 2013 09:10:04 -0500 Message-ID: <51238628.7000000@linaro.org> Date: Tue, 19 Feb 2013 15:03:20 +0100 From: Daniel Lezcano User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: John Stultz , Frederic Weisbecker , Linux Kernel Mailing List Subject: Timer broadcast question Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi John, Frederic, I am working on identifying the different wakeup sources from the interrupts and I have a question regarding the timer broadcast. The broadcast timer is setup to the next event and that will wake up any cpu, right ? The time framework will look at the different cpus next-event and send them an IPI to wake them up. Although, it is possible the sender of this IPI may not be concerned by the timer expiration and has been woken up just for sending the IPI, right ? If this is correct, is it possible to setup the timer irq affinity to a cpu which will be concerned by the timer expiration ? so we prevent an unnecessary wake up for a cpu. Did I missed something or does it sound correct ? Thanks -- Daniel -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog