From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751673Ab2JAAcp (ORCPT ); Sun, 30 Sep 2012 20:32:45 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:43768 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751197Ab2JAAco (ORCPT ); Sun, 30 Sep 2012 20:32:44 -0400 Date: Mon, 1 Oct 2012 09:32:33 +0900 From: Tejun Heo To: Viresh Kumar Cc: linux-kernel@vger.kernel.org, pjt@google.com, paul.mckenney@linaro.org, tglx@linutronix.de, suresh.b.siddha@intel.com, venki@google.com, mingo@redhat.com, peterz@infradead.org, robin.randhawa@arm.com, Steve.Bannister@arm.com, Arvind.Chauhan@arm.com, amit.kucheria@linaro.org, vincent.guittot@linaro.org, linaro-dev@lists.linaro.org, patches@linaro.org Subject: Re: [PATCH V2 3/3] workqueue: Schedule work on non-idle cpu instead of current one Message-ID: <20121001003233.GL10383@mtj.dyndns.org> References: <7d5c2cac08134446583624cc124d46d9726bdb2d.1348736069.git.viresh.kumar@linaro.org> <20120930085455.GJ10383@mtj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Sun, Sep 30, 2012 at 05:46:45PM +0530, Viresh Kumar wrote: > For the scheduler CPU is idle, if all below are true: > - current task is idle task > - nr_running == 0 > - wake_list is empty > > And during these conditions, there can be a timer running in background. > And when we reach its interrupt handler, then also these conditions hold true > and local cpu is idle. It isn't about the CPU being actually idle? Also, if it's only about timers, shouldn't it be enough to implement it for timer and delayed_work? It would be great if you explain what you're trying to achieve how. I can't tell what you're aiming for and why that would be beneficial from these submissions. Thanks. -- tejun