Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754247AbaDNJx3 (ORCPT ); Mon, 14 Apr 2014 05:53:29 -0400 Received: from mail-ob0-f176.google.com ([209.85.214.176]:56872 "EHLO mail-ob0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752142AbaDNJvY (ORCPT ); Mon, 14 Apr 2014 05:51:24 -0400 MIME-Version: 1.0 In-Reply-To: References: <20140410143857.GA27654@localhost.localdomain> <20140411145333.GC3438@localhost.localdomain> <20140411151825.GX11096@twins.programming.kicks-ass.net> Date: Mon, 14 Apr 2014 15:21:24 +0530 Message-ID: Subject: Re: [Query]: tick-sched: why don't we stop tick when we are running idle task? From: Viresh Kumar To: Preeti Murthy Cc: Peter Zijlstra , Frederic Weisbecker , Thomas Gleixner , Linux Kernel Mailing List , Lists linaro-kernel , Preeti U Murthy Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14 April 2014 15:18, Preeti Murthy wrote: > I am not too sure about the complexity or the worthiness of this patch but > just wanted to add that care must be taken to migrate the tick_sched_timer > of all the remote CPUs off a hotplugged out CPU if the latter was keeping > their time thus far. In the normal scenario I am guessing the tick_sched_timer > dies along with the hotplugged out CPU since there is no need for it any more. Agreed. Lets see if there is anybody in favor of this work as it is very important for some real time use cases we have. Like running data plane threads on isolated CPUs. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/