From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751969Ab1FDE0V (ORCPT ); Sat, 4 Jun 2011 00:26:21 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:55404 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751673Ab1FDE0U (ORCPT ); Sat, 4 Jun 2011 00:26:20 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=uyALhjdx9t0spukLRukIq1jCbTT7lS0rFV9AafBob6dScfZ/GxFFaDT7b6BtZUdqTq 8bDl6dUvC19yh6tRG0GJArqvf0+X+4L7h1u/wXcaZ7k3sJ87vCfnjqd91IcYC5pdJfOj 0Ax+p4y3BcKw2NlJfkvnnXLp3yerR+uG+gEjI= MIME-Version: 1.0 In-Reply-To: References: Date: Sat, 4 Jun 2011 12:26:18 +0800 Message-ID: Subject: Re: [PATCH] sched: remove resetting exec_start in put_prev_task_rt() From: Hillf Danton To: Yong Zhang Cc: LKML , Steven Rostedt , Mike Galbraith , Peter Zijlstra , Ingo Molnar Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 2, 2011 at 4:04 PM, Yong Zhang wrote: > On Wed, Jun 1, 2011 at 10:03 PM, Hillf Danton wrote: >> Resetting exec_start, after updated in update_curr_rt(), could open window for >> messing up the subsequent computations of delta_exec of the given task. > > I can't see how could this happen. what kind of 'subsequent computations' > do you mean? > > But because exec_start will be reset by _pick_next_task_rt()/set_curr_task_rt(), > you patch is ok. IMHO it is not critical, it's just cleanup instead. > H i Yong The window is closed in the two cases, as you tip fingered, would you please say a few more words about the window and tick timer? thanks Hillf