Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753167AbZIITB0 (ORCPT ); Wed, 9 Sep 2009 15:01:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752488AbZIITBZ (ORCPT ); Wed, 9 Sep 2009 15:01:25 -0400 Received: from zrtps0kp.nortel.com ([47.140.192.56]:32923 "EHLO zrtps0kp.nortel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752321AbZIITBZ (ORCPT ); Wed, 9 Sep 2009 15:01:25 -0400 Message-ID: <4AA7FB13.9060603@nortel.com> Date: Wed, 09 Sep 2009 12:59:31 -0600 From: "Chris Friesen" User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Thunderbird/3.0b3 MIME-Version: 1.0 To: Ingo Molnar CC: Theodore Tso , mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, efault@gmx.de, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:sched/core] sched: Turn off child_runs_first References: <1252486344.28645.18.camel@marge.simson.net> <20090909175724.GY22901@mit.edu> <20090909180856.GA7323@elte.hu> In-Reply-To: <20090909180856.GA7323@elte.hu> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 09 Sep 2009 19:00:18.0627 (UTC) FILETIME=[C6047930:01CA317F] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 789 Lines: 21 On 09/09/2009 12:08 PM, Ingo Molnar wrote: > > * Theodore Tso wrote: >> Wasn't one of the reasons why we historically did child_runs_first >> was so that for fork/exit workloads, the child has a chance to >> exec the new process? If the parent runs first, then more pages >> will probably need to be COW'ed. > > That kind of workload should be using vfork() anyway, and be even > faster because it can avoid the fork overhead, right? According to my man page, POSIX.1-2008 removes the specification of vfork(). Chris -- 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/