Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268753AbUJEDPc (ORCPT ); Mon, 4 Oct 2004 23:15:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268759AbUJEDPb (ORCPT ); Mon, 4 Oct 2004 23:15:31 -0400 Received: from smtp201.mail.sc5.yahoo.com ([216.136.129.91]:31572 "HELO smtp201.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S268753AbUJEDOy (ORCPT ); Mon, 4 Oct 2004 23:14:54 -0400 Message-ID: <416211A3.8060806@yahoo.com.au> Date: Tue, 05 Oct 2004 13:14:43 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.1) Gecko/20040726 Debian/1.7.1-4 X-Accept-Language: en MIME-Version: 1.0 To: Con Kolivas CC: Chen@vger.kernel.org, Kenneth W , linux-kernel@vger.kernel.org Subject: Re: bug in sched.c:activate_task() References: <200410050216.i952Gb620657@unix-os.sc.intel.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 830 Lines: 25 Con Kolivas wrote: > Chen, Kenneth W writes: > >> Update p->timestamp to "now" in activate_task() doesn't look right >> to me at all. p->timestamp records last time it was running on a >> cpu. activate_task shouldn't update that variable when it queues >> a task on the runqueue. >> >> This bug (and combined with others) triggers improper load balancing. > > > The updated timestamp was placed there by Ingo to detect on-runqueue > time. If it is being used for load balancing then it is being used in > error. > Load balancing wants to know if a task is considered cache hot. - 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/