From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755932AbZFAQkv (ORCPT ); Mon, 1 Jun 2009 12:40:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751346AbZFAQkn (ORCPT ); Mon, 1 Jun 2009 12:40:43 -0400 Received: from mx2.redhat.com ([66.187.237.31]:50560 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751148AbZFAQkn (ORCPT ); Mon, 1 Jun 2009 12:40:43 -0400 Message-ID: <4A240479.9040907@redhat.com> Date: Mon, 01 Jun 2009 12:40:25 -0400 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 2.0.0.17 (X11/20080915) MIME-Version: 1.0 To: J Louis CC: linux-kernel@vger.kernel.org Subject: Re: Linux scheduler capabilities for batch jobs. References: <6f41bd4b0906010641n1b360dffs6eaed72eb24f60f5@mail.gmail.com> In-Reply-To: <6f41bd4b0906010641n1b360dffs6eaed72eb24f60f5@mail.gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org J Louis wrote: > If it was possible to tell > the scheduler that it was OK not to be fair when scheduling these > processes, I think the total runtime could be reduced if it put some > of the processes to sleep while others completed. Is there a way to > tell the scheduler it is allowed to do this? Should there be? There is no way to do this currently, but I suspect that it would not be too difficult to add. Of course, if you have two tasks that are each a little larger than memory, your idea could lead to one of the processes being starved forever. This is probably not acceptable :) In fact, one single batch process that is swapping could trigger the algorithm you described, halting itself. Your idea would need very carefuly implementation to avoid these kinds of issues, but I believe it could definately be done. -- All rights reversed.