Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756641AbXICTV0 (ORCPT ); Mon, 3 Sep 2007 15:21:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753532AbXICTVN (ORCPT ); Mon, 3 Sep 2007 15:21:13 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:34038 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756227AbXICTU4 (ORCPT ); Mon, 3 Sep 2007 15:20:56 -0400 Date: Mon, 3 Sep 2007 21:20:50 +0200 From: Ingo Molnar To: Roman Zippel Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, Mike Galbraith Subject: Re: [ANNOUNCE/RFC] Really Simple Really Fair Scheduler Message-ID: <20070903192050.GA29049@elte.hu> References: <20070902120154.GA23769@elte.hu> <20070903185403.GA23479@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.14 (2007-02-12) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -1.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1632 Lines: 46 * Roman Zippel wrote: > On Mon, 3 Sep 2007, Ingo Molnar wrote: > > > If this basic model is correct, we can look further. > > The basic model is correct insofar I use an absolute time instead of a > relative time, but it's not the essence of my math, so I don't quite > understand the point of this exercise. thanks. (and i did not claim nor do i want to claim this to be the essence of your efforts - it is very clear from your mails where your focus is.) My next question then is about this code of yours in the wakeup path: +static void +enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) +{ + kclock_t min_time; + + verify_queue(cfs_rq, cfs_rq->curr != se, se); + min_time = get_time_avg(cfs_rq) - se->req_weight_inv; + if ((kclock_t)(se->time_norm - min_time) < 0) + se->time_norm = min_time; why do you only use the "min_time" if the pre-sleep time_norm is smaller than the min_time? Here 'min_time' is close to the current average. Shouldnt here the woken up task be set to the average time, like i did it in the crude prototype: + se->exec_runtime = avg_exec_runtime(cfs_rq); (and lets again only consider the special case of only having nice-0 tasks.) Or is it set in a similar way as my prototype does, and i missed some detail why that branch is there? Ingo - 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/