From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762916AbXGaOJl (ORCPT ); Tue, 31 Jul 2007 10:09:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754839AbXGaOJe (ORCPT ); Tue, 31 Jul 2007 10:09:34 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:60839 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756580AbXGaOJd (ORCPT ); Tue, 31 Jul 2007 10:09:33 -0400 Date: Tue, 31 Jul 2007 16:09:11 +0200 From: Ingo Molnar To: Miguel Figueiredo Cc: ck@vds.kolivas.org, Matthew Hawkins , Linux Kernel Mailing List , Linus Torvalds , Kasper Sandberg Subject: Re: [ck] Re: SD still better than CFS for 3d ?(was Re: 2.6.23-rc1) Message-ID: <20070731140911.GA22076@elte.hu> References: <20070731094526.GA16300@elte.hu> <200707311432.45214.elmig@debianpt.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200707311432.45214.elmig@debianpt.org> 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=3.1.7-deb -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 * Miguel Figueiredo wrote: > CFS does not requeue_task() on SCHED_YIELD (used by graphic drivers) > as until 2.6.22 and -ck. [...] as i pointed it out to you it does, the function's name changed: /* * sched_yield() support is very simple - we dequeue and enqueue */ static void yield_task_fair(struct rq *rq, struct task_struct *p) { struct cfs_rq *cfs_rq = task_cfs_rq(p); u64 now = __rq_clock(rq); /* * Dequeue and enqueue the task to update its * position within the tree: */ dequeue_entity(cfs_rq, &p->se, 0, now); enqueue_entity(cfs_rq, &p->se, 0, now); } plus others have tried the SD NOP-yield hack-patch and while it slightly improved the SD numbers it did not change the "CFS is smoother" experience. Ingo