From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934316AbXHIG73 (ORCPT ); Thu, 9 Aug 2007 02:59:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756708AbXHIG7V (ORCPT ); Thu, 9 Aug 2007 02:59:21 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:43458 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757652AbXHIG7U (ORCPT ); Thu, 9 Aug 2007 02:59:20 -0400 Date: Thu, 9 Aug 2007 08:59:16 +0200 From: Ingo Molnar To: Mitchell Erblich Cc: Linux Kernel Mailing List Subject: Re: Question: RT schedular : task_tick_rt(struct rq *rq, structtask_struct *p) : decreases overhead when rq->nr_running == 1 Message-ID: <20070809065916.GB30046@elte.hu> References: <000501c7da16$838dea40$6501a8c0@earthlink.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000501c7da16$838dea40$6501a8c0@earthlink.net> 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 * Mitchell Erblich wrote: > First, RT/RR tasks are not deprecated. [...] I'm confused, do you say this in reference to anything i said? I did not say that RR tasks are deprecated and you were top-posting so i cannot connect it to anything specific. I only said RR tasks are _rare_: >> this is a pretty rare codepath because the overwhelming majority of >> RT apps uses SCHED_FIFO [...] and i hope you can see the difference between 'rare' and 'deprecated' ;-) And i suspect you also missed the last bit of what i wrote: >> So this is on several levels an uncommon workload and by adding a >> check like that we'd increase the codesize. But ... no strong >> feelings against this optimization - if you send a proper patch we >> can apply it, it certainly makes sense from a logic POV. and you also missed the first bit it appears: >> your change is a possible optimization, [...] so you are banging, with full force, on completely open doors =B-) Ingo