Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269381AbUINPB5 (ORCPT ); Tue, 14 Sep 2004 11:01:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269021AbUINO6X (ORCPT ); Tue, 14 Sep 2004 10:58:23 -0400 Received: from mx2.elte.hu ([157.181.151.9]:47237 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S269029AbUINOxc (ORCPT ); Tue, 14 Sep 2004 10:53:32 -0400 Date: Tue, 14 Sep 2004 16:54:57 +0200 From: Ingo Molnar To: Nick Piggin Cc: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [patch] sched: fix scheduling latencies for !PREEMPT kernels Message-ID: <20040914145457.GA13113@elte.hu> References: <20040914104449.GA30790@elte.hu> <20040914105048.GA31238@elte.hu> <20040914105904.GB31370@elte.hu> <20040914110237.GC31370@elte.hu> <20040914110611.GA32077@elte.hu> <20040914112847.GA2804@elte.hu> <20040914114228.GD2804@elte.hu> <4146EA3E.4010804@yahoo.com.au> <20040914132225.GA9310@elte.hu> <4146F33C.9030504@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4146F33C.9030504@yahoo.com.au> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 814 Lines: 22 * Nick Piggin wrote: > Another thing, I don't mean this to sound like a rhetorical question, > but if we have a preemptible kernel, why is it a good idea to sprinkle ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > cond_rescheds everywhere? Isn't this now the worst of both worlds? Why > would someone who really cares about latency not enable preempt? two things: 1) none of the big distros enables CONFIG_PREEMPT in their kernels - not even SuSE. This is pretty telling. 2) 10 new cond_resched()'s are not precisely 'sprinkle everywhere'. 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/