From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263922AbTKJOwQ (ORCPT ); Mon, 10 Nov 2003 09:52:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263925AbTKJOwQ (ORCPT ); Mon, 10 Nov 2003 09:52:16 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:19686 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S263922AbTKJOwM (ORCPT ); Mon, 10 Nov 2003 09:52:12 -0500 Date: Mon, 10 Nov 2003 15:52:12 +0100 From: Jens Axboe To: Nick Piggin Cc: linux-kernel@vger.kernel.org, ckrm-tech@lists.sourceforge.net Subject: Re: [PATCH] cfq-prio #2 Message-ID: <20031110145212.GL32637@suse.de> References: <20031110140052.GC32637@suse.de> <3FAF9DAE.3070307@cyberone.com.au> <20031110142302.GF32637@suse.de> <3FAFA1E8.8080800@cyberone.com.au> <20031110143939.GJ32637@suse.de> <3FAFA401.5080404@cyberone.com.au> <20031110144412.GK32637@suse.de> <3FAFA52A.3050600@cyberone.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3FAFA52A.3050600@cyberone.com.au> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 11 2003, Nick Piggin wrote: > >>>>Its quite important. If the queue is full, and AS is waiting for a > >>>>process > >>>>to submit a request, its got a long wait. > >>>> > >>>>Maybe a lower limit for per process nr_requests. Ie. you may queue if > >>>>this > >>>>queue has less than 128 requests _or_ you have less than 8 requests > >>>>outstanding. This would solve my problem. It would also give you a much > >>>>more > >>>>appropriate scaling for server workloads, I think. Still, thats quite a > >>>>change in behaviour (simple to code though). > >>>> > >>>> > >>>That basically belongs inside your may_queue for the io scheduler, imo. > >>> > >>> > >>You can force it to disallow the request, but you can't force it to allow > >>one (depending on a successful memory allocation, of course). > >> > > > >Well that's back two mails then, make may_queue return whether you must > >queue, may queue, or can't queue. > > > > Yep, sounds good. I'll make a patch for it for 2.6.x > 0 sometime unless > you beat me to it. I'll include it in the next cfq patch, then it can be submitted when the freeze unthaws a bit. -- Jens Axboe