Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270579AbTGNMa6 (ORCPT ); Mon, 14 Jul 2003 08:30:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270609AbTGNMa5 (ORCPT ); Mon, 14 Jul 2003 08:30:57 -0400 Received: from perninha.conectiva.com.br ([200.250.58.156]:10165 "EHLO perninha.conectiva.com.br") by vger.kernel.org with ESMTP id S270579AbTGNMKu (ORCPT ); Mon, 14 Jul 2003 08:10:50 -0400 Date: Mon, 14 Jul 2003 09:23:09 -0300 (BRT) From: Marcelo Tosatti X-X-Sender: marcelo@freak.distro.conectiva To: Jens Axboe Cc: Andrea Arcangeli , Chris Mason , lkml , "Stephen C. Tweedie" , Alan Cox , Jeff Garzik , Andrew Morton , Alexander Viro Subject: Re: RFC on io-stalls patch In-Reply-To: <20030714054918.GD843@suse.de> Message-ID: References: <20030710135747.GT825@suse.de> <1057932804.13313.58.camel@tiny.suse.com> <20030712073710.GK843@suse.de> <1058034751.13318.95.camel@tiny.suse.com> <20030713090116.GU843@suse.de> <20030713191921.GI16313@dualathlon.random> <20030714054918.GD843@suse.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1735 Lines: 42 On Mon, 14 Jul 2003, Jens Axboe wrote: > On Sun, Jul 13 2003, Andrea Arcangeli wrote: > > On Sun, Jul 13, 2003 at 11:01:16AM +0200, Jens Axboe wrote: > > > No I don't have anything specific, it just seems like a bad heuristic to > > > get rid of. I can try and do some testing tomorrow. I do feel strongly > > > > well, it's not an heuristic, it's a simplification and it will certainly > > won't provide any benefit (besides saving some hundred kbytes of ram per > > harddisk that is a minor benefit). > > You are missing my point - I don't care about loosing the extra request > list, I never said anything about that in this thread. I care about > loosing the reserved requests for reads. And we can do that just fine > with just holding back a handful of requests. > > > > that we should at least make sure to reserve a few requests for reads > > > exclusively, even if you don't agree with the oversized check. Anything > > > else really contradicts all the io testing we have done the past years > > > that shows how important it is to get a read in ASAP. And doing that in > > > > Important for latency or throughput? Do you know which is the benchmarks > > that returned better results with the two queues, what's the theory > > behind this? > > Forget the two queues, noone has said anything about that. The reserved > reads are important for latency reasons, not throughput. So Jens, Please bench (as you said you would), and send us the results. Its very important. Thanks - 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/