Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 10 Feb 2003 02:11:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 10 Feb 2003 02:11:14 -0500 Received: from [195.223.140.107] ([195.223.140.107]:39041 "EHLO athlon.random") by vger.kernel.org with ESMTP id ; Mon, 10 Feb 2003 02:11:13 -0500 Date: Mon, 10 Feb 2003 08:20:38 +0100 From: Andrea Arcangeli To: Rik van Riel Cc: David Lang , Con Kolivas , lkml , Jens Axboe Subject: Re: stochastic fair queueing in the elevator [Re: [BENCHMARK] 2.4.20-ck3 / aa / rmap with contest] Message-ID: <20030210072038.GE31401@dualathlon.random> References:

Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4i X-GPG-Key: 1024D/68B9CB43 X-PGP-Key: 1024R/CB4660B9 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1050 Lines: 23 On Mon, Feb 10, 2003 at 02:29:20AM -0200, Rik van Riel wrote: > On Sun, 9 Feb 2003, David Lang wrote: > > > note that issuing a fsync should change all pending writes to 'syncronous' > > as should writes to any partition mounted with the sync option, or writes > > to a directory with the S flag set. > > Exactly. This is nasty with our current data structures; > probably not something to do during the current code slush. as I said, you can consider asychronous all requests submitted with current->mm, this will be 90% accurate. This whole thing is an heuristic, if the heuristic fails the behaviour become like w/o SFQ so no regression. Also the latency of fsync is less critical than the latency of a read() syscall, again, this is statistically, sometime it can be the other way around. Andrea - 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/