From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264858AbTFCJtV (ORCPT ); Tue, 3 Jun 2003 05:49:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264872AbTFCJtV (ORCPT ); Tue, 3 Jun 2003 05:49:21 -0400 Received: from ns.suse.de ([213.95.15.193]:43789 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S264858AbTFCJtT (ORCPT ); Tue, 3 Jun 2003 05:49:19 -0400 Date: Tue, 3 Jun 2003 12:02:55 +0200 From: Jens Axboe To: Andrew Morton Cc: adam@yggdrasil.com, linux-kernel@vger.kernel.org Subject: Re: Counter-kludge for 2.5.x hanging when writing to block device Message-ID: <20030603100255.GJ482@suse.de> References: <200306030848.h538mwE22282@freya.yggdrasil.com> <20030603091018.GI482@suse.de> <20030603030023.69d39d6e.akpm@digeo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030603030023.69d39d6e.akpm@digeo.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 03 2003, Andrew Morton wrote: > > Does something like this work? Andrew, what's the point of doing the > > wait if the queue isn't congested?! > > We need to wait until the amount of dirty memory in the machine is below > the designated limits. This is unrelated to queue congestion. The way the > logic is now we can have 256 megs worth of requests queues on a 32M machine > and everything throttles and clamps as intended. > > > There are several things wrong with blk_congestion_wait(), including: > > a) it should be called throttle_on_io() Well... > b) it should check that there are still requests in flight after parking > itself on the waitqueue rather than relying on the timeout. This is important, would be much nicer to pass in the backing dev. This is a big problem, imho. It's broken right now. > As for Adam's hang: dunno. I and many others have run mkfs and dd an > unbelievable number of times. He needs to debug it more. Agree -- Jens Axboe