From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754703AbYKKSVT (ORCPT ); Tue, 11 Nov 2008 13:21:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751646AbYKKSVG (ORCPT ); Tue, 11 Nov 2008 13:21:06 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:39064 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751512AbYKKSVE (ORCPT ); Tue, 11 Nov 2008 13:21:04 -0500 Date: Tue, 11 Nov 2008 13:21:02 -0500 From: Christoph Hellwig To: Christoph Hellwig , Mikulas Patocka , axboe@kernel.dk, dm-devel , linux-kernel@vger.kernel.org Subject: Re: Queue upcall locking (was: [dm-devel] [RFC][PATCH] fix dm_any_congested() to properly sync up with suspend code path) Message-ID: <20081111182102.GB25049@infradead.org> References: <1225944008.14830.1101.camel@chandra-ubuntu> <20081110135401.GA11606@infradead.org> <20081110142715.GD16649@agk.fab.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081110142715.GD16649@agk.fab.redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 10, 2008 at 02:27:15PM +0000, Alasdair G Kergon wrote: > Indeed - the blocking was a bug for which there's a patch, but that doesn't > deal with how the function should be operating in the first place. > > - If one device is found to be congested, why bother checking the remaining > devices? > > - If the device is suspended, the response should be that it is congested, I'd > have thought. Yes. device congested is a quick an dirty check - if you encounter anything long just return congested if I/O would hit this long delay, too or not congested if you can't really know.