Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754530AbZKQPIu (ORCPT ); Tue, 17 Nov 2009 10:08:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752968AbZKQPIt (ORCPT ); Tue, 17 Nov 2009 10:08:49 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:36684 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754116AbZKQPIs (ORCPT ); Tue, 17 Nov 2009 10:08:48 -0500 Date: Tue, 17 Nov 2009 07:05:18 -0800 (PST) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Tejun Heo cc: Andy Walls , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, jeff@garzik.org, mingo@elte.hu, akpm@linux-foundation.org, jens.axboe@oracle.com, rusty@rustcorp.com.au, cl@linux-foundation.org, dhowells@redhat.com, arjan@linux.intel.com, avi@redhat.com, peterz@infradead.org, andi@firstfloor.org, fweisbec@gmail.com Subject: Re: [PATCH 17/21] workqueue: simple reimplementation of SINGLE_THREAD workqueue In-Reply-To: <4B023340.90004@kernel.org> Message-ID: References: <1258391726-30264-1-git-send-email-tj@kernel.org> <1258391726-30264-18-git-send-email-tj@kernel.org> <1258418872.4096.28.camel@palomino.walls.org> <4B023340.90004@kernel.org> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1069 Lines: 27 On Tue, 17 Nov 2009, Tejun Heo wrote: > > Do you think that usage is wide-spread? Implementing strict ordering > shouldn't be too difficult but I can't help but feeling that such > assumption is abuse of implementation detail. I think it would be good if it were more than an implementation detail, and was something documented and known. The less random and timing-dependent our interfaces are, the better off we are. Guaranteeing that a single-threaded workqueue is done in order seems to me to be a GoodThing(tm), regardless of whether much code depends on it. Of course, if there is some fundamental reason why it wouldn't be the case, that's another thing. But if you think uit should be easy, and since there _are_ users, then it shouldn't be seen as an "implementation detail". It's a feature. Linus -- 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/