Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757674AbZJBMqs (ORCPT ); Fri, 2 Oct 2009 08:46:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756825AbZJBMqs (ORCPT ); Fri, 2 Oct 2009 08:46:48 -0400 Received: from hp3.statik.tu-cottbus.de ([141.43.120.68]:48126 "EHLO hp3.statik.tu-cottbus.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753576AbZJBMqr (ORCPT ); Fri, 2 Oct 2009 08:46:47 -0400 Message-ID: <4AC5F5FB.9050202@s5r6.in-berlin.de> Date: Fri, 02 Oct 2009 14:45:47 +0200 From: Stefan Richter User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8.1.22) Gecko/20090605 SeaMonkey/1.1.17 MIME-Version: 1.0 To: Tejun Heo CC: David Howells , jeff@garzik.org, mingo@elte.hu, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, jens.axboe@oracle.com, rusty@rustcorp.com.au, cl@linux-foundation.org, arjan@linux.intel.com Subject: Re: [RFC PATCHSET] workqueue: implement concurrency managed workqueue References: <1254384558-1018-1-git-send-email-tj@kernel.org> <9942.1254401629@redhat.com> <4AC5E7BA.5060700@kernel.org> In-Reply-To: <4AC5E7BA.5060700@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1579 Lines: 36 Tejun Heo wrote: > David Howells wrote: >> Sounds interesting as a replacement for slow-work. Some thoughts for you: >> >> The most important features of slow-work are: >> >> (1) Work items are not re-entered whilst they are executing. >> >> (2) The slow-work facility keeps references on its work items by asking the >> client to get and put on the client's refcount. >> >> (3) The slow-work facility can create a lot more threads than the number of >> CPUs on a system, and the system doesn't grind to a halt if they're all >> taken up with long term I/O (performing several mkdirs for example). >> >> I think you have (1) and (3) covered, but I'm unsure about (2). > > Given that slow-work isn't being used too extensively yet, I was > thinking whether that part could be pushed down to the caller. Or, we > can also wrap work and export an interface which supports the get/put > reference. BTW, not only slow-work users need reference counting, many existing regular workqueue users could use it as well. (Well, I guess I stated the obvious.) Currently we have local wrappers for that like these ones: http://lxr.linux.no/#linux+v2.6.31/drivers/firewire/core-card.c#L212 http://lxr.linux.no/#linux+v2.6.31/drivers/firewire/sbp2.c#L838 -- Stefan Richter -=====-==--= =-=- ---=- http://arcgraph.de/sr/ -- 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/