From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752696Ab3AWBIH (ORCPT ); Tue, 22 Jan 2013 20:08:07 -0500 Received: from mail-qc0-f177.google.com ([209.85.216.177]:33133 "EHLO mail-qc0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752612Ab3AWBID (ORCPT ); Tue, 22 Jan 2013 20:08:03 -0500 Date: Tue, 22 Jan 2013 17:07:58 -0800 From: Tejun Heo To: Joonsoo Kim Cc: linux-kernel@vger.kernel.org, Lai Jiangshan Subject: Re: [PATCHSET] workqueue: remove gcwq and make worker_pool the only backend abstraction Message-ID: <20130123010758.GH5359@htj.dyndns.org> References: <1358386969-945-1-git-send-email-tj@kernel.org> <20130122053702.GA10675@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130122053702.GA10675@lge.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey. On Tue, Jan 22, 2013 at 02:37:02PM +0900, Joonsoo Kim wrote: > > It seems like we'll need to support worker pools with custom > > attributes, which is planned to be implemented as extra worker_pools > > for the unbound CPU. Removing gcwq and having worker_pool as the top > > level abstraction makes things much simpler for such designs. Also, > > there's scalability benefit to not sharing locking and busy hash among > > different worker pools as worker pools w/ custom attributes are likely > > to have widely different memory / cpu locality characteristics. > > Could you tell me why extra worker_pools with custom attributes are needed? > Or could you give a reference link for this? Currently, there are two expected users - writeback and crypto. The former currently implements its own worker pool and the latter is using per-cpu workqueue but not particularly happy with it. Being bound to the issuing CPU seems a bit too limiting. Thanks. -- tejun