From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758070Ab2IZSii (ORCPT ); Wed, 26 Sep 2012 14:38:38 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:62651 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755401Ab2IZSih (ORCPT ); Wed, 26 Sep 2012 14:38:37 -0400 Date: Wed, 26 Sep 2012 11:38:33 -0700 From: Tejun Heo To: Lai Jiangshan Cc: linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 11/12] workqueue: add WQ_CPU_INTENSIVE to system_long_wq Message-ID: <20120926183833.GI12544@google.com> References: <1348680043-5077-1-git-send-email-laijs@cn.fujitsu.com> <1348680043-5077-12-git-send-email-laijs@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1348680043-5077-12-git-send-email-laijs@cn.fujitsu.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 27, 2012 at 01:20:42AM +0800, Lai Jiangshan wrote: > works in system_long_wq will be running long. > add WQ_CPU_INTENSIVE to system_long_wq to avoid these kinds of works occupy > the running wokers which delay the normal works. > > if system_long_wq is designed for only sleep-long works, not running-long works, > this patch makes no sense. There "long" doesn't mean it's gonna consume a lot of CPU cycles, so it should contribute to concurrency management. The plan is to remove system_long_wq once we got rid of flushing of system_wq via flush_scheduled_work() and directly through flush_workqueue(). I think we're pretty close, so let's not add more usage of it. Thanks. -- tejun