From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754749Ab3BEMHI (ORCPT ); Tue, 5 Feb 2013 07:07:08 -0500 Received: from mail-da0-f41.google.com ([209.85.210.41]:42430 "EHLO mail-da0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751378Ab3BEMHE (ORCPT ); Tue, 5 Feb 2013 07:07:04 -0500 Message-ID: <5110F5DE.6030407@gmail.com> Date: Tue, 05 Feb 2013 20:06:54 +0800 From: Lai Jiangshan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Tejun Heo CC: Lai Jiangshan , linux-kernel@vger.kernel.org Subject: Re: [PATCH 02/13] workqueue: fix work_busy() References: <1359657696-2767-1-git-send-email-laijs@cn.fujitsu.com> <1359657696-2767-3-git-send-email-laijs@cn.fujitsu.com> <20130204195458.GA27963@mtj.dyndns.org> In-Reply-To: <20130204195458.GA27963@mtj.dyndns.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 于 2013/2/5 3:54, Tejun Heo 写道: > Hello, Lai. > > On Fri, Feb 01, 2013 at 02:41:25AM +0800, Lai Jiangshan wrote: >> diff --git a/kernel/workqueue.c b/kernel/workqueue.c >> index 973b290..d474a6c 100644 >> --- a/kernel/workqueue.c >> +++ b/kernel/workqueue.c >> @@ -3443,8 +3443,6 @@ EXPORT_SYMBOL_GPL(workqueue_congested); >> * Test whether @work is currently pending or running. There is no >> * synchronization around this function and the test result is >> * unreliable and only useful as advisory hints or for debugging. >> - * Especially for reentrant wqs, the pending state might hide the >> - * running state. > > Yeap, this is no longer true. > >> * >> * RETURNS: >> * OR'd bitmask of WORK_BUSY_* bits. >> @@ -3453,15 +3451,13 @@ unsigned int work_busy(struct work_struct *work) >> { >> struct worker_pool *pool = get_work_pool(work); >> unsigned long flags; >> - unsigned int ret = 0; >> + unsigned int ret = work_pending(work) ? WORK_BUSY_PENDING : 0; > > I'd prefer this as a if() statement. > >> if (!pool) >> - return 0; >> + return ret; > > I'm a bit confused. When can we be pending w/o pool? > grab the pending bits <==time==> really queued ^ this patch considers the work is busy in this time