From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933537AbaEGNQz (ORCPT ); Wed, 7 May 2014 09:16:55 -0400 Received: from mail-qa0-f45.google.com ([209.85.216.45]:37035 "EHLO mail-qa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933450AbaEGNP1 (ORCPT ); Wed, 7 May 2014 09:15:27 -0400 Date: Wed, 7 May 2014 09:15:23 -0400 From: Tejun Heo To: Lai Jiangshan Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Peter Zijlstra Subject: Re: [PATCH 03/10] workqueue: async worker destruction Message-ID: <20140507131523.GC16702@htj.dyndns.org> References: <1398571754-12443-1-git-send-email-laijs@cn.fujitsu.com> <1398571754-12443-4-git-send-email-laijs@cn.fujitsu.com> <5369E11F.5010909@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5369E11F.5010909@cn.fujitsu.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 07, 2014 at 03:30:39PM +0800, Lai Jiangshan wrote: > On 04/27/2014 12:08 PM, Lai Jiangshan wrote: > > > > > spin_unlock_irq(&pool->lock); > > + > > + wait_event_cmd(pool->workers_unbound, > > + idr_is_empty(&pool->worker_idr), > > + mutex_unlock(&pool->manager_mutex), > > + mutex_lock(&pool->manager_mutex)); > > + > > > How about I wrap it as wait_event_mutex()? > (like wait_event_lock_irq() in kernel and pthread_cond_wait() in userspace) waitq tends to be trickier to get right. Can you please give completion a shot? completion is pretty convenient for (its only purpose after all) this sort of one-shot synchronizations. -- tejun