From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753084Ab1LLHPU (ORCPT ); Mon, 12 Dec 2011 02:15:20 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:56305 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750962Ab1LLHOA (ORCPT ); Mon, 12 Dec 2011 02:14:00 -0500 From: Lai Jiangshan To: Pekka Enberg , Ingo Molnar Cc: linux-kernel@vger.kernel.org, Lai Jiangshan Subject: [PATCH 01/11] kvm tools: check condition before wait Date: Mon, 12 Dec 2011 15:15:45 +0800 Message-Id: <1323674155-17570-2-git-send-email-laijs@cn.fujitsu.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1323674155-17570-1-git-send-email-laijs@cn.fujitsu.com> References: <1323674155-17570-1-git-send-email-laijs@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-12-12 15:13:20, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-12-12 15:13:21, Serialize complete at 2011-12-12 15:13:21 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We should check the condition before wait it, otherewise we may get deadlock. Signed-off-by: Lai Jiangshan --- tools/kvm/threadpool.c | 7 +++---- 1 files changed, 3 insertions(+), 4 deletions(-) diff --git a/tools/kvm/threadpool.c b/tools/kvm/threadpool.c index fdc5fa7..2e59e62 100644 --- a/tools/kvm/threadpool.c +++ b/tools/kvm/threadpool.c @@ -80,12 +80,11 @@ static void *thread_pool__threadfunc(void *param) struct thread_pool__job *curjob; mutex_lock(&job_mutex); - pthread_cond_wait(&job_cond, &job_mutex); - curjob = thread_pool__job_pop(); + while ((curjob = thread_pool__job_pop()) == NULL) + pthread_cond_wait(&job_cond, &job_mutex); mutex_unlock(&job_mutex); - if (curjob) - thread_pool__handle_job(curjob); + thread_pool__handle_job(curjob); } pthread_cleanup_pop(0); -- 1.7.4.4