From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757797AbaGPKJJ (ORCPT ); Wed, 16 Jul 2014 06:09:09 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:55806 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1757535AbaGPKJH (ORCPT ); Wed, 16 Jul 2014 06:09:07 -0400 X-IronPort-AV: E=Sophos;i="5.00,902,1396972800"; d="scan'208";a="33350985" From: Lai Jiangshan To: CC: Tejun Heo , Lai Jiangshan Subject: [PATCH 1/2] workqueue: remove unneeded test before wake up next worker Date: Wed, 16 Jul 2014 18:09:58 +0800 Message-ID: <1405505409-12058-1-git-send-email-laijs@cn.fujitsu.com> X-Mailer: git-send-email 1.7.4.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.167.226.103] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In this code: if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool)) wake_up_worker(pool); the first test is unneeded. Even the first test is removed, it doesn't affect the wake-up logic when WORKER_UNBOUND. And it will not introduce any useless wake-up when !WORKER_UNBOUND since the nr_running >= 1 except only one case. It will introduce useless/redundant wake-up when cpu_intensive, but this case is rare and next patch will also remove this redundant wake-up. Signed-off-by: Lai Jiangshan --- kernel/workqueue.c | 7 ++----- 1 files changed, 2 insertions(+), 5 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index f8d54c1..6d11b9a 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2047,11 +2047,8 @@ __acquires(&pool->lock) if (unlikely(cpu_intensive)) worker_set_flags(worker, WORKER_CPU_INTENSIVE, true); - /* - * Unbound pool isn't concurrency managed and work items should be - * executed ASAP. Wake up another worker if necessary. - */ - if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool)) + /* Wake up another worker if necessary. */ + if (need_more_worker(pool)) wake_up_worker(pool); /* -- 1.7.4.4