From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751568AbcGPIsm (ORCPT ); Sat, 16 Jul 2016 04:48:42 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:34982 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751431AbcGPIsi (ORCPT ); Sat, 16 Jul 2016 04:48:38 -0400 Date: Sat, 16 Jul 2016 14:18:34 +0530 From: Bhaktipriya Shridhar To: Sebastian Ott , Peter Oberparleiter , Martin Schwidefsky , Heiko Carstens Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Tejun Heo Subject: [PATCH] s390/cio/chp : Remove deprecated create_singlethread_workqueue Message-ID: <20160716084834.GA7728@Karyakshetra> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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 The workqueue "chp_wq" is involved in performing pending configure tasks for channel paths. It has a single work item(&cfg_work) and hence doesn't require ordering. Also, it is not being used on a memory reclaim path. Hence, the singlethreaded workqueue has been replaced with the use of system_wq. System workqueues have been able to handle high level of concurrency for a long time now and hence it's not required to have a singlethreaded workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue created with create_singlethread_workqueue(), system_wq allows multiple work items to overlap executions even on the same CPU; however, a per-cpu workqueue doesn't have any CPU locality or global ordering guarantee unless the target CPU is explicitly specified and thus the increase of local concurrency shouldn't make any difference. Signed-off-by: Bhaktipriya Shridhar --- drivers/s390/cio/chp.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c index 50597f9..92413c4 100644 --- a/drivers/s390/cio/chp.c +++ b/drivers/s390/cio/chp.c @@ -47,8 +47,6 @@ static DEFINE_MUTEX(info_lock); /* Time after which channel-path status may be outdated. */ static unsigned long chp_info_expires; -/* Workqueue to perform pending configure tasks. */ -static struct workqueue_struct *chp_wq; static struct work_struct cfg_work; /* Wait queue for configure completion events. */ @@ -714,7 +712,7 @@ static void cfg_func(struct work_struct *work) wake_up_interruptible(&cfg_wait_queue); return; } - queue_work(chp_wq, &cfg_work); + schedule_work(&cfg_work); } /** @@ -732,7 +730,7 @@ void chp_cfg_schedule(struct chp_id chpid, int configure) cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure); cfg_busy = 1; mutex_unlock(&cfg_lock); - queue_work(chp_wq, &cfg_work); + schedule_work(&cfg_work); } /** @@ -766,11 +764,6 @@ static int __init chp_init(void) ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw); if (ret) return ret; - chp_wq = create_singlethread_workqueue("cio_chp"); - if (!chp_wq) { - crw_unregister_handler(CRW_RSC_CPATH); - return -ENOMEM; - } INIT_WORK(&cfg_work, cfg_func); init_waitqueue_head(&cfg_wait_queue); if (info_update()) -- 2.1.4