From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sat, 16 Jul 2016 12:35:26 +0200 (CEST) From: Sebastian Ott Subject: Re: [PATCH] s390/cio/chp : Remove deprecated create_singlethread_workqueue In-Reply-To: <20160716084834.GA7728@Karyakshetra> References: <20160716084834.GA7728@Karyakshetra> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Message-Id: Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Bhaktipriya Shridhar Cc: Peter Oberparleiter , Martin Schwidefsky , Heiko Carstens , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Tejun Heo List-ID: On Sat, 16 Jul 2016, Bhaktipriya Shridhar wrote: > 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 Applied, thanks! Sebastian