From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from slow1-d.mail.gandi.net ([217.70.178.86]:37284 "EHLO slow1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752187AbcGSCn5 (ORCPT ); Mon, 18 Jul 2016 22:43:57 -0400 Subject: Re: [PATCH] [media] gspca: finepix: Remove deprecated create_singlethread_workqueue To: Bhaktipriya Shridhar , Hans de Goede , Mauro Carvalho Chehab References: <20160716085556.GA7841@Karyakshetra> Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Tejun Heo From: Frank Zago Message-ID: <578D9227.7040007@zago.net> Date: Mon, 18 Jul 2016 21:36:23 -0500 MIME-Version: 1.0 In-Reply-To: <20160716085556.GA7841@Karyakshetra> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 07/16/2016 03:55 AM, Bhaktipriya Shridhar wrote: > The workqueue "work_thread" is involved in streaming the camera data. > It has a single work item(&dev->work_struct) 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. > > Work item has been flushed in sd_stop0() to ensure that there are no > pending tasks while disconnecting the driver. > > Signed-off-by: Bhaktipriya Shridhar Acked-by: Frank Zago Thanks for the patch.