From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751851AbcGBMyE (ORCPT ); Sat, 2 Jul 2016 08:54:04 -0400 Received: from mail-io0-f194.google.com ([209.85.223.194]:33824 "EHLO mail-io0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751161AbcGBMyC (ORCPT ); Sat, 2 Jul 2016 08:54:02 -0400 Date: Sat, 2 Jul 2016 07:53:47 -0500 From: Tejun Heo To: Bhaktipriya Shridhar Cc: David Airlie , Tomi Valkeinen , Dave Airlie , Rob Clark , Arnd Bergmann , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/omap: panel-dsi-cm: Remove deprecated create_singlethread_workqueue Message-ID: <20160702125347.GN17431@htj.duckdns.org> References: <20160702094708.GA31263@Karyakshetra> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160702094708.GA31263@Karyakshetra> User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jul 02, 2016 at 03:17:08PM +0530, Bhaktipriya Shridhar wrote: > The workqueue "workqueue" has only a single workitem(&ddata->ulps_work) per > panel_drv_data 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. > > Occurrences of the label err_bl have also been removed because with the > usage of system_wq, calls to destroy_workqueue() have been dropped, > which makes the label unnecessary. > > Workitem is sync cancelled in dsicm_cancel_ulps_work() which is called > in dsicm_remove() to ensure that there are no workitems pending when the > driver is disconnected. > > Signed-off-by: Bhaktipriya Shridhar Acked-by: Tejun Heo Thanks. -- tejun