From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964844AbcHaO0y (ORCPT ); Wed, 31 Aug 2016 10:26:54 -0400 Received: from mail-yw0-f193.google.com ([209.85.161.193]:34069 "EHLO mail-yw0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934861AbcHaO0u (ORCPT ); Wed, 31 Aug 2016 10:26:50 -0400 Date: Wed, 31 Aug 2016 10:26:48 -0400 From: Tejun Heo To: Bhaktipriya Shridhar Cc: Liam Girdwood , Mark Brown , Jaroslav Kysela , Takashi Iwai , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] ASoC: Remove deprecated create_singlethread_workqueue Message-ID: <20160831142648.GP12660@htj.duckdns.org> References: <20160830192709.GA16591@Karyakshetra> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160830192709.GA16591@Karyakshetra> User-Agent: Mutt/1.7.0 (2016-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 31, 2016 at 12:57:09AM +0530, Bhaktipriya Shridhar wrote: > The workqueue "dac33_wq" queues a single work item &dac33->work and hence > doesn't require ordering. Also, it is not being used on a memory reclaim > path. Hence, it has been converted to use system_wq. > > The work item has been flushed in dac33_soc_remove to ensure that > there are no pending tasks while disconnecting the driver. > > The workqueue "post_msg_wq" queues a single work item > &drv->ipc_post_msg_wq and hence doesn't require ordering. Also, it is > not being used on a memory reclaim path. Hence, it has been converted to > use system_wq. > > The work item has been flushed in sst_context_cleanup to ensure that > there are no pending tasks while disconnecting the driver. > > 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 Acked-by: Tejun Heo Thanks. -- tejun