From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752118AbcGBLnB (ORCPT ); Sat, 2 Jul 2016 07:43:01 -0400 Received: from mail-oi0-f47.google.com ([209.85.218.47]:32939 "EHLO mail-oi0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751289AbcGBLm7 (ORCPT ); Sat, 2 Jul 2016 07:42:59 -0400 Date: Sat, 2 Jul 2016 06:42:57 -0500 From: Tejun Heo To: Bhaktipriya Shridhar Cc: Mark Brown , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] spi: spi-topcliff-pch: Remove deprecated create_singlethread_workqueue Message-ID: <20160702114257.GI17431@htj.duckdns.org> References: <20160702085334.GA28440@Karyakshetra> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160702085334.GA28440@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 02:23:34PM +0530, Bhaktipriya Shridhar wrote: > The workqueue "wk" serves as a queue for carrying out execution > of requests. It has a single work item(&drv_data->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. > > Work item has been flushed in pch_spi_free_resources() to ensure that > there are no pending tasks while disconnecting the driver. > > Signed-off-by: Bhaktipriya Shridhar Acked-by: Tejun Heo Thanks. -- tejun