From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932874AbcFTPNq (ORCPT ); Mon, 20 Jun 2016 11:13:46 -0400 Received: from mail-yw0-f195.google.com ([209.85.161.195]:34031 "EHLO mail-yw0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932845AbcFTPNh (ORCPT ); Mon, 20 Jun 2016 11:13:37 -0400 Date: Mon, 20 Jun 2016 11:11:23 -0400 From: Tejun Heo To: Bhaktipriya Shridhar Cc: Thierry Reding , Srinivas Kandagatla , Arnd Bergmann , dri-devel@lists.freedesktop.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] gpu: host1x: hw: intr_hw: Remove create_workqueue Message-ID: <20160620151123.GY3262@mtj.duckdns.org> References: <20160618090632.GA11246@Karyakshetra> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160618090632.GA11246@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, Jun 18, 2016 at 02:36:32PM +0530, Bhaktipriya Shridhar wrote: > System workqueues have been able to handle high level of concurrency > for a long time now and there's no reason to use dedicated workqueues > just to gain concurrency. Since the workqueue host->intr_wq is involved > in sync point interrupts, and sync point wait and is not being used on > a memory reclaim path, dedicated host->intr_wq has been replaced with the > use of system_wq. > > Unlike a dedicated per-cpu workqueue created with create_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 guarantees unless the target CPU is > explicitly specified and thus the increase of local concurrency > shouldn't make any difference. > > cancel_work_sync() has been used in _host1x_free_syncpt_irq() to ensure > that no work is pending by the time exit path runs. Alternatively, this could have used alloc_workqueue() w/o WQ_MEM_RECLAIM and used it just as a flush domain. Either way is fine. Acked-by: Tejun Heo Thanks. -- tejun