From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932221AbcEaQ4l (ORCPT ); Tue, 31 May 2016 12:56:41 -0400 Received: from mail-pf0-f196.google.com ([209.85.192.196]:36077 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751375AbcEaQ4g (ORCPT ); Tue, 31 May 2016 12:56:36 -0400 Date: Tue, 31 May 2016 22:26:30 +0530 From: Bhaktipriya Shridhar To: Boris Ostrovsky , David Vrabel , Juergen Gross Cc: Tejun Heo , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] xen: xenbus: Remove create_workqueue Message-ID: <20160531165630.GA21779@Karyakshetra> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Replace dedicated xenbus_frontend_wq 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 the increase of local concurrency shouldn't make any difference. In this case, there is only a single work item, increase of concurrency level by switching to system_wq should not make any difference. Signed-off-by: Bhaktipriya Shridhar --- drivers/xen/xenbus/xenbus_probe_frontend.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-) diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c b/drivers/xen/xenbus/xenbus_probe_frontend.c index bcb53bd..611a231 100644 --- a/drivers/xen/xenbus/xenbus_probe_frontend.c +++ b/drivers/xen/xenbus/xenbus_probe_frontend.c @@ -31,7 +31,6 @@ #include "xenbus_probe.h" -static struct workqueue_struct *xenbus_frontend_wq; /* device// => - */ static int frontend_bus_id(char bus_id[XEN_BUS_ID_SIZE], const char *nodename) @@ -109,13 +108,7 @@ static int xenbus_frontend_dev_resume(struct device *dev) if (xen_store_domain_type == XS_LOCAL) { struct xenbus_device *xdev = to_xenbus_device(dev); - if (!xenbus_frontend_wq) { - pr_err("%s: no workqueue to process delayed resume\n", - xdev->nodename); - return -EFAULT; - } - - queue_work(xenbus_frontend_wq, &xdev->work); + schedule_work(&xdev->work); return 0; } @@ -485,12 +478,6 @@ static int __init xenbus_probe_frontend_init(void) register_xenstore_notifier(&xenstore_notifier); - if (xen_store_domain_type == XS_LOCAL) { - xenbus_frontend_wq = create_workqueue("xenbus_frontend"); - if (!xenbus_frontend_wq) - pr_warn("create xenbus frontend workqueue failed, S3 resume is likely to fail\n"); - } - return 0; } subsys_initcall(xenbus_probe_frontend_init); -- 2.1.4