From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161876AbcFGT4i (ORCPT ); Tue, 7 Jun 2016 15:56:38 -0400 Received: from mail-bl2on0079.outbound.protection.outlook.com ([65.55.169.79]:52800 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1161743AbcFGT4f (ORCPT ); Tue, 7 Jun 2016 15:56:35 -0400 Authentication-Results: spf=pass (sender IP is 63.163.107.225) smtp.mailfrom=sandisk.com; vger.kernel.org; dkim=none (message not signed) header.d=none;vger.kernel.org; dmarc=bestguesspass action=none header.from=sandisk.com; X-AuditID: ac160c71-a17ff70000000efe-3e-57572605c0bc Subject: Re: [RFC] IB/srp: Remove create_workqueue To: Tejun Heo References: <20160607181617.GA6556@Karyakshetra> <20160607192106.GY31708@htj.duckdns.org> CC: Bhaktipriya Shridhar , Doug Ledford , Sean Hefty , Hal Rosenstock , "linux-rdma@vger.kernel.org" , "linux-kernel@vger.kernel.org" From: Bart Van Assche Message-ID: Date: Tue, 7 Jun 2016 12:56:25 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: <20160607192106.GY31708@htj.duckdns.org> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmpgkeLIzCtJLcpLzFFi42JZI8azSJdDLTzc4Ps3cYs3P6YyWrw8/4HV YuPmiYwWl3fNYbN4dqiXxaJ5/QYWi1/LjzI6sHvsnHWX3WPxnpdMHptWdbJ5vN93lc3j8ya5 ANYoLpuU1JzMstQifbsErowjuyazFfRxVPz49Z25gfEYWxcjJ4eEgInE5BuHmboYuTiEBOYy SSy9dhfK2c4o0dr2kAmm6tvRxWAdQgJLGSVWn2fuYuTgEBYwkjj5UhUkLCIgK3Fl2kNGiN4J jBJLXtxgB3GYBZYxSTxeM5UFpIoNqOHb+5ksIM28AnYSjx4HgJgsAioSK6YHglSICkRIfPr9 hRXE5hUQlDg58wlYNaeAqcTUdjGQMLOAhcTM+ecZIWx5ie1v5zCDbJIQOMsq8fXSW2aIM9Ul Ti6ZzzSBUXgWklGzkPTPQtK/gJF5FaNYbmZOcW56aoGhiV5xYl5KZnG2XnJ+7iZGSLwU7mB8 fdv7EKMAB6MSD++OL6HhQqyJZcWVuYcYJTiYlUR4u+XDw4V4UxIrq1KL8uOLSnNSiw8xSnOw 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fcd9ea9c-ae8c-460c-ab3c-3db42d7ac64d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=fcd9ea9c-ae8c-460c-ab3c-3db42d7ac64d;Ip=[63.163.107.225];Helo=[milsmgep14.sandisk.com] X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN1PR0201MB1773 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/07/2016 12:21 PM, Tejun Heo wrote: > On Tue, Jun 07, 2016 at 11:32:42AM -0700, Bart Van Assche wrote: >> On 06/07/2016 11:16 AM, Bhaktipriya Shridhar wrote: >>> alloc_workqueue replaces deprecated create_workqueue(). >>> >>> A dedicated workqueue has been used since the workqueue srp_remove_wq with >>> workitem &target->remove_work, is a work queue for the SRP target removal. >>> WQ_MEM_RECLAIM has been set to ensure forward progress under memory >>> pressure. >>> Since there are only a fixed number of work items, explicit >>> concurrency limit is unnecessary here. >>> >>> Is the workqueue being used on a memory reclaim path? >>> Does it require WQ_MEM_RECLAIM? >> >> Hello Bhaktipriya, >> >> srp_remove_wq is used for SRP target port removal work only. This work is >> neither queued from inside a shrinker nor by the page writeback code so I >> think it is safe to drop WQ_MEM_RECLAIM. > > It should be able to use system_wq then. No. I have tried that but that resulted in a deadlock. Bart.