From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932597AbaEPO6i (ORCPT ); Fri, 16 May 2014 10:58:38 -0400 Received: from mail-ie0-f170.google.com ([209.85.223.170]:51596 "EHLO mail-ie0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932311AbaEPO6h (ORCPT ); Fri, 16 May 2014 10:58:37 -0400 Message-ID: <53762799.2080403@kernel.dk> Date: Fri, 16 May 2014 08:58:33 -0600 From: Jens Axboe User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Christoph Hellwig CC: Ming Lei , linux-kernel@vger.kernel.org, Rusty Russell Subject: Re: [PATCH] virtio_blk: fix race between start and stop queue References: <1400157181-17800-1-git-send-email-tom.leiming@gmail.com> <53762662.2050702@kernel.dk> <20140516145450.GA5939@infradead.org> In-Reply-To: <20140516145450.GA5939@infradead.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014-05-16 08:54, Christoph Hellwig wrote: > On Fri, May 16, 2014 at 08:53:22AM -0600, Jens Axboe wrote: >>> This patch fixes the problem by starting/stopping blk-mq >>> with holding vq_lock. >> >> Why not just use blk_mq_start_hw_queues()? > > That would kick off a work item on every I/O completion, something > you didn't particularly like in scsi-mq :) It would suck, I sent a followup after that one :-) And yes, it still needs improving in scsi-mq too. -- Jens Axboe