From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933294AbaE3OJz (ORCPT ); Fri, 30 May 2014 10:09:55 -0400 Received: from mail-pd0-f177.google.com ([209.85.192.177]:61442 "EHLO mail-pd0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933058AbaE3OJy (ORCPT ); Fri, 30 May 2014 10:09:54 -0400 Message-ID: <5388912F.7010609@kernel.dk> Date: Fri, 30 May 2014 08:09:51 -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: Shaohua Li , Christoph Hellwig CC: linux-kernel@vger.kernel.org Subject: Re: [patch]blk-mq: blk_mq_tag_to_rq should handle flush request References: <20140509120733.GA27918@kernel.org> <20140509150018.GA26215@infradead.org> <20140510040023.GA13788@kernel.org> In-Reply-To: <20140510040023.GA13788@kernel.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 2014-05-09 22:00, Shaohua Li wrote: > On Fri, May 09, 2014 at 08:00:18AM -0700, Christoph Hellwig wrote: >> On Fri, May 09, 2014 at 08:07:33PM +0800, Shaohua Li wrote: >>> >>> flush request is special, which borrows tag from other request. Need a special >>> handling to get it from tag. >> >> Thanks, we probably need this one. But I think you can simply test >> REQ_FLUSH_SEQ the passed in request instead of the flush_rq_tag_valid >> flag/ > > fair enough. updated one. > > > Subject: blk-mq: blk_mq_tag_to_rq should handle flush request > > flush request is special, which borrows tag from other request. Need a special > handling to get it from tag. I have applied this one, but it irks me a little bit since we have to touch q->flush_rq->stuff from a potential hot path. I haven't thought much about this yet, but it would be a lot better if we could fold in the flush tag somehow. -- Jens Axboe