From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751572AbdKDStK (ORCPT ); Sat, 4 Nov 2017 14:49:10 -0400 Received: from mail-it0-f53.google.com ([209.85.214.53]:49982 "EHLO mail-it0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750750AbdKDStI (ORCPT ); Sat, 4 Nov 2017 14:49:08 -0400 X-Google-Smtp-Source: ABhQp+TWoKtiHKMv3+J673rxzjxwbRi53+jMYvZeoNRgr5f08OnzUoKYIruUqQUVop1YwoCAnvtGUw== Subject: Re: [PATCH V3 0/7] blk-mq: don't allocate driver tag beforehand for flush rq From: Jens Axboe To: Ming Lei , linux-block@vger.kernel.org, Christoph Hellwig Cc: Omar Sandoval , Bart Van Assche , Hannes Reinecke , linux-kernel@vger.kernel.org References: <20171102152438.25324-1-ming.lei@redhat.com> <20171104041703.GA2819@ming.t460p> <016e4ab3-c5db-9871-0e4d-cd3ff31eee22@kernel.dk> Message-ID: <38f3a132-0c0d-4ae1-ac05-86a492720a5f@kernel.dk> Date: Sat, 4 Nov 2017 12:49:06 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <016e4ab3-c5db-9871-0e4d-cd3ff31eee22@kernel.dk> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/04/2017 08:18 AM, Jens Axboe wrote: > On 11/03/2017 10:17 PM, Ming Lei wrote: >> On Thu, Nov 02, 2017 at 11:24:31PM +0800, Ming Lei wrote: >>> Hi Jens, >>> >>> This patchset avoids to allocate driver tag beforehand for flush rq >>> in case of I/O scheduler, then flush rq isn't treated specially >>> wrt. get/put driver tag, code gets cleanup much, such as, >>> reorder_tags_to_front() is removed, and we needn't to worry >>> about request order in dispatch list for avoiding I/O deadlock. >>> >>> 'dbench -t 30 -s 64' has been run on different devices(shared tag, >>> multi-queue, singele queue, ...), and no issues are observed, >>> even very low queue depth test are run, debench still works well. >>> >>> Please consider it for V4.15, thanks! >> >> Hi Jens, >> >> As we discussed before, this patch is a good cleanup on handling flush >> request, could you share your opinion on V3? > > It looks fine to me. But I'd really like to have the potential hang > in the current 4.15 branch ironed out, before we pile more stuff on > top. Meanwhile, I'll see if this passes my testing. Passes testing. I applied it, but a heads-up that I rewrote most of your changelogs and also changed formatting. Please at least follow the 72 char line rule for commit messages, otherwise git log ends up looking like a mess really quick. -- Jens Axboe