From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F10E7C4360C for ; Wed, 3 Mar 2021 06:51:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF2F764EBA for ; Wed, 3 Mar 2021 06:51:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348050AbhCCGoW (ORCPT ); Wed, 3 Mar 2021 01:44:22 -0500 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:40116 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235594AbhCCCXS (ORCPT ); Tue, 2 Mar 2021 21:23:18 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R211e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=10;SR=0;TI=SMTPD_---0UQADoLL_1614738083; Received: from admindeMacBook-Pro-2.local(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0UQADoLL_1614738083) by smtp.aliyun-inc.com(127.0.0.1); Wed, 03 Mar 2021 10:21:24 +0800 Subject: Re: [dm-devel] [PATCH 2/4] block: dont clear REQ_HIPRI for bio-based drivers To: Mikulas Patocka , Mike Snitzer , Heinz Mauelshagen , axboe@kernel.dk, caspar@linux.alibaba.com, io-uring@vger.kernel.org, linux-block@vger.kernel.org, joseph.qi@linux.alibaba.com, dm-devel@redhat.com, hch@lst.de References: <20210302190552.715551440@debian-a64.vm> From: JeffleXu Message-ID: <3e8b3b2e-f1f4-e946-4858-d2c78e2a8825@linux.alibaba.com> Date: Wed, 3 Mar 2021 10:21:23 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20210302190552.715551440@debian-a64.vm> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 3/3/21 3:05 AM, Mikulas Patocka wrote: > Don't clear REQ_HIPRI for bio-based drivers. Device mapper will need to > see this flag in order to support polling. > > Signed-off-by: Mikulas Patocka > > --- > block/blk-core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Index: linux-2.6/block/blk-core.c > =================================================================== > --- linux-2.6.orig/block/blk-core.c 2021-03-02 10:43:28.000000000 +0100 > +++ linux-2.6/block/blk-core.c 2021-03-02 10:53:50.000000000 +0100 I notice that the diff header indicates that the code base is from linux-2.6. Or it's just the name of your directory, while the code base is for the latest upstream 5.12? > @@ -836,7 +836,7 @@ static noinline_for_stack bool submit_bi > } > } > > - if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) > + if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags) && !bdev->bd_disk->fops->submit_bio) > bio->bi_opf &= ~REQ_HIPRI; > > switch (bio_op(bio)) { > > -- What if dm device is built upon mq devices that are not capable of polling, i.e., mq devices without QUEUE_FLAG_POLL set? Then this dm device shall not support polling. -- Thanks, Jeffle