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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23880C433F5 for ; Mon, 6 Dec 2021 19:34:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348541AbhLFTiC (ORCPT ); Mon, 6 Dec 2021 14:38:02 -0500 Received: from frasgout.his.huawei.com ([185.176.79.56]:4216 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348532AbhLFThx (ORCPT ); Mon, 6 Dec 2021 14:37:53 -0500 Received: from fraeml745-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4J7D693Pgrz67NyB; Tue, 7 Dec 2021 03:30:09 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml745-chm.china.huawei.com (10.206.15.226) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 6 Dec 2021 20:34:20 +0100 Received: from [10.47.82.161] (10.47.82.161) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 6 Dec 2021 19:34:19 +0000 Subject: Re: [PATCH v2 0/3] blk-mq: Optimise blk_mq_queue_tag_busy_iter() for shared tags To: Jens Axboe CC: , , , , References: <1638794990-137490-1-git-send-email-john.garry@huawei.com> <67feacc8-3da7-90de-cc0c-f8b529f84297@kernel.dk> From: John Garry Message-ID: <544f60f5-a367-a1a0-5a21-9708a7e8d2e1@huawei.com> Date: Mon, 6 Dec 2021 19:34:05 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: <67feacc8-3da7-90de-cc0c-f8b529f84297@kernel.dk> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.82.161] X-ClientProxiedBy: lhreml721-chm.china.huawei.com (10.201.108.72) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 06/12/2021 19:07, Jens Axboe wrote: > On 12/6/21 5:49 AM, John Garry wrote: >> In [0] Kashyap reports high CPU usage for blk_mq_queue_tag_busy_iter() >> and callees for shared tags. >> >> Indeed blk_mq_queue_tag_busy_iter() would be less optimum for moving to >> shared tags, but it was not optimum previously. >> >> This series optimises by having only a single iter (per regular and resv >> tags) for the shared tags, instead of an iter per HW queue. >> >> [0]https://lore.kernel.org/linux-block/e4e92abbe9d52bcba6b8cc6c91c442cc@mail.gmail.com/ Hi Jens, > The patch(es) are missing Fixes tags. The first two patches aren't fixes, but are general dev. As for the last, it prob should go as a fix for 5.16, but I was not sure how you would feel about that - it's not a trivial change, we're late in the cycle, and Kashyap was happy for 5.17 . Let me know if the last could be accepted as a fix and I'll re-send separately with a fixes tag. Thanks, John