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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 DD537C43461 for ; Tue, 18 May 2021 16:02:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BCBCD610CB for ; Tue, 18 May 2021 16:02:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350243AbhERQDl (ORCPT ); Tue, 18 May 2021 12:03:41 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:3588 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344303AbhERQDk (ORCPT ); Tue, 18 May 2021 12:03:40 -0400 Received: from dggems703-chm.china.huawei.com (unknown [172.30.72.60]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Fl10R4FdXzsRnY; Tue, 18 May 2021 23:59:35 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by dggems703-chm.china.huawei.com (10.3.19.180) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 19 May 2021 00:02:20 +0800 Received: from [10.47.83.99] (10.47.83.99) 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 15.1.2176.2; Tue, 18 May 2021 17:02:17 +0100 Subject: Re: [PATCH] blk-mq: plug request for shared sbitmap From: John Garry To: Ming Lei CC: Jens Axboe , Christoph Hellwig , , Yanhui Ma , Bart Van Assche , , chenxiang References: <20210514022052.1047665-1-ming.lei@redhat.com> <185d1d58-f4e3-2024-e5e4-0831af151e3d@huawei.com> <12a651a2-5a0e-15dc-ec40-fc3c57265cd2@huawei.com> Message-ID: <676e9667-3022-7fde-4518-e82eb0503ec8@huawei.com> Date: Tue, 18 May 2021 17:01:16 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <12a651a2-5a0e-15dc-ec40-fc3c57265cd2@huawei.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.83.99] X-ClientProxiedBy: lhreml716-chm.china.huawei.com (10.201.108.67) 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 18/05/2021 13:51, John Garry wrote: > n 18/05/2021 13:00, Ming Lei wrote: >>>> 'Before 620K' could be caused by busy queue when batching submission >>>> isn't >>>> applied, so merge chance is increased. This patch applies batching >>>> submission, so queue becomes not busy enough. >>>> >>>> BTW, what is the queue depth of sdev and can_queue of shost for your >>>> hisilision SAS? >>> sdev queue depth is 64 (see hisi_sas_slave_configure()) and host >>> depth is >>> 4096 - 96 (for reserved tags) = 4000 >> OK, so queue depth should get IO merged if there are too many requests >> queued. >> >> What is the same read test result without shared tags? still 430K? > > I never left a driver switch in place to disable it. > > I can forward-port "reply-map" support, which is not too difficult and I > will let you know the result. The 'after' results are similar to without shared sbitmap, i.e using reply-map: reply-map: 450K (read), 430K IOPs (randread) For reference, with shared shared sbitmap: Before 620K (read), 300K IOPs (randread) After 460K (read), 430K (randread)* These are all mq-deadline. * I mixed read and randread result earlier by accident > >> And what is your exact read test script? And how many cpu cores in >> your system? > Thanks, John