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 57FB5C433ED for ; Tue, 18 May 2021 12:52:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33D8F60FF0 for ; Tue, 18 May 2021 12:52:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244260AbhERMxY (ORCPT ); Tue, 18 May 2021 08:53:24 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:3586 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244238AbhERMxY (ORCPT ); Tue, 18 May 2021 08:53:24 -0400 Received: from dggems702-chm.china.huawei.com (unknown [172.30.72.58]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Fkwmt5hP0zsRpM; Tue, 18 May 2021 20:49:18 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by dggems702-chm.china.huawei.com (10.3.19.179) 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 20:52:03 +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 13:52:01 +0100 Subject: Re: [PATCH] blk-mq: plug request for shared sbitmap 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> From: John Garry Message-ID: <12a651a2-5a0e-15dc-ec40-fc3c57265cd2@huawei.com> Date: Tue, 18 May 2021 13:51:00 +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: 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 13:00, 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. > And what is your exact read test script? And how many cpu cores in > your system? 64 CPUs, 16x hw queues. [global] rw=read direct=1 ioengine=libaio iodepth=128 numjobs=1 bs=4k group_reporting=1 runtime=4500 loops = 10000 [job1] filename=/dev/sda: [job1] filename=/dev/sdc: [job1] filename=/dev/sde: [job1] filename=/dev/sdf: [job1] filename=/dev/sdg: [job1] filename=/dev/sdh: Thanks, John