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 87689C433B4 for ; Tue, 11 May 2021 07:34:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 43B5061288 for ; Tue, 11 May 2021 07:34:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229736AbhEKHfJ (ORCPT ); Tue, 11 May 2021 03:35:09 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3058 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229637AbhEKHfH (ORCPT ); Tue, 11 May 2021 03:35:07 -0400 Received: from fraeml735-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FfTzP62sVz6rnLt; Tue, 11 May 2021 15:28:01 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml735-chm.china.huawei.com (10.206.15.216) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Tue, 11 May 2021 09:33:58 +0200 Received: from [10.47.85.216] (10.47.85.216) 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, 11 May 2021 08:33:58 +0100 Subject: Re: [PATCH] blk-mq: Use request queue-wide tags for tagset-wide sbitmap To: Ming Lei CC: , , , , , , , Douglas Gilbert References: <1620037333-2495-1-git-send-email-john.garry@huawei.com> From: John Garry Message-ID: Date: Tue, 11 May 2021 08:33:18 +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: [10.47.85.216] X-ClientProxiedBy: lhreml740-chm.china.huawei.com (10.201.108.190) 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 11/05/2021 01:52, Ming Lei wrote: >> fixed. >> >> Ming and Yanhui report higher CPU usage and lower throughput in scenarios >> where the fixed total driver tag depth is appreciably lower than the total >> scheduler tag depth: >> https://lore.kernel.org/linux-block/440dfcfc-1a2c-bd98-1161-cec4d78c6dfc@huawei.com/T/#mc0d6d4f95275a2743d1c8c3e4dc9ff6c9aa3a76b >> > No difference any more wrt. fio running on scsi_debug with this patch in > Yanhui's test machine: > > modprobe scsi_debug host_max_queue=128 submit_queues=32 virtual_gb=256 delay=1 > vs. > modprobe scsi_debug max_queue=128 submit_queues=1 virtual_gb=256 delay=1 > > Without this patch, the latter's result is 30% higher than the former's. > ok, good. I'll post a v2 with comments addressed. > note: scsi_debug's queue depth needs to be updated to 128 for avoiding io hang, > which is another scsi issue. > I was just carrying Doug's patch to test. Thanks, John