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=-7.9 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 6EF75C433E0 for ; Mon, 28 Dec 2020 09:04:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C24320781 for ; Mon, 28 Dec 2020 09:04:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726555AbgL1JDq (ORCPT ); Mon, 28 Dec 2020 04:03:46 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:9652 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726509AbgL1JDq (ORCPT ); Mon, 28 Dec 2020 04:03:46 -0500 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4D4BPx464xz15ksV; Mon, 28 Dec 2020 17:02:13 +0800 (CST) Received: from [10.174.177.185] (10.174.177.185) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.498.0; Mon, 28 Dec 2020 17:02:51 +0800 Subject: Re: [PATCH 1/3] blk-mq: allow hardware queue to get more tag while sharing a tag set To: Ming Lei CC: , , , , References: <20201226102808.2534966-1-yukuai3@huawei.com> <20201226102808.2534966-2-yukuai3@huawei.com> <20201227115859.GA3282759@T590> <04c39621-0c4a-e593-5545-c4bd274c5fc2@huawei.com> <20201228082835.GB3304670@T590> From: "yukuai (C)" Message-ID: Date: Mon, 28 Dec 2020 17:02:50 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20201228082835.GB3304670@T590> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.185] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hi On 2020/12/28 16:28, Ming Lei wrote: > Another candidate solution may be to always return true from hctx_may_queue() > for this kind of queue because queue_depth has provided fair allocation for > each LUN, and looks not necessary to do that again. If always return true from hctx_may_queue() in this case, for example, we set queue_depth to 128(if can't, the biggger, the better) for all disks, and test with numjobs=64. The result should be one disk with high iops, and the rest very low. So I think it's better to ensure the max tags a disk can get in this case. Thanks! Yu Kuai