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 9A774C433EF for ; Mon, 25 Jul 2022 01:48:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232192AbiGYBsw (ORCPT ); Sun, 24 Jul 2022 21:48:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229821AbiGYBsu (ORCPT ); Sun, 24 Jul 2022 21:48:50 -0400 Received: from mail-pj1-f48.google.com (mail-pj1-f48.google.com [209.85.216.48]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8189ED62; Sun, 24 Jul 2022 18:48:47 -0700 (PDT) Received: by mail-pj1-f48.google.com with SMTP id t2-20020a17090a4e4200b001f21572f3a4so8927875pjl.0; Sun, 24 Jul 2022 18:48:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=HT09dBY8vUpXT4pAwp9hU5IYkpA64eMFd2Hf4rtewRU=; b=Mm90oEayZG+T3cwxeBYyH+MVmHKkb/cUBKaLRzfnQ+jTnJ/4SVK23muAKkqteOmH1Q dJcx4yWdTziLMA6gBTPI1pxS49cCkP4pEfgaO79Y+JsVkDujHYOljhTdd3LlK1K3b9af +0g9iWBR8+Zc+3f+dphUjQ7+Iv9sRv8TYi4kt8GqV7E2QQX1Wlasf37HTRZ3VVt/5V2M u3nw5wOSLp5Sph9joKwVp+etsU7mA4rjbUrKVzbQwhJ0vANDxx+ka84Jc4AAzSpC8Rib 42MFnN7jRwOGKIJpLTkof5g/yl2yEmPzbk4ICaZKx7+NA6If8z6Lha6oCsGTrUeDgOIU TkZQ== X-Gm-Message-State: AJIora+7SbW+Jv1MH+ud6vM4zXZ7+M2yhtABbJXLRbizvVRksDhRmgzl smd22rY9X89gGGsVZopDUZI= X-Google-Smtp-Source: AGRyM1uPN9pHcsZNA+/K1raafpFnBCZGJCaCSs0N23TarH3QJ1hL9Ma/JcNJv/aZrIv+78hDd3zv4w== X-Received: by 2002:a17:902:d48a:b0:16b:f0be:4e15 with SMTP id c10-20020a170902d48a00b0016bf0be4e15mr10344383plg.155.1658713726367; Sun, 24 Jul 2022 18:48:46 -0700 (PDT) Received: from [192.168.3.217] ([98.51.102.78]) by smtp.gmail.com with ESMTPSA id d10-20020a170902654a00b0016d1e514ec5sm7772608pln.139.2022.07.24.18.48.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 24 Jul 2022 18:48:45 -0700 (PDT) Message-ID: <57accb2a-828d-c532-d964-130a63faebe5@acm.org> Date: Sun, 24 Jul 2022 18:48:44 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v2 2/2] block/mq-deadline: Prioritize first request Content-Language: en-US To: Wang You Cc: axboe@kernel.dk, fio@vger.kernel.org, hch@lst.de, jaegeuk@kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, ming.lei@redhat.com, wangxiaohua@uniontech.com References: <20220723105909.440050-1-wangyoua@uniontech.com> From: Bart Van Assche In-Reply-To: <20220723105909.440050-1-wangyoua@uniontech.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/23/22 03:59, Wang You wrote: > Also, can I ask? If using fio or other tools, how should testing be done to get > more accurate and convincing data? Such as the perfectly sequential and random I/O > performance you mentioned above (fio's multi-threaded test does result in neither > perfectly sequential nor perfectly random, but single thread dispatch is too slow, > and cannot play the merge and sorting ability of elv). I'm not sure that there is agreement about for which data patterns to measure performance to conclude that certain code changes improve performance of an I/O scheduler. Thanks, Bart.