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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 20C3AC432BE for ; Fri, 27 Aug 2021 03:13:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 072BC60F6F for ; Fri, 27 Aug 2021 03:13:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244113AbhH0DOU (ORCPT ); Thu, 26 Aug 2021 23:14:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244100AbhH0DOT (ORCPT ); Thu, 26 Aug 2021 23:14:19 -0400 Received: from mail-il1-x129.google.com (mail-il1-x129.google.com [IPv6:2607:f8b0:4864:20::129]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E55FC061757 for ; Thu, 26 Aug 2021 20:13:31 -0700 (PDT) Received: by mail-il1-x129.google.com with SMTP id j15so5670885ila.1 for ; Thu, 26 Aug 2021 20:13:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=xnK5VpSXR680Pu/S8RrWUoqbOfQzHSydZ5l9QXM8IpI=; b=W4K7wt+y9lU+4C+whxkj5qrSjRqcdUcIsrYyDG2UMnSv/ZczLU9idypA0VtIUzZfSj rfDYt6RSE0tXyT/5lpWGjL27MCujtc8BgnGin6k4J2NWioZ/elUgddkj1C6RMxW+gPuv p3PKppIE4hAzeNry3FtimozGQYU6YyZst4g7/JL2wvpyqHspDDko7WTjpOLVWZmjW5q+ a45Al8dOGKR/6Wnm7dLrSdA9CU3+0q/4k40N1g0NJETdknhItVLWqz5mPZPtWGv7S58D URP0gWz1Kvh4dJSMQ+1A9HhmM9P3AsEnBQF7lAsc/ZNUtHsyTSjL45jSXrRl70MW7/Ix coJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=xnK5VpSXR680Pu/S8RrWUoqbOfQzHSydZ5l9QXM8IpI=; b=GqjhAfpqg96DgDL6M9YHDCvqkukKoy6eaLhwi8H6Bs7F48J2LjkVLE5QVK75OzUmpq Ke2nup+w48Upd+fSXbiREyiSc1N15ZaQNrN6z8k2tyqQBEvuD6aBj6CjybmMlbuLRyK+ zMRbzRLe8GSiaK/dX/9h7Zj/CqVunBgFmSYBWtENldAPi8mqUi9EKBpyikpmsByiy7ys t2HV74/StYT96caIICQIzT9CvW8Qlv47PouwPQU+59HzBCGvcEEoYJBQfKEMw3aD58sD Kzq8xmjZJaoJcJFGiKFpOR67+OJ+KeDAet4wV9WVHTtXEAi/DxijvKPJYvNd1pArDrIP 2zSQ== X-Gm-Message-State: AOAM530LEPa+vGtnOPMJdF/KpjuWD1yFIXbcJfY64vjObbuAQ1K7MdOp bgIWgEdXHUSwQiAqJI0vJiLTSA== X-Google-Smtp-Source: ABdhPJw4JvID2ayGXBpMacNSoYRJbGJYrx2pmy3BTsOjuyNKoopFH47/w9wttR6PL9wfVWVOmrtVcQ== X-Received: by 2002:a05:6e02:1107:: with SMTP id u7mr4696536ilk.39.1630034010849; Thu, 26 Aug 2021 20:13:30 -0700 (PDT) Received: from [192.168.1.116] ([66.219.217.159]) by smtp.gmail.com with ESMTPSA id g11sm2633444iom.46.2021.08.26.20.13.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 26 Aug 2021 20:13:30 -0700 (PDT) Subject: Re: [PATCH] block/mq-deadline: Speed up the dispatch of low-priority requests To: Bart Van Assche , Zhen Lei , linux-block Cc: Damien Le Moal References: <20210826144039.2143-1-thunder.leizhen@huawei.com> <537620de-646d-e78e-ccb8-4105bac398b3@kernel.dk> <82612be1-d61e-1ad5-8fb5-d592a5bc4789@kernel.dk> <59c19a63-f321-94e8-cb31-87e88bd4e3d5@acm.org> <0ef7865d-a9ce-c5d9-ff7f-c0ef58de3d21@kernel.dk> <2332cba0-efe6-3b35-0587-ee6355a3567d@acm.org> From: Jens Axboe Message-ID: <6ad27546-d61f-a98a-1633-9a4808a829ba@kernel.dk> Date: Thu, 26 Aug 2021 21:13:27 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 8/26/21 8:48 PM, Bart Van Assche wrote: > On 8/26/21 5:05 PM, Jens Axboe wrote: >> On 8/26/21 6:03 PM, Bart Van Assche wrote: >>> Here is an overview of the tests I ran so far, all on the same test >>> setup: >>> * No I/O scheduler: about 5630 K IOPS. >>> * Kernel v5.11 + mq-deadline: about 1100 K IOPS. >>> * block-for-next + mq-deadline: about 760 K IOPS. >>> * block-for-next with improved mq-deadline performance: about 970 K IOPS. >> >> So we're still off by about 12%, I don't think that is good enough. >> That's assuming that v5.11 + mq-deadline is the same as for-next with >> the mq-deadline change reverted? Because that would be the key number to >> compare it with. > > With the patch series that is available at > https://github.com/bvanassche/linux/tree/block-for-next the same test reports > 1090 K IOPS or only 1% below the v5.11 result. I will post that series on the > linux-block mailing list after I have finished testing that series. OK sounds good. I do think we should just do the revert at this point, any real fix is going to end up being bigger than I'd like at this point. Then we can re-introduce the feature once we're happy with the results. -- Jens Axboe