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=-4.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 64D1DC432BE for ; Tue, 27 Jul 2021 16:21:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 49F3161B73 for ; Tue, 27 Jul 2021 16:21:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229596AbhG0QVS (ORCPT ); Tue, 27 Jul 2021 12:21:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229441AbhG0QVR (ORCPT ); Tue, 27 Jul 2021 12:21:17 -0400 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2246AC061757; Tue, 27 Jul 2021 09:21:16 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id k1so16233982plt.12; Tue, 27 Jul 2021 09:21:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=aKSXNwDjopSziuCU/tjPk+z1jeKEq3gWP1NdV3AtHro=; b=p0y3P4/22F5hQkn3WFmpiaZsoG3SjwD9e4gQmaK7VA6kHL2uLm//Kv2uEa3ojTXZNc XwxeYKIpE5ECCXztRDAzRUyUY77SSexmcB38ytVKWg1dgKp45Xmej1t+YsnnliSFzJrn OMWdfRoXs218uT6SCOfCikE7/9GtnIjPzbP5jfRCTY/w4wdQALgtYlxSHXUg36/a3LD6 UG2gADHwg1LleP2jxPRM6H5sstIO4THOD1fXqD8HDzZL5G6K4D2/cXHaRE7XxHZNtsPj Y8DwM8N0T7h/cyO8ZJvBnyoSnmLpeX9JZUw0cyBA7pKQpBWkqVwoJhkAmgfrqnyXzsQn S8ew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=aKSXNwDjopSziuCU/tjPk+z1jeKEq3gWP1NdV3AtHro=; b=kPCqjhI2qeKN4F2w5UubIzA8/4zVJvnLs05o5yFDtcusP4S+LeUhWQsyD4aTF76tCa 46OAxTfGIRyzW9IWtfcPpuyVLoMJwnrULlqmdD3EpGHLeQWfdENRYv+2t796Vx9qSJ8c Fxz5F9A2M0hUFk1mLWlwe0gifp8b4cRfdrQzF5+VPIgTaELOkD4y9TF6w/KbCbeBsao+ R5BpRjfpQVSsRVUia2Tm+jrrA9pHDtLn1uUk+6oiV4756RqMcHMfNe9m5W0MmhGGiT8k 8mXMDWXWFIwcxt3KJIg+NumQsyPF+j/Px4wT8ppOXyFiRafM4rkSRfhpgTU/ItNMGdhZ OcdA== X-Gm-Message-State: AOAM530yis899O0G3Dn1jTj1rdq7rpMA/klRtY04sanvgJyiWdKRCYbc DsDrqs/dc4N1KdMiDFsi6SY= X-Google-Smtp-Source: ABdhPJweTq3Ojivolqcy6qYNEBQsLjn3/pc/Xj+J0oNtgS/8KrT/DtNGDcD88buZ9HFONA/Y+oJFUg== X-Received: by 2002:a17:90a:d595:: with SMTP id v21mr23649976pju.50.1627402875481; Tue, 27 Jul 2021 09:21:15 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::5:7502]) by smtp.gmail.com with ESMTPSA id 78sm4291181pfw.189.2021.07.27.09.21.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Jul 2021 09:21:15 -0700 (PDT) Sender: Tejun Heo Date: Tue, 27 Jul 2021 06:21:11 -1000 From: Tejun Heo To: brookxu Cc: axboe@kernel.dk, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] blk-throtl: optimize IOPS throttle for large IO scenarios Message-ID: References: <1626416569-30907-1-git-send-email-brookxu.cn@gmail.com> <957ab14d-c4bc-32f0-3f7d-af98832ab955@gmail.com> <34a6f4b5-9055-e519-5693-068f8dcb169c@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <34a6f4b5-9055-e519-5693-068f8dcb169c@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Jul 27, 2021 at 11:06:18AM +0800, brookxu wrote: > Make blk-throttle use rq-qos may be more elegant. But I found that there may be at least > one problem that is difficult to solve. blk-throttle supports separate throttle for read > and write IOs, which means that we cannot suspend tasks during throttle, but rq-qos > throttle IOs by suspending tasks. Ah, right, I forgot about that. > We may be able to relocate the blk-throttle hooks to the rq-qos hooks. Since we may not > be able to replace the throttle hook, in this case, if we register a rq-qos to the system, > part of the blk-throttle hooks is in rq-qos and part hooks not, which feels a bit confusing. > In addition, we may need to implement more hooks, such as IO merge hook. Would it be possible to just move the blk-throtl throttling hook right next to the rq-qos hook so that it gets throttled after splitting? Thanks. -- tejun