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,DKIM_SIGNED, DKIM_VALID,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 47436C43460 for ; Fri, 23 Apr 2021 14:55:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1AAFF61445 for ; Fri, 23 Apr 2021 14:55:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231932AbhDWOz5 (ORCPT ); Fri, 23 Apr 2021 10:55:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229549AbhDWOzz (ORCPT ); Fri, 23 Apr 2021 10:55:55 -0400 Received: from mail-pj1-x1036.google.com (mail-pj1-x1036.google.com [IPv6:2607:f8b0:4864:20::1036]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68A31C06174A for ; Fri, 23 Apr 2021 07:55:18 -0700 (PDT) Received: by mail-pj1-x1036.google.com with SMTP id u14-20020a17090a1f0eb029014e38011b09so1397149pja.5 for ; Fri, 23 Apr 2021 07:55:18 -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=indv+sTzB8V0DaD9jhIsOZ/lTdYunjH6lFec8oQTNTA=; b=CY/l+ZK6CBcdE+VMkEdKAXrdGdKPfMd4pNAkB3nRn3FI8dRRE6ElWJ2wMHNtckPGGf XE+RN1jmRXwNJroy9TveVPLb12mmv0gyS1ZMHPb+goyHgsap/vrFVh9GKw3rSXZb2Ujy WZbX4E/QAdUVPswsmELdRHrvh5aK79suXSGKxPqIdCZbSJDtHrPthsLdEW+Tp8ucnV// 7obWn45XyiVKrtZm9kuzRmCZUJka58xgI6LU/grTRZ6zYqRJYCK1HaChWHCsiml0+WcD fu6rxfGUbtM2acSzk/kqaENbfPPGCsMTfzbp151VedLl/PyKtQczl2nAqzd7Un8SFcYg FK/g== 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=indv+sTzB8V0DaD9jhIsOZ/lTdYunjH6lFec8oQTNTA=; b=XahSWYfXq/v+kRyPmC8LBd2qN5qKYpaYEivAWcI/PY9WVbui3ml0kcOBcQK0WhT1kn Rb+Pi+RIPgdMTEbFgBKr5Pf4xZ5TpMo9QMkGgbED1AYS16ESF0rhgGSHQ3WjSuc8y3lK 983QAT9A5JReiAYsYMb7scGfVE4of/huCD3kldJvSgYXcNne3YdAa8Uf2eEEQ7cYaWGe mzTuowj9WeGpxbsJdWqlFnrNVAT0JJawXdiVBDd618f2NCB5vhSwo97DSk32wyZc06PP 1tIxXm7iThtXAl2To4NEHo1DJrKpBJpad05DslXOEPz77XP31U5zgGUM71JxQPMwfc26 czCQ== X-Gm-Message-State: AOAM531fDGJFUznPvIfu8jqWlePVclQ2vsbPCw8sODl8Bk2GW3ggkZCF BCBXQs3gLEECfA31dK99fpltO9jw15hjpBVd X-Google-Smtp-Source: ABdhPJx41vTAtKsA2s8JOSnczAwo6pnS0GAJbGKaYwtgKtOo9RGGNzzDPVubuZimCjCPRO41vmNl4Q== X-Received: by 2002:a17:90a:5b0a:: with SMTP id o10mr6021566pji.82.1619189717650; Fri, 23 Apr 2021 07:55:17 -0700 (PDT) Received: from ?IPv6:2600:380:497c:70df:6bb6:caf7:996c:9229? ([2600:380:497c:70df:6bb6:caf7:996c:9229]) by smtp.gmail.com with ESMTPSA id i14sm4869853pfa.156.2021.04.23.07.55.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 23 Apr 2021 07:55:17 -0700 (PDT) Subject: Re: [PATCH for-5.13/block] blk-iocost: don't ignore vrate_min on QD contention To: Tejun Heo Cc: linux-block@vger.kernel.org, kernel-team@fb.com, dskarlat@fb.com, dschatzberg@fb.com, linux-kernel@vger.kernel.org References: From: Jens Axboe Message-ID: Date: Fri, 23 Apr 2021 08:55:15 -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-kernel@vger.kernel.org On 4/22/21 7:54 PM, Tejun Heo wrote: > ioc_adjust_base_vrate() ignored vrate_min when rq_wait_pct indicates that > there is QD contention. The reasoning was that QD depletion always reliably > indicates device saturation and thus it's safe to override user specified > vrate_min. However, this sometimes leads to unnecessary throttling, > especially on really fast devices, because vrate adjustments have delays and > inertia. It also confuses users because the behavior violates the explicitly > specified configuration. > > This patch drops the special case handling so that vrate_min is always > applied. Applied, thanks. -- Jens Axboe