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=-5.5 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 CE14BC4727D for ; Fri, 25 Sep 2020 14:35:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 869A720708 for ; Fri, 25 Sep 2020 14:35:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="E55wmYy6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729084AbgIYOfd (ORCPT ); Fri, 25 Sep 2020 10:35:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729069AbgIYOfc (ORCPT ); Fri, 25 Sep 2020 10:35:32 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F451C0613CE for ; Fri, 25 Sep 2020 07:35:32 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id kk9so1863240pjb.2 for ; Fri, 25 Sep 2020 07:35:32 -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=3sVDrl7nq71b7+Tl95Id30AEaStu5JjNu+SbInS86S8=; b=E55wmYy6/zrsq1xauJ75mYZUcCl/7T8kL0VfI5mCOUuYURZxcMOOCuqthu+IF2L+NV eVlWeUXhu5vEq18VjsiZrD8N8Pk0YBn3UJ20S0yUhwxU/3UiyJ/bTPgCZCRlHIKCtqf+ 4t22c3hKJyeQK7cv5zEt6qCepixo/cNSB3/qhci7vp34g73P5vhesH4X/NDeo6RfV2ub BIV8GJZkeuY5TiDZ/1rLHDCSOwqaT7mQ6eKLpRjVzo0yU2z/zidZBszbbUK642laboim qTAd7a0vjHf0JpTsjxT/CmJDVk2TnsS+rzCwxP9U/4bTuRRs+8MwUdkc8Raqtx1O3cZ2 h+fQ== 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=3sVDrl7nq71b7+Tl95Id30AEaStu5JjNu+SbInS86S8=; b=nhdqWsSNQorCGZWk7hSZ3s/yKtSkBHuvi6WCq7EoQwHSjeYB2aRr8F4fG7YA2BJAcN YkK+57R/ELCu3tfJjI4kmiRXTT/p1TlVxIgE7pEIj/gGiNU2HU9S/LZshyoaL8bfu21x 4GHeBtgjkbCUmWTDAAkWlVD67rrhFEJBaFm5mBa23ySDa7KGjaWRcrLUoQW+7koYny99 ZyBDKH5PMKPasbRW+E01vwffeIzhLFyE2hjtcK9igwQM4CspfezRw8d1ScqRB6UBtnYh wKnIXGoFsFVwVCzv6RXJabGpY8R5erLa9hmBtp2MXko8Ui7GW0TWrpZN2NhvJhKdbz/u C60g== X-Gm-Message-State: AOAM530/rQYXeMeyM0YCyatwvO29NN/MJtzvz5biqOHYpNumvR8Igic/ y8TFfWVT65GP5/6Qz4GKebfZYAgkeYgd0Q== X-Google-Smtp-Source: ABdhPJxxZ/jipQ6UmFyIc2cAtDZeTloKi918d+xUfqX+TxGNVI9NqJKGAzht2a4+S8FbMh21YYiD/w== X-Received: by 2002:a17:90a:e984:: with SMTP id v4mr599004pjy.202.1601044531755; Fri, 25 Sep 2020 07:35:31 -0700 (PDT) Received: from [192.168.1.30] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id r16sm2257501pjo.19.2020.09.25.07.35.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 25 Sep 2020 07:35:31 -0700 (PDT) Subject: Re: [PATCHSET for-5.10/block] iocost: improve debt forgiveness logic To: Tejun Heo Cc: linux-block@vger.kernel.org, cgroups@vger.kernel.org, kernel-team@fb.com, linux-kernel@vger.kernel.org References: <20200918004456.593983-1-tj@kernel.org> From: Jens Axboe Message-ID: Date: Fri, 25 Sep 2020 08:35:30 -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: <20200918004456.593983-1-tj@kernel.org> 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 9/17/20 6:44 PM, Tejun Heo wrote: > Hello, > > Debt reduction logic was recently added by dda1315f1853 ("blk-iocost: halve > debts if device stays idle"). While it was effective at avoiding > pathological cases where some iocgs were kept delayed while the device was > most idle, it wasn't very effective at addressing more complex conditions > and could leave low priority cgroups unnecessarily harshly throttled under > moderate load. Applied, thanks. -- Jens Axboe