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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 0CCF8C433DF for ; Thu, 14 May 2020 14:51:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF0D320643 for ; Thu, 14 May 2020 14:51:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589467888; bh=E0a+apJr31FkSRWpqsCDpRfntjbRBD8yeqKP6BnYfGA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=NQcT1aYgGw1cvHfrOGR0LgdakHJwZZ8qMnry2w7aLV4wRmIHfRVBn7Kz+awPyygXP X7mOYdNAbXpcTpVaYgj8MLgzjEvolJcQB1zAKINSyFt+RMGydQwL0hVanU9sgu60tm y7I/Wx8SMnb6hQeeyxt9og0M1rB2BG39he5WS1DE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728025AbgENOvU (ORCPT ); Thu, 14 May 2020 10:51:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726763AbgENOvT (ORCPT ); Thu, 14 May 2020 10:51:19 -0400 Received: from mail-qv1-xf42.google.com (mail-qv1-xf42.google.com [IPv6:2607:f8b0:4864:20::f42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 98C78C061A0C; Thu, 14 May 2020 07:51:17 -0700 (PDT) Received: by mail-qv1-xf42.google.com with SMTP id l3so1788038qvo.7; Thu, 14 May 2020 07:51:17 -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=aNtTa2d+n4621gDfYTPbcUqqYbeIm8uB0/qear6cWpg=; b=QeELnO1WNJbZma6EEnHeMi9LPg6qMoJehC+wk+8XY7BwCHhBJHE3zUOcgdbrSSnsxE hszjO+n7oLZR3ozCX/Frm7E5wqFeNhikXHOg0kZDTUEUTjbcqvWlCOh/B6ncBE62iIjZ QfCSBa5O0hsIhlEHRBPV2+XpEaoZSKpM4XFSe8TU2dV2Sw4bY7I3SYMEYWG8kgpjbHjQ BwUWXlmwGLeuAgz1kvr3rZwFnblqwDY789h3F2COPvbxYxOeS0iwb2zXrKRFnqUpCYA8 hGASsSrtmA0K9nRnOyT3+NrQIjXbvfAZyRW4PjnyM3hMyl0zypiqiYHiNPDqlCUCH1zK mG1A== 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=aNtTa2d+n4621gDfYTPbcUqqYbeIm8uB0/qear6cWpg=; b=k5L7s3Z1Yge/Ezwv0xALbKehSy0EGxCnNk04ZX3+Af8EF2kjD1mIvzOxvc7oVtGLnj aQ1ARNEhGz++HQuzPUJ6HZFQnZmWMcjE7DGnRB5T2BaLiNr/0524ysLpuKPEJseVkSvX Q6A5ChlqwtaxuUpKGMVyzymgyJL0p52N4jmrVjlhhRrHoySLazFRZTZVmMWxNpgQ3b/C 3KV6yoBfoaftDRNdcR9CAb28fX9Pl9CT9G+zL9LN65OrANJTrWRFEy3MvNt6zEUi94Vr btvhktMLssROj9jobSn952uiSEf/jUuY8VCDLLCFFWuTqXZrA02AVj8daG+tRoABZYsh /GDg== X-Gm-Message-State: AOAM5337O9XV68aM83oo4ZJy5rrGFEGUwjY4W7X7+s/iYqfEiqo6dYqI K6ijOFWFLxSGPrr7frO6/q5mC/9EnD8= X-Google-Smtp-Source: ABdhPJw7cclIwTgpzaD7MAC6RXRqYWlqzeZnNk0O3UghwCaxqW1QxUitfWlT15ZSc2SfonojOLuZXw== X-Received: by 2002:a05:6214:1543:: with SMTP id t3mr3002030qvw.122.1589467876536; Thu, 14 May 2020 07:51:16 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:97a6]) by smtp.gmail.com with ESMTPSA id n20sm2623277qtk.89.2020.05.14.07.51.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 May 2020 07:51:15 -0700 (PDT) Date: Thu, 14 May 2020 10:51:14 -0400 From: Tejun Heo To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, newella@fb.com Subject: Re: [PATCH block/for-linus] iocost: don't let vrate run wild while there's no saturation signal Message-ID: <20200514145114.GG16815@mtj.duckdns.org> References: <20191015001811.GI18794@devbig004.ftw2.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191015001811.GI18794@devbig004.ftw2.facebook.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Oct 14, 2019 at 05:18:11PM -0700, Tejun Heo wrote: > When the QoS targets are met and nothing is being throttled, there's > no way to tell how saturated the underlying device is - it could be > almost entirely idle, at the cusp of saturation or anywhere inbetween. > Given that there's no information, it's best to keep vrate as-is in > this state. Before 7cd806a9a953 ("iocost: improve nr_lagging > handling"), this was the case - if the device isn't missing QoS > targets and nothing is being throttled, busy_level was reset to zero. ... > Signed-off-by: Tejun Heo > Reported-by: Andy Newell > Fixes: 7cd806a9a953 ("iocost: improve nr_lagging handling") Jens, this one fell through the cracks. It still applies with only a small offset. Can you please apply? Thanks. -- tejun