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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 3E5C3C49ED6 for ; Tue, 10 Sep 2019 12:55:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 201EB208E4 for ; Tue, 10 Sep 2019 12:55:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392675AbfIJMzX (ORCPT ); Tue, 10 Sep 2019 08:55:23 -0400 Received: from mx2.suse.de ([195.135.220.15]:49918 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730525AbfIJMzX (ORCPT ); Tue, 10 Sep 2019 08:55:23 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D2174B8EF; Tue, 10 Sep 2019 12:55:20 +0000 (UTC) Date: Tue, 10 Sep 2019 14:55:14 +0200 From: Michal =?iso-8859-1?Q?Koutn=FD?= To: Tejun Heo Cc: hannes@cmpxchg.org, clm@fb.com, dennisz@fb.com, newella@fb.com, lizefan@huawei.com, axboe@kernel.dk, josef@toxicpanda.com, Josef Bacik , kernel-team@fb.com, Rik van Riel , cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Paolo Valente Subject: Re: [PATCH 08/10] blkcg: implement blk-iocost Message-ID: <20190910125513.GA6399@blackbody.suse.cz> References: <20190828220600.2527417-1-tj@kernel.org> <20190828220600.2527417-9-tj@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="1yeeQ81UyVL57Vl7" Content-Disposition: inline In-Reply-To: <20190828220600.2527417-9-tj@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --1yeeQ81UyVL57Vl7 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hello. On Wed, Aug 28, 2019 at 03:05:58PM -0700, Tejun Heo wrote: > diff --git a/block/blk-iocost.c b/block/blk-iocost.c > [...] > +static struct cftype ioc_files[] = { > + .name = "weight", > [...] This adds the generic io.weight attribute. How will this compose with the weight from IO schedulers? (AFAIK, only BFQ allows proportional control as of now. +CC Paolo.) I see this attributes are effectively per-cgroup per-device. Apparently, one device should have only one weight across hierarchy. Would it make sense to have io.bfq.weight and io.cost.weight with disjunctive devices? (Alas, I have no idea how to make the users of io.weight happy, when proportionality control mechanism seems orthogonal to the weight. (Vector weights?)) > + .name = "cost.qos", > + .flags = CFTYPE_ONLY_ON_ROOT, > [...] > + .name = "cost.model", > + .flags = CFTYPE_ONLY_ON_ROOT, I'm concerned that these aren't true cgroup attributes. The root cgroup would act as container for global configuration options. Wouldn't these values better fit as (configurable) attributes of the respective devices? Secondly, how is CFTYPE_ONLY_ON_ROOT supposed to be presented in cgroup namespaces? Thanks, Michal --1yeeQ81UyVL57Vl7 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEEoQaUCWq8F2Id1tNia1+riC5qSgFAl13nSUACgkQia1+riC5 qShK8w//Q7gh2wjcYmn/uuKlxF40/MhRa8LwT9aDjZp3gEiRmMQbHUHpx3Td5aAl nPOQEp/W2sucYziohHPIokkeXIx+RwJliOEYfOCP+47ZOtWpeBXe6bTfmeRe87Ak xSZ6M3ibr2Y4mNLdcvjSzSeh1T0qAha9B5DBEuK7C4xqK45DKSekLjVmd9jd71cE CoYm56fVYZpDcYAHdTW7kjMie85QTLbiEY0WsuC563fxAoHDBZCDReIEtuAeMMog lgOgBquPb6OCObzkE9CYMSroWMCRPkq2F9BTnk85fnpXkeQeE1cP8FbFt8CXGSh2 wsaz3dP8z7TAkUHRGySQiqaxsWDKRh/6KBk8Lv/wxffF3nSGLXuHC8tKcQIWHP45 y+e6utaK47XA7JDZcXObloE200Vpko5MhYM6vKsUYNDQ8BQjew/+xs5aYdU7yO/z RtstUYBwgH6WWufm7D4yezdWGaJCZCuqtd46hy9vz8sJpm7iuJFbQdIQRD9z4kSf NieSVJLSO3p6QJVYOdbtN1xzEEz1Qm8UJaHcgyjaUckKVjnkB7UWe/U5wj7D+b5R sI0i0ACF6fdMsM0UnVArg4usmuFcwhO7NkngLrY85c6UTP75At+FhmTRJA3ZaIXI l3T8OtIYNXt3+PBYIGwcPHLDa+HbPOToKpeP6ePE1r9ZzSV8bzI= =VCDP -----END PGP SIGNATURE----- --1yeeQ81UyVL57Vl7--