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=-6.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 33614C10F13 for ; Mon, 8 Apr 2019 14:54:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 010D1217F4 for ; Mon, 8 Apr 2019 14:54:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="obnO+0Al" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727132AbfDHOyn (ORCPT ); Mon, 8 Apr 2019 10:54:43 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:37820 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726577AbfDHOyn (ORCPT ); Mon, 8 Apr 2019 10:54:43 -0400 Received: by mail-wr1-f65.google.com with SMTP id w10so16804214wrm.4 for ; Mon, 08 Apr 2019 07:54:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=Z/2RmRNtPgKwy1Rq5NgLuc4ghN93/5Qas/l/yLOSyxM=; b=obnO+0Altk7PyU+mrtRKy+0ywg877ntUuQuLPnEqil0Hm4Np6xNGa9RIYB8bj4ehPd skRtvUJGp787bHJBzlYz2dKWRheDIvAPdmO/vozu02s+9auYYHi1Wox2hfjH/SSQymKF +kN8kUhcjuWh5ffh7Zl5R22LuREsZMA+Xe9f3iBd8zB3xMTWb2dDfeCb0yqGr43KQcUN Lw7L/V30TWCnb/FutLdgaDAQ5bDf8CW5foZJdnqEkT/Udu1KxUcLjCsQUFaILx8Hkqcd W2YSvWT+ycNKzulbXLl4A9FVCOtR8WgsD6Xr77pntkbLDtwoeqLR8hrPpSt9VwIhJv4u 2OOw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=Z/2RmRNtPgKwy1Rq5NgLuc4ghN93/5Qas/l/yLOSyxM=; b=b6ukbI7XF/2+MDPCBc+qb1RgKzhRPysjgDEkDnutpdEopE/apDpP33XlSumRiq1w3f 8BUzhu9ShZvAKPR5gBcxFjoT4Hx/cMC04lqSgMXUYs5dZ7yRYlTe1TjTVJIZuNuX+1BY 08duoLBg+G5k1EEvfdagZAzZVlayzwqVUcut89/snwDbwRqjdLql3uX107sxsBohhceV W/UEROFqwkZ5MrwBwobmkJhZxwBZFgNgOn0xTmnr9jgZ2+jx32YsQdlxpBSenRABuJLm ZhAexUlFSTNYChqkGl/+bckcNHRwFbzjH1P0memzLnhDP/cCfvEbqUvVhd+3zVcUM25N 6S/Q== X-Gm-Message-State: APjAAAXkAVMK/dk8zr9BY2P0kAsX7tr/5tjHBuGii9T3QJEL0Xeu6mau mYl1N4pv1Z4dJvdrIi6uc83rcw== X-Google-Smtp-Source: APXvYqyregy2gJj5n6ki7YwmxuOLLNvSxgdS+wg0BBsta9wZPMgFabS5w8MwQTqKLvkeU3VZ2pqGYw== X-Received: by 2002:adf:f80c:: with SMTP id s12mr11725809wrp.72.1554735281340; Mon, 08 Apr 2019 07:54:41 -0700 (PDT) Received: from [192.168.0.100] ([88.147.51.116]) by smtp.gmail.com with ESMTPSA id w11sm89463124wre.15.2019.04.08.07.54.40 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 08 Apr 2019 07:54:40 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 12.2 \(3445.102.3\)) Subject: Re: [PATCH 1/1] block, bfq: delete "bfq" prefix from cgroup filenames From: Paolo Valente In-Reply-To: <20190408144925.GA23021@linux-x5ow.site> Date: Mon, 8 Apr 2019 16:54:39 +0200 Cc: Jens Axboe , linux-block , linux-kernel , Ulf Hansson , Linus Walleij , Mark Brown , 'Paolo Valente' via bfq-iosched , Oleksandr Natalenko , Angelo Ruocco , lennart@poettering.net Content-Transfer-Encoding: quoted-printable Message-Id: <7B68DAA9-61D9-4AE0-9FA9-05C07C7FE408@linaro.org> References: <20190408143935.9062-1-paolo.valente@linaro.org> <20190408143935.9062-2-paolo.valente@linaro.org> <20190408144925.GA23021@linux-x5ow.site> To: Johannes Thumshirn X-Mailer: Apple Mail (2.3445.102.3) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org > Il giorno 8 apr 2019, alle ore 16:49, Johannes Thumshirn = ha scritto: >=20 > On Mon, Apr 08, 2019 at 04:39:35PM +0200, Paolo Valente wrote: >> From: Angelo Ruocco >>=20 >> When bfq was merged into mainline, there were two I/O schedulers that >> implemented the proportional-share policy: bfq for blk-mq and cfq for >> legacy blk. bfq's interface files in the blkio/io controller have the >> same names as cfq. But the cgroups interface doesn't allow two >> entities to use the same name for their files, so for bfq we had to >> prepend the "bfq" prefix to each of its files. However no legacy code >> uses these modified file names. This naming also causes confusion, = as, >> e.g., in [1]. >>=20 >> Now cfq has gone with legacy blk, so there is no need any longer for >> these prefixes in (the never used) bfq names. In view of this fact, = this >> commit removes these prefixes, thereby enabling legacy code to truly >> use the proportional share policy in blk-mq. >>=20 >> [1] https://github.com/systemd/systemd/issues/7057 >=20 > Hmm, but isn't this a user-space facing interface and thus some sort = of ABI? > Do you know what's using it and what breaks due to this conversion? >=20 Yep, but AFAIK, the problem is exactly the opposite: nobody uses these names for the proportional-share policy, or wants to use these names. = I'm CCing Lennart too, in case he has some improbable news on this. So the idea is to align names to what people expect, possibly before more confusion arises. Thanks, Paolo > --=20 > Johannes Thumshirn SUSE Labs Filesystems > jthumshirn@suse.de +49 911 74053 689 > SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg > GF: Felix Imend=C3=B6rffer, Mary Higgins, Sri Rasiah > HRB 21284 (AG N=C3=BCrnberg) > Key fingerprint =3D EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850