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=-7.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 D4FD3C10F13 for ; Mon, 8 Apr 2019 14:49:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A53A1214C6 for ; Mon, 8 Apr 2019 14:49:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726372AbfDHOt1 (ORCPT ); Mon, 8 Apr 2019 10:49:27 -0400 Received: from mx2.suse.de ([195.135.220.15]:38920 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726005AbfDHOt1 (ORCPT ); Mon, 8 Apr 2019 10:49:27 -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 C07E4B00F; Mon, 8 Apr 2019 14:49:25 +0000 (UTC) Date: Mon, 8 Apr 2019 16:49:25 +0200 From: Johannes Thumshirn To: Paolo Valente Cc: Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, ulf.hansson@linaro.org, linus.walleij@linaro.org, broonie@kernel.org, bfq-iosched@googlegroups.com, oleksandr@natalenko.name, Angelo Ruocco Subject: Re: [PATCH 1/1] block, bfq: delete "bfq" prefix from cgroup filenames Message-ID: <20190408144925.GA23021@linux-x5ow.site> References: <20190408143935.9062-1-paolo.valente@linaro.org> <20190408143935.9062-2-paolo.valente@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190408143935.9062-2-paolo.valente@linaro.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Apr 08, 2019 at 04:39:35PM +0200, Paolo Valente wrote: > From: Angelo Ruocco > > 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]. > > 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. > > [1] https://github.com/systemd/systemd/issues/7057 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? -- Johannes Thumshirn SUSE Labs Filesystems jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850