From patchwork Mon Apr 8 14:39:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Valente X-Patchwork-Id: 10889671 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4AA841669 for ; Mon, 8 Apr 2019 14:39:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 350EC27F9F for ; Mon, 8 Apr 2019 14:39:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2848C28389; Mon, 8 Apr 2019 14:39:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BC59127F9F for ; Mon, 8 Apr 2019 14:39:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726927AbfDHOjy (ORCPT ); Mon, 8 Apr 2019 10:39:54 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:51836 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726349AbfDHOjx (ORCPT ); Mon, 8 Apr 2019 10:39:53 -0400 Received: by mail-wm1-f65.google.com with SMTP id 4so14666076wmf.1 for ; Mon, 08 Apr 2019 07:39:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=u+vmddB8EPhLmq89u2MDX4J7x+h19OXK3BtBDxYPEZc=; b=WwJPw8xAEIceR/RAgSlJfvmVrzLFsNxBW7XVR0W5p+8vhWSrJKspLoG+sJf0kL8acZ TYS58O94CPHohA6nEgo80lm9PkQJ9PhZq+V6kn75fE1CNdTE1cmY0A8GCUOzFXYhQz3/ txc0lXgqfF7wyqJ6yfBfOrMiyVeW0p0ze1SY1FjRMrdiNH9T2nI+PicPBLGa+ZO2u2nN RCWdA/qxpm468U0baLl5yMd9SkgvE3Ls54jh7Yty8zv8KWvczWaIONOB9sT74jaqJMGp 8KUex0dG8zUGF2vmo65XmMcKr18mMQTtkQ0FgiD+Wnkzd3zS46QLndD19TybUQ6xmZd6 6Baw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=u+vmddB8EPhLmq89u2MDX4J7x+h19OXK3BtBDxYPEZc=; b=lEZzKgujx16dF6VbGbN1SrAHO23gU0WdSIcovqlmOvjsF5f9fwHbGQjT4nXuYCk7xa x6Z90SJIFTBcMS3bk4OAKgnkfT9Qytxe+x1PCufIe7lVUU7mKppEuf4nQ5e6XMHAwxvv 77Fpgv+loss84GX4WinoLHG94LAIBiLGxzP0v5hLbhIqE+2IedH/L1LMc6nAGTSx54Ut 1sv3PXFcnxMlxmbnO6TC3ZBklmGfVqkV6+JllXV8kNboq/C1gHS15JUFLEbMMpAXNEbQ 5d/MhFTU0sKse1TEOeXhz6Q35E53ZlaBmm1plYTpUPr98avdpX5eHSm36wci1CpDUBP6 UGTQ== X-Gm-Message-State: APjAAAX5p4yeK1XwTUS9X6HU8IuxNhyvRkqP2oQQuIzBKAkPq9crjFXk 3JfAc9kMB0Yz4Hbx8mc/+3Z1NQ== X-Google-Smtp-Source: APXvYqy0BPBsNTRbbaFlj7z49mzU1KFW6cJADhIzMBdFRSa5SrGRBhF7ga6zE6qAHso4ANbG2cr3Ag== X-Received: by 2002:a1c:e90f:: with SMTP id q15mr17467575wmc.1.1554734391893; Mon, 08 Apr 2019 07:39:51 -0700 (PDT) Received: from localhost.localdomain ([88.147.51.116]) by smtp.gmail.com with ESMTPSA id r196sm15113852wmf.22.2019.04.08.07.39.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 08 Apr 2019 07:39:51 -0700 (PDT) From: Paolo Valente To: Jens Axboe Cc: 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, Paolo Valente Subject: [PATCH 0/1] bfq: remove prefixes from cgroup filenames Date: Mon, 8 Apr 2019 16:39:34 +0200 Message-Id: <20190408143935.9062-1-paolo.valente@linaro.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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]. So we tried to propose a solution to enable entities to share interface files for identical parameters [2]. But our solution didn't convince Tejun, and we got stuck. Fortunately, now cfq has gone with legacy blk, so there is no need any longer for prefixes in (the never used) bfq names. In view of this fact, here's an alternative patch, which simply removes these prefixes, thereby enabling legacy code to truly use the proportional share policy in blk-mq. This postpones the problem of sharing common interface files, to when, e.g., some new proportional-share policy gets proposed. Paolo [1] https://github.com/systemd/systemd/issues/7057 [2] https://lwn.net/ml/linux-block/20181119103424.3853-1-paolo.valente@linaro.org/ Angelo Ruocco (1): block, bfq: delete "bfq" prefix from cgroup filenames block/bfq-cgroup.c | 46 +++++++++++++++++++++++----------------------- 1 file changed, 23 insertions(+), 23 deletions(-) --- 2.20.1