From patchwork Mon Nov 19 10:34:24 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Valente X-Patchwork-Id: 10688457 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 AB5691923 for ; Mon, 19 Nov 2018 10:35:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9C05E287F8 for ; Mon, 19 Nov 2018 10:35:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8F5DB294C4; Mon, 19 Nov 2018 10:35:23 +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 0941F287F8 for ; Mon, 19 Nov 2018 10:35:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728431AbeKSU6U (ORCPT ); Mon, 19 Nov 2018 15:58:20 -0500 Received: from mail-wm1-f65.google.com ([209.85.128.65]:53363 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728426AbeKSU6T (ORCPT ); Mon, 19 Nov 2018 15:58:19 -0500 Received: by mail-wm1-f65.google.com with SMTP id g131so4347008wmg.3 for ; Mon, 19 Nov 2018 02:35:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=2PZH8WwXkvnGeOOTNTp/CB09k6USJvSSB6C0CaaMGjI=; b=hcuU6/VqTQwptGHjtIMvqO0p51x14o0CH8VynZz+6pAYFV8wdEQyx+ljlgfV6rV2w7 ITCCyWJsgcX5EmmWYweoyDAMoKM4kZS/0KIuLLINuDr3CFzBBAYSz+58G1YiRCRMTQrt ivc6Bbj1bt5nmThOu57faArw/3BCDnwjUELl8= 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:in-reply-to :references; bh=2PZH8WwXkvnGeOOTNTp/CB09k6USJvSSB6C0CaaMGjI=; b=tKWGN2H2EQXK5UX2xb+/ac9ThMLbrJaBnfTf8AF406rL4H6yjmd1KdyBFLSC6XTRhC 7f/1nfs7WNDxXq+naPX+JBG9Q3KvHBXfS0s4mpIyj+lCyOkb2QKFJ9XFwkbRgb1f+OKT /Lf4I1LRh8MKHGJRswfxBUY8+9UXwQX4YN12o+GwMmhU3IBuagpFGEeXV98grJDwfn+d xeAran4E7kZ5c3Qac0ErYQVTJs4d2zUYqCuMOskvJXaJgxpHNWvmDzy4cI1MDTeXpLbw A5sHuu0valS0++tDstmh6UpjFFLShUJysGT/EDoYcZJgj74PmIysUdIET/MxdqUFy2fk k/ZA== X-Gm-Message-State: AGRZ1gJClcXd31Y4C6/BPfBEIc4BpRl2rrOzhraIDvSQbnjGVd74Lyce vsBpDuhzT7EKLBfAtfuEQirIOw== X-Google-Smtp-Source: AFSGD/V/PzPvdMmgio2MMuksaWEdLCDo8SfjRuu380b7ZwE1q0ngjmXv93lavCq2gXUdRW2aWbo06w== X-Received: by 2002:a1c:ddc3:: with SMTP id u186mr6436592wmg.110.1542623705169; Mon, 19 Nov 2018 02:35:05 -0800 (PST) Received: from localhost.localdomain ([37.162.18.180]) by smtp.gmail.com with ESMTPSA id e9sm14973298wro.16.2018.11.19.02.35.02 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 19 Nov 2018 02:35:04 -0800 (PST) From: Paolo Valente To: Jens Axboe , Greg Kroah-Hartman , Tejun Heo , Li Zefan , Angelo Ruocco , Dennis Zhou , Josef Bacik , Liu Bo , Bart Van Assche , Johannes Weiner 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, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, Jonathan Corbet , Paolo Valente Subject: [PATCH V2 10/10] doc, bfq-iosched: make it consistent with the new cgroup interface Date: Mon, 19 Nov 2018 11:34:24 +0100 Message-Id: <20181119103424.3853-11-paolo.valente@linaro.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20181119103424.3853-1-paolo.valente@linaro.org> References: <20181119103424.3853-1-paolo.valente@linaro.org> 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 BFQ now shares interface files with CFQ, for the proportional-share policy. Make documentation consistent with that. Signed-off-by: Paolo Valente --- Documentation/block/bfq-iosched.txt | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/Documentation/block/bfq-iosched.txt b/Documentation/block/bfq-iosched.txt index 6d7dd5ab8554..3d7ef138ce6a 100644 --- a/Documentation/block/bfq-iosched.txt +++ b/Documentation/block/bfq-iosched.txt @@ -508,12 +508,14 @@ process. To get proportional sharing of bandwidth with BFQ for a given device, BFQ must of course be the active scheduler for that device. -Within each group directory, the names of the files associated with -BFQ-specific cgroup parameters and stats begin with the "bfq." -prefix. So, with cgroups-v1 or cgroups-v2, the full prefix for -BFQ-specific files is "blkio.bfq." or "io.bfq." For example, the group -parameter to set the weight of a group with BFQ is blkio.bfq.weight -or io.bfq.weight. +BFQ uses the standard interface files of the proportional-share +policy, previously used by CFQ. If one such file is read/written, then +the operation associated with the file is performed by BFQ for each +device where BFQ is the active scheduler. In addition, BFQ is +configured so as to share interface files with other entities (if some +of these files does happen to be shared, then its associated operation +is performed also by any of the other entities that is using the +file). As for cgroups-v1 (blkio controller), the exact set of stat files created, and kept up-to-date by bfq, depends on whether @@ -521,13 +523,13 @@ CONFIG_DEBUG_BLK_CGROUP is set. If it is set, then bfq creates all the stat files documented in Documentation/cgroup-v1/blkio-controller.txt. If, instead, CONFIG_DEBUG_BLK_CGROUP is not set, then bfq creates only the files -blkio.bfq.io_service_bytes -blkio.bfq.io_service_bytes_recursive -blkio.bfq.io_serviced -blkio.bfq.io_serviced_recursive +blkio.io_service_bytes +blkio.io_service_bytes_recursive +blkio.io_serviced +blkio.io_serviced_recursive The value of CONFIG_DEBUG_BLK_CGROUP greatly influences the maximum -throughput sustainable with bfq, because updating the blkio.bfq.* +throughput sustainable with BFQ, because updating the blkio.* stats is rather costly, especially for some of the stats enabled by CONFIG_DEBUG_BLK_CGROUP. @@ -536,8 +538,8 @@ Parameters to set For each group, there is only the following parameter to set. -weight (namely blkio.bfq.weight or io.bfq-weight): the weight of the -group inside its parent. Available values: 1..10000 (default 100). The +weight (namely blkio.weight or io.weight): the weight of the group +inside its parent. Available values: 1..10000 (default 100). The linear mapping between ioprio and weights, described at the beginning of the tunable section, is still valid, but all weights higher than IOPRIO_BE_NR*10 are mapped to ioprio 0.