From patchwork Wed Dec 1 18:29:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Michal_Koutn=C3=BD?= X-Patchwork-Id: 12650783 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 619A7C433EF for ; Wed, 1 Dec 2021 18:30:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244917AbhLASdk (ORCPT ); Wed, 1 Dec 2021 13:33:40 -0500 Received: from smtp-out2.suse.de ([195.135.220.29]:47176 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244805AbhLASdj (ORCPT ); Wed, 1 Dec 2021 13:33:39 -0500 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 1DD761FD58; Wed, 1 Dec 2021 18:30:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1638383417; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=6YNK4361Ad+JUdZKL6SG8udr8ARQK6U9vpURkxKNy8I=; b=jZW868ItkaDd9TWV/11V3TrkD14HcP17JeJjYnMMJcgv/NgD3c3ibyBrvNKGuI5fbU7DDW S68adx2gDkvU96tYj6tUJlTtpSQA8NqzUfzr7Yzf8nujkrGlMCQRhubX0xmyF4OJKbG2l8 UwOGZvkVU13DXQTwVUy8helCukN7UUg= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id ECB9513DA2; Wed, 1 Dec 2021 18:30:16 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id TOQaOTi/p2FPTgAAMHmgww (envelope-from ); Wed, 01 Dec 2021 18:30:16 +0000 From: =?utf-8?q?Michal_Koutn=C3=BD?= To: Jens Axboe Cc: Paolo Valente , Tejun Heo , Zefan Li , Johannes Weiner , Jonathan Corbet , cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] block, bfq: Accept symmetric weight adjustments Date: Wed, 1 Dec 2021 19:29:09 +0100 Message-Id: <20211201182909.44271-1-mkoutny@suse.com> X-Mailer: git-send-email 2.33.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org The allowed range for BFQ weights is currently 1..1000 with 100 being the default. There is no apparent reason to not accept weight adjustments of same ratio on both sides of the default. This change makes the attribute domain consistent with other cgroup (v2) knobs with the weight semantics. This extension of the range does not restrict existing configurations (quite the opposite). This may affect setups where weights >1000 were attempted to be set but failed with the default 100. Such cgroups would attain their intended weight now. This is a changed behavior but it rectifies the situation (similar intention to the commit 69d7fde5909b ("blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchy") for CFQ formerly (and v2 only)). Additionally, the changed range does not imply all IO workloads can be really controlled to achieve the widest possible ratio 1:10^4. Signed-off-by: Michal Koutný Acked-by: Tejun Heo Acked-by: Paolo Valente --- Documentation/admin-guide/cgroup-v1/blkio-controller.rst | 2 +- Documentation/block/bfq-iosched.rst | 2 +- block/bfq-iosched.h | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) Changes since v2 https://lore.kernel.org/r/20211015135352.57245-1-mkoutny@suse.com/ - rebase on v5.16-rc3 (+master) - effectively a re-resend Changes since v1 https://lore.kernel.org/r/20210826131212.GE4520@blackbody.suse.cz/ - collect acks, reformat commit message - effectively a resend Hello Jens, could you please merge this via your tree (unless there are objections, I saw none so far)? Thanks, Michal diff --git a/Documentation/admin-guide/cgroup-v1/blkio-controller.rst b/Documentation/admin-guide/cgroup-v1/blkio-controller.rst index 16253eda192e..48559541c9d8 100644 --- a/Documentation/admin-guide/cgroup-v1/blkio-controller.rst +++ b/Documentation/admin-guide/cgroup-v1/blkio-controller.rst @@ -102,7 +102,7 @@ Proportional weight policy files on all the devices until and unless overridden by per device rule (see `blkio.bfq.weight_device` below). - Currently allowed range of weights is from 1 to 1000. For more details, + Currently allowed range of weights is from 1 to 10000. For more details, see Documentation/block/bfq-iosched.rst. blkio.bfq.weight_device diff --git a/Documentation/block/bfq-iosched.rst b/Documentation/block/bfq-iosched.rst index df3a8a47f58c..88b5251734ce 100644 --- a/Documentation/block/bfq-iosched.rst +++ b/Documentation/block/bfq-iosched.rst @@ -560,7 +560,7 @@ For each group, the following parameters can be set: weight This specifies the default weight for the cgroup inside its parent. - Available values: 1..1000 (default: 100). + Available values: 1..10000 (default: 100). For cgroup v1, it is set by writing the value to `blkio.bfq.weight`. diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index a73488eec8a4..f1abb8b90091 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -16,7 +16,7 @@ #define BFQ_CL_IDLE_TIMEOUT (HZ/5) #define BFQ_MIN_WEIGHT 1 -#define BFQ_MAX_WEIGHT 1000 +#define BFQ_MAX_WEIGHT 10000 #define BFQ_WEIGHT_CONVERSION_COEFF 10 #define BFQ_DEFAULT_QUEUE_IOPRIO 4