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=-7.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C513BC43331 for ; Thu, 7 Nov 2019 19:28:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9804A21882 for ; Thu, 7 Nov 2019 19:28:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="pVKXsw6i" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726882AbfKGT2u (ORCPT ); Thu, 7 Nov 2019 14:28:50 -0500 Received: from mail-io1-f65.google.com ([209.85.166.65]:44624 "EHLO mail-io1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726275AbfKGT2u (ORCPT ); Thu, 7 Nov 2019 14:28:50 -0500 Received: by mail-io1-f65.google.com with SMTP id j20so3321800ioo.11 for ; Thu, 07 Nov 2019 11:28:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=LsQBOGT7wlBeTtd5DGVJ1cAFGBGmgxUQGz4CBk4TLCk=; b=pVKXsw6iTlJ2Rzs/YUhd1cSagr7G85BPX4jvG88avd78mLhxpwKSuSup+KefjXgIzd D99eKJyFKqrIcZz8kgmmwl8B7bGRqu8tHo6szfdV1XbTdJ6NW7Daw49AkY/gMmuKncRn t5QMRH81Y3OOOXlCBRJRI8iZUCYzpSb4T3mleVCNGWEdUdF1GzrTwDjUe9aEUSneQL4B uGtLuJbyPxquXYAPyeyX8vY0Bgl/FCPAwmmQGAHRZObaR2TK/+SlD7+smuzdVvztSDN1 xpINYOf1vFWkuiS8IiRdmGwfG3W5cTmNRSeHvQH6W7ubVPkL/J0BJfpWgkDHYxjfInUl uxNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=LsQBOGT7wlBeTtd5DGVJ1cAFGBGmgxUQGz4CBk4TLCk=; b=bzDFrbeDuqBNVr1iXNd3R8vgCdCB4ggttXwDDtcmXrRVwV0aMJm4LBlmzuGAby/RGd V9tyL6MNVc0IbKljrvMq7bJcFqtxo402bGcaDefL6taBrjtRn7+wM5wx13DLx/Iam/I5 hn6VuBLsTU8fAlQvDa22vaEJjoPUfRt2JU+W6Y4NQgst1csNCQJbsSgt9ZJuFK0e+sNb 1W4zNU5reORXxhJeVWlcqfUqIGAKsquq68KV6WP+8LG3LiBo934TjMLgR2XYTC5lUm59 3Mwk5IMyxGiciqhECI/N/d1jrsy+9tkHDWhviWnLUR/+V41rANQE4TbRsEBH43yFQWZj PIGQ== X-Gm-Message-State: APjAAAUzfjZtAHAasMcPXnlp7WdiWbU4tjO/Y7pnsD4JyNbG9QV5nwiI DIOOPJegjYGrMcZWLDmE655f9A== X-Google-Smtp-Source: APXvYqytRM2OaAe3ZSxiJMqKi+CwRvtOJTQx6oa467TEQdWnroU8YHYetutKqI3f0YDuqGs+xrjF2A== X-Received: by 2002:a02:c9d2:: with SMTP id c18mr5844902jap.108.1573154929192; Thu, 07 Nov 2019 11:28:49 -0800 (PST) Received: from [192.168.1.159] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id r25sm437420ilb.16.2019.11.07.11.28.47 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 07 Nov 2019 11:28:48 -0800 (PST) Subject: Re: [PATCHSET v2 block/for-next] blk-cgroup: use cgroup rstat for IO stats To: Tejun Heo Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, lizefan@huawei.com, hannes@cmpxchg.org, kernel-team@fb.com References: <20191107191804.3735303-1-tj@kernel.org> From: Jens Axboe Message-ID: <2a6dd76b-6063-92b9-7b20-97f69bb4b344@kernel.dk> Date: Thu, 7 Nov 2019 12:28:47 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191107191804.3735303-1-tj@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/7/19 12:17 PM, Tejun Heo wrote: > Hello, > > v2: Build fix when !DEBUG. > > blk-cgroup IO stats currently use blkg_rwstat which unforutnately > requires walking all descendants recursively on read. On systems with > a large number of cgroups (dead or alive), this can make each stat > read a substantially expensive operation. > > This patch updates blk-cgroup to use cgroup rstat which makes stat > reading O(# descendants which have been active since last reading) > instead of O(# descendants). > > 0001-bfq-iosched-relocate-bfqg_-rwstat-helpers.patch > 0002-bfq-iosched-stop-using-blkg-stat_bytes-and-stat_ios.patch > 0003-blk-throtl-stop-using-blkg-stat_bytes-and-stat_ios.patch > 0004-blk-cgroup-remove-now-unused-blkg_print_stat_-bytes-.patch > 0005-blk-cgroup-reimplement-basic-IO-stats-using-cgroup-r.patch > 0006-blk-cgroup-separate-out-blkg_rwstat-under-CONFIG_BLK.patch > > 0001-0003 make bfq-iosched and blk-throtl use their own blkg_rwstat to > track basic IO stats on cgroup1 instead of sharing blk-cgroup core's. > 0004 is a follow-up cleanup. > > 0005 switches blk-cgroup to cgroup rstat. > > 0006 moves blkg_rwstat to its own files and gate it under a config > option as it's now only used by blk-throtl and bfq-iosched. > > The patchset is on top of > > block/for-next 40afbe18b03a ("Merge branch 'for-5.5/drivers-post' into for-next") > + block/for-linus b0814361a25c ("blkcg: make blkcg_print_stat() print stats only for online blkgs") > > and also available in the following git branch. > > git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git review-blkcg-rstat Thanks, applied! -- Jens Axboe