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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD0F0C46467 for ; Wed, 23 Nov 2022 17:12:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239181AbiKWRMS (ORCPT ); Wed, 23 Nov 2022 12:12:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238325AbiKWRLy (ORCPT ); Wed, 23 Nov 2022 12:11:54 -0500 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12919FD17; Wed, 23 Nov 2022 09:11:52 -0800 (PST) Received: by mail-pl1-x62f.google.com with SMTP id p12so17218882plq.4; Wed, 23 Nov 2022 09:11:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=NwhqRAJvGavoaGuqSrfgQhHpNiR8ljuOsT2sziprE50=; b=kR4KehW+/5RtfQodotENKJN9+dUBrQYSP1Drnr1ELPapshjSBc05FeCs5WKFwRYhPF 5/evnW19Z3/WuKviaZQkBgYmYVsWl54dhOH3YawdfFrVbiz2wuB0KlNo28H3ATQVCRRj gHOjfUzqr58hJitHQP3GkzeZasRkD9Cj71Pzok8i3r4muU/UqM93A+54CXeCmatNkCTc VVwar/ZCrszc0IepuyjwUKg1EopF2V0JjDJSy82HO2WVCWX/zuXTY8vHKCzL/J50PqEu o83KfGYbocXqlMkcuW3cugTYUWCoznHe9HubGFCHzhJRIq/KqnA/eNfF0C/L1x59QrhS H27Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=NwhqRAJvGavoaGuqSrfgQhHpNiR8ljuOsT2sziprE50=; b=Co4yWGCHqdRzNHXe6DPgG7TVGF5q1GAmgzoZ+kYgacAGAXHSyGen2dQVDDRLqOSc6j YwdJuVpnzhFhYRX0q/mVEz9umXMDlKnrpO9ag9QfLxKf74e4RLvGlhqUH/HYE+IW+g4D 4sCoibcD9wIuWtahKCcJRuYORAF0TG5P5udwDytUHl3PWKY3bdin6Z564NBREmJOdDwE 3ENTlQaee4GpDgRCyF6ZSIGm2gvdudGDF8l0KZv+f6tinfIbYwI5AvUpo5Gj9ArTalGe UYonRkYWxhPUc8ItAINYA1YMNNNvr8RUoR62EEZ4riw8SiuvPN2I40bXnALvAUEJez3R CNAg== X-Gm-Message-State: ANoB5pnWLWeuThrLGZTVhH+ZnzQFpVY0dtIeTxMSz2j/Q8wX1SYZnW+8 FS3+DdGJpz4B0qoL5LaF+q8= X-Google-Smtp-Source: AA0mqf7KjgkN0jHcAVsy1r3Y3omUVQzpCEPHQxo9NJVMwkW9jfSM32OXw9Os8zoKtYe13fyfd4lXrA== X-Received: by 2002:a17:903:3311:b0:183:ee9e:4988 with SMTP id jk17-20020a170903331100b00183ee9e4988mr9331102plb.56.1669223511298; Wed, 23 Nov 2022 09:11:51 -0800 (PST) Received: from localhost (2603-800c-1a02-1bae-a7fa-157f-969a-4cde.res6.spectrum.com. [2603:800c:1a02:1bae:a7fa:157f:969a:4cde]) by smtp.gmail.com with ESMTPSA id j3-20020a17090a318300b00218722ecac2sm1646531pjb.18.2022.11.23.09.11.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Nov 2022 09:11:50 -0800 (PST) Sender: Tejun Heo Date: Wed, 23 Nov 2022 07:11:49 -1000 From: Tejun Heo To: Kemeng Shi Cc: josef@toxicpanda.com, axboe@kernel.dk, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 01/11] blk-throttle: Limit whole system if root group is configured when on the default hierarchy Message-ID: References: <20221123060401.20392-1-shikemeng@huawei.com> <20221123060401.20392-2-shikemeng@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221123060401.20392-2-shikemeng@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 23, 2022 at 02:03:51PM +0800, Kemeng Shi wrote: > Quoted from comment in throtl_pd_init: "If on the default hierarchy, we > switch to properly hierarchical behavior where limits on a given > throtl_grp are applied to the whole subtree rather than just the group > itself. e.g. If 16M read_bps limit is set on the root group, the whole > system can' exceed 16M for the device." On the default hierarchy (cgroup2), the throttle interface files don't exist in the root cgroup. In general, cgroup doesn't wanna be in the business of restricting resources at the system level. Thanks. -- tejun