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 5E8E2C433F5 for ; Fri, 27 May 2022 08:48:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243543AbiE0Isu (ORCPT ); Fri, 27 May 2022 04:48:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232051AbiE0Isq (ORCPT ); Fri, 27 May 2022 04:48:46 -0400 Received: from mail-pl1-x633.google.com (mail-pl1-x633.google.com [IPv6:2607:f8b0:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8DA33BF9C; Fri, 27 May 2022 01:48:41 -0700 (PDT) Received: by mail-pl1-x633.google.com with SMTP id q4so3572892plr.11; Fri, 27 May 2022 01:48:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=F/TuFldqNWvbTR7kMknQ2sKjIOSGzhXUVTHp1Dts3Bw=; b=Waerq1Kg5SvqcLdZ91WgRWzCShy7ZEJw5Th3INevO7MYiKqxU166flLRKYb6F3n2WE +/jhiCUpHLjXscO+mQm+qzYfcQ6QVGscfz94TDWbs+505PMsEP+VLtuM0nmfmnKsORsx e2rNwgY0TNH0ff4YJnyjGYKYCKLwXdHus/fT3gypmPcIAeRq3baIiEb27H10uQWXYWfr 86WDeESm08ae9QxBJNHTwBk5pwNcblO1VibwZ1AnB5yigJm8+lsU84fszGAC0X4wtRRI 3kHnhOT13M7HHIjATivsUNe1oExErxDO5MThHSnlAo+zQhu7ZP6+XxwioyoBbQaf/HJZ NFhw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=F/TuFldqNWvbTR7kMknQ2sKjIOSGzhXUVTHp1Dts3Bw=; b=V8g66Om94JDOy3U2U+66WDF/nKz9hK1KIUOrVnoAzNWWvpm49FRFX+SXVADuYmUS2i EtZP3RpXv+zhlReOdsCXbJVviIoKSlnF65OGs118F5ek1GrQf83jOtv/xai8qhgFWm1Z G5RAIoZHavRch5GAVfChoJ+0N10U+VppByBhoJ1tRzc5zOIuCmeg0fp2YmYHphTmpQbB XrUCUL6Fs+YX7gGF3bxIBpsVibLG4B9r7WO5tq8tJphdyUD2euy4/HTvlTUBLhW5T/y+ mSxhv2gVfmltMJAykF6Wdf8UyYDtHlq6m4lLHDX1IeeGhz63y3b9xAXVTd69+4+WNGGl b+kA== X-Gm-Message-State: AOAM531UB3jazNMgi+/H0wW471n+ifP7xbKtdw4NtK3sNQ77XIlk77lK 73Ib3G4D0TzjWixwFLepcA8= X-Google-Smtp-Source: ABdhPJwqtjzGV0uG1WoBE3y9BQjc+1acwVdSs33qFdDUPmDyP1NaqwM6CP6aSD4H6E3KNP5tm3n0Yw== X-Received: by 2002:a17:902:7781:b0:161:c85a:8fff with SMTP id o1-20020a170902778100b00161c85a8fffmr42066123pll.97.1653641321290; Fri, 27 May 2022 01:48:41 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::4:ac0e]) by smtp.gmail.com with ESMTPSA id a16-20020aa78650000000b0050dc7628137sm3002469pfo.17.2022.05.27.01.48.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 May 2022 01:48:40 -0700 (PDT) Sender: Tejun Heo Date: Thu, 26 May 2022 22:48:39 -1000 From: Tejun Heo To: Hongchen Zhang Cc: Zefan Li , Johannes Weiner , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] cgroup: wait for css offline when rmdir Message-ID: References: <1653619158-27607-1-git-send-email-zhanghongchen@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1653619158-27607-1-git-send-email-zhanghongchen@loongson.cn> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 27, 2022 at 10:39:18AM +0800, Hongchen Zhang wrote: > when remove a cgroup dir, make sure all the csses associated which > the cgroup are all offlined,so that we will be sure that the resources > allocated by the csses are all freed when rmdir exit successfully. Offlining doesn't guarantee that resources are freed and there's no definite time limit on how long it'd take to free all resources. e.g. for memcg, if there isn't sufficient memory pressure, its page cache can remain indefinitely. Is there something practical you're trying to achieve? Thanks. -- tejun