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=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 E2D55C4360F for ; Tue, 19 Feb 2019 22:03:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A8CFD2147A for ; Tue, 19 Feb 2019 22:03:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="C7absAyl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730001AbfBSWDS (ORCPT ); Tue, 19 Feb 2019 17:03:18 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:35863 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729884AbfBSWDK (ORCPT ); Tue, 19 Feb 2019 17:03:10 -0500 Received: by mail-pg1-f196.google.com with SMTP id r124so10770238pgr.3; Tue, 19 Feb 2019 14:03:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=0hgV92wDT2ZmcOau/wgDvn2O7fusGY5Cr61uoT+/hFU=; b=C7absAylMscTk4Wjtt7Y4IbaIyGuHygs0J94JlBR7eQX7eVs9S1ayeofPfpDjrKJK3 45a6P1EgyNgQxDbGU3ZpHrTyGYFZGCwNf1VOe5gmznWb/4Ppz8HIZVfVr0LrGIb2jdiv gk3Pi9USbefmrKl9z/DrgtP7XLh8bXvhK3UW+go7HEhNnFi5nu6iuDAbx/5TDPLCEWNg 1lRvkfVrk2zFBfm+jkImsL1WcU1/6D902qxA0m3JFvt5ZKNOLeAdfKIKeSOhxM0Jn396 kV3J+FObFkdo957p4OSioHkZP5N9iCkpp9JghZ3qdrcmn56lkILFWxMSDu08rSTAmMac h4yA== 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:mime-version:content-transfer-encoding; bh=0hgV92wDT2ZmcOau/wgDvn2O7fusGY5Cr61uoT+/hFU=; b=JX5C7CR33wJLmGnQCKuxJtQd7dSNfzKAE787m0YXs932gtkC+aU20dLdAheU2c17Ec f11DRS0eXSkUTNsPF0BNKYncwR0GYsg7cCy/8It+E3laPQ4Trebq2M33KHKwR555EQlO CpyXzZQ4MNRiFoTF+Wtg99PrXTSUEsYYZv8tTb6uyymxqOeVeTHyIY1LZSRhgebFu+19 3qLv1jcf2htxrZvUNtEWaVxGxd5OkjDQkmk1Cq2roqJbWjJAmpS0HoQdqoa2Ea1LlY55 u2e7mPhVxYKnwy+4uyLQdhGWCiTEdv3+U+N31T8L2ObU4u1BIn+YH1ZkypKc6GaeUAM9 3gGA== X-Gm-Message-State: AHQUAuY1sTeVz+Ke07d9VyrH5dvrVZyWTJKdBD15sRVY3h9KOdc2P+ia t9OrhReW9B6baK80MnqwAqaN5TjgcYc= X-Google-Smtp-Source: AHgI3IZK/aAcXXln+ubV5L0uRdVx43Y7pNJRTzMywNs93NFIfXPSMEzZJJEQyGJ20s7zIg8M95jiCg== X-Received: by 2002:a63:ed42:: with SMTP id m2mr26126163pgk.147.1550613789961; Tue, 19 Feb 2019 14:03:09 -0800 (PST) Received: from tower.thefacebook.com ([2620:10d:c090:200::5:161b]) by smtp.gmail.com with ESMTPSA id e6sm33539779pfe.59.2019.02.19.14.03.08 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 19 Feb 2019 14:03:09 -0800 (PST) From: Roman Gushchin X-Google-Original-From: Roman Gushchin To: Tejun Heo , Oleg Nesterov Cc: kernel-team@fb.com, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Roman Gushchin , Mike Rapoport , linux-doc@vger.kernel.org Subject: [PATCH v8 7/7] cgroup: document cgroup v2 freezer interface Date: Tue, 19 Feb 2019 14:02:52 -0800 Message-Id: <20190219220252.4906-8-guro@fb.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190219220252.4906-1-guro@fb.com> References: <20190219220252.4906-1-guro@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Describe cgroup v2 freezer interface in the cgroup v2 admin guide. Signed-off-by: Roman Gushchin Reviewed-by: Mike Rapoport Cc: Tejun Heo Cc: linux-doc@vger.kernel.org Cc: kernel-team@fb.com --- Documentation/admin-guide/cgroup-v2.rst | 27 +++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 61f8bbb0a1b2..78f078ddbe9c 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -864,6 +864,8 @@ All cgroup core files are prefixed with "cgroup." populated 1 if the cgroup or its descendants contains any live processes; otherwise, 0. + frozen + 1 if the cgroup is frozen; otherwise, 0. cgroup.max.descendants A read-write single value files. The default is "max". @@ -897,6 +899,31 @@ All cgroup core files are prefixed with "cgroup." A dying cgroup can consume system resources not exceeding limits, which were active at the moment of cgroup deletion. + cgroup.freeze + A read-write single value file which exists on non-root cgroups. + Allowed values are "0" and "1". The default is "0". + + Writing "1" to the file causes freezing of the cgroup and all + descendant cgroups. This means that all belonging processes will + be stopped and will not run until the cgroup will be explicitly + unfrozen. Freezing of the cgroup may take some time; when this action + is completed, the "frozen" value in the cgroup.events control file + will be updated to "1" and the corresponding notification will be + issued. + + A cgroup can be frozen either by its own settings, or by settings + of any ancestor cgroups. If any of ancestor cgroups is frozen, the + cgroup will remain frozen. + + Processes in the frozen cgroup can be killed by a fatal signal. + They also can enter and leave a frozen cgroup: either by an explicit + move by a user, or if freezing of the cgroup races with fork(). + If a process is moved to a frozen cgroup, it stops. If a process is + moved out of a frozen cgroup, it becomes running. + + Frozen status of a cgroup doesn't affect any cgroup tree operations: + it's possible to delete a frozen (and empty) cgroup, as well as + create new sub-cgroups. Controllers =========== -- 2.20.1