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=-8.8 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,URIBL_BLOCKED,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 0B295C282CE for ; Fri, 5 Apr 2019 17:47:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D0E2D2171F for ; Fri, 5 Apr 2019 17:47:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dkTZWcoc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731796AbfDERr5 (ORCPT ); Fri, 5 Apr 2019 13:47:57 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:37894 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731722AbfDERro (ORCPT ); Fri, 5 Apr 2019 13:47:44 -0400 Received: by mail-pf1-f193.google.com with SMTP id 10so3671956pfo.5; Fri, 05 Apr 2019 10:47:43 -0700 (PDT) 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=sPwqK0qKQccz1rnM8spQH4fx1OfXTPfbuyAOOQ+8AD0=; b=dkTZWcoctKvv3aWGfJ+h5Whk/0MAavdY7xUT5DQ7kJVHQtRlg/JrdskB3bZPgjs1g9 76JbeYYkdvA3DNH5puqxF/F6SzZyGnHj9eYb675X5n6iCh1oBMzHxkRfLqOdf8www1U9 gtf2W8hpXxXkz3nAtnnquaVQMjRIUeXi8DlGUcq63gCvLtE9nocg8Sl+OeWIte+gv7Hl YOOKnqHG/zX+haCgiYcilgCgt8MF5/EacFL+a112Z87UPWKCdDY0quZpZfJk61z6+Nyu jqjnjXr7OYBN/yVNHl0bn6hrM/Dl2RB3UOZPjy3VfA6I1UB0UzUaoOSfZ08vGZKTy22q yNuw== 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=sPwqK0qKQccz1rnM8spQH4fx1OfXTPfbuyAOOQ+8AD0=; b=rO2eW34r8UjChdINXjSqokYX4M3/Cf9PL6QhfVm+mM1zu/fPM8Q4egpnA5uZOq/FaY kcJe7GfXJ/cXjwhmhi87c9is/7hJ4QMRILcl57SLbQmfEfjBA5MhOH6CCiRNBPfcMMN3 pfPo2d4gr0Z2YidbYzQnSevN13z9QfGbXcduBOd4u+E9wZxhkgeCr8mMQOiDes79JCgn ePcDvYiHT9y5+ouRZ10s+3bgea6Oh/rpu3c70w3hUMoOZZllwByxLljBm70arNd09EqS 7XHfofSxM7CBzosTlLMtDfs2NJVlF8Wkjv0qRz3+p7PDvpicESh7ng42fGuZRrHd7Cq7 6y2Q== X-Gm-Message-State: APjAAAVYtxBvxe4qtL+xdzpt0+G/LeSgRP9LVPqHwDPcSaQzP4cESiGS oHGAXWzYBLWY/0Sd6Wj4k4QhBgu0WIA= X-Google-Smtp-Source: APXvYqx5U4EYEL1jeJPCKaahsNc2CoXuxI0q37/vE4wAmhHSrfwXodXMhJH4J0nsHhaKpMEfO3ObHQ== X-Received: by 2002:a62:5797:: with SMTP id i23mr13612319pfj.12.1554486463355; Fri, 05 Apr 2019 10:47:43 -0700 (PDT) Received: from tower.thefacebook.com ([2620:10d:c090:200::1:ad20]) by smtp.gmail.com with ESMTPSA id m2sm33169135pgr.74.2019.04.05.10.47.42 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 05 Apr 2019 10:47:42 -0700 (PDT) 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 v10 9/9] cgroup: document cgroup v2 freezer interface Date: Fri, 5 Apr 2019 10:47:08 -0700 Message-Id: <20190405174708.1010-10-guro@fb.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190405174708.1010-1-guro@fb.com> References: <20190405174708.1010-1-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 20f92c16ffbf..88e746074252 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