From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 301987D8A3 for ; Fri, 7 Dec 2018 20:16:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726402AbeLGUPo (ORCPT ); Fri, 7 Dec 2018 15:15:44 -0500 Received: from mail-pg1-f194.google.com ([209.85.215.194]:41357 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726356AbeLGUPo (ORCPT ); Fri, 7 Dec 2018 15:15:44 -0500 Received: by mail-pg1-f194.google.com with SMTP id 70so2177340pgh.8; Fri, 07 Dec 2018 12:15:43 -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; bh=6XRT3PIBruu3XRiswo1BJ+me6VnnM1g5UdR6upb//c0=; b=maFrqRoQMw6RJAiN+/YYnssncI3k9OlpsrMUv7FEh16SuZ45JstfYzUf9uMlPh9WRA /zd75KPy6OVK8X70t6tpl5nDDe2cdd7Dh4nh2Ku0fhUkyCTqfO019AIL6PEP7H1lxcHp g57AXbNAM1Aq4yA8Vj/EqJ7qbPUQEFiKZl6aZd29F1V4nT4oMcNnXfN1TEAh7pb9H/8R U8jFjCapNI8+hUfeQ6r0Oc9lKd3HNFo/5wT0LsgaFx9v0EUr3ew1apeThc8hOM/yX6cH WmsOeJvNXAcx91miWcdDhPui/STM9WNivjzuxP5shd5r5JaXmLT6w/Ib6eOVHbdSQgd9 rHAg== 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; bh=6XRT3PIBruu3XRiswo1BJ+me6VnnM1g5UdR6upb//c0=; b=U60VNyyb1R+ikiXMDTCwz95pGdcNvKSN4YQ4SnvOtdUAXkcEB51VtDzTYTPkUUhyNi 5Nik6emnFnKR+FC0hSE91H3nZJhECYK8WQATiXodH+1/u4C6FsiyRlq3M+tr456cO+Ms u++uZ9/luJpO3IhVCmn2eb+r9foRToqzdI/WPl0o1wdsb68PWsImQNhEv5pArx1Fut2i VoO3/vrfb7tioh7UESPrm15CvXy1iRrF6VpTsa43lqTEbmvAVPmlZU2XNtkzCtnVeCS+ jvcxBqhMtMkl91nTXwTH7+SlMUI5vgO/afqbo4Bm62QO+5MB7rYuzt0xmP8d1s3CGs4W upjA== X-Gm-Message-State: AA+aEWaADSGjt0GDs1xvZWoqVyer2/Vt7/MFcusV3ZVGZ49LR2Z5mczJ q8ShtEMqGxHUVdfUyp4HNHY= X-Google-Smtp-Source: AFSGD/VdMEYyNiUoHkJYeeMUxvH9SlaNto4w0ncm3zWYJFeAYCkVgOgrHBp9lNwdAyEXXXbMvQ1ejg== X-Received: by 2002:a63:cc12:: with SMTP id x18mr3138914pgf.33.1544213743049; Fri, 07 Dec 2018 12:15:43 -0800 (PST) Received: from castle.thefacebook.com ([2620:10d:c090:200::6:d83b]) by smtp.gmail.com with ESMTPSA id q75sm5870898pfa.38.2018.12.07.12.15.41 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 07 Dec 2018 12:15:42 -0800 (PST) From: Roman Gushchin X-Google-Original-From: Roman Gushchin To: Tejun Heo , Oleg Nesterov Cc: Dan Carpenter , Mike Rapoport , cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Roman Gushchin Subject: [PATCH v5 7/7] cgroup: document cgroup v2 freezer interface Date: Fri, 7 Dec 2018 12:15:31 -0800 Message-Id: <20181207201531.1665-8-guro@fb.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20181207201531.1665-1-guro@fb.com> References: <20181207201531.1665-1-guro@fb.com> Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@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 07e06136a550..f8335e26b362 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 =========== -- 2.17.2