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=-9.1 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 15D4DC282C4 for ; Tue, 12 Feb 2019 18:48:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9EEF2190B for ; Tue, 12 Feb 2019 18:48:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XOdAZ4ej" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732180AbfBLSsd (ORCPT ); Tue, 12 Feb 2019 13:48:33 -0500 Received: from mail-pl1-f193.google.com ([209.85.214.193]:40698 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732158AbfBLSsZ (ORCPT ); Tue, 12 Feb 2019 13:48:25 -0500 Received: by mail-pl1-f193.google.com with SMTP id bj4so1711978plb.7; Tue, 12 Feb 2019 10:48:25 -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=XOdAZ4ejroaV8XQrbRNs0Bo9BtzFbOVrVwqyUebTzCyOdhZf4ZBNLWi30bbeHVYcKK XI8XOTU81zGsFSZoukFtA6eQJva7mkLs7zpqhnZiI1C8fU0VGHPovaLeZjRP95HMAHZb HW/XRcRxjERl+cDMu5KzyXlqCVLTAywtdN7l3r84bRmbYAFDuBK6DIu3+jysI3ra1xs1 V2HdoIczc8kmGA+/SddU6DWhrnEWr5D3rNfX4osYhjNQf71L20ZrdOf7nAu4bZ/oaqeB AF6PWWWnTbNFU1lWR5gAgEIc7c4M6uluA6avxYsUc0D82sUV5bwa86kSeUkHoFHPepE7 Aqcg== 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=YED5Sqexfr533wQL13mubPJFM1NGCYdrJC1Byms0csReIPeqi2DGPrdrk9EbDs7j+u Tm2WmTLk9YUUnT6UE28tBZcJ1lwSrIyZkTe0bS970Zlm67z9q/10rLxvO9JOm8DB8g7R CHrv+94IG+KH6nBJsgFmD9cEAh348R0iUZfYafIMWxyO+T03kWtIOJn7yHCc2oOHFv8k 0okUrZmGqc0Hk6L+KvwycVZDy6eLKQvFsS/EWFCVS4j2YDawXnZsLr5EMl/cl+7cGClI QcYYzRNdofyGOr2gXF64adJ20pfh9JDYbPo4eVl8MQpj1YfOCNxUmpJwlfwOXB/XHC3H 52TA== X-Gm-Message-State: AHQUAuZydxFixjL04adI+aKWVyClIqZRosCs2m5XLG8lJ1Vaalktgfe1 qD14Tqn95hS3m+xJdP6kFomBWI4310Q= X-Google-Smtp-Source: AHgI3IYeuDp1vcysP0tH2EoKM0pCJ0lPuK4U1AEQ5YqQ5NsmTeDVAQ3HWrp6An3Et9Z/srpcijixhw== X-Received: by 2002:a17:902:112c:: with SMTP id d41mr5245192pla.144.1549997305108; Tue, 12 Feb 2019 10:48:25 -0800 (PST) Received: from tower.thefacebook.com ([2620:10d:c090:200::5:4d62]) by smtp.gmail.com with ESMTPSA id f67sm25480102pfc.141.2019.02.12.10.48.23 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 12 Feb 2019 10:48:24 -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 v7 7/7] cgroup: document cgroup v2 freezer interface Date: Tue, 12 Feb 2019 10:48:07 -0800 Message-Id: <20190212184807.20304-8-guro@fb.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190212184807.20304-1-guro@fb.com> References: <20190212184807.20304-1-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