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 C225DC43381 for ; Sat, 16 Mar 2019 17:58:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 972392190A for ; Sat, 16 Mar 2019 17:58:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bq8Z5xDL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727313AbfCPR6j (ORCPT ); Sat, 16 Mar 2019 13:58:39 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:44299 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727253AbfCPR6b (ORCPT ); Sat, 16 Mar 2019 13:58:31 -0400 Received: by mail-pg1-f194.google.com with SMTP id h34so8571344pgh.11; Sat, 16 Mar 2019 10:58:30 -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=0hgV92wDT2ZmcOau/wgDvn2O7fusGY5Cr61uoT+/hFU=; b=bq8Z5xDLMUpVyZDmZKNrHca9f4h2TOgOFC6MAyvLeNJ8msBy0iw/h5Qpkhwh9OYK5R dedffsd1mwPJM+1TT3RBPzFwbLsksOqJP8wax3iRSkiec7k3l19tX2XK55YxlREUHAaH QgzOcK34ZFqwLybW9vS9/zFRmbD+BWTdYNHYLFQ7qNL9iSIq4mGukaAg5zd+YLvdDfQH U6oke1JAM3t00xbVb0CAngbd/x7FYbffMDxttxK5hzwDSFa25G0q1xxJAqUau5/SWlX6 zHgNHPylL8SrbIg67pcedzdjjW/s3C1kOv+AHFrPKtSOg0oVFzl0ZhEQqNqXMMta2nTR EAQA== 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=oHHMCP9+s+TyJNo7ggIUEYUnUPBsYT6IPfZlysxI06AZfo9GobFBaQ4YPaNbjeyUEi blIIQQ0YK5uTV7aHXQgOYuSEbTHAimFJInfuEkeA4/NS6nl8PaNMXmJsRtm3yUOBgfCw fVZKFjvjvs8G5zsUagJqRaTts9Dq6iPlwMNFaYuiDDKD4lUwksu42U2DCaF7q4yknf57 wiCSF3CQPX+2Zz/ig62R09JS4J32OpM+Sj3ZzZECIskXFEYnFnQY5I2fV/gP682sX5PH kV1V7aKcmS3dxnFl+5aloJE3vVbZMrPRhIQgFDO7AycU3/GBKtPaYg4HvZDFfwEf2aAX YAQw== X-Gm-Message-State: APjAAAXH3Hb9kZXaIAomnnprMKewO0WcuPiko3y+afdG+KGXRK1rWoFC IwJfo83wlN3rjy8+m6c+tZY= X-Google-Smtp-Source: APXvYqzbtQgkg75MepPz3Rdsyo2uJzcezugEBhKq0wcwZ4AHdyVZaC4w6Uu5dvmZuUcuSiqhmoyUBA== X-Received: by 2002:a17:902:a24:: with SMTP id 33mr10382469plo.275.1552759110593; Sat, 16 Mar 2019 10:58:30 -0700 (PDT) Received: from castle.hsd1.ca.comcast.net ([2603:3024:1704:3e00::d657]) by smtp.gmail.com with ESMTPSA id p86sm11025638pfa.104.2019.03.16.10.58.29 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sat, 16 Mar 2019 10:58:29 -0700 (PDT) From: Roman Gushchin X-Google-Original-From: Roman Gushchin To: Tejun Heo , Oleg Nesterov Cc: Roman Gushchin , kernel-team@fb.com, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Mike Rapoport , linux-doc@vger.kernel.org Subject: [PATCH v9 9/9] cgroup: document cgroup v2 freezer interface Date: Sat, 16 Mar 2019 10:58:12 -0700 Message-Id: <20190316175812.6787-10-guro@fb.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190316175812.6787-1-guro@fb.com> References: <20190316175812.6787-1-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