Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753709Ab1CJRHz (ORCPT ); Thu, 10 Mar 2011 12:07:55 -0500 Received: from mail-qy0-f181.google.com ([209.85.216.181]:42827 "EHLO mail-qy0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751959Ab1CJRHv (ORCPT ); Thu, 10 Mar 2011 12:07:51 -0500 From: Eric B Munson To: linux-doc@vger.kernel.org Cc: containers@lists.linux-foundation.org, rdunlap@xenotime.net, linux-kernel@vger.kernel.org, kirill@shutemov.name, menage@google.com, mike@librato.com, Eric B Munson Subject: [PATCH V2] Documentation: cgroups: Add notes on removing PIDs from tasks and cgroups requiring setup Date: Thu, 10 Mar 2011 12:07:42 -0500 Message-Id: <1299776862-6931-1-git-send-email-emunson@mgebm.net> X-Mailer: git-send-email 1.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2136 Lines: 52 The cgroup documentation does not specify how a process can be removed from a particular group. This patch adds a note at the end of the simple example about how this is done. Also, some cgroups (like cpusets) require user input before a new group can be used. This is noted in the patch as well. Signed-off-by: Eric B Munson --- Changes from V1: Rework the note about removing a process from a cgroup Add note about ns cgroup causing failure when moving processes between groups Documentation/cgroups/cgroups.txt | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-) diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 44b8b7a..cbdfb7d 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -349,6 +349,10 @@ To mount a cgroup hierarchy with all available subsystems, type: The "xxx" is not interpreted by the cgroup code, but will appear in /proc/mounts so may be any useful identifying string that you like. +Note: Some subsystems do not work without some user input first. For instance, +if cpusets are enabled the user will have to populate the cpus and mems files +for each new cgroup created before that group can be used. + To mount a cgroup hierarchy with just the cpuset and memory subsystems, type: # mount -t cgroup -o cpuset,memory hier1 /dev/cgroup @@ -426,6 +430,14 @@ You can attach the current shell task by echoing 0: # echo 0 > tasks +Note: Since every task is always a member of exactly one cgroup in each +mounted hierarchy, to remove a task from its current cgroup you must +move it into a new cgroup (possibly the root cgroup) by writing to the +new cgroup's tasks file. + +Note: If the ns cgroup is active, moving a process to another cgroup can +fail. + 2.3 Mounting hierarchies by name -------------------------------- -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/