cgroup documentation was moved to Documentation/cgroups/. There are some
places that still refer to Documentation/controllers/,
Documentation/cgroups.txt and Documentation/cpusets.txt. Fix those.
Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Reviewed-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPaul Menage <menage@google.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

While the Documentation example creates /cgroup/test, it removes
/test/cgroup, which is clearly not the intended path. Change that to
/cgroup/test.
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Minor typo and spelling corrections fixed whilst reading
to learn about cgroups capabilities.
Signed-off-by: NChris Samuel <chris@csamuel.org>
Acked-by: NPaul Menage <menage@google.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

I noticed the old commit 8f5aa26c
("cpusets: update_cpumask documentation fix") is not a complete fix,
resulting in inconsistent paragraphs.  This patch fixes it and does other
fixes and updates:

- s/migrate_all_tasks()/migrate_live_tasks()/
- describe more cpuset control files
- s/cpumask_t/struct cpumask/
- document cpu hotplug and change of 'sched_relax_domain_level' may cause
  domain rebuild
- document various ways to query and modify cpusets
- the equivalent of "mount -t cpuset" is "mount -t cgroup -o cpuset,noprefix"
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The css_set hash table was introduced in 2.6.26, so update the
documentation accordingly.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPaul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Considering the recently found problem "memcg: fix refcnt handling at
swapoff", it's better to mention swapoff behavior in the memcg_test
document.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move Documentation/cpusets.txt and Documentation/controllers/* to
Documentation/cgroups/
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: NPaul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These patches introduce new locking/refcount support for cgroups to
reduce the need for subsystems to call cgroup_lock(). This will
ultimately allow the atomicity of cgroup_rmdir() (which was removed
recently) to be restored.

These three patches give:

1/3 - introduce a per-subsystem hierarchy_mutex which a subsystem can
     use to prevent changes to its own cgroup tree

2/3 - use hierarchy_mutex in place of calling cgroup_lock() in the
     memory controller

3/3 - introduce a css_tryget() function similar to the one recently
      proposed by Kamezawa, but avoiding spurious refcount failures in
      the event of a race between a css_tryget() and an unsuccessful
      cgroup_rmdir()

Future patches will likely involve:

- using hierarchy mutex in place of cgroup_lock() in more subsystems
 where appropriate

- restoring the atomicity of cgroup_rmdir() with respect to cgroup_create()

This patch:

Add a hierarchy_mutex to the cgroup_subsys object that protects changes to
the hierarchy observed by that subsystem.  It is taken by the cgroup
subsystem (in addition to cgroup_mutex) for the following operations:

- linking a cgroup into that subsystem's cgroup tree
- unlinking a cgroup from that subsystem's cgroup tree
- moving the subsystem to/from a hierarchy (including across the
  bind() callback)

Thus if the subsystem holds its own hierarchy_mutex, it can safely
traverse its own hierarchy.
Signed-off-by: NPaul Menage <menage@google.com>
Tested-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- remove 'releasable' since it has been moved to the debug subsys.
- update lock requirements of subsys callbacks.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With this change, control file 'freezer.state' doesn't exist in root
cgroup, making root cgroup unfreezable.

I think it's reasonable to disallow freeze tasks in the root cgroup.  And
then we can avoid fork overhead when freezer subsystem is compiled but not
used.

Also make writing invalid value to freezer.state returns EINVAL rather
than EIO.  This is more consistent with other cgroup subsystem.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPaul Menage <menage@google.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Describe why we need the freezer subsystem and how to use it in a
documentation file.  Since the cgroups.txt file is focused on the
subsystem-agnostic portions of cgroups make a directory and move the old
cgroups.txt file at the same time.
Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: containers@lists.linux-foundation.org
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>