cgroups: subsystem module unloading
Provides support for unloading modular subsystems.
This patch adds a new function cgroup_unload_subsys which is to be used
for removing a loaded subsystem during module deletion. Reference
counting of the subsystems' modules is moved from once (at load time) to
once per attached hierarchy (in parse_cgroupfs_options and
rebind_subsystems) (i.e., 0 or 1).
Signed-off-by: Ben Blum <bblum@andrew.cmu.edu>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt
index ae8a037..764007b 100644
--- a/Documentation/cgroups/cgroups.txt
+++ b/Documentation/cgroups/cgroups.txt
@@ -489,8 +489,9 @@
- define a cgroup_subsys object called <name>_subsys
If a subsystem can be compiled as a module, it should also have in its
-module initcall a call to cgroup_load_subsys(&its_subsys_struct). It
-should also set its_subsys.module = THIS_MODULE in its .c file.
+module initcall a call to cgroup_load_subsys(), and in its exitcall a
+call to cgroup_unload_subsys(). It should also set its_subsys.module =
+THIS_MODULE in its .c file.
Each subsystem may export the following methods. The only mandatory
methods are create/destroy. Any others that are null are presumed to
