From 4fca88c87b7969c698912e2de9b1b31088c777cb Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Thu, 7 Feb 2008 00:14:27 -0800 Subject: memory cgroup enhancements: add- pre_destroy() handler Add a handler "pre_destroy" to cgroup_subsys. It is called before cgroup_rmdir() checks all subsys's refcnt. I think this is useful for subsys which have some extra refs even if there are no tasks in cgroup. By adding pre_destroy(), the kernel keeps the rule "destroy() against subsystem is called only when refcnt=0." and allows css ref to be used by other objects than tasks. Signed-off-by: KAMEZAWA Hiroyuki Cc: "Eric W. Biederman" Cc: Balbir Singh Cc: David Rientjes Cc: Herbert Poetzl Cc: Kirill Korotaev Cc: Nick Piggin Cc: Paul Menage Cc: Pavel Emelianov Cc: Peter Zijlstra Cc: Vaidyanathan Srinivasan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/cgroup.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 87479328d46d..d8e92223a79c 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -233,6 +233,7 @@ int cgroup_is_descendant(const struct cgroup *cont); struct cgroup_subsys { struct cgroup_subsys_state *(*create)(struct cgroup_subsys *ss, struct cgroup *cont); + void (*pre_destroy)(struct cgroup_subsys *ss, struct cgroup *cont); void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cont); int (*can_attach)(struct cgroup_subsys *ss, struct cgroup *cont, struct task_struct *tsk); -- cgit v1.2.3