diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cgroup.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index ada239253ec7..4b38e2d6110d 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -154,6 +154,14 @@ struct cgroup { /* the number of attached css's */ int nr_css; + /* + * If this cgroup contains any tasks, it contributes one to + * populated_cnt. All children with non-zero popuplated_cnt of + * their own contribute one. The count is zero iff there's no task + * in this cgroup or its subtree. + */ + int populated_cnt; + atomic_t refcnt; /* @@ -166,6 +174,7 @@ struct cgroup { struct cgroup *parent; /* my parent */ struct kernfs_node *kn; /* cgroup kernfs entry */ struct kernfs_node *control_kn; /* kn for "cgroup.subtree_control" */ + struct kernfs_node *populated_kn; /* kn for "cgroup.subtree_populated" */ /* * Monotonically increasing unique serial number which defines a @@ -264,6 +273,12 @@ enum { * * - "cgroup.clone_children" is removed. * + * - "cgroup.subtree_populated" is available. Its value is 0 if + * the cgroup and its descendants contain no task; otherwise, 1. + * The file also generates kernfs notification which can be + * monitored through poll and [di]notify when the value of the + * file changes. + * * - If mount is requested with sane_behavior but without any * subsystem, the default unified hierarchy is mounted. * |