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authorLi Zefan <lizf@cn.fujitsu.com>2009-01-07 18:07:41 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-08 08:31:03 -0800
commite5f6a8609bab0c2d7543ab1505105e011832afd7 (patch)
tree07591b1fb27431cee41ea4ca097b514a0e773ba7 /kernel
parent7534432dcc3c654a8671b6b0cdffd1dbdbc73074 (diff)
cgroups: make root_list contains active hierarchies only
Don't link rootnode to the root list, so root_list contains active hierarchies only as the comment indicates. And rename for_each_root() to for_each_active_root(). Also remove redundant check in cgroup_kill_sb(). Signed-off-by: Li 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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c19
1 files changed, 7 insertions, 12 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index f55af3daffc..fd572d05769 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -84,7 +84,7 @@ struct cgroupfs_root {
/* Tracks how many cgroups are currently defined in hierarchy.*/
int number_of_cgroups;
- /* A list running through the mounted hierarchies */
+ /* A list running through the active hierarchies */
struct list_head root_list;
/* Hierarchy-specific flags */
@@ -148,8 +148,8 @@ static int notify_on_release(const struct cgroup *cgrp)
#define for_each_subsys(_root, _ss) \
list_for_each_entry(_ss, &_root->subsys_list, sibling)
-/* for_each_root() allows you to iterate across the active hierarchies */
-#define for_each_root(_root) \
+/* for_each_active_root() allows you to iterate across the active hierarchies */
+#define for_each_active_root(_root) \
list_for_each_entry(_root, &roots, root_list)
/* the list of cgroups eligible for automatic release. Protected by
@@ -1111,10 +1111,9 @@ static void cgroup_kill_sb(struct super_block *sb) {
}
write_unlock(&css_set_lock);
- if (!list_empty(&root->root_list)) {
- list_del(&root->root_list);
- root_count--;
- }
+ list_del(&root->root_list);
+ root_count--;
+
mutex_unlock(&cgroup_mutex);
kfree(root);
@@ -2559,7 +2558,6 @@ int __init cgroup_init_early(void)
INIT_HLIST_NODE(&init_css_set.hlist);
css_set_count = 1;
init_cgroup_root(&rootnode);
- list_add(&rootnode.root_list, &roots);
root_count = 1;
init_task.cgroups = &init_css_set;
@@ -2666,15 +2664,12 @@ static int proc_cgroup_show(struct seq_file *m, void *v)
mutex_lock(&cgroup_mutex);
- for_each_root(root) {
+ for_each_active_root(root) {
struct cgroup_subsys *ss;
struct cgroup *cgrp;
int subsys_id;
int count = 0;
- /* Skip this hierarchy if it has no active subsystems */
- if (!root->actual_subsys_bits)
- continue;
seq_printf(m, "%lu:", root->subsys_bits);
for_each_subsys(root, ss)
seq_printf(m, "%s%s", count++ ? "," : "", ss->name);