1 files changed, 25 insertions, 17 deletions

diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index a3f358fb8a0c..9cea7de22ffb 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -77,7 +77,7 @@ static inline bool hugetlb_cgroup_have_usage(struct cgroup *cg)
         return false;
 }
 
-static struct cgroup_subsys_state *hugetlb_cgroup_create(struct cgroup *cgroup)
+static struct cgroup_subsys_state *hugetlb_cgroup_css_alloc(struct cgroup *cgroup)
 {
         int idx;
         struct cgroup *parent_cgroup;
@@ -101,7 +101,7 @@ static struct cgroup_subsys_state *hugetlb_cgroup_create(struct cgroup *cgroup)
         return &h_cgroup->css;
 }
 
-static void hugetlb_cgroup_destroy(struct cgroup *cgroup)
+static void hugetlb_cgroup_css_free(struct cgroup *cgroup)
 {
         struct hugetlb_cgroup *h_cgroup;
 
@@ -155,18 +155,13 @@ out:
  * Force the hugetlb cgroup to empty the hugetlb resources by moving them to
  * the parent cgroup.
  */
-static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup)
+static void hugetlb_cgroup_css_offline(struct cgroup *cgroup)
 {
         struct hstate *h;
         struct page *page;
-        int ret = 0, idx = 0;
+        int idx = 0;
 
         do {
-                if (cgroup_task_count(cgroup) ||
-                    !list_empty(&cgroup->children)) {
-                        ret = -EBUSY;
-                        goto out;
-                }
                 for_each_hstate(h) {
                         spin_lock(&hugetlb_lock);
                         list_for_each_entry(page, &h->hugepage_activelist, lru)
@@ -177,8 +172,6 @@ static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup)
                 }
                 cond_resched();
         } while (hugetlb_cgroup_have_usage(cgroup));
-out:
-        return ret;
 }
 
 int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
@@ -340,7 +333,7 @@ static char *mem_fmt(char *buf, int size, unsigned long hsize)
         return buf;
 }
 
-int __init hugetlb_cgroup_file_init(int idx)
+static void __init __hugetlb_cgroup_file_init(int idx)
 {
         char buf[32];
         struct cftype *cft;
@@ -382,7 +375,22 @@ int __init hugetlb_cgroup_file_init(int idx)
 
         WARN_ON(cgroup_add_cftypes(&hugetlb_subsys, h->cgroup_files));
 
-        return 0;
+        return;
+}
+
+void __init hugetlb_cgroup_file_init(void)
+{
+        struct hstate *h;
+
+        for_each_hstate(h) {
+                /*
+                 * Add cgroup control files only if the huge page consists
+                 * of more than two normal pages. This is because we use
+                 * page[2].lru.next for storing cgroup details.
+                 */
+                if (huge_page_order(h) >= HUGETLB_CGROUP_MIN_ORDER)
+                        __hugetlb_cgroup_file_init(hstate_index(h));
+        }
 }
 
 /*
@@ -411,8 +419,8 @@ void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage)
 
 struct cgroup_subsys hugetlb_subsys = {
         .name = "hugetlb",
-        .create     = hugetlb_cgroup_create,
-        .pre_destroy = hugetlb_cgroup_pre_destroy,
-        .destroy    = hugetlb_cgroup_destroy,
-        .subsys_id  = hugetlb_subsys_id,
+        .css_alloc      = hugetlb_cgroup_css_alloc,
+        .css_offline    = hugetlb_cgroup_css_offline,
+        .css_free       = hugetlb_cgroup_css_free,
+        .subsys_id      = hugetlb_subsys_id,
 };