hugetlb/cgroup: add the cgroup pointer to page lru

[deliverable/linux.git] / include / linux / hugetlb_cgroup.h

diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h
index f19889e56b472a82cab80c8b4dab67344f0cf23f..e5451a3b4ebc07156c829bc79ad6b8f9795aeceb 100644 (file)
--- a/include/linux/hugetlb_cgroup.h
+++ b/include/linux/hugetlb_cgroup.h
@@ -18,8 +18,34 @@
 #include <linux/res_counter.h>
 
 struct hugetlb_cgroup;
+/*
+ * Minimum page order trackable by hugetlb cgroup.
+ * At least 3 pages are necessary for all the tracking information.
+ */
+#define HUGETLB_CGROUP_MIN_ORDER       2
 
 #ifdef CONFIG_CGROUP_HUGETLB
+
+static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
+{
+       VM_BUG_ON(!PageHuge(page));
+
+       if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
+               return NULL;
+       return (struct hugetlb_cgroup *)page[2].lru.next;
+}
+
+static inline
+int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg)
+{
+       VM_BUG_ON(!PageHuge(page));
+
+       if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
+               return -1;
+       page[2].lru.next = (void *)h_cg;
+       return 0;
+}
+
 static inline bool hugetlb_cgroup_disabled(void)
 {
        if (hugetlb_subsys.disabled)
@@ -28,6 +54,17 @@ static inline bool hugetlb_cgroup_disabled(void)
 }
 
 #else
+static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
+{
+       return NULL;
+}
+
+static inline
+int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg)
+{
+       return 0;
+}
+
 static inline bool hugetlb_cgroup_disabled(void)
 {
        return true;