hugetlb/cgroup: add the cgroup pointer to page lru
Add the hugetlb cgroup pointer to 3rd page lru.next. This limit the usage
to hugetlb cgroup to only hugepages with 3 or more normal pages. I guess
that is an acceptable limitation.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h
index f19889e..e5451a3 100644
--- 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 @@
}
#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;