hugetlb/cgroup: migrate hugetlb cgroup info from oldpage to new page during migration
With HugeTLB pages, hugetlb cgroup is uncharged in compound page
destructor. Since we are holding a hugepage reference, we can be sure
that old page won't get uncharged till the last put_page().
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>
Cc: 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 73f1e60..d73878c 100644
--- a/include/linux/hugetlb_cgroup.h
+++ b/include/linux/hugetlb_cgroup.h
@@ -63,6 +63,8 @@
extern void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
struct hugetlb_cgroup *h_cg);
extern int hugetlb_cgroup_file_init(int idx) __init;
+extern void hugetlb_cgroup_migrate(struct page *oldhpage,
+ struct page *newhpage);
#else
static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
@@ -114,5 +116,11 @@
return 0;
}
+static inline void hugetlb_cgroup_migrate(struct page *oldhpage,
+ struct page *newhpage)
+{
+ return;
+}
+
#endif /* CONFIG_MEM_RES_CTLR_HUGETLB */
#endif
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index d1ca119..680e481 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -386,6 +386,26 @@
return 0;
}
+void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage)
+{
+ struct hugetlb_cgroup *h_cg;
+
+ if (hugetlb_cgroup_disabled())
+ return;
+
+ VM_BUG_ON(!PageHuge(oldhpage));
+ spin_lock(&hugetlb_lock);
+ h_cg = hugetlb_cgroup_from_page(oldhpage);
+ set_hugetlb_cgroup(oldhpage, NULL);
+ cgroup_exclude_rmdir(&h_cg->css);
+
+ /* move the h_cg details to new cgroup */
+ set_hugetlb_cgroup(newhpage, h_cg);
+ spin_unlock(&hugetlb_lock);
+ cgroup_release_and_wakeup_rmdir(&h_cg->css);
+ return;
+}
+
struct cgroup_subsys hugetlb_subsys = {
.name = "hugetlb",
.create = hugetlb_cgroup_create,
diff --git a/mm/migrate.c b/mm/migrate.c
index fdce3a2..6c37c51 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -33,6 +33,7 @@
#include <linux/memcontrol.h>
#include <linux/syscalls.h>
#include <linux/hugetlb.h>
+#include <linux/hugetlb_cgroup.h>
#include <linux/gfp.h>
#include <asm/tlbflush.h>
@@ -931,6 +932,10 @@
if (anon_vma)
put_anon_vma(anon_vma);
+
+ if (!rc)
+ hugetlb_cgroup_migrate(hpage, new_hpage);
+
unlock_page(hpage);
out:
put_page(new_hpage);