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>

1 files changed, 5 insertions, 0 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index fdce3a29fc4c..6c37c51565e5 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 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
 
         if (anon_vma)
                 put_anon_vma(anon_vma);
+
+        if (!rc)
+                hugetlb_cgroup_migrate(hpage, new_hpage);
+
         unlock_page(hpage);
 out:
         put_page(new_hpage);