mm: memcontrol: remove unnecessary PCG_MEM memory charge flag
PCG_MEM is a remnant from an earlier version of 0a31bc97c80c ("mm:
memcontrol: rewrite uncharge API"), used to tell whether migration cleared
a charge while leaving pc->mem_cgroup valid and PCG_USED set. But in the
final version, mem_cgroup_migrate() directly uncharges the source page,
rendering this distinction unnecessary. Remove it.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@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/page_cgroup.h b/include/linux/page_cgroup.h
index da62ee2..97536e6 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -4,7 +4,6 @@
enum {
/* flags for mem_cgroup */
PCG_USED = 0x01, /* This page is charged to a memcg */
- PCG_MEM = 0x02, /* This page holds a memory charge */
};
struct pglist_data;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index baf3b53..3dfb56a 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2614,7 +2614,7 @@
* have the page locked
*/
pc->mem_cgroup = memcg;
- pc->flags = PCG_USED | PCG_MEM;
+ pc->flags = PCG_USED;
if (lrucare)
unlock_page_lru(page, isolated);
@@ -6156,8 +6156,6 @@
if (!PageCgroupUsed(pc))
return;
- VM_BUG_ON_PAGE(!(pc->flags & PCG_MEM), oldpage);
-
if (lrucare)
lock_page_lru(oldpage, &isolated);