mm: memcontrol: remove unnecessary PCG_MEM memory charge flag

PCG_MEM is a remnant from an earlier version of 0a31bc97c8 ("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>
This commit is contained in:
Johannes Weiner 2014-12-10 15:44:00 -08:00 committed by Linus Torvalds
parent 18eca2e636
commit f4aaa8b43d
2 changed files with 1 additions and 4 deletions

View file

@ -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;

View file

@ -2614,7 +2614,7 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg,
* 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 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
if (!PageCgroupUsed(pc))
return;
VM_BUG_ON_PAGE(!(pc->flags & PCG_MEM), oldpage);
if (lrucare)
lock_page_lru(oldpage, &isolated);