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 <[email protected]>
---
 include/linux/page_cgroup.h | 1 -
 mm/memcontrol.c             | 4 +---
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index da62ee2be28b..97536e685843 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 9bab35fc3e9e..1d66ac49e702 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2606,7 +2606,7 @@ 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);
@@ -6177,8 +6177,6 @@ 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);
 
-- 
2.1.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to