mm: memcg: remove mem_cgroup_move_account_page_stat()

It used to disable preemption and run sanity checks but now it's only
taking a number out of one percpu counter and putting it into another.
Do this directly in the callsite and save the indirection.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6e0f781..b992823 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3744,16 +3744,6 @@ void mem_cgroup_split_huge_fixup(struct page *head)
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
-static void mem_cgroup_move_account_page_stat(struct mem_cgroup *from,
-                                             struct mem_cgroup *to,
-                                             unsigned int nr_pages,
-                                             enum mem_cgroup_stat_index idx)
-{
-       /* Update stat data for mem_cgroup */
-       __this_cpu_sub(from->stat->count[idx], nr_pages);
-       __this_cpu_add(to->stat->count[idx], nr_pages);
-}
-
 /**
  * mem_cgroup_move_account - move account of the page
  * @page: the page
@@ -3799,13 +3789,19 @@ static int mem_cgroup_move_account(struct page *page,
 
        move_lock_mem_cgroup(from, &flags);
 
-       if (!anon && page_mapped(page))
-               mem_cgroup_move_account_page_stat(from, to, nr_pages,
-                       MEM_CGROUP_STAT_FILE_MAPPED);
+       if (!anon && page_mapped(page)) {
+               __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
+                              nr_pages);
+               __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
+                              nr_pages);
+       }
 
-       if (PageWriteback(page))
-               mem_cgroup_move_account_page_stat(from, to, nr_pages,
-                       MEM_CGROUP_STAT_WRITEBACK);
+       if (PageWriteback(page)) {
+               __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_WRITEBACK],
+                              nr_pages);
+               __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_WRITEBACK],
+                              nr_pages);
+       }
 
        mem_cgroup_charge_statistics(from, page, anon, -nr_pages);