mm: memcg: remove unneeded shmem charge type

shmem page charges have not needed a separate charge type to tell them
from regular file pages since 08e552c ("memcg: synchronized LRU").

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Wanpeng Li <liwp.linux@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
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 3be1afa..17a79e5 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -379,7 +379,6 @@ static bool move_file(void)
 enum charge_type {
        MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
        MEM_CGROUP_CHARGE_TYPE_ANON,
-       MEM_CGROUP_CHARGE_TYPE_SHMEM,   /* used by page migration of shmem */
        MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
        MEM_CGROUP_CHARGE_TYPE_DROP,    /* a page was unused swap cache */
        NR_CHARGE_TYPE,
@@ -2902,8 +2901,6 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
 
        if (unlikely(!mm))
                mm = &init_mm;
-       if (!page_is_file_cache(page))
-               type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
 
        if (!PageSwapCache(page))
                ret = mem_cgroup_charge_common(page, mm, gfp_mask, type);
@@ -3310,10 +3307,8 @@ void mem_cgroup_prepare_migration(struct page *page, struct page *newpage,
         */
        if (PageAnon(page))
                ctype = MEM_CGROUP_CHARGE_TYPE_ANON;
-       else if (page_is_file_cache(page))
-               ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
        else
-               ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
+               ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
        /*
         * The page is committed to the memcg, but it's not actually
         * charged to the res_counter since we plan on replacing the
@@ -3407,10 +3402,6 @@ void mem_cgroup_replace_page_cache(struct page *oldpage,
         */
        if (!memcg)
                return;
-
-       if (PageSwapBacked(oldpage))
-               type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
-
        /*
         * Even if newpage->mapping was NULL before starting replacement,
         * the newpage may be on LRU(or pagevec for LRU) already. We lock