mm: memcg: move swapin charge functions above callsites
Johannes Weiner [Tue, 31 Jul 2012 23:45:36 +0000 (16:45 -0700)]
Charging cache pages may require swapin in the shmem case.  Save the
forward declaration and just move the swapin functions above the cache
charging functions.

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>

mm/memcontrol.c

index 29bc440..3be1afa 100644 (file)
@@ -2796,37 +2796,6 @@ int mem_cgroup_newpage_charge(struct page *page,
                                        MEM_CGROUP_CHARGE_TYPE_ANON);
 }
 
-static void
-__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
-                                       enum charge_type ctype);
-
-int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
-                               gfp_t gfp_mask)
-{
-       struct mem_cgroup *memcg = NULL;
-       enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
-       int ret;
-
-       if (mem_cgroup_disabled())
-               return 0;
-       if (PageCompound(page))
-               return 0;
-
-       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);
-       else { /* page is swapcache/shmem */
-               ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg);
-               if (!ret)
-                       __mem_cgroup_commit_charge_swapin(page, memcg, type);
-       }
-       return ret;
-}
-
 /*
  * While swap-in, try_charge -> commit or cancel, the page is locked.
  * And when try_charge() successfully returns, one refcnt to memcg without
@@ -2873,6 +2842,15 @@ charge_cur_mm:
        return ret;
 }
 
+void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
+{
+       if (mem_cgroup_disabled())
+               return;
+       if (!memcg)
+               return;
+       __mem_cgroup_cancel_charge(memcg, 1);
+}
+
 static void
 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
                                        enum charge_type ctype)
@@ -2910,13 +2888,31 @@ void mem_cgroup_commit_charge_swapin(struct page *page,
                                          MEM_CGROUP_CHARGE_TYPE_ANON);
 }
 
-void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
+int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
+                               gfp_t gfp_mask)
 {
+       struct mem_cgroup *memcg = NULL;
+       enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
+       int ret;
+
        if (mem_cgroup_disabled())
-               return;
-       if (!memcg)
-               return;
-       __mem_cgroup_cancel_charge(memcg, 1);
+               return 0;
+       if (PageCompound(page))
+               return 0;
+
+       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);
+       else { /* page is swapcache/shmem */
+               ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg);
+               if (!ret)
+                       __mem_cgroup_commit_charge_swapin(page, memcg, type);
+       }
+       return ret;
 }
 
 static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg,