memcg: memory swap controller: fix limit check

There are scatterd calls of res_counter_check_under_limit(), and most of
them don't take mem+swap accounting into account.

define mem_cgroup_check_under_limit() and avoid direct use of
res_counter_check_limit().

Reported-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
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 b837900..6ad309e 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -571,6 +571,18 @@ done:
        return ret;
 }
 
+static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
+{
+       if (do_swap_account) {
+               if (res_counter_check_under_limit(&mem->res) &&
+                       res_counter_check_under_limit(&mem->memsw))
+                       return true;
+       } else
+               if (res_counter_check_under_limit(&mem->res))
+                       return true;
+       return false;
+}
+
 /*
  * Dance down the hierarchy if needed to reclaim memory. We remember the
  * last child we reclaimed from, so that we don't end up penalizing
@@ -592,7 +604,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
         * have left.
         */
        ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap);
-       if (res_counter_check_under_limit(&root_mem->res))
+       if (mem_cgroup_check_under_limit(root_mem))
                return 0;
 
        next_mem = mem_cgroup_get_first_node(root_mem);
@@ -606,7 +618,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
                        continue;
                }
                ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap);
-               if (res_counter_check_under_limit(&root_mem->res))
+               if (mem_cgroup_check_under_limit(root_mem))
                        return 0;
                cgroup_lock();
                next_mem = mem_cgroup_get_next_node(next_mem, root_mem);
@@ -709,12 +721,8 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
                 * current usage of the cgroup before giving up
                 *
                 */
-               if (do_swap_account) {
-                       if (res_counter_check_under_limit(&mem_over_limit->res) &&
-                           res_counter_check_under_limit(&mem_over_limit->memsw))
-                               continue;
-               } else if (res_counter_check_under_limit(&mem_over_limit->res))
-                               continue;
+               if (mem_cgroup_check_under_limit(mem_over_limit))
+                       continue;
 
                if (!nr_retries--) {
                        if (oom) {
@@ -1334,7 +1342,7 @@ int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
 
        do {
                progress = try_to_free_mem_cgroup_pages(mem, gfp_mask, true);
-               progress += res_counter_check_under_limit(&mem->res);
+               progress += mem_cgroup_check_under_limit(mem);
        } while (!progress && --retry);
 
        css_put(&mem->css);