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>

1 files changed, 17 insertions, 9 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b83790083087..6ad309e9825f 100644
--- 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);