mm/memcontrol.c: try harder to decrease [memory,memsw].limit_in_bytes

[linux-2.6-block.git] / mm / memcontrol.c

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3d7a3d02b16892a7531c5a087b73eddbacc1688e..0ae2dc3a17486de390201e7327c0ef75dd7c6639 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1176,20 +1176,6 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
        }
 }
 
-/*
- * This function returns the number of memcg under hierarchy tree. Returns
- * 1(self count) if no children.
- */
-static int mem_cgroup_count_children(struct mem_cgroup *memcg)
-{
-       int num = 0;
-       struct mem_cgroup *iter;
-
-       for_each_mem_cgroup_tree(iter, memcg)
-               num++;
-       return num;
-}
-
 /*
  * Return the memory (and swap, if configured) limit for a memcg.
  */
@@ -2463,24 +2449,11 @@ static DEFINE_MUTEX(memcg_limit_mutex);
 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
                                   unsigned long limit, bool memsw)
 {
-       unsigned long curusage;
-       unsigned long oldusage;
        bool enlarge = false;
-       int retry_count;
        int ret;
        bool limits_invariant;
        struct page_counter *counter = memsw ? &memcg->memsw : &memcg->memory;
 
-       /*
-        * For keeping hierarchical_reclaim simple, how long we should retry
-        * is depends on callers. We set our retry-count to be function
-        * of # of children which we should visit in this loop.
-        */
-       retry_count = MEM_CGROUP_RECLAIM_RETRIES *
-                     mem_cgroup_count_children(memcg);
-
-       oldusage = page_counter_read(counter);
-
        do {
                if (signal_pending(current)) {
                        ret = -EINTR;
@@ -2507,15 +2480,12 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
                if (!ret)
                        break;
 
-               try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, !memsw);
-
-               curusage = page_counter_read(counter);
-               /* Usage is reduced ? */
-               if (curusage >= oldusage)
-                       retry_count--;
-               else
-                       oldusage = curusage;
-       } while (retry_count);
+               if (!try_to_free_mem_cgroup_pages(memcg, 1,
+                                       GFP_KERNEL, !memsw)) {
+                       ret = -EBUSY;
+                       break;
+               }
+       } while (true);
 
        if (!ret && enlarge)
                memcg_oom_recover(memcg);