mm: oom_kill: simplify OOM killer locking

[cascardo/linux.git] / mm / memcontrol.c

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 20a7e87..8da44a0 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1530,6 +1530,8 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
        unsigned int points = 0;
        struct task_struct *chosen = NULL;
 
+       mutex_lock(&oom_lock);
+
        /*
         * If current has a pending SIGKILL or is exiting, then automatically
         * select it.  The goal is to allow it to allocate so that it may
@@ -1537,7 +1539,7 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
         */
        if (fatal_signal_pending(current) || task_will_free_mem(current)) {
                mark_oom_victim(current);
-               return;
+               goto unlock;
        }
 
        check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL, memcg);
@@ -1564,7 +1566,7 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
                                mem_cgroup_iter_break(memcg, iter);
                                if (chosen)
                                        put_task_struct(chosen);
-                               return;
+                               goto unlock;
                        case OOM_SCAN_OK:
                                break;
                        };
@@ -1585,11 +1587,13 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
                css_task_iter_end(&it);
        }
 
-       if (!chosen)
-               return;
-       points = chosen_points * 1000 / totalpages;
-       oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg,
-                        NULL, "Memory cgroup out of memory");
+       if (chosen) {
+               points = chosen_points * 1000 / totalpages;
+               oom_kill_process(chosen, gfp_mask, order, points, totalpages,
+                                memcg, NULL, "Memory cgroup out of memory");
+       }
+unlock:
+       mutex_unlock(&oom_lock);
 }
 
 #if MAX_NUMNODES > 1