1 files changed, 34 insertions, 23 deletions

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 3291e82d4352..5340f6b91312 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -258,8 +258,6 @@ enum oom_scan_t oom_scan_process_thread(struct task_struct *task,
 		unsigned long totalpages, const nodemask_t *nodemask,
 		bool force_kill)
 {
-	if (task->exit_state)
-		return OOM_SCAN_CONTINUE;
 	if (oom_unkillable_task(task, NULL, nodemask))
 		return OOM_SCAN_CONTINUE;
 
@@ -406,6 +404,23 @@ static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
 		dump_tasks(memcg, nodemask);
 }
 
+/*
+ * Number of OOM killer invocations (including memcg OOM killer).
+ * Primarily used by PM freezer to check for potential races with
+ * OOM killed frozen task.
+ */
+static atomic_t oom_kills = ATOMIC_INIT(0);
+
+int oom_kills_count(void)
+{
+	return atomic_read(&oom_kills);
+}
+
+void note_oom_kill(void)
+{
+	atomic_inc(&oom_kills);
+}
+
 #define K(x) ((x) << (PAGE_SHIFT-10))
 /*
  * Must be called while holding a reference to p, which will be released upon
@@ -559,28 +574,25 @@ EXPORT_SYMBOL_GPL(unregister_oom_notifier);
  * if a parallel OOM killing is already taking place that includes a zone in
  * the zonelist.  Otherwise, locks all zones in the zonelist and returns 1.
  */
-int try_set_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_mask)
+bool oom_zonelist_trylock(struct zonelist *zonelist, gfp_t gfp_mask)
 {
 	struct zoneref *z;
 	struct zone *zone;
-	int ret = 1;
+	bool ret = true;
 
 	spin_lock(&zone_scan_lock);
-	for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask)) {
-		if (zone_is_oom_locked(zone)) {
-			ret = 0;
+	for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask))
+		if (test_bit(ZONE_OOM_LOCKED, &zone->flags)) {
+			ret = false;
 			goto out;
 		}
-	}
 
-	for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask)) {
-		/*
-		 * Lock each zone in the zonelist under zone_scan_lock so a
-		 * parallel invocation of try_set_zonelist_oom() doesn't succeed
-		 * when it shouldn't.
-		 */
-		zone_set_flag(zone, ZONE_OOM_LOCKED);
-	}
+	/*
+	 * Lock each zone in the zonelist under zone_scan_lock so a parallel
+	 * call to oom_zonelist_trylock() doesn't succeed when it shouldn't.
+	 */
+	for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask))
+		set_bit(ZONE_OOM_LOCKED, &zone->flags);
 
 out:
 	spin_unlock(&zone_scan_lock);
@@ -592,15 +604,14 @@ out:
  * allocation attempts with zonelists containing them may now recall the OOM
  * killer, if necessary.
  */
-void clear_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_mask)
+void oom_zonelist_unlock(struct zonelist *zonelist, gfp_t gfp_mask)
 {
 	struct zoneref *z;
 	struct zone *zone;
 
 	spin_lock(&zone_scan_lock);
-	for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask)) {
-		zone_clear_flag(zone, ZONE_OOM_LOCKED);
-	}
+	for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask))
+		clear_bit(ZONE_OOM_LOCKED, &zone->flags);
 	spin_unlock(&zone_scan_lock);
 }
 
@@ -694,9 +705,9 @@ void pagefault_out_of_memory(void)
 	if (mem_cgroup_oom_synchronize(true))
 		return;
 
-	zonelist = node_zonelist(first_online_node, GFP_KERNEL);
-	if (try_set_zonelist_oom(zonelist, GFP_KERNEL)) {
+	zonelist = node_zonelist(first_memory_node, GFP_KERNEL);
+	if (oom_zonelist_trylock(zonelist, GFP_KERNEL)) {
 		out_of_memory(NULL, 0, 0, NULL, false);
-		clear_zonelist_oom(zonelist, GFP_KERNEL);
+		oom_zonelist_unlock(zonelist, GFP_KERNEL);
 	}
 }