oom: move constraints to enum

The OOM killer's CONSTRAINT definitions are really more appropriate in an
enum, so define them in include/linux/oom.h.

Cc: Andrea Arcangeli <andrea@suse.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/oom.h

@@ -11,6 +11,15 @@
 
 #ifdef __KERNEL__
 
+/*
+ * Types of limitations to the nodes from which allocations may occur
+ */
+enum oom_constraint {
+	CONSTRAINT_NONE,
+	CONSTRAINT_CPUSET,
+	CONSTRAINT_MEMORY_POLICY,
+};
+
 extern void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order);
 extern int register_oom_notifier(struct notifier_block *nb);
 extern int unregister_oom_notifier(struct notifier_block *nb);

mm/oom_kill.c

@@ -163,17 +163,11 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
 	return points;
 }
 
-/*
- * Types of limitations to the nodes from which allocations may occur
- */
-#define CONSTRAINT_NONE 1
-#define CONSTRAINT_MEMORY_POLICY 2
-#define CONSTRAINT_CPUSET 3
-
 /*
  * Determine the type of allocation constraint.
  */
-static inline int constrained_alloc(struct zonelist *zonelist, gfp_t gfp_mask)
+static inline enum oom_constraint constrained_alloc(struct zonelist *zonelist,
+						    gfp_t gfp_mask)
 {
 #ifdef CONFIG_NUMA
 	struct zone **z;
@@ -393,7 +387,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
 	struct task_struct *p;
 	unsigned long points = 0;
 	unsigned long freed = 0;
-	int constraint;
+	enum oom_constraint constraint;
 
 	blocking_notifier_call_chain(&oom_notify_list, 0, &freed);
 	if (freed > 0)