[patch] make sysctl_overcommit_memory enumeration sensible

[Coywolf Qi Hunt <qiyong@fc-cn.com>]

I see system admins often confused when they sysctl vm.overcommit_memory.
This patch makes overcommit_memory enumeration sensible.

0 - no overcommit
1 - always overcommit
2 - heuristic overcommit (default)

I don't feel this would break any userspace scripts. If it seems OK, I'll
update the documents.

Signed-off-by: Coywolf Qi Hunt <qiyong@fc-cn.com>
---
diff --git a/include/linux/mman.h b/include/linux/mman.h
index 18a5689..e50f5ad 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -10,9 +10,9 @@
 #define MREMAP_MAYMOVE	1
 #define MREMAP_FIXED	2
 
-#define OVERCOMMIT_GUESS		0
+#define OVERCOMMIT_NEVER		0
 #define OVERCOMMIT_ALWAYS		1
-#define OVERCOMMIT_NEVER		2
+#define OVERCOMMIT_GUESS		2
 extern int sysctl_overcommit_memory;
 extern int sysctl_overcommit_ratio;
 extern atomic_t vm_committed_space;

-- 
Coywolf Qi Hunt