include/linux/mmdebug.h: add VM_WARN_ON() and VM_WARN_ON_ONCE()

WARN_ON() and WARN_ON_ONCE(), dependent on CONFIG_DEBUG_VM

Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h
index 2d57efa..a3499d7 100644
--- a/include/linux/mmdebug.h
+++ b/include/linux/mmdebug.h
@@ -11,9 +11,13 @@
 #define VM_BUG_ON(cond) BUG_ON(cond)
 #define VM_BUG_ON_PAGE(cond, page) \
 	do { if (unlikely(cond)) { dump_page(page, NULL); BUG(); } } while (0)
+#define VM_WARN_ON(cond) WARN_ON(cond)
+#define VM_WARN_ON_ONCE(cond) WARN_ON_ONCE(cond)
 #else
 #define VM_BUG_ON(cond) BUILD_BUG_ON_INVALID(cond)
 #define VM_BUG_ON_PAGE(cond, page) VM_BUG_ON(cond)
+#define VM_WARN_ON(cond) BUILD_BUG_ON_INVALID(cond)
+#define VM_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond)
 #endif
 
 #ifdef CONFIG_DEBUG_VIRTUAL