[PATCH] mm: VM_BUG_ON

[linux-2.6-block.git] / include / linux / mm.h

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 224178a000d2e1930c13b5db60642de3d0bd4ff6..7d20b25c58fcb055f1644759af6552dd394f3636 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -278,6 +278,12 @@ struct page {
  */
 #include <linux/page-flags.h>
 
+#ifdef CONFIG_DEBUG_VM
+#define VM_BUG_ON(cond) BUG_ON(cond)
+#else
+#define VM_BUG_ON(condition) do { } while(0)
+#endif
+
 /*
  * Methods to modify the page usage count.
  *
@@ -297,7 +303,7 @@ struct page {
  */
 static inline int put_page_testzero(struct page *page)
 {
-       BUG_ON(atomic_read(&page->_count) == 0);
+       VM_BUG_ON(atomic_read(&page->_count) == 0);
        return atomic_dec_and_test(&page->_count);
 }
 
@@ -307,6 +313,7 @@ static inline int put_page_testzero(struct page *page)
  */
 static inline int get_page_unless_zero(struct page *page)
 {
+       VM_BUG_ON(PageCompound(page));
        return atomic_inc_not_zero(&page->_count);
 }
 
@@ -323,6 +330,7 @@ static inline void get_page(struct page *page)
 {
        if (unlikely(PageCompound(page)))
                page = (struct page *)page_private(page);
+       VM_BUG_ON(atomic_read(&page->_count) == 0);
        atomic_inc(&page->_count);
 }