[PATCH] mm: VM_BUG_ON

Introduce a VM_BUG_ON, which is turned on with CONFIG_DEBUG_VM.  Use this
in the lightweight, inline refcounting functions; PageLRU and PageActive
checks in vmscan, because they're pretty well confined to vmscan.  And in
page allocate/free fastpaths which can be the hottest parts of the kernel
for kbuilds.

Unlike BUG_ON, VM_BUG_ON must not be used to execute statements with
side-effects, and should not be used outside core mm code.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/internal.h b/mm/internal.h
index d20e3cc4aef0..d527b80b292f 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -24,8 +24,8 @@ static inline void set_page_count(struct page *page, int v)
  */
 static inline void set_page_refcounted(struct page *page)
 {
-        BUG_ON(PageCompound(page) && page_private(page) != (unsigned long)page);
-        BUG_ON(atomic_read(&page->_count));
+        VM_BUG_ON(PageCompound(page) && page_private(page) != (unsigned long)page);
+        VM_BUG_ON(atomic_read(&page->_count));
         set_page_count(page, 1);
 }