diff options
| author | Nick Piggin <npiggin@suse.de> | 2006-09-25 23:30:55 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-26 08:48:44 -0700 |
| commit | 725d704ecaca4a43f067092c140d4f3271cf2856 (patch) | |
| tree | 320cf8ab5457ac6c01c05da8c30d6026538ee259 /include/linux | |
| parent | a6ca1b99ed434f3fb41bbed647ed36c0420501e5 (diff) | |
[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>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/mm.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 224178a000d..7d20b25c58f 100644 --- 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); } |