[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>
diff --git a/mm/swap.c b/mm/swap.c
index 687686a..600235e 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -233,7 +233,7 @@
struct zone *zone = page_zone(page);
spin_lock_irqsave(&zone->lru_lock, flags);
- BUG_ON(!PageLRU(page));
+ VM_BUG_ON(!PageLRU(page));
__ClearPageLRU(page);
del_page_from_lru(zone, page);
spin_unlock_irqrestore(&zone->lru_lock, flags);
@@ -284,7 +284,7 @@
zone = pagezone;
spin_lock_irq(&zone->lru_lock);
}
- BUG_ON(!PageLRU(page));
+ VM_BUG_ON(!PageLRU(page));
__ClearPageLRU(page);
del_page_from_lru(zone, page);
}
@@ -337,7 +337,7 @@
for (i = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];
- BUG_ON(PageLRU(page));
+ VM_BUG_ON(PageLRU(page));
if (put_page_testzero(page))
pagevec_add(&pages_to_free, page);
}
@@ -364,7 +364,7 @@
zone = pagezone;
spin_lock_irq(&zone->lru_lock);
}
- BUG_ON(PageLRU(page));
+ VM_BUG_ON(PageLRU(page));
SetPageLRU(page);
add_page_to_inactive_list(zone, page);
}
@@ -391,9 +391,9 @@
zone = pagezone;
spin_lock_irq(&zone->lru_lock);
}
- BUG_ON(PageLRU(page));
+ VM_BUG_ON(PageLRU(page));
SetPageLRU(page);
- BUG_ON(PageActive(page));
+ VM_BUG_ON(PageActive(page));
SetPageActive(page);
add_page_to_active_list(zone, page);
}