slub: Use kmem_cache flags to detect if slab is in debugging mode.
The cacheline with the flags is reachable from the hot paths after the
percpu allocator changes went in. So there is no need anymore to put a
flag into each slab page. Get rid of the SlubDebug flag and use
the flags in kmem_cache instead.
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
diff --git a/mm/slub.c b/mm/slub.c
index b89a7c9..9cf5dae 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -107,11 +107,17 @@
* the fast path and disables lockless freelists.
*/
+#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
+ SLAB_TRACE | SLAB_DEBUG_FREE)
+
+static inline int kmem_cache_debug(struct kmem_cache *s)
+{
#ifdef CONFIG_SLUB_DEBUG
-#define SLABDEBUG 1
+ return unlikely(s->flags & SLAB_DEBUG_FLAGS);
#else
-#define SLABDEBUG 0
+ return 0;
#endif
+}
/*
* Issues still to be resolved:
@@ -1157,9 +1163,6 @@
inc_slabs_node(s, page_to_nid(page), page->objects);
page->slab = s;
page->flags |= 1 << PG_slab;
- if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON |
- SLAB_STORE_USER | SLAB_TRACE))
- __SetPageSlubDebug(page);
start = page_address(page);
@@ -1186,14 +1189,13 @@
int order = compound_order(page);
int pages = 1 << order;
- if (unlikely(SLABDEBUG && PageSlubDebug(page))) {
+ if (kmem_cache_debug(s)) {
void *p;
slab_pad_check(s, page);
for_each_object(p, s, page_address(page),
page->objects)
check_object(s, page, p, 0);
- __ClearPageSlubDebug(page);
}
kmemcheck_free_shadow(page, compound_order(page));
@@ -1415,8 +1417,7 @@
stat(s, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
} else {
stat(s, DEACTIVATE_FULL);
- if (SLABDEBUG && PageSlubDebug(page) &&
- (s->flags & SLAB_STORE_USER))
+ if (kmem_cache_debug(s) && (s->flags & SLAB_STORE_USER))
add_full(n, page);
}
slab_unlock(page);
@@ -1624,7 +1625,7 @@
object = c->page->freelist;
if (unlikely(!object))
goto another_slab;
- if (unlikely(SLABDEBUG && PageSlubDebug(c->page)))
+ if (kmem_cache_debug(s))
goto debug;
c->freelist = get_freepointer(s, object);
@@ -1783,7 +1784,7 @@
stat(s, FREE_SLOWPATH);
slab_lock(page);
- if (unlikely(SLABDEBUG && PageSlubDebug(page)))
+ if (kmem_cache_debug(s))
goto debug;
checks_ok:
@@ -3398,16 +3399,6 @@
} else
printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n",
s->name, page);
-
- if (s->flags & DEBUG_DEFAULT_FLAGS) {
- if (!PageSlubDebug(page))
- printk(KERN_ERR "SLUB %s: SlubDebug not set "
- "on slab 0x%p\n", s->name, page);
- } else {
- if (PageSlubDebug(page))
- printk(KERN_ERR "SLUB %s: SlubDebug set on "
- "slab 0x%p\n", s->name, page);
- }
}
static int validate_slab_node(struct kmem_cache *s,