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slub: Use kmem_cache flags to detect if slab is in debugging mode.

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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>
This commit is contained in:
Christoph Lameter 2010-07-09 14:07:14 -05:00 committed by Pekka Enberg
parent f5b801ac38
commit af537b0a6c
2 changed files with 12 additions and 23 deletions
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2
include/linux/page-flags.h
View File

@ -128,7 +128,6 @@ enum pageflags {
/* SLUB */
PG_slub_frozen = PG_active,
PG_slub_debug = PG_error,
};
#ifndef __GENERATING_BOUNDS_H
@ -215,7 +214,6 @@ PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked)
__PAGEFLAG(SlobFree, slob_free)
__PAGEFLAG(SlubFrozen, slub_frozen)
__PAGEFLAG(SlubDebug, slub_debug)
/*
* Private page markings that may be used by the filesystem that owns the page

33
mm/slub.c
View File

@ -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 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
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 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
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 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
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 @@ load_freelist:
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 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
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 @@ static void validate_slab_slab(struct kmem_cache *s, struct page *page,
} 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,