sl[au]b: always get the cache from its page in kmem_cache_free()

struct page already has this information.  If we start chaining caches,
this information will always be more trustworthy than whatever is passed
into the function.

Signed-off-by: Glauber Costa <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Greg Thelen <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: JoonSoo Kim <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Suleiman Souhlal <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Glauber Costa 2012-12-18 14:22:46 -08:00 • committed by Linus Torvalds
commit b9ce5ef49f
5 changed files with 53 additions and 14 deletions

View file

@ -116,6 +116,13 @@ static inline bool cache_match_memcg(struct kmem_cache *cachep,
return (is_root_cache(cachep) && !memcg) ||
(cachep->memcg_params->memcg == memcg);
}
static inline bool slab_equal_or_root(struct kmem_cache *s,
struct kmem_cache *p)
{
return (p == s) ||
(s->memcg_params && (p == s->memcg_params->root_cache));
}
#else
static inline bool is_root_cache(struct kmem_cache *s)
{
@ -127,5 +134,37 @@ static inline bool cache_match_memcg(struct kmem_cache *cachep,
{
return true;
}
static inline bool slab_equal_or_root(struct kmem_cache *s,
struct kmem_cache *p)
{
return true;
}
#endif
static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
{
struct kmem_cache *cachep;
struct page *page;
/*
* When kmemcg is not being used, both assignments should return the
* same value. but we don't want to pay the assignment price in that
* case. If it is not compiled in, the compiler should be smart enough
* to not do even the assignment. In that case, slab_equal_or_root
* will also be a constant.
*/
if (!memcg_kmem_enabled() && !unlikely(s->flags & SLAB_DEBUG_FREE))
return s;
page = virt_to_head_page(x);
cachep = page->slab_cache;
if (slab_equal_or_root(cachep, s))
return cachep;
pr_err("%s: Wrong slab cache. %s but object is from %s\n",
__FUNCTION__, cachep->name, s->name);
WARN_ON_ONCE(1);
return s;
}
#endif