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author | Glauber Costa <glommer@parallels.com> | 2012-12-18 14:22:46 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-18 15:02:14 -0800 |
commit | b9ce5ef49f00daf2254c6953c8d31f79aabccd34 (patch) | |
tree | 1da6afdbb3dc2e2d31f588dbfbf502e984af48a6 | |
parent | 0e9d92f2d02d8c8320f0502307c688d07bdac2b3 (diff) | |
download | linux-b9ce5ef49f00daf2254c6953c8d31f79aabccd34.tar.gz linux-b9ce5ef49f00daf2254c6953c8d31f79aabccd34.tar.bz2 linux-b9ce5ef49f00daf2254c6953c8d31f79aabccd34.zip |
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 <glommer@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | include/linux/memcontrol.h | 5 | ||||
-rw-r--r-- | mm/slab.c | 6 | ||||
-rw-r--r-- | mm/slab.h | 39 | ||||
-rw-r--r-- | mm/slob.c | 2 | ||||
-rw-r--r-- | mm/slub.c | 15 |
5 files changed, 53 insertions, 14 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index bd9b5d73bc2b..2298122e71ad 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -554,6 +554,11 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp) return __memcg_kmem_get_cache(cachep, gfp); } #else +static inline bool memcg_kmem_enabled(void) +{ + return false; +} + static inline bool memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg, int order) { diff --git a/mm/slab.c b/mm/slab.c index c26ab9fbe1f5..bab6fec765a7 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -87,7 +87,6 @@ */ #include <linux/slab.h> -#include "slab.h" #include <linux/mm.h> #include <linux/poison.h> #include <linux/swap.h> @@ -128,6 +127,8 @@ #include "internal.h" +#include "slab.h" + /* * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON. * 0 for faster, smaller code (especially in the critical paths). @@ -3883,6 +3884,9 @@ EXPORT_SYMBOL(__kmalloc); void kmem_cache_free(struct kmem_cache *cachep, void *objp) { unsigned long flags; + cachep = cache_from_obj(cachep, objp); + if (!cachep) + return; local_irq_save(flags); debug_check_no_locks_freed(objp, cachep->object_size); diff --git a/mm/slab.h b/mm/slab.h index abe582d20c79..c95e922b166d 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -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 diff --git a/mm/slob.c b/mm/slob.c index 795bab7d391d..a99fdf7a0907 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -58,7 +58,6 @@ #include <linux/kernel.h> #include <linux/slab.h> -#include "slab.h" #include <linux/mm.h> #include <linux/swap.h> /* struct reclaim_state */ @@ -73,6 +72,7 @@ #include <linux/atomic.h> +#include "slab.h" /* * slob_block has a field 'units', which indicates size of block if +ve, * or offset of next block if -ve (in SLOB_UNITs). diff --git a/mm/slub.c b/mm/slub.c index 985332b38852..6d5f2305d7a4 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2611,19 +2611,10 @@ redo: void kmem_cache_free(struct kmem_cache *s, void *x) { - struct page *page; - - page = virt_to_head_page(x); - - if (kmem_cache_debug(s) && page->slab_cache != s) { - pr_err("kmem_cache_free: Wrong slab cache. %s but object" - " is from %s\n", page->slab_cache->name, s->name); - WARN_ON_ONCE(1); + s = cache_from_obj(s, x); + if (!s) return; - } - - slab_free(s, page, x, _RET_IP_); - + slab_free(s, virt_to_head_page(x), x, _RET_IP_); trace_kmem_cache_free(_RET_IP_, x); } EXPORT_SYMBOL(kmem_cache_free); |