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authorIngo Molnar <mingo@elte.hu>2006-07-03 03:25:28 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-07-03 18:27:09 -0400
commit2b2d5493e10051694ae3a57ea6a153e3cb4d4488 (patch)
treee44a89aa4d9c7c635770cb8891703f555d48b08d /mm
parent897c6ff9568bcb102ffc6b465ebe1def0cba829d (diff)
[PATCH] lockdep: annotate SLAB code
Teach special (recursive) locking code to the lock validator. Has no effect on non-lockdep kernels. Fix initialize-locks-via-memcpy assumptions. Effects on non-lockdep kernels: the subclass nesting parameter is passed into cache_free_alien() and __cache_free(), and turns one internal kmem_cache_free() call into an open-coded __cache_free() call. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/slab.c59
1 files changed, 48 insertions, 11 deletions
diff --git a/mm/slab.c b/mm/slab.c
index 3936af344542..85c2e03098a7 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1021,7 +1021,8 @@ static void drain_alien_cache(struct kmem_cache *cachep,
1021 } 1021 }
1022} 1022}
1023 1023
1024static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) 1024static inline int cache_free_alien(struct kmem_cache *cachep, void *objp,
1025 int nesting)
1025{ 1026{
1026 struct slab *slabp = virt_to_slab(objp); 1027 struct slab *slabp = virt_to_slab(objp);
1027 int nodeid = slabp->nodeid; 1028 int nodeid = slabp->nodeid;
@@ -1039,7 +1040,7 @@ static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1039 STATS_INC_NODEFREES(cachep); 1040 STATS_INC_NODEFREES(cachep);
1040 if (l3->alien && l3->alien[nodeid]) { 1041 if (l3->alien && l3->alien[nodeid]) {
1041 alien = l3->alien[nodeid]; 1042 alien = l3->alien[nodeid];
1042 spin_lock(&alien->lock); 1043 spin_lock_nested(&alien->lock, nesting);
1043 if (unlikely(alien->avail == alien->limit)) { 1044 if (unlikely(alien->avail == alien->limit)) {
1044 STATS_INC_ACOVERFLOW(cachep); 1045 STATS_INC_ACOVERFLOW(cachep);
1045 __drain_alien_cache(cachep, alien, nodeid); 1046 __drain_alien_cache(cachep, alien, nodeid);
@@ -1068,7 +1069,8 @@ static inline void free_alien_cache(struct array_cache **ac_ptr)
1068{ 1069{
1069} 1070}
1070 1071
1071static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) 1072static inline int cache_free_alien(struct kmem_cache *cachep, void *objp,
1073 int nesting)
1072{ 1074{
1073 return 0; 1075 return 0;
1074} 1076}
@@ -1272,6 +1274,11 @@ static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
1272 1274
1273 local_irq_disable(); 1275 local_irq_disable();
1274 memcpy(ptr, list, sizeof(struct kmem_list3)); 1276 memcpy(ptr, list, sizeof(struct kmem_list3));
1277 /*
1278 * Do not assume that spinlocks can be initialized via memcpy:
1279 */
1280 spin_lock_init(&ptr->list_lock);
1281
1275 MAKE_ALL_LISTS(cachep, ptr, nodeid); 1282 MAKE_ALL_LISTS(cachep, ptr, nodeid);
1276 cachep->nodelists[nodeid] = ptr; 1283 cachep->nodelists[nodeid] = ptr;
1277 local_irq_enable(); 1284 local_irq_enable();
@@ -1398,7 +1405,7 @@ void __init kmem_cache_init(void)
1398 } 1405 }
1399 /* 4) Replace the bootstrap head arrays */ 1406 /* 4) Replace the bootstrap head arrays */
1400 { 1407 {
1401 void *ptr; 1408 struct array_cache *ptr;
1402 1409
1403 ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); 1410 ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
1404 1411
@@ -1406,6 +1413,11 @@ void __init kmem_cache_init(void)
1406 BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache); 1413 BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
1407 memcpy(ptr, cpu_cache_get(&cache_cache), 1414 memcpy(ptr, cpu_cache_get(&cache_cache),
1408 sizeof(struct arraycache_init)); 1415 sizeof(struct arraycache_init));
1416 /*
1417 * Do not assume that spinlocks can be initialized via memcpy:
1418 */
1419 spin_lock_init(&ptr->lock);
1420
1409 cache_cache.array[smp_processor_id()] = ptr; 1421 cache_cache.array[smp_processor_id()] = ptr;
1410 local_irq_enable(); 1422 local_irq_enable();
1411 1423
@@ -1416,6 +1428,11 @@ void __init kmem_cache_init(void)
1416 != &initarray_generic.cache); 1428 != &initarray_generic.cache);
1417 memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep), 1429 memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
1418 sizeof(struct arraycache_init)); 1430 sizeof(struct arraycache_init));
1431 /*
1432 * Do not assume that spinlocks can be initialized via memcpy:
1433 */
1434 spin_lock_init(&ptr->lock);
1435
1419 malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] = 1436 malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
1420 ptr; 1437 ptr;
1421 local_irq_enable(); 1438 local_irq_enable();
@@ -1743,6 +1760,8 @@ static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
1743} 1760}
1744#endif 1761#endif
1745 1762
1763static void __cache_free(struct kmem_cache *cachep, void *objp, int nesting);
1764
1746/** 1765/**
1747 * slab_destroy - destroy and release all objects in a slab 1766 * slab_destroy - destroy and release all objects in a slab
1748 * @cachep: cache pointer being destroyed 1767 * @cachep: cache pointer being destroyed
@@ -1766,8 +1785,17 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
1766 call_rcu(&slab_rcu->head, kmem_rcu_free); 1785 call_rcu(&slab_rcu->head, kmem_rcu_free);
1767 } else { 1786 } else {
1768 kmem_freepages(cachep, addr); 1787 kmem_freepages(cachep, addr);
1769 if (OFF_SLAB(cachep)) 1788 if (OFF_SLAB(cachep)) {
1770 kmem_cache_free(cachep->slabp_cache, slabp); 1789 unsigned long flags;
1790
1791 /*
1792 * lockdep: we may nest inside an already held
1793 * ac->lock, so pass in a nesting flag:
1794 */
1795 local_irq_save(flags);
1796 __cache_free(cachep->slabp_cache, slabp, 1);
1797 local_irq_restore(flags);
1798 }
1771 } 1799 }
1772} 1800}
1773 1801
@@ -3072,7 +3100,16 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
3072 if (slabp->inuse == 0) { 3100 if (slabp->inuse == 0) {
3073 if (l3->free_objects > l3->free_limit) { 3101 if (l3->free_objects > l3->free_limit) {
3074 l3->free_objects -= cachep->num; 3102 l3->free_objects -= cachep->num;
3103 /*
3104 * It is safe to drop the lock. The slab is
3105 * no longer linked to the cache. cachep
3106 * cannot disappear - we are using it and
3107 * all destruction of caches must be
3108 * serialized properly by the user.
3109 */
3110 spin_unlock(&l3->list_lock);
3075 slab_destroy(cachep, slabp); 3111 slab_destroy(cachep, slabp);
3112 spin_lock(&l3->list_lock);
3076 } else { 3113 } else {
3077 list_add(&slabp->list, &l3->slabs_free); 3114 list_add(&slabp->list, &l3->slabs_free);
3078 } 3115 }
@@ -3098,7 +3135,7 @@ static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
3098#endif 3135#endif
3099 check_irq_off(); 3136 check_irq_off();
3100 l3 = cachep->nodelists[node]; 3137 l3 = cachep->nodelists[node];
3101 spin_lock(&l3->list_lock); 3138 spin_lock_nested(&l3->list_lock, SINGLE_DEPTH_NESTING);
3102 if (l3->shared) { 3139 if (l3->shared) {
3103 struct array_cache *shared_array = l3->shared; 3140 struct array_cache *shared_array = l3->shared;
3104 int max = shared_array->limit - shared_array->avail; 3141 int max = shared_array->limit - shared_array->avail;
@@ -3141,14 +3178,14 @@ free_done:
3141 * Release an obj back to its cache. If the obj has a constructed state, it must 3178 * Release an obj back to its cache. If the obj has a constructed state, it must
3142 * be in this state _before_ it is released. Called with disabled ints. 3179 * be in this state _before_ it is released. Called with disabled ints.
3143 */ 3180 */
3144static inline void __cache_free(struct kmem_cache *cachep, void *objp) 3181static void __cache_free(struct kmem_cache *cachep, void *objp, int nesting)
3145{ 3182{
3146 struct array_cache *ac = cpu_cache_get(cachep); 3183 struct array_cache *ac = cpu_cache_get(cachep);
3147 3184
3148 check_irq_off(); 3185 check_irq_off();
3149 objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); 3186 objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));
3150 3187
3151 if (cache_free_alien(cachep, objp)) 3188 if (cache_free_alien(cachep, objp, nesting))
3152 return; 3189 return;
3153 3190
3154 if (likely(ac->avail < ac->limit)) { 3191 if (likely(ac->avail < ac->limit)) {
@@ -3387,7 +3424,7 @@ void kmem_cache_free(struct kmem_cache *cachep, void *objp)
3387 BUG_ON(virt_to_cache(objp) != cachep); 3424 BUG_ON(virt_to_cache(objp) != cachep);
3388 3425
3389 local_irq_save(flags); 3426 local_irq_save(flags);
3390 __cache_free(cachep, objp); 3427 __cache_free(cachep, objp, 0);
3391 local_irq_restore(flags); 3428 local_irq_restore(flags);
3392} 3429}
3393EXPORT_SYMBOL(kmem_cache_free); 3430EXPORT_SYMBOL(kmem_cache_free);
@@ -3412,7 +3449,7 @@ void kfree(const void *objp)
3412 kfree_debugcheck(objp); 3449 kfree_debugcheck(objp);
3413 c = virt_to_cache(objp); 3450 c = virt_to_cache(objp);
3414 debug_check_no_locks_freed(objp, obj_size(c)); 3451 debug_check_no_locks_freed(objp, obj_size(c));
3415 __cache_free(c, (void *)objp); 3452 __cache_free(c, (void *)objp, 0);
3416 local_irq_restore(flags); 3453 local_irq_restore(flags);
3417} 3454}
3418EXPORT_SYMBOL(kfree); 3455EXPORT_SYMBOL(kfree);