diff options
| author | Arjan van de Ven | 2006-07-13 14:46:03 +0200 |
|---|---|---|
| committer | Linus Torvalds | 2006-07-13 12:02:44 -0700 |
| commit | f1aaee53f2877a7afa55e8245c241ff60a86367d (patch) | |
| tree | 38ce12147987355d78be1c568941a01266262234 /mm/slab.c | |
| parent | 873623dfabaa6ebbdc1ce16c1766a3c0ec5d9923 (diff) | |
[PATCH] lockdep: annotate mm/slab.c
mm/slab.c uses nested locking when dealing with 'off-slab'
caches, in that case it allocates the slab header from the
(on-slab) kmalloc caches. Teach the lock validator about
this by putting all on-slab caches into a separate class.
this patch has no effect on non-lockdep kernels.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/slab.c')
| -rw-r--r-- | mm/slab.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/mm/slab.c b/mm/slab.c index fd1e4c4c1397..5a57cda7490d 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -674,6 +674,37 @@ static struct kmem_cache cache_cache = { #endif }; +#ifdef CONFIG_LOCKDEP + +/* + * Slab sometimes uses the kmalloc slabs to store the slab headers + * for other slabs "off slab". + * The locking for this is tricky in that it nests within the locks + * of all other slabs in a few places; to deal with this special + * locking we put on-slab caches into a separate lock-class. + */ +static struct lock_class_key on_slab_key; + +static inline void init_lock_keys(struct cache_sizes *s) +{ + int q; + + for (q = 0; q < MAX_NUMNODES; q++) { + if (!s->cs_cachep->nodelists[q] || OFF_SLAB(s->cs_cachep)) + continue; + lockdep_set_class(&s->cs_cachep->nodelists[q]->list_lock, + &on_slab_key); + } +} + +#else +static inline void init_lock_keys(struct cache_sizes *s) +{ +} +#endif + + + /* Guard access to the cache-chain. */ static DEFINE_MUTEX(cache_chain_mutex); static struct list_head cache_chain; @@ -1391,6 +1422,7 @@ void __init kmem_cache_init(void) ARCH_KMALLOC_FLAGS|SLAB_PANIC, NULL, NULL); } + init_lock_keys(sizes); sizes->cs_dmacachep = kmem_cache_create(names->name_dma, sizes->cs_size, |