Messages in this thread Patch in this message | | | Date | Thu, 13 Jul 2006 14:46:03 +0200 | From | Ingo Molnar <> | Subject | [patch] lockdep: annotate mm/slab.c |
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Subject: lockdep: annotate mm/slab.c From: Arjan van de Ven <arjan@infradead.org>
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> --- mm/slab.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
Index: linux/mm/slab.c =================================================================== --- linux.orig/mm/slab.c +++ linux/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, - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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