From: Alok Kataria Date: Wed, 14 Sep 2005 19:17:53 +0000 (-0700) Subject: [PATCH] Fix slab BUG_ON() triggered by change in array cache size X-Git-Tag: v2.6.14-rc2~34 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c7e43c78ae4d8630c418ce3495787b995e61a580;p=linux-2.6 [PATCH] Fix slab BUG_ON() triggered by change in array cache size With the new changes that we made in the initialization of the slab allocator, we first setup the cache from which array caches are allocated, and then the cache, from which kmem_list3's are allocated. Now if the array cache comes from a cache in which objsize > 32, (in this instance size-64) then, first size-64 cache will be allocated and then the size-128 (if this is the cache from which kmem_list3's are going to be allocated). So with these new changes, we are not guaranteed that we will be initializing the malloc_sizes array in a serialized order. Thus there is a bug in __find_general_cachep, as we are checking whether the first cache_sizes ptr is NULL. This is replaced by checking whether the array-cache cache is initialized. Attached is a patch which does that. Boots fine on a x86-64, with DEBUG_SPIN, DEBUG_SLAB, and preempt. Attached is a patch which does that. Boots fine on a x86-64, with DEBUG_SPIN, DEBUG_SLAB, and preempt.Thanks & Regards, Alok Signed-off-by: Alok N Kataria Signed-off-by: Shobhit Dayal Cc: Manfred Spraul Cc: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/slab.c b/mm/slab.c index 9e876d6dfa..437d338805 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -659,7 +659,7 @@ static inline kmem_cache_t *__find_general_cachep(size_t size, * kmem_cache_create(), or __kmalloc(), before * the generic caches are initialized. */ - BUG_ON(csizep->cs_cachep == NULL); + BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL); #endif while (size > csizep->cs_size) csizep++;