3.7-stable review patch. If anyone has any objections, please let me know.
------------------ From: CAI Qian <[email protected]> This is for stable-3.7.y only and this problem has already been solved in mainline through some slab/slub re-work which isn't suitable to backport here. See create_kmalloc_cache() in mm/slab_common.c there. commit cce89f4f6911286500cf7be0363f46c9b0a12ce0('Move kmem_cache refcounting to common code') moves some refcount manipulation code to common code. Unfortunately, it also removed refcount assignment for kmalloc_caches. So, kmalloc_caches's refcount is initially 0. This makes erroneous situation. Paul Hargrove report that when he create a 8-byte kmem_cache and destory it, he encounter below message. 'Objects remaining in kmalloc-8 on kmem_cache_close()' 8-byte kmem_cache merge with 8-byte kmalloc cache and refcount is increased by one. So, resulting refcount is 1. When destroy it, it hit refcount = 0, then kmem_cache_close() is executed and error message is printed. This patch assign initial refcount 1 to kmalloc_caches, so fix this erroneous situation. Reported-by: Paul Hargrove <[email protected]> Cc: Christoph Lameter <[email protected]> Signed-off-by: Joonsoo Kim <[email protected]> Signed-off-by: CAI Qian <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- mm/slub.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/slub.c +++ b/mm/slub.c @@ -3279,6 +3279,7 @@ static struct kmem_cache *__init create_ if (kmem_cache_open(s, flags)) goto panic; + s->refcount = 1; list_add(&s->list, &slab_caches); return s; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
