> On Jan 17, 2017, at 10:33 AM, Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> wrote: > > On Mon, Jan 16, 2017 at 04:04:59PM +0900, Kyunghwan Kwon wrote: >> The first kmem_cache created at booting up is supposed neither mergeable >> nor destroyable but was possible to destroy. So prevent it. >> >> Signed-off-by: Kyunghwan Kwon <kwon@xxxxxxxxxxxx> >> --- >> mm/slab_common.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/mm/slab_common.c b/mm/slab_common.c >> index 1dfc209..2d30ace 100644 >> --- a/mm/slab_common.c >> +++ b/mm/slab_common.c >> @@ -744,7 +744,7 @@ void kmem_cache_destroy(struct kmem_cache *s) >> bool need_rcu_barrier = false; >> int err; >> >> - if (unlikely(!s)) >> + if (unlikely(!s) || s->refcount == -1) >> return; > > Hello, Kyunghwan. > > Few lines below, s->refcount is checked. > > if (s->refcount) > goto unlock; > > Am I missing something? > > Thanks. Hello, Joonsoo. In case it is called the number of int size times. refcount would finally reach to 0 since decreased every time the function called. When refcount is -1, the count will not change in the patch so no lock would be need to be taken prior, I believe. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href