Messages in this thread | | | Date | Wed, 26 Dec 2012 00:30:15 +0900 | Subject | Re: [PATCH] slub: assign refcount for kmalloc_caches | From | JoonSoo Kim <> |
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2012/12/26 Joonsoo Kim <js1304@gmail.com>: > 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 errornous 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 destory 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 > errornous situtation. > > Cc: <stable@vger.kernel.org> # v3.7 > Cc: Christoph Lameter <cl@linux.com> > Reported-by: Paul Hargrove <phhargrove@lbl.gov> > Signed-off-by: Joonsoo Kim <js1304@gmail.com> > > diff --git a/mm/slub.c b/mm/slub.c > index a0d6984..321afab 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -3279,6 +3279,7 @@ static struct kmem_cache *__init create_kmalloc_cache(const char *name, > if (kmem_cache_open(s, flags)) > goto panic; > > + s->refcount = 1; > list_add(&s->list, &slab_caches); > return s; > > -- > 1.7.9.5 >
I missed some explanation. In v3.8-rc1, this problem is already solved. See create_kmalloc_cache() in mm/slab_common.c. So this patch is just for v3.7 stable.
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