On Tue, Aug 09, 2016 at 06:45:39PM +0300, Vladimir Davydov wrote:
> On Tue, Aug 09, 2016 at 04:27:46PM +0100, Chris Wilson wrote:
> ...
> > diff --git a/mm/slub.c b/mm/slub.c
> > index 825ff45..58f0eb6 100644
> > --- a/mm/slub.c
> > +++ b/mm/slub.c
> > @@ -3479,6 +3479,7 @@ static void list_slab_objects(struct kmem_cache *s,
> > struct page *page,
> > */
> > static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
> > {
> > + LIST_HEAD(partial_list);
>
> nit: slabs added to this list are not partially used - they are free, so
> let's call it 'free_slabs' or 'discard_list' or just 'discard', please
Ok.
> > struct page *page, *h;
> >
> > BUG_ON(irqs_disabled());
> > @@ -3486,13 +3487,16 @@ static void free_partial(struct kmem_cache *s,
> > struct kmem_cache_node *n)
> > list_for_each_entry_safe(page, h, &n->partial, lru) {
> > if (!page->inuse) {
> > remove_partial(n, page);
> > - discard_slab(s, page);
> > + list_add(&page->lru, &partial_list);
>
> If there are objects left in the cache on destruction, the cache won't
> be destroyed. Instead it will be left on the slab_list and can get
> reused later. So we should use list_move() here to always leave
> n->partial in a consistent state, even in case of a leak.
Since remove_partial() does an unconditional list_del(),
I presume you want to perform the list_move() even if we hit the error
path, right?
i.e.
list_for_each_entry_safe(page, h, &n->partial, lru) {
if (!page->inuse) {
remove_partial(n, page);
- list_add(&page->lru, &partial_list);
} else {
list_slab_objects(s, page,
"Objects remaining in %s on __kmem_cache_shutdown()");
}
+ list_move(&page->lru, &discard);
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
