On Mon, Jun 15, 2020 at 2:23 PM Joonsoo Kim <js1304@xxxxxxxxx> wrote:
>
> 2020년 6월 14일 (일) 오후 9:39, Muchun Song <songmuchun@xxxxxxxxxxxxx>님이 작성:
> >
> > The function of __kmem_cache_shutdown() is that release all resources
> > used by the slab cache, while currently it stop release resources when
> > the preceding node is not empty.
> >
> > Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> > ---
> > mm/slub.c | 7 ++++---
> > 1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/mm/slub.c b/mm/slub.c
> > index b73505df3de2..4e477ef0f2b9 100644
> > --- a/mm/slub.c
> > +++ b/mm/slub.c
> > @@ -3839,6 +3839,7 @@ bool __kmem_cache_empty(struct kmem_cache *s)
> > */
> > int __kmem_cache_shutdown(struct kmem_cache *s)
> > {
> > + int ret = 0;
> > int node;
> > struct kmem_cache_node *n;
> >
> > @@ -3846,11 +3847,11 @@ int __kmem_cache_shutdown(struct kmem_cache *s)
> > /* Attempt to free all objects */
> > for_each_kmem_cache_node(s, node, n) {
> > free_partial(s, n);
> > - if (node_nr_slabs(n))
> > - return 1;
> > + if (!ret && node_nr_slabs(n))
> > + ret = 1;
> > }
>
> I don't think that this is an improvement.
>
> If the shutdown condition isn't met, we don't need to process further.
> Just 'return 1' looks okay to me.
>
> And, with this change, sysfs_slab_remove() is called even if the
> shutdown is failed.
> It's better not to have side effects when failing.
If someone calls __kmem_cache_shutdown, he may want to release
resources used by the slab cache as much as possible. If we continue,
we may release more pages. From this point, is it an improvement?
--
Yours,
Muchun
