On Tue, 19 Jun 2018, Shakeel Butt wrote:
> diff --git a/mm/slub.c b/mm/slub.c
> index a3b8467c14af..731c02b371ae 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -3673,9 +3673,23 @@ static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
>
> bool __kmem_cache_empty(struct kmem_cache *s)
> {
> - int node;
> + int cpu, node;
Nit: wouldn't cpu be unused if CONFIG_SLUB_DEBUG is disabled?
> struct kmem_cache_node *n;
>
> + /*
> + * slabs_node will always be 0 for !CONFIG_SLUB_DEBUG. So, manually
> + * check slabs for all cpus.
> + */
> + if (!IS_ENABLED(CONFIG_SLUB_DEBUG)) {
> + for_each_online_cpu(cpu) {
> + struct kmem_cache_cpu *c;
> +
> + c = per_cpu_ptr(s->cpu_slab, cpu);
> + if (c->page || slub_percpu_partial(c))
> + return false;
> + }
> + }
> +
> for_each_kmem_cache_node(s, node, n)
> if (n->nr_partial || slabs_node(s, node))
> return false;
Wouldn't it just be better to allow {inc,dec}_slabs_node() to adjust the
nr_slabs counter instead of doing the per-cpu iteration on every shutdown?
