On Thu, Nov 2, 2023 at 12:24 PM <chengming.zhou@xxxxxxxxx> wrote:
>
> From: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
>
> Now the partially empty slub will be frozen when taken out of node partial
> list, so the __slab_free() will know from "was_frozen" that the partially
> empty slab is not on node partial list and is a cpu or cpu partial slab
> of some cpu.
>
> But we will change this, make partial slabs leave the node partial list
> with unfrozen state, so we need to change __slab_free() to use the new
> slab_test_node_partial() we just introduced.
>
> Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
> Tested-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
> ---
> mm/slub.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index eed8ae0dbaf9..1880b483350e 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -3631,6 +3631,7 @@ static void __slab_free(struct kmem_cache *s, struct slab *slab,
> unsigned long counters;
> struct kmem_cache_node *n = NULL;
> unsigned long flags;
> + bool on_node_partial;
>
> stat(s, FREE_SLOWPATH);
>
> @@ -3678,6 +3679,7 @@ static void __slab_free(struct kmem_cache *s, struct slab *slab,
> */
> spin_lock_irqsave(&n->list_lock, flags);
>
> + on_node_partial = slab_test_node_partial(slab);
> }
> }
>
> @@ -3706,6 +3708,15 @@ static void __slab_free(struct kmem_cache *s, struct slab *slab,
> return;
> }
>
> + /*
> + * This slab was partially empty but not on the per-node partial list,
> + * in which case we shouldn't manipulate its list, just return.
> + */
> + if (prior && !on_node_partial) {
> + spin_unlock_irqrestore(&n->list_lock, flags);
> + return;
> + }
> +
> if (unlikely(!new.inuse && n->nr_partial >= s->min_partial))
> goto slab_empty;
>
Looks good to me,
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
> --
> 2.20.1
>
