On Tue, Feb 16, 2021 at 4:13 PM Yang Shi <shy828301@xxxxxxxxx> wrote:
>
> Using kvfree_rcu() to free the old shrinker_maps instead of call_rcu().
> We don't have to define a dedicated callback for call_rcu() anymore.
>
> Signed-off-by: Yang Shi <shy828301@xxxxxxxxx>
> ---
> mm/vmscan.c | 7 +------
> 1 file changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 2e753c2516fa..c2a309acd86b 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -192,11 +192,6 @@ static inline int shrinker_map_size(int nr_items)
> return (DIV_ROUND_UP(nr_items, BITS_PER_LONG) * sizeof(unsigned long));
> }
>
> -static void free_shrinker_map_rcu(struct rcu_head *head)
> -{
> - kvfree(container_of(head, struct memcg_shrinker_map, rcu));
> -}
> -
> static int expand_one_shrinker_map(struct mem_cgroup *memcg,
> int size, int old_size)
> {
> @@ -219,7 +214,7 @@ static int expand_one_shrinker_map(struct mem_cgroup *memcg,
> memset((void *)new->map + old_size, 0, size - old_size);
>
> rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, new);
> - call_rcu(&old->rcu, free_shrinker_map_rcu);
> + kvfree_rcu(old);
Please use kvfree_rcu(old, rcu) instead of kvfree_rcu(old). The single
param can call synchronize_rcu().
