Re: [PATCH net-next v2 1/2] page_pool: use relaxed atomic for release side accounting

[Jesper Dangaard Brouer]

On 20/08/2021 08.56, Yunsheng Lin wrote:
> There is no need to synchronize the account updating, so
> use the relaxed atomic to avoid some memory barrier in the
> data path.
>
> Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>

LGTM

Acked-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>

> ---
>   net/core/page_pool.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> index e140905..1a69784 100644
> --- a/net/core/page_pool.c
> +++ b/net/core/page_pool.c
> @@ -370,7 +370,7 @@ void page_pool_release_page(struct page_pool *pool, struct page *page)
>   	/* This may be the last page returned, releasing the pool, so
>   	 * it is not safe to reference pool afterwards.
>   	 */
> -	count = atomic_inc_return(&pool->pages_state_release_cnt);
> +	count = atomic_inc_return_relaxed(&pool->pages_state_release_cnt);
>   	trace_page_pool_state_release(pool, page, count);
>   }
>   EXPORT_SYMBOL(page_pool_release_page);