Re: [PATCH net v1 1/2] page_pool: expose max page pool ring size

[Jesper Dangaard Brouer <hawk@kernel.org>]

On 05/11/2025 21.07, Mina Almasry wrote:
> Expose this as a constant so we can reuse it in drivers.
> 
> Signed-off-by: Mina Almasry <almasrymina@google.com>
> ---
>   include/net/page_pool/types.h | 2 ++
>   net/core/page_pool.c          | 2 +-
>   2 files changed, 3 insertions(+), 1 deletion(-)


Looks good to me

Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>

> diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
> index 1509a536cb85..5edba3122b10 100644
> --- a/include/net/page_pool/types.h
> +++ b/include/net/page_pool/types.h
> @@ -58,6 +58,8 @@ struct pp_alloc_cache {
>   	netmem_ref cache[PP_ALLOC_CACHE_SIZE];
>   };
>   
> +#define PAGE_POOL_MAX_RING_SIZE 16384
> +

IIRC this was recently reduced to 16384 (from 32K), do you have a
use-case for higher limits?

>   /**
>    * struct page_pool_params - page pool parameters
>    * @fast:	params accessed frequently on hotpath
> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> index 1a5edec485f1..7b2808da294f 100644
> --- a/net/core/page_pool.c
> +++ b/net/core/page_pool.c
> @@ -211,7 +211,7 @@ static int page_pool_init(struct page_pool *pool,
>   		return -EINVAL;
>   
>   	if (pool->p.pool_size)
> -		ring_qsize = min(pool->p.pool_size, 16384);
> +		ring_qsize = min(pool->p.pool_size, PAGE_POOL_MAX_RING_SIZE);
>   
>   	/* DMA direction is either DMA_FROM_DEVICE or DMA_BIDIRECTIONAL.
>   	 * DMA_BIDIRECTIONAL is for allowing page used for DMA sending,
> 
> base-commit: 327c20c21d80e0d87834b392d83ae73c955ad8ff