Re: [PATCH v7 net-next 1/4] net: add generic percpu page_pool allocator

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

On 02/02/2024 09.12, Lorenzo Bianconi wrote:
> Introduce generic percpu page_pools allocator.
> Moreover add page_pool_create_percpu() and cpuid filed in page_pool struct
> in order to recycle the page in the page_pool "hot" cache if
> napi_pp_put_page() is running on the same cpu.
> This is a preliminary patch to add xdp multi-buff support for xdp running
> in generic mode.
> 
> Signed-off-by: Lorenzo Bianconi<lorenzo@kernel.org>
> ---
>   include/net/page_pool/types.h |  3 +++
>   net/core/dev.c                | 45 +++++++++++++++++++++++++++++++++++
>   net/core/page_pool.c          | 23 ++++++++++++++----
>   net/core/skbuff.c             |  5 ++--
>   4 files changed, 70 insertions(+), 6 deletions(-)
> 
> diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
> index 76481c465375..3828396ae60c 100644
> --- a/include/net/page_pool/types.h
> +++ b/include/net/page_pool/types.h
> @@ -128,6 +128,7 @@ struct page_pool_stats {
>   struct page_pool {
>   	struct page_pool_params_fast p;
>   
> +	int cpuid;
>   	bool has_init_callback;
>   
>   	long frag_users;
> @@ -203,6 +204,8 @@ struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp);
>   struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int *offset,
>   				  unsigned int size, gfp_t gfp);
>   struct page_pool *page_pool_create(const struct page_pool_params *params);
> +struct page_pool *page_pool_create_percpu(const struct page_pool_params *params,
> +					  int cpuid);
>   
>   struct xdp_mem_info;
>   
> diff --git a/net/core/dev.c b/net/core/dev.c
> index b53b9c94de40..5a100360389f 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -153,6 +153,8 @@
>   #include <linux/prandom.h>
>   #include <linux/once_lite.h>
>   #include <net/netdev_rx_queue.h>
> +#include <net/page_pool/types.h>
> +#include <net/page_pool/helpers.h>
>   
>   #include "dev.h"
>   #include "net-sysfs.h"
> @@ -450,6 +452,12 @@ static RAW_NOTIFIER_HEAD(netdev_chain);
>   DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
>   EXPORT_PER_CPU_SYMBOL(softnet_data);
>   
> +/* Page_pool has a lockless array/stack to alloc/recycle pages.
> + * PP consumers must pay attention to run APIs in the appropriate context
> + * (e.g. NAPI context).
> + */
> +static DEFINE_PER_CPU_ALIGNED(struct page_pool *, system_page_pool);

Thanks for adding comment.

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