Re: 答复: [PATCH][v2] page_pool: handle page recycle for NUMA_NO_NODE condition

[Ilias Apalodimas <ilias.apalodimas@linaro.org>]

Hi, 

On Tue, Dec 10, 2019 at 09:39:14AM +0000, Li,Rongqing wrote:
> > 
> > static int mvneta_create_page_pool(struct mvneta_port *pp,
> > 				   struct mvneta_rx_queue *rxq, int size) {
> > 	struct bpf_prog *xdp_prog = READ_ONCE(pp->xdp_prog);
> > 	struct page_pool_params pp_params = {
> > 		.order = 0,
> > 		.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
> > 		.pool_size = size,
> > 		.nid = cpu_to_node(0),
> 
> This kind of device should only be installed to vendor's platform which did not support numa
> 
> But as you say , Saeed advice maybe cause that recycle always fail, if nid is configured like upper, and different from running NAPI node id
> 
> And maybe we can catch this case by the below
> 
> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> index 3c8b51ccd1c1..973235c09487 100644
> --- a/net/core/page_pool.c
> +++ b/net/core/page_pool.c
> @@ -328,6 +328,11 @@ static bool pool_page_reusable(struct page_pool *pool, struct page *page)
>  void __page_pool_put_page(struct page_pool *pool, struct page *page,
>                           unsigned int dma_sync_size, bool allow_direct)
>  {
> +       allow_direct = allow_direct && in_serving_softirq();
> +
> +       if (allow_direct)
> +               WARN_ON_ONCE((pool->p.nid != NUMA_NO_NODE) &&
> +                                    (pool->p.nid != numa_mem_id()));

Isn't this a duplicate of what Saeed proposed?
Instead of marking the page as recyclable we just throw a warning here.

>         /* This allocator is optimized for the XDP mode that uses
>          * one-frame-per-page, but have fallbacks that act like the
>          * regular page allocator APIs.
> @@ -342,7 +347,7 @@ void __page_pool_put_page(struct page_pool *pool, struct page *page,
>                         page_pool_dma_sync_for_device(pool, page,
>                                                       dma_sync_size);
>  

Thanks
/Ilias