netdev - Re: [PATCH] page_pool: mark unbound node page as reusable pages

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Date:   Thu, 5 Dec 2019 08:55:20 +0800
From:   Yunsheng Lin <linyunsheng@...wei.com>
To:     Li RongQing <lirongqing@...du.com>, <netdev@...r.kernel.org>,
        <saeedm@...lanox.com>
Subject: Re: [PATCH] page_pool: mark unbound node page as reusable pages

On 2019/12/4 18:14, Li RongQing wrote:
> some drivers uses page pool, but not require to allocate
> page from bound node, so pool.p.nid is NUMA_NO_NODE, and
> this fixed patch will block this kind of driver to
> recycle
> 
> Fixes: d5394610b1ba ("page_pool: Don't recycle non-reusable pages")
> Signed-off-by: Li RongQing <lirongqing@...du.com>
> Cc: Saeed Mahameed <saeedm@...lanox.com>
> ---
>  net/core/page_pool.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> index a6aefe989043..4054db683178 100644
> --- a/net/core/page_pool.c
> +++ b/net/core/page_pool.c
> @@ -317,7 +317,9 @@ static bool __page_pool_recycle_direct(struct page *page,
>   */
>  static bool pool_page_reusable(struct page_pool *pool, struct page *page)
>  {
> -	return !page_is_pfmemalloc(page) && page_to_nid(page) == pool->p.nid;
> +	return !page_is_pfmemalloc(page) &&
> +		(page_to_nid(page) == pool->p.nid ||
> +		 pool->p.nid == NUMA_NO_NODE);

If I understand it correctly, you are allowing recycling when
pool->p.nid is NUMA_NO_NODE, which does not seems match the commit
log: "this fixed patch will block this kind of driver to recycle".

Maybe you mean "commit d5394610b1ba" by this fixed patch?

Also, maybe it is better to allow recycling if the below condition
is matched:

	pool->p.nid == NUMA_NO_NODE && page_to_nid(page) == numa_mem_id()

>  }
>  
>  void __page_pool_put_page(struct page_pool *pool, struct page *page,
>