linux-kernel - Re: [PATCH net-next v1 2/2] selftests: pp-bench: remove page_pool_put

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Message-ID: <3bd1e6ef-cf3d-4ace-85e8-7f98cf92cc1f@kernel.org>
Date: Tue, 1 Jul 2025 17:49:14 +0200
From: Jesper Dangaard Brouer <hawk@...nel.org>
To: Mina Almasry <almasrymina@...gle.com>, netdev@...r.kernel.org,
 linux-kselftest@...r.kernel.org, linux-kernel@...r.kernel.org
Cc: "David S. Miller" <davem@...emloft.net>,
 Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>,
 Paolo Abeni <pabeni@...hat.com>, Simon Horman <horms@...nel.org>,
 Shuah Khan <shuah@...nel.org>, Toke Høiland-Jørgensen
 <toke@...hat.com>, Ilias Apalodimas <ilias.apalodimas@...aro.org>,
 kernel test robot <lkp@...el.com>
Subject: Re: [PATCH net-next v1 2/2] selftests: pp-bench: remove
 page_pool_put_page wrapper

On 27/06/2025 22.04, Mina Almasry wrote:
> Minor cleanup: remove the pointless looking _ wrapper around
> page_pool_put_page, and just do the call directly.
> 
> Signed-off-by: Mina Almasry <almasrymina@...gle.com>
> ---
>   .../net/bench/page_pool/bench_page_pool_simple.c     | 12 +++---------
>   1 file changed, 3 insertions(+), 9 deletions(-)
> 
> diff --git a/tools/testing/selftests/net/bench/page_pool/bench_page_pool_simple.c b/tools/testing/selftests/net/bench/page_pool/bench_page_pool_simple.c
> index 1cd3157fb6a9..cb6468adbda4 100644
> --- a/tools/testing/selftests/net/bench/page_pool/bench_page_pool_simple.c
> +++ b/tools/testing/selftests/net/bench/page_pool/bench_page_pool_simple.c
> @@ -16,12 +16,6 @@
>   static int verbose = 1;
>   #define MY_POOL_SIZE 1024
>   
> -static void _page_pool_put_page(struct page_pool *pool, struct page *page,
> -				bool allow_direct)
> -{
> -	page_pool_put_page(pool, page, -1, allow_direct);
> -}
> -
>   /* Makes tests selectable. Useful for perf-record to analyze a single test.
>    * Hint: Bash shells support writing binary number like: $((2#101010)
>    *
> @@ -121,7 +115,7 @@ static void pp_fill_ptr_ring(struct page_pool *pp, int elems)
>   	for (i = 0; i < elems; i++)
>   		array[i] = page_pool_alloc_pages(pp, gfp_mask);
>   	for (i = 0; i < elems; i++)
> -		_page_pool_put_page(pp, array[i], false);
> +		page_pool_put_page(pp, array[i], -1, false);
>   
>   	kfree(array);
>   }
> @@ -180,14 +174,14 @@ static int time_bench_page_pool(struct time_bench_record *rec, void *data,
>   
>   		} else if (type == type_ptr_ring) {
>   			/* Normal return path */
> -			_page_pool_put_page(pp, page, false);
> +			page_pool_put_page(pp, page, -1, false);
>   
>   		} else if (type == type_page_allocator) {
>   			/* Test if not pages are recycled, but instead
>   			 * returned back into systems page allocator
>   			 */
>   			get_page(page); /* cause no-recycling */
> -			_page_pool_put_page(pp, page, false);
> +			page_pool_put_page(pp, page, -1, false);
>   			put_page(page);

The get_page() + put_page() trick is a fairly ugly workaround that I
added when Jakub removed page_pool_release_page() in commit 535b9c61bdef
("net: page_pool: hide page_pool_release_page()").

These extra refcnt increments will make the test slower, but if we are
just aware of this, then we can still compare incremental changes.

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

>   		} else {
>   			BUILD_BUG();