On Thu, Jan 05, 2023 at 09:46:14PM +0000, Matthew Wilcox (Oracle) wrote:
> Removes the call to compound_head() hidden in put_page() which
> saves 169 bytes of kernel text as __page_pool_put_page() is
> inlined twice.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> net/core/page_pool.c | 29 +++++++++++++++++++----------
> 1 file changed, 19 insertions(+), 10 deletions(-)
>
> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> index b606952773a6..8f3f7cc5a2d5 100644
> --- a/net/core/page_pool.c
> +++ b/net/core/page_pool.c
> @@ -558,8 +558,8 @@ static bool page_pool_recycle_in_cache(struct page *page,
> * If the page refcnt != 1, then the page will be returned to memory
> * subsystem.
> */
> -static __always_inline struct page *
> -__page_pool_put_page(struct page_pool *pool, struct page *page,
> +static __always_inline struct netmem *
> +__page_pool_put_netmem(struct page_pool *pool, struct netmem *nmem,
> unsigned int dma_sync_size, bool allow_direct)
> {
> /* This allocator is optimized for the XDP mode that uses
> @@ -571,19 +571,20 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
> * page is NOT reusable when allocated when system is under
> * some pressure. (page_is_pfmemalloc)
> */
> - if (likely(page_ref_count(page) == 1 && !page_is_pfmemalloc(page))) {
> - /* Read barrier done in page_ref_count / READ_ONCE */
> + if (likely(netmem_ref_count(nmem) == 1 &&
> + !netmem_is_pfmemalloc(nmem))) {
> + /* Read barrier done in netmem_ref_count / READ_ONCE */
>
> if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
> - page_pool_dma_sync_for_device(pool, page,
> + page_pool_dma_sync_for_device(pool, netmem_page(nmem),
> dma_sync_size);
>
> if (allow_direct && in_serving_softirq() &&
> - page_pool_recycle_in_cache(page, pool))
> + page_pool_recycle_in_cache(netmem_page(nmem), pool))
> return NULL;
>
> /* Page found as candidate for recycling */
> - return page;
> + return nmem;
> }
> /* Fallback/non-XDP mode: API user have elevated refcnt.
> *
> @@ -599,13 +600,21 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
> * will be invoking put_page.
> */
> recycle_stat_inc(pool, released_refcnt);
> - /* Do not replace this with page_pool_return_page() */
> - page_pool_release_page(pool, page);
> - put_page(page);
> + /* Do not replace this with page_pool_return_netmem() */
> + page_pool_release_netmem(pool, nmem);
> + netmem_put(nmem);
>
> return NULL;
> }
>
> +static __always_inline struct page *
> +__page_pool_put_page(struct page_pool *pool, struct page *page,
> + unsigned int dma_sync_size, bool allow_direct)
> +{
> + return netmem_page(__page_pool_put_netmem(pool, page_netmem(page),
> + dma_sync_size, allow_direct));
> +}
> +
> void page_pool_put_defragged_page(struct page_pool *pool, struct page *page,
> unsigned int dma_sync_size, bool allow_direct)
> {
> --
> 2.35.1
>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@xxxxxxxxxx>
