Re: [PATCH net-next] bnxt_en: Add page_pool_destroy() during RX ring cleanup.

[Andy Gospodarek]

On Tue, Jul 09, 2019 at 03:50:07AM -0400, Michael Chan wrote:
> Add page_pool_destroy() in bnxt_free_rx_rings() during normal RX ring
> cleanup, as Ilias has informed us that the following commit has been
> merged:
> 
> 1da4bbeffe41 ("net: core: page_pool: add user refcnt and reintroduce 
> page_pool_destroy")
> 
> The special error handling code to call page_pool_free() can now be
> removed.  bnxt_free_rx_rings() will always be called during normal
> shutdown or any error paths.
> 
> Fixes: 322b87ca55f2 ("bnxt_en: add page_pool support")
> Cc: Ilias Apalodimas <ilias.apalodi...@linaro.org>
> Cc: Andy Gospodarek <go...@broadcom.com>
> Signed-off-by: Michael Chan <michael.c...@broadcom.com>
> ---
>  drivers/net/ethernet/broadcom/bnxt/bnxt.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c 
> b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> index e9d3bd8..2b5b0ab 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> @@ -2500,6 +2500,7 @@ static void bnxt_free_rx_rings(struct bnxt *bp)
>               if (xdp_rxq_info_is_reg(&rxr->xdp_rxq))
>                       xdp_rxq_info_unreg(&rxr->xdp_rxq);
>  
> +             page_pool_destroy(rxr->page_pool);
>               rxr->page_pool = NULL;
>  
>               kfree(rxr->rx_tpa);
> @@ -2560,19 +2561,14 @@ static int bnxt_alloc_rx_rings(struct bnxt *bp)
>                       return rc;
>  
>               rc = xdp_rxq_info_reg(&rxr->xdp_rxq, bp->dev, i);
> -             if (rc < 0) {
> -                     page_pool_free(rxr->page_pool);
> -                     rxr->page_pool = NULL;
> +             if (rc < 0)
>                       return rc;
> -             }
>  
>               rc = xdp_rxq_info_reg_mem_model(&rxr->xdp_rxq,
>                                               MEM_TYPE_PAGE_POOL,
>                                               rxr->page_pool);
>               if (rc) {
>                       xdp_rxq_info_unreg(&rxr->xdp_rxq);
> -                     page_pool_free(rxr->page_pool);
> -                     rxr->page_pool = NULL;

Rather than deleting these lines it would also be acceptable to do:

                if (rc) {
                        xdp_rxq_info_unreg(&rxr->xdp_rxq);
-                       page_pool_free(rxr->page_pool);
+                       page_pool_destroy(rxr->page_pool);
                        rxr->page_pool = NULL;
                        return rc;
                }

but anytime there is a failure to bnxt_alloc_rx_rings the driver will
immediately follow it up with a call to bnxt_free_rx_rings, so
page_pool_destroy will be called.

Thanks for pushing this out so quickly!

Acked-by: Andy Gospodarek <go...@broadcom.com>