Re: [dpdk-stable] [dpdk-dev] [PATCH] net/bnxt: fix fallback mbuf allocation logic

[Ajit Khaparde <ajitkhaparde@gmail.com>]

On Wed, Dec 16, 2020 at 7:06 AM Lance Richardson
<h.lance.richardson@gmail.com> wrote:
>
> From: Lance Richardson <lance.richardson@broadcom.com>
>
> Fixes for fallback mbuf allocation logic.
>    - Preserve raw (unmasked) producer index.
>    - Iterate over all processed descriptors (representor and
>      non-representor) when checking allocation status.
>    - Invoke fallback allocation logic when an allocation
>      failure has occurred for any received packet, not
>      just the last.
>
> Fixes: 6dc83230b43b ("net/bnxt: support port representor data path")
> Fixes: d9dd0b29ed31 ("net/bnxt: fix Rx handling and buffer allocation logic")
> Fixes: 8b8dc3f783ff ("net/bnxt: modify ring index logic")
> Cc: stable@dpdk.org
> Signed-off-by: Lance Richardson <lance.richardson@broadcom.com>

Updated the commit-id for one of the Fixes tag.

Patch applied to dpdk-next-net-brcm.

> ---
>  drivers/net/bnxt/bnxt_rxr.c | 28 +++++++++++++++++-----------
>  1 file changed, 17 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/net/bnxt/bnxt_rxr.c b/drivers/net/bnxt/bnxt_rxr.c
> index ffdeeecc3a..288b403bf0 100644
> --- a/drivers/net/bnxt/bnxt_rxr.c
> +++ b/drivers/net/bnxt/bnxt_rxr.c
> @@ -839,6 +839,7 @@ uint16_t bnxt_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
>         uint16_t rx_raw_prod = rxr->rx_raw_prod;
>         uint16_t ag_raw_prod = rxr->ag_raw_prod;
>         uint32_t raw_cons = cpr->cp_raw_cons;
> +       bool alloc_failed = false;
>         uint32_t cons;
>         int nb_rx_pkts = 0;
>         int nb_rep_rx_pkts = 0;
> @@ -885,12 +886,16 @@ uint16_t bnxt_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
>                 /* TODO: Avoid magic numbers... */
>                 if ((CMP_TYPE(rxcmp) & 0x30) == 0x10) {
>                         rc = bnxt_rx_pkt(&rx_pkts[nb_rx_pkts], rxq, &raw_cons);
> -                       if (likely(!rc) || rc == -ENOMEM)
> +                       if (!rc)
>                                 nb_rx_pkts++;
> -                       if (rc == -EBUSY)       /* partial completion */
> +                       else if (rc == -EBUSY)  /* partial completion */
>                                 break;
> -                       if (rc == -ENODEV)      /* completion for representor */
> +                       else if (rc == -ENODEV) /* completion for representor */
>                                 nb_rep_rx_pkts++;
> +                       else if (rc == -ENOMEM) {
> +                               nb_rx_pkts++;
> +                               alloc_failed = true;
> +                       }
>                 } else if (!BNXT_NUM_ASYNC_CPR(rxq->bp)) {
>                         evt =
>                         bnxt_event_hwrm_resp_handler(rxq->bp,
> @@ -929,23 +934,24 @@ uint16_t bnxt_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
>                 bnxt_db_write(&rxr->ag_db, rxr->ag_raw_prod);
>
>         /* Attempt to alloc Rx buf in case of a previous allocation failure. */
> -       if (rc == -ENOMEM) {
> -               int i = RING_NEXT(rx_raw_prod);
> -               int cnt = nb_rx_pkts;
> +       if (alloc_failed) {
> +               uint16_t cnt;
>
> -               for (; nb_rx_pkts; i = RING_NEXT(i), cnt--) {
> +               rx_raw_prod = RING_NEXT(rx_raw_prod);
> +               for (cnt = 0; cnt < nb_rx_pkts + nb_rep_rx_pkts; cnt++) {
>                         struct rte_mbuf **rx_buf;
> -                       uint16_t rx_raw_prod = RING_IDX(rxr->rx_ring_struct, i);
> +                       uint16_t ndx;
>
> -                       rx_buf = &rxr->rx_buf_ring[rx_raw_prod];
> +                       ndx = RING_IDX(rxr->rx_ring_struct, rx_raw_prod + cnt);
> +                       rx_buf = &rxr->rx_buf_ring[ndx];
>
>                         /* Buffer already allocated for this index. */
>                         if (*rx_buf != NULL && *rx_buf != &rxq->fake_mbuf)
>                                 continue;
>
>                         /* This slot is empty. Alloc buffer for Rx */
> -                       if (!bnxt_alloc_rx_data(rxq, rxr, i)) {
> -                               rxr->rx_raw_prod = i;
> +                       if (!bnxt_alloc_rx_data(rxq, rxr, rx_raw_prod + cnt)) {
> +                               rxr->rx_raw_prod = rx_raw_prod + cnt;
>                                 bnxt_db_write(&rxr->rx_db, rxr->rx_raw_prod);
>                         } else {
>                                 PMD_DRV_LOG(ERR, "Alloc  mbuf failed\n");
> --
> 2.25.1
>


-- 
Ajit Khaparde