>
> To get better performance, Rx bulk alloc recv function will scan 8 descs
> in one time, but the statuses are not consistent on ARM platform because
> the memory allocated for Rx descriptors is cacheable hugepages.
> This patch is to calculate the number of received packets by scan DD bit
> sequentially, and stops when meeting the first packet with DD bit unset.
>
> Signed-off-by: Jianbo Liu <jianbo....@linaro.org>
> ---
> drivers/net/ixgbe/ixgbe_rxtx.c | 16 +++++++++-------
> 1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
> index 36f1c02..613890e 100644
> --- a/drivers/net/ixgbe/ixgbe_rxtx.c
> +++ b/drivers/net/ixgbe/ixgbe_rxtx.c
> @@ -1460,17 +1460,19 @@ static inline int __attribute__((always_inline))
> for (i = 0; i < RTE_PMD_IXGBE_RX_MAX_BURST;
> i += LOOK_AHEAD, rxdp += LOOK_AHEAD, rxep += LOOK_AHEAD) {
> /* Read desc statuses backwards to avoid race condition */
> - for (j = LOOK_AHEAD-1; j >= 0; --j)
> + for (j = 0; j < LOOK_AHEAD; j++)
> s[j] = rte_le_to_cpu_32(rxdp[j].wb.upper.status_error);
>
> - for (j = LOOK_AHEAD - 1; j >= 0; --j)
> - pkt_info[j] = rte_le_to_cpu_32(rxdp[j].wb.lower.
> - lo_dword.data);
> + rte_smp_rmb();
>
> /* Compute how many status bits were set */
> - nb_dd = 0;
> - for (j = 0; j < LOOK_AHEAD; ++j)
> - nb_dd += s[j] & IXGBE_RXDADV_STAT_DD;
> + for (nb_dd = 0; nb_dd < LOOK_AHEAD &&
> + (s[nb_dd] & IXGBE_RXDADV_STAT_DD); nb_dd++)
> + ;
> +
> + for (j = 0; j < nb_dd; j++)
> + pkt_info[j] = rte_le_to_cpu_32(rxdp[j].wb.lower.
> + lo_dword.data);
>
> nb_rx += nb_dd;
>
> --
Acked-by: Konstantin Ananyev <konstantin.anan...@intel.com>
> 1.8.3.1
