Re: [dpdk-stable] [PATCH v2 1/2] net/mlx5: fix num seg assumption on vPMD

["Nélio Laranjeiro" <nelio.laranjeiro@6wind.com>]

On Wed, Aug 30, 2017 at 10:07:07AM +0300, Shahaf Shuler wrote:
> vPMD Tx function assumes that after the scatter of the
> multi-segment packets the next packet will be a single segment packet.
> 
> This is not current as the function can return due to lack of resources
> without sending all of the multi-segment mbufs sequence.
> 
> Fixes: 6cb559d67b83 ("net/mlx5: add vectorized Rx/Tx burst for x86")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
> Acked-by: Yongseok Koh <yskoh@mellanox.com>
> ---
> This patch should be applied only after the series:
> http://dpdk.org/dev/patchwork/patch/27367/
> 
> on v2:
>  - different approach to fix the issue.
> ---
>  drivers/net/mlx5/mlx5_rxtx_vec_sse.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_rxtx_vec_sse.c b/drivers/net/mlx5/mlx5_rxtx_vec_sse.c
> index 37854a73b..f89762ff8 100644
> --- a/drivers/net/mlx5/mlx5_rxtx_vec_sse.c
> +++ b/drivers/net/mlx5/mlx5_rxtx_vec_sse.c
> @@ -112,8 +112,7 @@ txq_wr_dseg_v(struct txq *txq, __m128i *dseg,
>  }
>  
>  /**
> - * Count the number of continuous single segment packets. The first packet must
> - * be a single segment packet.
> + * Count the number of continuous single segment packets.
>   *
>   * @param pkts
>   *   Pointer to array of packets.
> @@ -130,9 +129,8 @@ txq_check_multiseg(struct rte_mbuf **pkts, uint16_t pkts_n)
>  
>  	if (!pkts_n)
>  		return 0;
> -	assert(NB_SEGS(pkts[0]) == 1);
>  	/* Count the number of continuous single segment packets. */
> -	for (pos = 1; pos < pkts_n; ++pos)
> +	for (pos = 0; pos < pkts_n; ++pos)
>  		if (NB_SEGS(pkts[pos]) > 1)
>  			break;
>  	return pos;
> -- 
> 2.12.0
 
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>

-- 
Nélio Laranjeiro
6WIND