[dpdk-dev] [PATCH] [new]ixgbe:set txep.mbuf to NULL when calling ixgbe_tx_free_bufs

[Lu, Wenzhuo]

Hi Peng,

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of hepeng
> Sent: Saturday, August 1, 2015 9:27 AM
> To: dev at dpdk.org
> Subject: [dpdk-dev] [PATCH] [new]ixgbe:set txep.mbuf to NULL when calling
> ixgbe_tx_free_bufs
> 
> In *ixgbe_tx_free_bufs*, after recycling some tx entries, one should set their
> mbuf pointers to NULL.
> 
> The first path is not correct, the txep->mbuf should be set to NULL no matter if
> it is recycled into mempool
> Signed-off-by: hepeng <xnhp0320 at icloud.com>
> ---
>  drivers/net/ixgbe/ixgbe_rxtx_vec.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ixgbe/ixgbe_rxtx_vec.c
> b/drivers/net/ixgbe/ixgbe_rxtx_vec.c
> index 1c16dec..e7ce740 100644
> --- a/drivers/net/ixgbe/ixgbe_rxtx_vec.c
> +++ b/drivers/net/ixgbe/ixgbe_rxtx_vec.c
> @@ -612,6 +612,7 @@ ixgbe_tx_free_bufs(struct ixgbe_tx_queue *txq)
>  	 */
>  	txep = &txq->sw_ring_v[txq->tx_next_dd - (n - 1)];
>  	m = __rte_pktmbuf_prefree_seg(txep[0].mbuf);
> +    txep[0].mbuf = NULL;
>  	if (likely(m != NULL)) {
>  		free[0] = m;
>  		nb_free = 1;
> @@ -632,11 +633,21 @@ ixgbe_tx_free_bufs(struct ixgbe_tx_queue *txq)
>  	} else {
>  		for (i = 1; i < n; i++) {
>  			m = __rte_pktmbuf_prefree_seg(txep[i].mbuf);
> -			if (m != NULL)
> +			if (m != NULL) {
>  				rte_mempool_put(m->pool, m);
> +            }
>  		}
>  	}
> 
> +    /*
> +     * No matter the mbufs have been put back to mempool or not,
> +     * we should set the txep[i].mbuf to NULL
> +     */
> +
> +    for( i = 1; i < n; i++) {
> +        txep[i].mbuf = NULL;
> +    }
> +
>  	/* buffers were freed, update counters */
>  	txq->nb_tx_free = (uint16_t)(txq->nb_tx_free + txq->tx_rs_thresh);
>  	txq->tx_next_dd = (uint16_t)(txq->tx_next_dd + txq->tx_rs_thresh);
> --
> 1.9.1

NACK.
Thanks for looking into this code. But it's designed behavior, not an issue.
BTW, if you want to send a new version, the tittle should be like this [PATCH v2] ixgbe: ..., and add "--in-reply-to your original mail" when sending the mail, and add a v2 comments. You can reference the other's v2 patches for detail.