[dpdk-dev] [PATCH] net/af_xdp: enqueue buf ring when allocate Tx queue fails

[Ye Xiaolong]

On 04/10, David Marchand wrote:
>On Tue, Apr 9, 2019 at 5:24 PM Xiaolong Ye <xiaolong.ye at intel.com> wrote:
>
>> When it fails to allocate enough slots in Tx queue for transmitting
>> packets, we need to return the dequeued addrs to buf ring.
>>
>> Fixes: f1debd77efaf ("net/af_xdp: introduce AF_XDP PMD")
>>
>> Signed-off-by: Xiaolong Ye <xiaolong.ye at intel.com>
>> ---
>>  drivers/net/af_xdp/rte_eth_af_xdp.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c
>> b/drivers/net/af_xdp/rte_eth_af_xdp.c
>> index 007a1c6b4..5cc643ce2 100644
>> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
>> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
>> @@ -276,6 +276,7 @@ eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs,
>> uint16_t nb_pkts)
>>
>>         if (xsk_ring_prod__reserve(&txq->tx, nb_pkts, &idx_tx) != nb_pkts)
>> {
>>                 kick_tx(txq);
>> +               rte_ring_enqueue_bulk(umem->buf_ring, addrs, nb_pkts,
>> NULL);
>>                 return 0;
>>         }
>>
>> --
>> 2.17.1
>>
>
>Looks good to me.
>But I have an additional question.
>
>After the for loop that only picks the mbufs it can copy to the xdp desc,
>is it normal to call xsk_ring_prod__submit(&txq->tx, nb_pkts); rather than
>with valid count ?

Good catch, I think it needs to submit valid count other than nb_pkts, and return back
(nb_pkts - count) addrs to buf ring.

I'll send a fix patch for it.

Thanks,
Xiaolong
>
>-- 
>David Marchand