On 10/10/2019 19:35, Stephen Hemminger wrote:
On Thu, 10 Oct 2019 18:34:30 +0100
Flavia Musatescu <flavia.musate...@intel.com> wrote:

When sendto call fails and ENOBUFS error is being set some of the
packets are actually successfully transmitted. There is no available
count of those packets, so in order to make the statistics more
accurate, all the previously enqueued packets will be considered
successful, even though this is not entirely correct.

Before:
    testpmd Tx statistics:
       TX-packets: 7529062   TX-errors: 3702150  TX-bytes:  451743720
    pktgen Rx statistics:
       Total Rx Pkts: 10700700

After:
    testpmd TX statistics:
       TX-packets: 11510625  TX-errors: 0        TX-bytes:  690637500
    pktgen Rx statistics:
       Total Rx Pkts: 10974307

Fixes: 74b7fc0a0ff1 ("net/af_packet: fix packet bytes counting")
Cc: ciwil...@brocade.com
Cc: sta...@dpdk.org

Signed-off-by: Flavia Musatescu <flavia.musate...@intel.com>

---
v2:
* Changed the comment
---
  drivers/net/af_packet/rte_eth_af_packet.c | 8 ++++++--
  1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/af_packet/rte_eth_af_packet.c 
b/drivers/net/af_packet/rte_eth_af_packet.c
index 6df09f2..df281bf 100644
--- a/drivers/net/af_packet/rte_eth_af_packet.c
+++ b/drivers/net/af_packet/rte_eth_af_packet.c
@@ -244,8 +244,12 @@ eth_af_packet_tx(void *queue, struct rte_mbuf **bufs, 
uint16_t nb_pkts)
        }
/* kick-off transmits */
-       if (sendto(pkt_q->sockfd, NULL, 0, MSG_DONTWAIT, NULL, 0) == -1) {
-               /* error sending -- no packets transmitted */
+       if (sendto(pkt_q->sockfd, NULL, 0, MSG_DONTWAIT, NULL, 0) == -1 &&
+                       errno != ENOBUFS) {
+               /*
+                * In case of a ENOBUFS error all of the enqueued packets will
+                * be considered successful even though only some are sent.
+                */
                num_tx = 0;
                num_tx_bytes = 0;
        }
What about EINTR or EAGAIN?
Hi Stephen,

I agree with EAGAIN error case as I was able to test this scenario and check the statistics.

Can we get an EINTR error in case of a nonblocking operation (MSG_DONTWAIT flag is being used)? Is this a common situation and will the gain justify the cost of an additional check? Do you have any suggestions for how I could test this scenario?

Thanks,
Flavia

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