On Tue, Jul 16, 2019 at 03:23:03PM +0100, Ferruh Yigit wrote: > On 7/16/2019 1:23 PM, Andrew Rybchenko wrote: > > On 7/15/19 5:53 PM, Ferruh Yigit wrote: > >> On 7/12/2019 9:32 AM, A.McLoughlin wrote: > >>> The 'Accumulated forward statistics for all ports' incorrectly displayed > >>> double the actual value for 'total_tx_dropped'. This was because 2 > >>> lines in the same function both incremented total_tx_dropped every time > >>> a packet was dropped. I removed one of these lines to fix this issue. > >>> > >>> Fixes: 53324971a14e ("app/testpmd: display/clear forwarding stats on > >>> demand") > >>> Cc: david.march...@redhat.com > >>> Cc: sta...@dpdk.org > >>> > >>> Signed-off-by: A.McLoughlin <aideen.mclough...@intel.com> > >>> --- > >>> app/test-pmd/testpmd.c | 1 - > >>> 1 file changed, 1 deletion(-) > >>> > >>> diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c > >>> index 3ed3523b7..c41bada50 100644 > >>> --- a/app/test-pmd/testpmd.c > >>> +++ b/app/test-pmd/testpmd.c > >>> @@ -1555,7 +1555,6 @@ fwd_stats_display(void) > >>> total_recv += stats.ipackets; > >>> total_xmit += stats.opackets; > >>> total_rx_dropped += stats.imissed; > >>> - total_tx_dropped += ports_stats[pt_id].tx_dropped; > >>> total_tx_dropped += stats.oerrors; > >>> total_rx_nombuf += stats.rx_nombuf; > >>> > >>> > >> > >> Hi Aideen, > >> > >> Indeed 'rte_eth_stats->oerrors' and 'tx_dropped' are different values, > >> > >> in testpmd, 'TX-total' is taken as "total_xmit + total_tx_dropped", from > >> this > >> description it may be fair to say > >> "total_tx_dropped = oerrors + tx_dropped" > >> > >> This is easier to see in HW devices, 'oerrors' is the packets sent to HW > >> but HW > >> reported failure for some reason, so these packets not transmitted to the > >> medium. > >> 'tx_dropped' is mostly calculated by application, driver returns packets > >> that > >> can't able to sent to HW, so application can re-try to send or free them > >> and > >> increase 'tx_dropped' counter. > >> > >> > >> The problem is in the virtual drivers, the packets not able to sent are > >> calculated as 'oerrors' and tx_burst functions returns the number of the > >> successfully sent packets which cause application calculate remaining ones > >> as > >> 'tx_dropped' which cause the duplication. > > > > I don't understand how it is. Tx burst returns a number of owned packets > > (either successfully transmitted or internally dropped/freed). If it is > > smaller than number of packets in request, other packets are either > > retried or calculated as tx_dropped. > > Virtual PMDs, at least the ones I checked, calculating not sent packets as > error, also application calculates them as tx_dropped. > > Like: > https://git.dpdk.org/dpdk/tree/drivers/net/ring/rte_eth_ring.c?h=v19.08-rc1#n97 > That is probably incorrect to do. Virtual PMDs should behave as real ones do as far as possible. I think we should change them to not count as errors any that are not handled by the driver, provided those are returned to the app.
/Bruce