On Tue, Jul 16, 2019 at 5:29 PM Ferruh Yigit <ferruh.yi...@intel.com> wrote: > > On 7/16/2019 4:00 PM, Andrew Rybchenko wrote: > > On 7/16/19 5:28 PM, Bruce Richardson wrote: > >> 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. > > > > I agree with Bruce. It is a bug in ring PMD. If so, too fast attempts to > > transmit packets will blow up err_pkts counter. > > > > +1, as far as I can see following PMDs requires fixing: > ring > kni > pcap > tap
I already have fixes for some of them (found when I started to look at the stats). -- David Marchand