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 > >> In virtual drivers we need to give a decision, if free the wrong packets and >> increase the 'oerrors' or return packets backs to application without >> increasing >> the 'oerrors', so that application can try to do something with packets or >> free >> them increasing 'tx_dropped'. >> >> @David, @Andrew, do you have a suggestion? >