hi,


I'm testing dpdk on ubuntu 14, it's quite easy to try dpdk with tools/setup.sh now. but i am confusing that there is always TX-dropped when test with testpmd, i changed the burst num from 32 to 8, but still lots of TX-dropped happened.


so anyone can share some ideas ? why so many TX-dropped ? 


Details:


Enviroment:


Linux ubuntu14319 3.19.0-25-generic #26~14.04.1-Ubuntu SMP Fri Jul 24 21:16:20 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
gcc version 4.8.5 (Ubuntu 4.8.5-2ubuntu1~14.04.1) 


CPU: 2*6 cores


root@ubuntu14319:~/dpdk16/x86_64-native-linuxapp-gcc/app# cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 63
model name      : Intel(R) Xeon(R) CPU E5-2603 v3 @ 1.60GHz
stepping        : 2
microcode       : 0x36
cpu MHz         : 1599.998
cache size      : 15360 KB
physical id     : 0
siblings        : 6
core id         : 0
cpu cores       : 6
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 15
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss ht syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx hypervisor lahf_lm arat epb pln pts dtherm
bugs            :
bogomips        : 3199.99
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:


NIC binding:


Network devices using DPDK-compatible driver
============================================
0000:02:01.0 '82545EM Gigabit Ethernet Controller (Copper)' drv=igb_uio unused=
0000:02:02.0 '82545EM Gigabit Ethernet Controller (Copper)' drv=igb_uio unused=


Network devices using kernel driver
===================================
0000:03:00.0 'VMXNET3 Ethernet Controller' if=eth0 drv=vmxnet3 unused=igb_uio *Active*


Other network devices
=====================




testpmd:


testpmd> start
  io packet forwarding - CRC stripping disabled - packets/burst=32
  nb forwarding cores=1 - nb forwarding ports=2
  RX queues=1 - RX desc=128 - RX free threshold=0
  RX threshold registers: pthresh=0 hthresh=0 wthresh=0
  TX queues=1 - TX desc=512 - TX free threshold=0
  TX threshold registers: pthresh=0 hthresh=0 wthresh=0
  TX RS bit threshold=0 - TXQ flags=0x0
testpmd> stop
Telling cores to stop...
Waiting for lcores to finish...


  ---------------------- Forward statistics for port 0  ----------------------
  RX-packets: 1977364        RX-dropped: 0             RX-total: 1977364
  TX-packets: 1852639        TX-dropped: 113346        TX-total: 1965985
  ----------------------------------------------------------------------------


  ---------------------- Forward statistics for port 1  ----------------------
  RX-packets: 1966151        RX-dropped: 0             RX-total: 1966151
  TX-packets: 1864575        TX-dropped: 112789        TX-total: 1977364
  ----------------------------------------------------------------------------


  +++++++++++++++ Accumulated forward statistics for all ports+++++++++++++++
  RX-packets: 3943515        RX-dropped: 0             RX-total: 3943515
  TX-packets: 3717214        TX-dropped: 226135        TX-total: 3943349
  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++