<div dir="ltr"><div><div><div><div>Hello, all.<br><br></div>I play the dpdk-1.2.3r1 with examples. <br><br>But I can not achieve the line-rate packet receive performance,<br>and the performance is not scale with multiple ports.<br>
</div><br></div>For example, in example l2fwd, I have tested two cases with 2 ports, and 4 ports,<br></div>using belowed command line each<br><div><br>./build/l2fwd -cf -n3 -- -p3<br>./build/l2fwd -cf -n3 -- -pf<br><br></div>
<div>But both cases, the aggregated performance are not scale.<br><br></div><div>== experiments environments ==<br></div><div>- Two Intel 82599 NICs (total 4 ports)<br>- Intel Xeon X5690  @ 3.47GHz * 2 (total 12 cores)<br>
</div><div>- 1024 * 2MB hugepages<br>- Linux 2.6.38-15-server<br>- Each ports receiving 10Gbps of traffic of 64 bytes packets, 14.88Mpps.<br></div><div><br></div><div><b>1. Packet forwarding performance</b><br><br></div><div>
In 2 ports case,  receive performance is 13Mpps, <br></div><div>In 4 ports case,  not 26Mbps, only 16.8Mpps.<br></div><div><br>Port statistics ====================================<br>Statistics for port 0 ------------------------------<br>
Packets sent:                  4292256<br>Packets received:              6517396<br>Packets dropped:               2224776<br>Statistics for port 1 ------------------------------<br>Packets sent:                  4291840<br>
Packets received:              6517044<br>Packets dropped:               2225556<br>Aggregate statistics ===============================<br>Total packets sent:            8584128<br>Total packets received:       13034472<br>
Total packets dropped:         4450332<br>====================================================<br><br>Port statistics ====================================<br>Statistics for port 0 ------------------------------<br>Packets sent:                  1784064<br>
Packets received:              2632700<br>Packets dropped:                848128<br>Statistics for port 1 ------------------------------<br>Packets sent:                  1784104<br>Packets received:              2632196<br>
Packets dropped:                848596<br>Statistics for port 2 ------------------------------<br>Packets sent:                  3587616<br>Packets received:              5816344<br>Packets dropped:               2200176<br>
Statistics for port 3 ------------------------------<br>Packets sent:                  3587712<br>Packets received:              5787848<br>Packets dropped:               2228684<br>Aggregate statistics ===============================<br>
Total packets sent:           10743560<br>Total packets received:       16869152<br>Total packets dropped:         6125608<br>====================================================<br><br><b>2. Packet receiving performance</b><br>
</div><div>I fix the codes for only receiving packets (not forwarding),<br></div><div>the performance is still not scalable as each 13.3Mpps, 18Mpps.<br></div><div><br>Port statistics ====================================<br>
Statistics for port 0 ------------------------------<br>Packets sent:                        0<br>Packets received:              6678860<br>Packets dropped:                     0<br>Statistics for port 1 ------------------------------<br>
Packets sent:                        0<br>Packets received:              6646120<br>Packets dropped:                     0<br>Aggregate statistics ===============================<br>Total packets sent:                  0<br>
Total packets received:       13325012<br>Total packets dropped:               0<br>====================================================<br><br>Port statistics ====================================<br>Statistics for port 0 ------------------------------<br>
Packets sent:                        0<br>Packets received:              3129624<br>Packets dropped:                     0<br>Statistics for port 1 ------------------------------<br>Packets sent:                        0<br>
Packets received:              3131292<br>Packets dropped:                     0<br>Statistics for port 2 ------------------------------<br>Packets sent:                        0<br>Packets received:              6260908<br>
Packets dropped:                     0<br>Statistics for port 3 ------------------------------<br>Packets sent:                        0<br>Packets received:              6238764<br>Packets dropped:                     0<br>
Aggregate statistics ===============================<br>Total packets sent:                  0<br>Total packets received:       18760640<br>Total packets dropped:               0<br>====================================================<br>
<br></div><div>The question is that<br></div><div>1. How I can achieve each port receiving full 14.88Mpps ?<br></div><div>    What might be the bottleneck in current environment?<br></div><div>2. Why the performance using multiple ports is not scale?<br>
</div><div>    I guess doubling ports shows the doubling the receiving performance, <br></div><div>    but it shows not. I am curious about what is limiting the packet receivng performance.<br><br></div><div>Thanks,<br>Shinae<br>
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