[dpdk-dev] Performances are not scale with multiple ports

[Naoto MATSUMOTO]

FYI: Disruptive IP Networking with Intel DPDK on Linux
http://slidesha.re/SeVFZo


On Tue, 28 May 2013 11:26:30 +0900
Shinae Woo <shinae2012 at gmail.com> wrote:

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

-- 
SAKURA Internet Inc. / Senior Researcher
Naoto MATSUMOTO <n-matsumoto at sakura.ad.jp>
SAKURA Internet Research Center <http://research.sakura.ad.jp/>