[LEDE-DEV] [PATCH] ar71xx: Add GRO support to ag71xx

[Christian Lamparter]

On Sunday, September 3, 2017 11:35:46 AM CEST Rosen Penev wrote:
> On a TL-WN710N, this patch increases iperf performance from ~92.5 to ~93.5 mbps. Keep in mind the WN710N is a 100mbps device. I expect greater numbers from gigabit devices.
> 
> Signed-off-by: Rosen Penev <rosenp at gmail.com>
> ---
I've done a quick test of the patch on my WD Range Extender.
(It has a Atheros AR9344 rev 2 SoC @ CPU:560.000MHz, DDR:400.000MHz
The PHY is a AR8035, which supports 1 GBit/s Links)

The range extender (DUT) was running iperf3 server in both tests.
Another desktop PC was acting as the iperf3 client.

without the patch:

Connecting to host range-extender, port 5201
[  4] local 192.168.8.7 port 51518 connected to 192.168.8.204 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  23.5 MBytes   197 Mbits/sec    0    105 KBytes
[  4]   1.00-2.00   sec  23.7 MBytes   199 Mbits/sec    0    105 KBytes
[  4]   2.00-3.00   sec  23.6 MBytes   198 Mbits/sec    0    105 KBytes
[  4]   3.00-4.00   sec  23.0 MBytes   193 Mbits/sec    0    105 KBytes
[  4]   4.00-5.00   sec  23.4 MBytes   197 Mbits/sec    0    105 KBytes
[  4]   5.00-6.00   sec  23.3 MBytes   195 Mbits/sec    0    105 KBytes
[  4]   6.00-7.00   sec  23.4 MBytes   196 Mbits/sec    0    105 KBytes
[  4]   7.00-8.00   sec  23.6 MBytes   198 Mbits/sec    0    105 KBytes
[  4]   8.00-9.00   sec  23.1 MBytes   194 Mbits/sec    0    105 KBytes
[  4]   9.00-10.00  sec  22.1 MBytes   185 Mbits/sec    0    105 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec   233 MBytes   195 Mbits/sec    0             sender
[  4]   0.00-10.00  sec   232 MBytes   195 Mbits/sec                  receiver

iperf Done.

with the patch (gro enabled - this is done by default):

Connecting to host range-extender, port 5201
[  4] local 192.168.8.7 port 52004 connected to 192.168.8.204 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  32.7 MBytes   274 Mbits/sec    0    106 KBytes       
[  4]   1.00-2.00   sec  32.6 MBytes   274 Mbits/sec    0    106 KBytes       
[  4]   2.00-3.00   sec  32.4 MBytes   272 Mbits/sec    0    106 KBytes       
[  4]   3.00-4.00   sec  32.3 MBytes   271 Mbits/sec    0    106 KBytes       
[  4]   4.00-5.00   sec  32.5 MBytes   273 Mbits/sec    0    106 KBytes       
[  4]   5.00-6.00   sec  32.5 MBytes   273 Mbits/sec    0    106 KBytes       
[  4]   6.00-7.00   sec  32.6 MBytes   273 Mbits/sec    0    106 KBytes       
[  4]   7.00-8.00   sec  32.4 MBytes   272 Mbits/sec    0    106 KBytes       
[  4]   8.00-9.00   sec  32.6 MBytes   273 Mbits/sec    0    106 KBytes       
[  4]   9.00-10.00  sec  31.4 MBytes   264 Mbits/sec    0    106 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec   324 MBytes   272 Mbits/sec    0             sender
[  4]   0.00-10.00  sec   324 MBytes   272 Mbits/sec                  receiver

iperf Done.

(range-extender) # ethtool -K eth0 gro off

Connecting to host range-extender, port 5201
[  4] local 192.168.8.7 port 52120 connected to 192.168.8.204 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  24.8 MBytes   208 Mbits/sec    0    105 KBytes       
[  4]   1.00-2.00   sec  23.6 MBytes   198 Mbits/sec    0    105 KBytes       
[  4]   2.00-3.00   sec  24.5 MBytes   206 Mbits/sec    0    105 KBytes       
[  4]   3.00-4.00   sec  23.9 MBytes   201 Mbits/sec    0    105 KBytes       
[  4]   4.00-5.00   sec  24.6 MBytes   207 Mbits/sec    0    105 KBytes       
[  4]   5.00-6.00   sec  24.7 MBytes   207 Mbits/sec    0    105 KBytes       
[  4]   6.00-7.00   sec  24.5 MBytes   206 Mbits/sec    0    105 KBytes       
[  4]   7.00-8.00   sec  24.0 MBytes   201 Mbits/sec    0    105 KBytes       
[  4]   8.00-9.00   sec  24.3 MBytes   204 Mbits/sec    0    105 KBytes       
[  4]   9.00-10.00  sec  24.5 MBytes   206 Mbits/sec    0    105 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec   244 MBytes   204 Mbits/sec    0             sender
[  4]   0.00-10.00  sec   243 MBytes   204 Mbits/sec                  receiver

iperf Done.

So, the throughput went from 195 Mbits/sec to 272 Mbits/sec.
The gain would be (272 Mbps - 195 Mbps) / 195 Mbps = 0.3949 ~ 40%

Regards,
Christian