serious networking (em) performance (ggate and NFS) problem

[Shunsuke SHINOMIYA]

 I did FastEthernet throughput test by Smartbits with SmartApp.
 It's simpler than TCP throughput measurement. :)
 This Smartbits has some FastEthernet ports, has no GbE ports.

 The router is consist of single Xeon 2.4GHz which is HTT enabled and
two on-boarded em interfaces. The kernel is 5.3-RELEASE with option SMP.
if_em.c is version 1.44.2.3 with the sysctl-able patch.
kern.random.sys.harvest.ethernet is set to 0.

 `Interrupt Moderation on' means the combination of parameters,
hw.em?.rx_int_delay: 0
hw.em?.tx_int_delay: 66
hw.em?.rx_abs_int_delay: 66
hw.em?.tx_abs_int_delay: 66
hw.em?.int_throttle_ceil: 8000.

 `Interrupt Moderation off' means the combination of parameters,
hw.em?.rx_int_delay: 0
hw.em?.tx_int_delay: 0
hw.em?.rx_abs_int_delay: 0
hw.em?.tx_abs_int_delay: 0
hw.em?.int_throttle_ceil: 0.

`on/off' means input side interface(em0)'s moderation is `on' and output
side interface(em1)'s moderation is `off'.

 hmm ..., the results of off/on are unstable.

(A) ... Passed Rate(%)
(B) ... Passed Rate(pps)

Interrupt Moderation on/on
Frame      1st Trial       2nd Trial       3rd Trial
Size      (A)     (B)     (A)     (B)     (A)     (B)
  64	 28.14	 41876	 28.14	 41876	 28.14	 41876
 128	 50.08	 42301	 49.50	 41805	 49.50	 41806
 256	 93.24	 42229	 92.00	 41666	 92.62	 41946
 512	100.00	 23496	100.00	 23496	100.00	 23496
1024	100.00	 11973	100.00	 11973	100.00	 11973
1280	100.00	  9615	100.00	  9615	100.00	  9615
1518	100.00	  8127	100.00	  8127	100.00	  8127

Interrupt Moderation on/off
Frame      1st Trial       2nd Trial       3rd Trial
Size      (A)     (B)     (A)     (B)     (A)     (B)
  64	 28.14	 41876	 27.50	 40916	 28.14	 41876
 128	 50.08	 42301	 48.85	 41254	 49.50	 41806
 256	 93.24	 42229	 92.00	 41666	 92.62	 41946
 512	100.00	 23496	100.00	 23496	100.00	 23496
1024	100.00	 11973	100.00	 11973	100.00	 11973
1280	100.00	  9615	100.00	  9615	100.00	  9615
1518	100.00	  8127	100.00	  8127	100.00	  8127

Interrupt Moderation off/on
Frame      1st Trial       2nd Trial       3rd Trial
Size      (B)    (C)      (B)     (C)     (B)     (C)
  64	100.00	148807	100.00	148807	 99.41	147927
 128	100.00	 84458	 55.74	 47080	 61.41	 51867
 256	100.00	 45289	 98.75	 44722	100.00	 45289
 512	100.00	 23496	100.00	 23496	100.00	 23496
1024	100.00	 11973	100.00	 11973	100.00	 11973
1280	100.00	  9615	100.00	  9615	100.00	  9615
1518	100.00	  8127	100.00	  8127	100.00	  8127


Interrupt Moderation off/off
Frame      1st Trial       2nd Trial       3rd Trial
Size      (B)    (C)      (B)     (C)     (B)     (C)
  64	 81.55	121358	 81.55	121358	 82.35	122547
 128	100.00	 84458	100.00	 84458	100.00	 84458
 256	100.00	 45289	100.00	 45289	100.00	 45289
 512	100.00	 23496	100.00	 23496	100.00	 23496
1024	100.00	 11973	100.00	 11973	100.00	 11973
1280	100.00	  9615	100.00	  9615	100.00	  9615
1518	100.00	  8127	100.00	  8127	100.00	  8127

-- 
Shunsuke SHINOMIYA <shino at fornext.org>