CPU affinity with ULE scheduler

[Archimedes Gaviola]

To Whom It May Concerned:

Can someone explain or share about ULE scheduler (latest version 2 if
I'm not mistaken) dealing with CPU affinity? Is there any existing
benchmarks on this with FreeBSD? Because I am currently using 4BSD
scheduler and as what I have observed especially on processing high
network load traffic on multiple CPU cores, only one CPU were being
stressed with network interrupt while the rests are mostly in idle
state. This is an AMD-64 (4x) dual-core IBM system with GigE Broadcom
network interface cards (bce0 and bce1). Below is the snapshot of the
case.

 PID USERNAME  THR PRI NICE   SIZE    RES STATE  C   TIME   WCPU COMMAND
  17 root        1 171   52     0K    16K RUN    0  96:04 97.71% idle: cpu0
  15 root        1 171   52     0K    16K RUN    2  98:41 97.07% idle: cpu2
  14 root        1 171   52     0K    16K RUN    3 103:56 95.90% idle: cpu3
  13 root        1 171   52     0K    16K RUN    4 104:17 88.23% idle: cpu4
  12 root        1 171   52     0K    16K RUN    5  97:59 86.57% idle: cpu5
  10 root        1 171   52     0K    16K RUN    7  81:51 82.08% idle: cpu7
  11 root        1 171   52     0K    16K RUN    6  95:28 81.35% idle: cpu6
  16 root        1 171   52     0K    16K RUN    1 102:15 77.78% idle: cpu1
  36 root        1 -68 -187     0K    16K WAIT   7  19:37  4.59%
irq23: bce0 bce1
  18 root        1 -32 -151     0K    16K CPU0   0   2:13  0.00%
swi4: clock sio
 4488 root        1  96    0 30728K  4292K select 3   1:51  0.00% sshd
  43 root        1 171   52     0K    16K pgzero 3   1:08  0.00% pagezero
 218 root        1  96    0  3852K  1380K select 3   0:38  0.00% syslogd
  20 root        1 -44 -163     0K    16K WAIT   7   0:32  0.00% swi1: net


Thanks,
Archimedes