throughput and interrupts

[Bachilo Dmitry]

В сообщении от Вторник 15 августа 2006 23:45 Tofik Suleymanov написал(a):
> Bachilo Dmitry wrote:
> > Hello.
> > I am completely stuck. I have a router, that rules three subnets. At
> > first there were Allied Telesyn's netcards with realtek chipsets. I am
> > using ipfw+natd and I had like 3,5 megabytes per second with 20 per cent
> > of interrupt load. I had "discarded oversized frame" too often so I've
> > replaced two main cards with 3Com 905 and now my xl0 and xl1 never
> > discard frames. But I saw no speed boost and interrupts were also very
> > high. I have discovered some IRQ conflicts and removed them, now I have
> > single device per IRQ, but still i have near 20-30 % of interrupt load,
> > when i download something through this router (and natd takes rest % of
> > CPU). Some people advised me to use polling, so I've built kernel with
> > HZ=1000, polling and tried it. Interrupts grew to 40-50% and speed
> > decreased to 200-300 kb/s, so I had to turn the polling off.
> >
> > I just don't know what to try, to gain at least 9 mb/s, because this is
> > what I get at home with the same cards, the same processor, with no
> > polling and throgh the same provider.
> >
> > Best regards,
> > Bachilo Dmitry
>
> Dmitry,
>
> Could you please try natd+kqueue patch from
> http://www.freebsd.az/patches.html  and report results (difference it
> made etc etc) ?
> I did not have any chance to test it in heavy load environment.yet.
>
> Thank you,
> Tofig Suleymanov

patch applied successfully, but the same throughput and the same picture in 
top -S:

CPU states:  3.5% user,  0.0% nice, 68.4% system, 28.1% interrupt,  0.0% idle
Mem: 127M Active, 670M Inact, 137M Wired, 48M Cache, 111M Buf, 15M Free
Swap: 64M Total, 272K Used, 64M Free

  PID USERNAME PRI NICE   SIZE    RES STATE    TIME   WCPU    CPU COMMAND
87524 root     111    0  1300K   828K RUN      0:16 31.96% 31.69% natd
   11 root     171   52     0K     8K RUN    422.8H 10.94% 10.94% idle
   37 root     -44 -163     0K     8K WAIT    99:14  6.88%  6.88% swi1: net
   30 root     -68 -187     0K     8K WAIT    40:42  5.27%  5.27% irq20: xl1
   29 root     -68 -187     0K     8K RUN     59:14  4.00%  4.00% irq19: xl0
   35 root     -28 -147     0K     8K WAIT   141:06  0.05%  0.05% swi5: clock 
sio

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С уважением, Бачило Дмитрий
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