device polling takes more CPU hits??

[Kelly Yancey]

On Mon, 26 Jul 2004, Don Bowman wrote:

> kern.polling.burst: 1000
> kern.polling.each_burst: 80
> kern.polling.burst_max: 1000
> kern.polling.idle_poll: 1
> kern.polling.poll_in_trap: 0
> kern.polling.user_frac: 5
> kern.polling.reg_frac: 120
> kern.polling.short_ticks: 29
> kern.polling.lost_polls: 55004
> kern.polling.pending_polls: 0
> kern.polling.residual_burst: 0
> kern.polling.handlers: 4
> kern.polling.enable: 1
> kern.polling.phase: 0
> kern.polling.suspect: 50690
> kern.polling.stalled: 25

  Out of curiousity, what sort of testing did you do to arrive at these
settings?  I did some testing a while back with a SmartBits box pumping
packets through a FreeBSD 2.8Ghz box configured to route between two em
gigabit interfaces; I found that changing the burst_max and each_burst
parameters had almost no effect on throughput (maximum 1% difference).
That was completely contrary to expectations and would love to hear how I
could improve my test setup to see how changing those values are supposed
to affect performance.

  Thanks,

  Kelly

--
Kelly Yancey  -  kbyanc@{posi.net,FreeBSD.org}  -  kelly at nttmcl.com
"The information of the people at large can alone make them the safe as they
 are the sole depositary of our political and religious freedom."
	-- Thomas Jefferson to William Duane, 1810. ME 12:417