Re: Intel EM tuning (PT1000 adaptors)

At 12:30 PM 1/30/2007, Jack Vogel wrote:

Performance tuning is not something that I have yet had time to focus
on, our Linux team is able to do a lot more of that. Just at a glance,
try increasing your mbuf pool size and the number of receive descriptors
for a start.


OK, I setup a test box the pass packets through and I am getting results I dont understand. Increasing hw.em.rxd in loader.conf (and rebooting each time), I am getting worse results.

With hw.em.rxd=4096
Jan 30 17:19:10 em-test kernel: em0: Receive No Buffers = 5707564

With hw.em.rxd=1024
Jan 30 17:22:31 em-test kernel: em0: Receive No Buffers = 351


With hw.em.rxd=512
Jan 30 17:27:24 em-test kernel: em0: Receive No Buffers = 230

with default 256

Jan 30 16:55:44 em-test kernel: em0: Receive No Buffers = 77


with 128, its gets much worse. This is with a stock UP kernel, no INET6, net.inet.ip.fastforwarding=1


Box A ------Box B (with dual Intel NIC) ----- Box C

Box A is generating packets routed through firewall Box B towards Box C. They are connected together with 2 cross over cables.





Oh, and try increasing your processing limit to 200 and see
what effect that has.


I will try that next.

---Mike

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