bge driver, how to increase performance?

[Atanas Yankov]

for bge0
#ifconfig bge0 mtu 9000
N.B  MTU has to be consistent on LAN and you need Gigabit equipment that can handle jumbo frames 
for fxp0 
#ifconfig fxp0 link0 

              
            Some chip revisions have loadable microcode which can be used to
            reduce the interrupt load on the host cpu.  Not all boards have
            microcode support.  Setting the link0 flag with ifconfig(8) will
            download the microcode to the chip if it is available.

for all system you cand try

net.inet.ip.fastforwarding=1

But do this carefully there some problems on 4.x with fastforwarding 
feature and dummynet and dot.1q vlans on 5.x its seems to work :))


br,

CCNP Atanas Yankov
Network Administrator
AngelSoft Ltd.


Ferdinand Goldmann wrote:

> Hello,
>
> I have a 3com 3c996-SX card running under FreeBSD 5.4-STABLE.
> Performance is quite ok so far, but interrupt load is very high.
> (Machine is working as a traffic shaping device/firewall)
>
> # vmstat -i
> interrupt                          total       rate
> irq18: bge0                    153244636       5014
> irq27: fxp0                    102056377       3339
>
> Often, interrupt load will hit almost 100%. I guess the bge driver 
> does not support polling, but I remember reading somewhere that it 
> supports interrupt moderation? How would I enable this? On the em 
> driver, this could be done via sysctl. Does anyone have hints on 
> performance improvement concerning interrupt load?
>
> TIA