finding optimal ipfw strategy

[Victor Gamov]

On 27/08/2019 22:59, Eugene Grosbein wrote:
> 28.08.2019 2:22, Victor Gamov wrote:
> 
>>> Also, you should monitor interrupt numbers shown by "systat -vm 3" for igb* devices
>>> at hours of most load. If they approach 8000 limit but not exceed it,
>>> you may be suffering from this and should raise the limit with /boot/loader.conf:
>>>
>>> hw.igb.max_interrupt_rate=32000
>>
>> It's about 5000-7000 per rxq
> 
> 7000 is quite close considering it is average for quite long period (a second or seconds).
> It can hit 8000 for some ticks easily in your case.

Eugene,  can you explain me what max_interrupt_rate means?  Calomel 
explain it as  "# maximum number of interrupts per second generated by 
single igb".  So if I increase it then more irq per sec will be 
generated and more context switch produced.  Why I need to increase it?


> You should raise the limit as soon as possible. I'd advise to double it upto 16000 first
> but if you cannot afford extra reboot better use 32000 as it's just fine for 1Gbps link.

# sysctl hw.igb.max_interrupt_rate
sysctl: unknown oid 'hw.igb.max_interrupt_rate'
#

Is it possible to set it at boot time only?

--
CU,
Victor Gamov