[Users] how to use sample control for port counters

[Black.S]

Hello all

I want to monitoring ports in IB fabric.

I happened to notice in the out of perfquery some counter like a ticks 
and port sampling. Its will be great for accurate monitoring. But I cant 
found some info about setup and using sampling controi for IB ports.

How to configure and use sampling contol for IB ports? Can anybody give 
me documentations/links or examples? I cant found it In Google.
Are there any restrictions on the amount of data collected in this 
sampling mode?

If its offtop then redirect me please

Thanks for you time