On 09/23/2009 11:50 AM, Peter P Waskiewicz Jr wrote:

quoted

That's a bummer.  I'm guessing you might get close to right on average with some
trivial math, but if someone is sending you pkts with size of 1000 and
your MTU is 1500, would there be any way to tell that the pkts were originally
1000 bytes instead of 1500?

Good point.

quoted

Next time you guys re-compile your hardware, please consider adding byte counters :)

On 10G adapters, byte counters can skyrocket quickly, so we'd need to
read them often to avoid them wrapping.  But I will forward your request
to our HW design folks and see if they have other ideas to implement
these counters and make them efficient.

It still takes a while to wrap 64-bit counters :)

But, you do have to read every 3 secs or so if you're using 32-bit counters.

This can be dealt with in user-space easily enough as long as polling
the NIC for counters is efficient.

Thanks,
Ben

-- 
Ben Greear [off-list ref]
Candela Technologies Inc  http://www.candelatech.com