>> Based on my investigations the packet get only copied if it isI've measured it now: with my patch it was 5.2 Gbps, without it 5.4. Both cases iperf in Dom0 maxed out its CPU, mostly in soft interrupt context, based on top.
delivered to
>>Dom0 stack, which is due to this patch:
>>https://lkml.org/lkml/2012/7/20/363
>>That's a bit unfortunate, but as far as I know for the huge majority
this use
>>case is not too important.
Likely to be true, but it would still be interesting to know how badlyI can't find my numbers, but as far as I remember it wasn't
this use case suffers with this change, and any increase in CPU usage
would be interesting to know about as well.
significantly worse than grant copy. I will check that again.