K 10
svn:author
V 5
luigi
K 8
svn:date
V 27
2013-05-22T16:32:18.607440Z
K 7
svn:log
V 688
Increase the (arbitrary) limit for the number of packets per tick
from 1k to 20k The previous value was good 10 years ago, but not
anymore now.

More importantly, lots of good surprises:
polling is incredibly effective under virtualization, and not only
prevents livelock but also saves most of the VM exit overhead in
receive mode.

Using polling, a FreeBSD instance under qemu-kvm remains perfectly
responsive even when bombed with 10 Mpps over an emulated e1000,
and happily processes 1.7 Mpps through ipfw.

Note that some incompatibilities still remain: e.g. polling is not
(yet) compatible with netmap, and seems to freeze the guest when
kern.polling.idle_poll=1

MFC after:	3 days

END