svn commit: r250911 - head/sys/kern

[Luigi Rizzo]

On Wed, May 22, 2013 at 04:55:51PM -0700, Adrian Chadd wrote:
> Odd, this reads like one of those things that's better off being
> time-capped, rather than packet-count capped.

this is in fact how it works: the control loop in the polling
code dynamically adjusts the actual number of packets so that the
fraction of CPU cycles spent in the polling routine
does not exceed the threshold (100 - kern.polling.user_frac).
Working in batches avoids reading the clock and calling
the poll method at every packet, which would be too expensive.

	cheers
	luigi