DragonFly doesn't use kern.hz for much beyond the callout timers and
tsleep. It uses independant systimers for scheduling and network
polling. FreeBSD upped their hz default primarily for their scheduler
and network polling insofar as I remember.
This is why DragonFly's hz was left at 100, and changing hz in DragonFly
will not have much of an effect.
Our scheduler clock is currently hardwired via ESTCPUFREQ in sys/proc.h
We could make it programmable via sysctl... changing the frequency is
really easy since it uses a systimer. That would be a fun project for
someone if they wanted to do it. Calculations based on ESTCPUFREQ would
have to be adjusted to be based on a variable instead. ESTCPUFREQ
is 50Hz at the moment.
The networking polling frequency is set with a sysctl and only used
if one or more interfaces has polling turned on.
-Matt
Matthew Dillon
<dil...@backplane.com>
