Kernel Variables Sanity Check

Jason C. Wells jcw at
Wed Dec 24 04:13:11 UTC 2008

Based on someone elses historical message I tried changing the time 
counter from TSC to i8254

# sysctl kern.timecounter.hardware=i8254

and after doing some manual calculations I tweaked

# sysctl machdep.i8254_freq=1187216
# machdep.i8254_freq: 1193182 -> 1187216

Is doing this safe?  I'm concerned that there are unforeseen 
consequences to messing with these kernel variables.  Ntpd seems to like 
this setup.  Anything to make ntpd happy.

And if I may, why can't ntpd do this? (Don't answer that.) I use the 
FINE software to set my clock so I don't have to.  It's supposed to make 
my life easier.


More information about the freebsd-questions mailing list