tbr/decrementer and SMP -- do the cpus stay in sync?

[Chris Friesen]

I thought I remembered some discussion on this a while back, but I can't find it 
in my archived messages or online, so here goes.

With SMP PowerPC machines (specifically the dual G5) we sync up the timebase 
when we bring up the second CPU.  Are we guaranteed that they stay in sync after 
that point, or will they drift?  If they drift, do we have any idea how much?

Thanks,

Chris