On Jan 21, 8:25 pm, [email protected] (David Mills) wrote: > Dave (and others), > > On a laptop and where spread-spectrum clock is required, it might be > better to tolerate a timer-interrut clock, but only if the various > systematic errors can be averaged out. See the libntp/systeim.c routine > and the sys_tick variable, which is intended to reduce the residuals for > thos systems that have only a 100-Hz timer interrupt. This is > conditioned on the system type define. It should be easy to do the same > kind of thing for other systems.
Thanks for your response. ports/winnt/nt_clockstuff.c adj_systime has much the same logic, though instead of sys_tick, the variable there is called ppm_per_adjust_unit. As with the systime.c version, care is taken to carry over residual from each adjustment. You can see that in action with a Windows ntpd.exe built with DEBUG, running with debug > 2 I believe. grep (findstr) for SetSystemTimeAdjustment and you'll note the adjustment units will show a residual pattern like 1 2 1 2 or 6 6 7 6 6 7. Cheers, Dave Hart _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
