In article <[EMAIL PROTECTED]>, Poul-Henning Kamp <[EMAIL PROTECTED]> wrote: > In message <[EMAIL PROTECTED]>, John Polstra writes: > >In article <[EMAIL PROTECTED]>, > >John Baldwin <[EMAIL PROTECTED]> wrote: > >> > >> > like, "If X is never locked out for longer than Y, this problem > >> > cannot happen." I'm looking for definitions of X and Y. X might be > >> > hardclock() or softclock() or non-interrupt kernel processing. Y > >> > would be some measure of time, probably a function of HZ and/or the > >> > timecounter frequency. > >> > >> X is hardclock I think, since hardclock() calls tc_windup(). > > > >That makes sense, but on the other hand hardclock seems unlikely to be > >delayed by much. The only thing that can block hardclock is another > >hardclock, an splclock, or an splhigh. And, maybe, splstatclock. I'm > >talking about -stable here, which is where I'm doing my experiments. > > Try swapping so you use the RTC for hardclock & statclock. > > Let the i8254 run with 65536 divisor and do only timecounter service. > > That would be a very interresting experiment.
Agreed. But in the cases I'm worrying about right now, the timecounter is the TSC. John -- John Polstra John D. Polstra & Co., Inc. Seattle, Washington USA "Disappointment is a good sign of basic intelligence." -- Chögyam Trungpa To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
