[ntp:questions] drifting on crystal

prep at prep.synonet.com prep at prep.synonet.com
Fri Jan 21 18:54:11 UTC 2005

Ulrich Windl <Ulrich.Windl at RZ.Uni-Regensburg.DE> writes:

>> It is still possible for Linux to miss a clock interrupt, if some
>> other device switches off the interrupts for an extended period of
>> time.  But I believe such devices are slowly dying unmaintained in
>> the vast plains under /usr/src/linux/drivers/char/*.  In any case
>> it should not bite you if you do not have any such device in your
>> computer.

> It all depends: Usually just test your hardware in a typical
> use-case: if it doesn't loose interrupts the first day, it most
> likely won't the other day.

All the time tick interupt code has to do is increment a counter,
and return.

When the system get back to exit to the user or idle loop, it tests the
tick counter and if it is not zero, runs the `clock tick' code. Wash,

This allows you to run with out ever masking out the clock interupt.

Paul Repacholi                               1 Crescent Rd.,
+61 (08) 9257-1001                           Kalamunda.
                                             West Australia 6076
comp.os.vms,- The Older, Grumpier Slashdot
Raw, Cooked or Well-done, it's all half baked.
EPIC, The Architecture of the future, always has been, always will be.

More information about the questions mailing list