-------- Tom Van Baak writes: >If you do your kernel timekeeping in integers and modulus arithmetic you >are essentially doing cycle counting and the kernel will keep perfect >time relative to the external oscillator. So that should be the goal. >Not e-6, not e-9, not e-10, but perfect cycle counting. Consider this a >strong plea for someone in both BSD- and Linux- land to pull that off.
But not all of us have masers Tom :-) Problem is, you still need fractions when NTP tells you that the X-tal is 7.1PPM off frequency. When I did timecounters, I tried a couple of things of the sort you suggest, but when I benchmarked it, a single brutal 64 bit multiply with a 32bit shift invariably ran faster, had more predictable latency, worked with any frequency the hardware happened to have and did NTP's bidding: http://phk.freebsd.dk/pubs/timecounter.pdf -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.