Michael L. Semon wrote: > 1) Use my current Linux 2.6.18.1 + LinuxPPS and sit and watch as ntpd > darts +/- 120 us over the course of a few hours, even when idle. > > 2) Reboot to FreeBSD and let the kernel, hardpps, and the NTP kernel > code make more radical short-term adjustments, and ntpd will dart +/- 10 > us over a few hours. > > 3) Recompile glibc with support with older kernels without breaking my > system, then fetch Linux 2.6.17.8, fetch Ulrich's last PPSkit alpha, and > hope it all works.
If you do try a 2.6.17.X kernel maybe try with linuxpps. It seems there were changes to the linux clock in 2.6.18 that make convergence a lot slower. With 2.6.17 or 2.6.16 + linuxpps and default minpoll maxpoll my time usually stays within +/- 10us. Minpoll 4 maxpoll 4 and it is down to +/- 3us. For me 2.6.18 and later with default minpoll maxpoll means +/- 250us. Minpoll 4 maxpoll 4 and I am still looking at +/- 40us. My drift changes by less than 0.6ppm during the temperature cycle of a day. Freebsd or 2.6.17 (and lower) + linuxpps have no trouble following that change. 2.6.18 and later react too slowly. James _______________________________________________ questions mailing list [EMAIL PROTECTED] https://lists.ntp.isc.org/mailman/listinfo/questions
