[ntp:questions] Re: ntpd transmit timestamp precision
Harlan Stenn
stenn at ntp.isc.org
Thu Feb 16 05:40:36 UTC 2006
>>> In article <TuTIf.1718$k6.34212 at nasal.pacific.net.au>, Damion de Soto <damion at cyberguard.com.au> writes:
Damion> ... (incidently, in the two libraries i've just looked in - glibc &
Damion> uClibc - the clock_gettime() function just calls gettimeofday()
Damion> anyway - so they definately shouldn't be treated differently)
Interesting - what does clock_getres() tell you on those systems?
Damion> the system clock precision is calculated in default_get_precision()
Damion> in ntp_proto.c - this function uses consecutive calls to
Damion> get_systime() to calculate the minimum tick difference. Won't this
Damion> be always wrong if the random fuzz code in get_systime() is used,
Damion> and give a much higher precision than is really available?
This could easily be fixed by adding another parameter to get_systime() that
would disable the fuzz, assuming it really is a problem (from my initial
glance I think it is a problem, but I am working on way too many things
right now).
H
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