[ntp:questions] Re: program to test actual resolution of Linux?

David L. Mills mills at udel.edu
Sat Sep 6 19:42:08 UTC 2003


Drk,

See the jitter.c program in the NTP software distribution. Please also
reprise recent messages to this group on this topic.

Dave

Drk Ryan wrote:
> 
> >>>But Windows provides a function, GetSystemTimeAsFileTime(), that
> >>>allows you to query the system time in 100 nanosecond intervals.
> 
> >>What you mean is that the function returns time with a theoretical
> >>resolution of 100ns. However it would appear likely that the actual
> >>times returned have a resolution of 10ms.  [rearranged slightly]
> >>Write a program that busy loop calls this function and saves the results
> >>over say 1000 calls.
> 
> >I wrote a program that retrieved 10,000 unique values from the
> >GetSystemTimeAsFileTime() function, then analyzed the delta between
> >consecutive times. Out of 9,999 deltas, 9,974 of them were 10.144
> >milliseconds.
> 
> Does anyone have code available to do this for Linux?



More information about the questions mailing list