[ntp:questions] Writing the drift file

Harlan Stenn stenn at ntp.org
Fri Mar 6 11:07:24 UTC 2015


David Taylor writes:
> On 06/03/2015 09:35, Harlan Stenn wrote:
> > Folks,
> >
> > A while ago we got a request from the embedded folks asking for a way to
> > limit the writing of the drift file unless there was a "big enough"
> > change in the value to warrant this.
> >
> > Somebody came up with an interesting way to do this that involves
> > looking to see how much the drift value has changed and only writing the
> > value if the change was "big enough".
> >
> > By my read of the code and the comments:
> >
> > 1) it looks like the code is implementing something other  than what the
> > comments want, and
> >
> > 2) what's described *or* implemented seems way more complicated than
> > what we need.
> >
> > I'm wondering if we should just let folks specify a drift/wander
> > threshold, and if the current value is more than that amount we write
> > the file, and if the current value is less than that amount we don't
> > bother updating the file.  If folks are on a filesystem where the number
> > of writes doesn't matter, no value would be set (or we could use 0.0)
> > and it's not an issue.
> >
> > Thoughts?
> 
> Sounds good to me.  But do you really mean "current value" or 
> "difference from last written value"?

Yes, I mean the difference from the last written value, thanks!
-- 
Harlan Stenn <stenn at ntp.org>
http://networktimefoundation.org - be a member!


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