Re: Ktimer / -rt9 (+custom) monotonic_clock going backwards.

From: Steven Rostedt
Date: Thu Oct 20 2005 - 01:40:40 EST




On Wed, 19 Oct 2005, Daniel Walker wrote:

> On Wed, 19 Oct 2005, Steven Rostedt wrote:
>
> >
> > Hi Thomas,
> >
> > I switched my custom kernel timer to use the ktimers with the prio of -1
> > as you mentioned to me offline. I set up the timer to be monotonic and
> > have a requirement that the returned time is always greater or equal to
> > the last time returned from do_get_ktime_mono.
> >
> > Now here's the results that I got between two calls of do_get_ktime_mono
> >
> > 358.069795728 secs then later 355.981483177. Should this ever happen?
>
> Are you running NTP ?
>

Yes, but that shouldn't make a difference. NTP can slow down or speed up
the clock, but it should never make it go backwards. Especially for a
monotonic clock (as the name suggests).

-- Steve

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