[ltt-dev] Time in trace passes too slowly

[Mathieu Desnoyers]

* Francis Giraldeau (francis.giraldeau at usherbrooke.ca) wrote:
> Hi, 
> 
> In a trace, the time difference between two timestamps doesn't match the
> time it should have elapsed. For example, when measuring the duration of
> "sleep 1" in the trace, 0.358s is obtained. The real duration of the
> sleep is indeed 1 second. The error seems proportional to a constant
> factor. 
> 
> I get this behavior on a 32 bits Ubuntu with 2.6.35-24-lttng from the
> PPA. I'm running the same version of kernel but configured with 64 bits
> and durations are correct. 
> 
> I put a sample trace here:
> 
> http://secretaire.dorsal.polymtl.ca/~fgiraldeau/sleep-1x-1sec.tar.gz
> 
> Seems a bug to me, or maybe I'm doing something wrong?

What is the output of your /proc/cpuinfo ?

Can you paste your dmesg ?

Thanks,

Mathieu

> 
> Cheer, 
> 
> Francis
> 
> 
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-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com