[lttng-dev] kernel Tracer Clock

[Mathieu Desnoyers]

* Salman Rafiq (salman.rafiq at esk.fraunhofer.de) wrote:
> Hi Mathieu,
> 
> By looking into traces generated using kernel tracer, I see the
> frequency in metadata file to be default.
> I would like to know if there is a way to change default clock
> frequency (1e9 Hz) for the tracer to current Core clock frequency?
> using lttng command line tool or any other way?

Hi Salman,

You just have to modifiy lttng to implement your own trace clock, and
use that instead of the monotonic clock. Then, you must, for your
architecture, override the clock {} metadata description generated by
lttng, ideally by providing an arch-specific implementation in a header
added to lttng-modules (and moving a #define of the monotonic clock
description to a generic header).

Thanks,

Mathieu

> 
> Thanks.
> 
> Best Regards,
> Salman
> 
> --
> Salman Rafiq
> Industrial Communication
> Fraunhofer-Einrichtung für Systeme der Kommunikationstechnik ESK
> 
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> 
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-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com