Re: [PATCH 0/11] LTTng-core (basic tracing infrastructure) 0.5.108

Jose R. Santos
2006-09-15T21:08:35Z

Mathieu Desnoyers wrote:
> Please Ingo, stop repeating false argument without taking in account people's
> corrections :
>
> * Ingo Molnar (mingo@elte.hu) wrote:
> > sorry, but i disagree. There _is_ a solution that is superior in every
> > aspect: kprobes + SystemTap. (or any other equivalent dynamic tracer)
> >
>
> I am sorry to have to repeat myself, but this is not true for heavy loads.
>

This thread has already discuss the merits of static instrumentation
when it comes to the performance impacts. The key is now to find a
balance between static vs dynamic probes. While it is true that static
probes will provide less overhead compared to dynamic probes, some probe
point will see less of an impact in measurable performance impact of
dynamic probes due to the nature of the probe. We need to find what
that balance is.

To some people performance is the #1 priority and to other it is
flexibility. I would like to come up with a list of those probe point
that absolutely need to be inserted into the code statically. Those
that are not absolutely critical to have statically should be
implemented dynamically.

-JRS