Re: [PATCH 3/3] tracing/function-return-tracer: add the overrunfield

From: Steven Rostedt
Date: Tue Nov 18 2008 - 11:43:52 EST



On Tue, 18 Nov 2008, Fr?d?ric Weisbecker wrote:
> >>
> >> Yeah, it was just a recommendation, and perhaps not a good one ;-)
> >>
> >> Frederic, it is better if you move the array from the thread info to
> >> the task struct. It will take up more memory but it is a hell of a
> >> lot safer. The pro here definitely outways the con.
> >
> > if the memory footprint starts mattering we could turn this into a
> > single pointer to an array - and add/remove these arrays (from all
> > tasks currently running) as the tracer is turned on/off.
> >
> > Ingo
> >
>
> Ok. So what do you suggest once? Do I begin to move the array from
> thread info to struct task but by keeping the static
> array or should I directly use a dynamic allocation and add/remove dynamically?

I would recommend using a static array in task struct (say 200?) and keep
the max recorded for later output. This way we can find a better size.

As for the dynamic use of different arrays. Put that towards the end. We
want to get this working solid first before adding more variables to the
equation.

-- Steve

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