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Re: Hitachi djprobe mechanism
Mathieu Lacage wrote:
> This problem probably should be addressed in userspace and the way this
> should be solved is by calculating the location of the basic blocks of
> the function in which you want to insert the probe. Then, any basic
> block bigger than 5 bytes will be an acceptable candidate for probe
> insertion.
>
> Clearly, this is one of the reasons the kerninst people built a system-
> wide daemon which did perform the basic-block calculation.
>
> The attached ugly perl script evaluates the basic blocks and outputs
> statistics about their size. Please, note the "evaluate" verb used
> above. It means that I am pretty sure this script is not 100% reliable
> but it should give non-skewed results given the size of most binaries.
> Beware: this thing will suck away your CPU time.
This would certainly be a step in the right direction. I too am suprised
of the results. It would really be interesting to see how this compares
to the output from the compiler, as Michel suggests. ... there's still
that problem of finding out what's on a process' stack though ...
Karim
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