Thoughts on SystemTap, Perf and LTTng ?

[Frank Ch. Eigler]

Hi Davide -


dblistsub-fedora wrote:

> [...]  I am considering using one of the above to see if they can
> usefully substitute the practice of peppering code with tracing
> statements (logging or performance analysis are not the focus). As I
> would be a beginner in any of them, I was curious about the current
> and expected state of the three in Fedora and opinions about the
> relative merits. [...]

Each of them is small and interesting enough that time taken to play
with them all won't be wasted.  They are different in many ways, and
have different capabilities / restrictions, but each should roughly be
able to do what you need.

http://sourceware.org/systemtap/wiki/SystemtapDtraceComparison


For purposes of avoiding peppering code with tracing statements, I
suspect systemtap would be the easiest, in theory:

# stap -e 'probe process.statement("function at foo/bar.c:2322") {
     printf("var1=%d var2=%s\n", $var1, user_string($var2))
}' -c "./a.out ARGS"


- FChE