Re: [PATCH v4 2/3] Support for perf to probe into SDT markers:

[Frank Ch. Eigler]

Pekka Enberg <penberg@xxxxxxxxxx> writes:

> Is there a technical reason why 'perf list' could not show all the
> available SDT markers on a system and that the 'mark to event'
> mapping cannot happen automatically? [...]

A quick experiment with:

  find `echo $PATH | tr : ' '` -type f -perm -555 | 
       xargs readelf -n 2>/dev/null | 
       grep STAP 2>/dev/null 

suggests reasonable performance for my F19 workstation (a second or
two over ~6000 executables), once all the ELF content is in the block
cache.  According to a stap eventcount.stp run, that required about
50000 syscall.read events.

Note that a $PATH search excludes shared libraries, which can also
carry <sys/sdt.h> markers.  Adding /usr/lib* in more than doubles the
work, then there's /usr/libexec etc.

- FChE
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