On 10/26/2013 02:16 PM, Frank Ch. Eigler wrote:
Pekka Enberg <penb...@kernel.org> 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.
Thanks for providing numbers to the discussion. AFAICT, we
might even be able to just scan everything for 'perf list' by
default.
Pekka
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