Messages in this thread | | | Subject | Re: [PATCH v4 2/3] Support for perf to probe into SDT markers: | From | (Frank Ch. Eigler) | Date | Sat, 26 Oct 2013 07:16:05 -0400 |
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Pekka Enberg <penberg@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.
- FChE
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