Messages in this thread | | | Date | Fri, 22 Jun 2012 12:32:34 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [RFC/PATCHSET 0/8] perf tools: Minimal build without libelf dependency (v2) |
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Em Fri, Jun 22, 2012 at 09:18:34AM -0600, David Ahern escreveu: > On 6/22/12 9:05 AM, Namhyung Kim wrote: > >2012-06-22 (금), 11:47 +0200, Peter Zijlstra: > >>On Fri, 2012-06-22 at 14:37 +0900, Namhyung Kim wrote: > >>>And then I realized that the perf record needs to know about the > >>>build-id's anyway. :( So I implemented a poor man's version of elf > >>>parser only for parsing the build-id info.
> >>Why? the very first versions didn't know about any of that nonsense :-) > >>It works just fine as long as you don't go change binaries around. > >> > >>That said, you did the work already, so no objection, just saying > >>builtids aren't that important.
> >I'm not sure I understood you correctly. But 'perf record' needs to know > >about the build-id's to save them to perf.data for 'perf report' later. > >And 'perf archive' also needs to know about them to select necessary > >binaries for the session.
> And build-id's are not required for report (-B option for record).
> Also, the intent is for a small footprint binary for embedded > systems. On such a system I would expect binaries and libraries to > be stripped, so no point in running perf-archive.
Right, build ids are not a strict requirement, its just a safeguard, when available, to prevent WTF moments at post processing time (report, annotate, etc) if different binaries are used to resolve symbols.
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