Messages in this thread | | | Date | Tue, 12 Jan 2016 16:34:40 +0100 | From | Peter Zijlstra <> | Subject | Re: [RFC] perf record: missing buildid for callstack modules |
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On Tue, Jan 12, 2016 at 11:38:05AM -0300, Arnaldo Carvalho de Melo wrote: > > Also, just parsing the gigabytes of data that comes out of perf-record > > takes significant time, let alone poking around the filesystem and > > Right, that is what we would elliminate with stashing the content-based > cookie into a PERF_RECORD_MMAP3 record.
Again, how would you go about getting that cookie for a DSO? The whole kernel isn't involved with dlopen(), all it sees is a mmap(PROT_EXEC).
> BTW, mtime would incur in postprocessing it all.
mtime can still warn you if things are non-matching at report time without this post-processing, and thereby solves the problem of staring at broken/wrong data.
It doesn't get you right data, but knowing your data is broken allows you to manually do things 'right'.
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