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A comment on 60x speed-up of Linux “perf”. Parent comment

Re:60x speed-up of Linux “perf” by tonyg on Thursday September 09, 2021 @10:35AM (#28470140)
Steinar Gunderson (who suggested [1] the talk-through-a-pipe approach) just now compared [2] the `libbfd` variant to the pipe-to-`addr2line` version, and found them to take similar amounts of time.

This agrees with what I saw in `top` while testing: with the patch, I see `perf` using ~95% CPU, with `addr2line` using the remaining ~5%.

So speeding up `addr2line` probably wouldn't result in very much of an overall improvement for this workload.

[1]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=911815#28 [2]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=911815#38

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Re:60x speed-up of Linux “perf” by vlovich123 on Thursday September 09, 2021 @11:07AM (#28470501)
The piping is a good chunk of the gain but the gimli library is still much faster than addr2line & uses less memory if used correctly. Since libbfd shows similar results, I'm thinking there might be a speed bump from switching to use it (some care has to be taken to preserve 0-copy semantics across FFI).
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Re:60x speed-up of Linux “perf” by tonyg on Thursday September 09, 2021 @11:10AM (#28470545)
It'd definitely be interesting to find out!
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