Re: [PROBLEM] perf report is broken in latest linus git

From: Ingo Molnar
Date: Thu Aug 13 2009 - 05:37:17 EST



* Pekka Enberg <penberg@xxxxxxxxxxxxxx> wrote:

> Latest Linus git kernel with -rc4 perf userspace:
>
> penberg@penberg-laptop:~/testing/jato$ perf record -f jato HelloWorldSwing
> [ perf record: Captured and wrote 1.402 MB perf.data (~61261 samples) ]
>
> penberg@penberg-laptop:~/testing/jato$ perf report --sort comm,dso,symbol|head -30
> # Samples: 60457
> #
> # Overhead Command Shared Object Symbol
> # ........ ....... ....................................... ......
> #
>
> [ Note: the jato executable doesn't appear anywhere in the trace. I'm
> pretty sure the libzip functions, for example, are from jato, not perf. ]
>
> 36.14% perf /home/penberg/bin/perf [.] dso__synthesize_plt_symbols
> 35.20% perf /home/penberg/bin/perf [.] dso__new
> 3.57% perf /home/penberg/bin/jato [.] 0x0000000000c910

Perhaps it's this commit:

4d1e00a: perf symbol: Fix symbol parsing in certain cases: use the build-id as a symlink

it does not revert cleanly, so you might want to check out these two
commits:

4d1e00a
4d1e00a~1

and build perf on both, and check with your anomalous perf.data
(without changing it) whether the output makes most sense.

Ingo
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