Re: Implement lbr-as-callgraph v10

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Wed, Nov 12, 2014 at 06:05:18PM -0800, Andi Kleen escreveu:
> [Reworks to address all the review feedback. Rebased to latest tree]
> [Just a repost after a rebase]
> [Even more review feedback and some bugs addressed.]
> [Only port to changes in perf/core. No other changes.]
> [Rebase to latest perf/core]
> [Another rebase. No changes]
> 
> This patchkit implements lbr-as-callgraphs in per freport,
> as an alternative way to present LBR information.

Ok, I have this in my perf/core branch, but I need to test it further,
as I couldn't get the output that appears on some of the changelogs.

If you could take a look at

git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux perf/core

To see if I made some mistake, that would be of help,

Thanks

- Arnaldo
 
> Current perf report does a histogram over the branch edges,
> which is useful to look at basic blocks, but doesn't tell
> you anything about the larger control flow behaviour.
> 
> This patchkit adds a new option --branch-history that
> adds the branch paths to the callgraph history instead.
> 
> This allows to reason about individual branch paths leading
> to specific samples.
> 
> Also available at
> git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-misc perf/lbr-callgraph8
> 
> v2:
> - rebased on perf/core
> - fix various issues
> - rename the option to --branch-history
> - various fixes to display the information more concise
> v3:
> - White space changes
> - Consolidate some patches
> - Update some descriptions
> v4:
> - Fix various display problems
> - Unknown srcline is now printed as symbol+offset
> - Refactor some code to address review feedback
> - Merge with latest tip
> - Fix missing srcline display in stdio hist output.
> v5:
> - Rename functions
> - Fix gtk build problem
> - Fix crash without -g
> - Improve error messages
> - Improve srcline display in various ways
> v6:
> - Port to latest perf/core
> v7:
> - Really port to latest perf/core
> v8:
> - Rebased on 3.16-rc1
> v9:
> - Rebase on 3.17-rc* tip/perf/core
> v10:
> - Rebase to latest tree.
> - Address review feedback (except where commented). See
> the individual patches for changelog. I dropped the -v 
> option support.
> 
> Example output:
> 
>     % perf record -b -g ./tsrc/tcall
>     [ perf record: Woken up 1 times to write data ]
>     [ perf record: Captured and wrote 0.044 MB perf.data (~1923 samples) ]
>     % perf report --branch-history
>     ...
>         54.91%  tcall.c:6  [.] f2                      tcall
>                 |
>                 |--65.53%-- f2 tcall.c:5
>                 |          |
>                 |          |--70.83%-- f1 tcall.c:11
>                 |          |          f1 tcall.c:10
>                 |          |          main tcall.c:18
>                 |          |          main tcall.c:18
>                 |          |          main tcall.c:17
>                 |          |          main tcall.c:17
>                 |          |          f1 tcall.c:13
>                 |          |          f1 tcall.c:13
>                 |          |          f2 tcall.c:7
>                 |          |          f2 tcall.c:5
>                 |          |          f1 tcall.c:12
>                 |          |          f1 tcall.c:12
>                 |          |          f2 tcall.c:7
>                 |          |          f2 tcall.c:5
>                 |          |          f1 tcall.c:11
>