Home
Reading
Searching
Subscribe
Sponsors
Statistics
Posting
Contact
Spam
Lists
Links
About
Hosting
Filtering
Features Download
Marketing
Archives
FAQ
Blog
 
Gmane
From: Andi Kleen <andi <at> firstfloor.org>
Subject: Implement lbr-as-callgraph v5
Newsgroups: gmane.linux.kernel
Date: Tuesday 11th March 2014 01:05:13 UTC (over 2 years ago)
[Even more review feedback and some bugs addressed.]

This patchkit implements lbr-as-callgraphs in per freport,
as an alternative way to present LBR information.

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-callgraph4

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

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
 
CD: 4ms