Messages in this thread | | | From | Andi Kleen <> | Subject | mplement lbr-as-callgraph v6 | Date | Mon, 12 May 2014 16:20:20 -0700 |
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[Even more review feedback and some bugs addressed.] [Only port to changes in perf/core. No other changes.]
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 v6: - Port to latest perf/core
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
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