• Milian Wolff's avatar
    perf report: Enable sorting by srcline as key · 5dfa210e
    Milian Wolff authored
    Often it is interesting to know how costly a given source line is in
    total. Previously, one had to build these sums manually based on all
    addresses that pointed to the same source line. This patch introduces
    srcline as a sort key, which will do the aggregation for us.
    
    Paired with the recent addition of showing inline frames, this makes
    perf report much more useful for many C++ work loads.
    
    The following shows the new feature in action. First, let's show the
    status quo output when we sort by address. The result contains many hist
    entries that generate the same output:
    
      ~~~~~~~~~~~~~~~~
      $ perf report --stdio --inline -g address
      # Children      Self  Command       Shared Object        Symbol
      # ........  ........  ............  ...................  .........................................
      #
          99.89%    35.34%  cpp-inlining  cpp-inlining         [.] main
                |
                |--64.55%--main complex:655
                |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
                |          /usr/include/c++/6.3.1/complex:664 (inline)
                |          |
                |          |--60.31%--hypot +20
                |          |          |
                |          |          |--8.52%--__hypot_finite +273
                |          |          |
                |          |          |--7.32%--__hypot_finite +411
    ...
                 --35.34%--_start +4194346
                           __libc_start_main +241
                           |
                           |--6.65%--main random.tcc:3326
                           |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:1809 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:1818 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:185 (inline)
                           |
                           |--2.70%--main random.tcc:3326
                           |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:1809 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:1818 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:185 (inline)
                           |
                           |--1.69%--main random.tcc:3326
                           |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:1809 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:1818 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:185 (inline)
      ...
      ~~~~~~~~~~~~~~~~
    
    With this patch and `-g srcline` we instead get the following output:
    
      ~~~~~~~~~~~~~~~~
      $ perf report --stdio --inline -g srcline
      # Children      Self  Command       Shared Object        Symbol
      # ........  ........  ............  ...................  .........................................
      #
          99.89%    35.34%  cpp-inlining  cpp-inlining         [.] main
                |
                |--64.55%--main complex:655
                |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
                |          /usr/include/c++/6.3.1/complex:664 (inline)
                |          |
                |          |--64.02%--hypot
                |          |          |
                |          |           --59.81%--__hypot_finite
                |          |
                |           --0.53%--cabs
                |
                 --35.34%--_start
                           __libc_start_main
                           |
                           |--12.48%--main random.tcc:3326
                           |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:1809 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:1818 (inline)
                           |          /usr/include/c++/6.3.1/bits/random.h:185 (inline)
      ...
      ~~~~~~~~~~~~~~~~
    Signed-off-by: default avatarMilian Wolff <milian.wolff@kdab.com>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Cc: Yao Jin <yao.jin@linux.intel.com>
    Link: http://lkml.kernel.org/r/20170318214928.9047-1-milian.wolff@kdab.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    5dfa210e
sort.c 69 KB