perf intel-pt: Change branch stack support to use thread-stacks

Browse source

Change Intel PT's branch stack support to use thread stacks. The
advantages of using branch stack support from the thread-stack are:

1. the branches are accumulated separately for each thread
2. the branch stack is cleared only in between continuous traces

This helps pave the way for adding branch stacks to regular events, not
just synthesized events as at present.

While the 2 approaches are not identical, in simple cases the results
can be identical e.g.

  Before:

    # perf record --kcore -e intel_pt// uname
    # perf script --itrace=i10usl -F+brstacksym,+addr,+flags > cmp1.txt

  After:

    # perf script --itrace=i10usl -F+brstacksym,+addr,+flags > cmp2.txt
    # diff -s cmp1.txt cmp2.txt
    Files cmp1.txt and cmp2.txt are identical

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200429150751.12570-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

...

This commit is contained in:

Adrian Hunter 2020-04-29 18:07:45 +03:00 • committed by Arnaldo Carvalho de Melo

parent 1ef998ff18

commit cf888e08a0

1 changed files with 39 additions and 102 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

141

tools/perf/util/intel-pt.c

View file