[PATCH v3 00/11] Better fixes for grouping of events

[Ian Rogers]

The rules for grouping events have grown more complex. Topdown events
must be grouped, but flags like --metric-no-group and flags on metrics
don't respect this. Uncore events may be expanded using wild cards for
PMU names, but then the events need reordering so the group members
are adjacent. Rather than fixing metrics, this change fixes the main
event parsing code to first sort and then regroup evsels.

As this is shared functionality changes to it should cause
concern. The change is done with the intent of simplifying and making
more robust the grouping logic, examples are given. If additional
changes are necessary, they are most likely necessary to the
evsel__group_pmu_name logic as the code avoids breaking groups that
are on the same "group" PMU. The group_pmu_name is a variant of the
pmu_name tweaked in the case of software and aux events, that use
groups in a slightly different manner to conventional events.

The code was manually tested as well as passing perf test on a Intel
tigerlake CPU with intel-pt.

v3. Rename pmu_name to group_pmu_name and add patch to warn when events are regrouped
    as requested by Namhyung.
v2. Fix up the commit message on 4/10 (thanks Arnaldo). Drop
    unnecessary v1 5/10 (thanks Kan). evlist->core.nr_groups wasn't
    being correctly maintained after the sort/regrouping and so the
    new patch 10/10 removes that variable and computes it from the
    evlist when necessary, generally just tests.

Ian Rogers (11):
  libperf evlist: Avoid a use of evsel idx
  perf stat: Don't remove all grouped events when CPU maps disagree
  perf record: Early auxtrace initialization before event parsing
  perf stat: Modify the group test
  perf evsel: Allow const evsel for certain accesses
  perf evsel: Add function to compute group PMU name
  perf parse-events: Pass ownership of the group name
  perf parse-events: Sort and group parsed events
  perf evsel: Remove use_uncore_alias
  perf evlist: Remove nr_groups
  perf parse-events: Warn when events are regrouped

 tools/lib/perf/evlist.c                  |  31 ++-
 tools/lib/perf/include/internal/evlist.h |   1 -
 tools/lib/perf/include/perf/evlist.h     |   1 +
 tools/perf/arch/x86/util/auxtrace.c      |  17 +-
 tools/perf/arch/x86/util/evlist.c        |  39 ++--
 tools/perf/builtin-record.c              |   8 +-
 tools/perf/builtin-report.c              |   2 +-
 tools/perf/builtin-stat.c                |  24 +-
 tools/perf/tests/bpf.c                   |   1 -
 tools/perf/tests/parse-events.c          |  24 +-
 tools/perf/tests/pfm.c                   |  12 +-
 tools/perf/tests/pmu-events.c            |   2 +-
 tools/perf/util/auxtrace.h               |   2 +
 tools/perf/util/evlist.c                 |   2 +-
 tools/perf/util/evlist.h                 |   8 +-
 tools/perf/util/evsel.c                  |  27 ++-
 tools/perf/util/evsel.h                  |   8 +-
 tools/perf/util/header.c                 |   3 +-
 tools/perf/util/metricgroup.c            |   3 +-
 tools/perf/util/parse-events.c           | 268 +++++++++++------------
 tools/perf/util/parse-events.h           |  14 +-
 tools/perf/util/parse-events.y           |  28 +--
 tools/perf/util/pfm.c                    |   1 -
 tools/perf/util/pmu.c                    |   6 +-
 tools/perf/util/python.c                 |   2 +-
 tools/perf/util/stat-shadow.c            |   2 +-
 26 files changed, 292 insertions(+), 244 deletions(-)

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2.40.0.rc0.216.gc4246ad0f0-goog