[PATCH v1 0/3] Improve event groups for topdown, add X event modifier

[Ian Rogers]

In:
https://lore.kernel.org/lkml/20250822082233.1850417-1-dapeng1.mi@xxxxxxxxxxxxxxx/#t
Dapeng Mi and Xudong Hao reported that Intel topdown events have
issues with parsing when events are duplicated. While some of that is
intended, things could be better. These patches:

1) give error messages specific to topdown event grouping constraints,
2) fail groups if non-leaders fail to open (this appears to be old tech debt),
3) adds an 'X' event modifier to allow events to opt-out of being regrouped.

The 'X' modifier should also give a means to side-step future issues
in parse_events__sort_events_and_fix_groups should they come up.

Ian Rogers (3):
  perf evsel: Give warning for broken Intel topdown event grouping
  perf stat: Don't skip failing group events
  perf parse-events: Add 'X' modifier to exclude an event from being
    regrouped

 tools/perf/Documentation/perf-list.txt |  1 +
 tools/perf/arch/x86/util/evsel.c       | 62 ++++++++++++++++++++++++--
 tools/perf/builtin-stat.c              | 48 +++++++++-----------
 tools/perf/util/evsel.c                |  7 ++-
 tools/perf/util/evsel.h                |  3 +-
 tools/perf/util/parse-events.c         |  5 ++-
 tools/perf/util/parse-events.h         |  1 +
 tools/perf/util/parse-events.l         |  5 ++-
 8 files changed, 94 insertions(+), 38 deletions(-)

-- 
2.51.0.261.g7ce5a0a67e-goog