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[v2,0/2] Consistently prioritize legacy events

Message ID 20250312211623.2495798-1-irogers@google.com (mailing list archive)
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Series Consistently prioritize legacy events | expand

Message

Ian Rogers March 12, 2025, 9:16 p.m. UTC 
Legacy events were historically the priority over sysfs/json
events. This behavior was changed in commit a24d9d9dc096 ("perf
parse-events: Make legacy events lower priority than sysfs/JSON") to
fix issues on ARM Apple-M CPUs. Sysfs/json being the priority makes
most sense, was preferred by RISC-V and gives abilities impossible
with legacy events. Making this encoding consistent is proving
impossible with endless bike shedding, people saying they see
something as a fix then when that fix is provided continuing to
object, etc. Given that in the RFC [1] legacy events are seen as being
preferrable let's just follow up on that and make their use
consistent.

If it isn't clear, I think this is the wrong decision and landing [2]
should be the priority. When I try to have this conversation it just
gets ignored and I want consistency more than my preferred
prioritization.

[1] https://lore.kernel.org/lkml/Z7Z5kv75BMML2A1q@google.com/
[2] https://lore.kernel.org/linux-perf-users/20250109222109.567031-1-irogers@google.com/

v2: Missed revert of stat-display logic for json event prioritization.

Ian Rogers (2):
  perf parse-events: Make legacy events always have priority over
    sysfs/json
  Revert "perf evsel: Add alternate_hw_config and use in evsel__match"

 tools/perf/builtin-diff.c       |  6 +--
 tools/perf/tests/parse-events.c | 13 ++----
 tools/perf/util/evsel.c         | 21 ---------
 tools/perf/util/evsel.h         | 19 +++++++-
 tools/perf/util/parse-events.c  | 81 ++++++++++++---------------------
 tools/perf/util/parse-events.h  |  8 +---
 tools/perf/util/parse-events.y  |  2 +-
 tools/perf/util/pmu.c           |  6 +--
 tools/perf/util/pmu.h           |  2 +-
 tools/perf/util/stat-display.c  |  6 ---
 10 files changed, 57 insertions(+), 107 deletions(-)