[PATCH v2 0/9] jevents/pmu-events improvements

Ian Rogers irogers at google.com
Thu Dec 22 09:34:11 AEDT 2022


Add an optimization to jevents using the metric code, rewrite metrics
in terms of each other in order to minimize size and improve
readability. For example, on Power8
other_stall_cpi is rewritten from:
"PM_CMPLU_STALL / PM_RUN_INST_CMPL - PM_CMPLU_STALL_BRU_CRU / PM_RUN_INST_CMPL - PM_CMPLU_STALL_FXU / PM_RUN_INST_CMPL - PM_CMPLU_STALL_VSU / PM_RUN_INST_CMPL - PM_CMPLU_STALL_LSU / PM_RUN_INST_CMPL - PM_CMPLU_STALL_NTCG_FLUSH / PM_RUN_INST_CMPL - PM_CMPLU_STALL_NO_NTF / PM_RUN_INST_CMPL"
to:
"stall_cpi - bru_cru_stall_cpi - fxu_stall_cpi - vsu_stall_cpi - lsu_stall_cpi - ntcg_flush_cpi - no_ntf_stall_cpi"
Which more closely matches the definition on Power9.

A limitation of the substitutions are that they depend on strict
equality and the shape of the tree. This means that for "a + b + c"
then a substitution of "a + b" will succeed while "b + c" will fail
(the LHS for "+ c" is "a + b" not just "b").

Separate out the events and metrics in the pmu-events tables saving
14.8% in the table size while making it that metrics no longer need to
iterate over all events and vice versa. These changes remove evsel's
direct metric support as the pmu_event no longer has a metric to
populate it. This is a minor issue as the code wasn't working
properly, metrics for this are rare and can still be properly ran
using '-M'.

Add an ability to just build certain models into the jevents generated
pmu-metrics.c code. This functionality is appropriate for operating
systems like ChromeOS, that aim to minimize binary size and know all
the target CPU models.

v2. Rebase. Modify the code that skips rewriting a metric with the
    same name with itself, to make the name check case insensitive.

Ian Rogers (9):
  perf jevents metric: Correct Function equality
  perf jevents metric: Add ability to rewrite metrics in terms of others
  perf jevents: Rewrite metrics in the same file with each other
  perf pmu-events: Separate metric out of pmu_event
  perf stat: Remove evsel metric_name/expr
  perf jevents: Combine table prefix and suffix writing
  perf pmu-events: Introduce pmu_metrics_table
  perf jevents: Generate metrics and events as separate tables
  perf jevents: Add model list option

 tools/perf/arch/arm64/util/pmu.c         |  23 +-
 tools/perf/arch/powerpc/util/header.c    |   4 +-
 tools/perf/builtin-list.c                |  20 +-
 tools/perf/builtin-stat.c                |   1 -
 tools/perf/pmu-events/Build              |   3 +-
 tools/perf/pmu-events/empty-pmu-events.c | 111 ++++++-
 tools/perf/pmu-events/jevents.py         | 353 ++++++++++++++++++-----
 tools/perf/pmu-events/metric.py          |  79 ++++-
 tools/perf/pmu-events/metric_test.py     |  10 +
 tools/perf/pmu-events/pmu-events.h       |  26 +-
 tools/perf/tests/expand-cgroup.c         |   4 +-
 tools/perf/tests/parse-metric.c          |   4 +-
 tools/perf/tests/pmu-events.c            |  68 ++---
 tools/perf/util/cgroup.c                 |   1 -
 tools/perf/util/evsel.c                  |   2 -
 tools/perf/util/evsel.h                  |   2 -
 tools/perf/util/metricgroup.c            | 203 +++++++------
 tools/perf/util/metricgroup.h            |   4 +-
 tools/perf/util/parse-events.c           |   2 -
 tools/perf/util/pmu.c                    |  44 +--
 tools/perf/util/pmu.h                    |  10 +-
 tools/perf/util/print-events.c           |  32 +-
 tools/perf/util/print-events.h           |   3 +-
 tools/perf/util/python.c                 |   7 -
 tools/perf/util/stat-shadow.c            | 112 -------
 tools/perf/util/stat.h                   |   1 -
 26 files changed, 666 insertions(+), 463 deletions(-)

-- 
2.39.0.314.g84b9a713c41-goog



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