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

[Ian Rogers]

On Wed, Dec 21, 2022 at 2:34 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> 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

Ping. Looking for reviews.

Thanks,
Ian

>  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
>