[PATCH v1 00/15] Compress the pmu_event tables

Ian Rogers irogers at google.com
Thu Jul 14 23:36:38 PDT 2022


jevents.py creates a number of large arrays from the json events. The
arrays contain pointers to strings that need relocating. The
relocations have file size, run time and memory costs. These changes
refactor the pmu_events API so that the storage of the pmu_event
struct isn't exposed. The format is then changed to an offset within a
combined big string, with adjacent pmu_event struct variables being
next to each other in the string separated by \0 - meaning only the
first variable of the struct needs its offset recording.

Some related fixes are contained with the patches. The architecture
jevents.py creates tables for can now be set by the JEVENTS_ARCH make
variable, with a new 'all' that generates the events and metrics for
all architectures.

An example of the improvement to the file size on x86 is:
no jevents - the same 19,579,104bytes
x86 jevents - ~12.5% file size saving 22,088,944bytes vs 25,235,048bytes
all jevents - ~15.8% file size saving 22,821,896bytes vs 27,106,648bytes
default build options plus NO_LIBBFD=1.

I originally suggested fixing this problem in:
https://lore.kernel.org/linux-perf-users/CAP-5=fVB8G4bdb9T=FncRTh9oBVKCS=+=eowAO+YSgAhab+Dtg@mail.gmail.com/

Ian Rogers (15):
  perf jevents: Simplify generation of C-string
  perf jevents: Add JEVENTS_ARCH make option
  perf jevent: Add an 'all' architecture argument
  perf jevents: Remove the type/version variables
  perf jevents: Provide path to json file on error
  perf jevents: Sort json files entries
  perf pmu-events: Hide pmu_sys_event_tables
  perf pmu-events: Avoid passing pmu_events_map
  perf pmu-events: Hide pmu_events_map
  perf test: Use full metric resolution
  perf pmu-events: Move test events/metrics to json
  perf pmu-events: Don't assume pmu_event is an array
  perf pmu-events: Hide the pmu_events
  perf metrics: Copy entire pmu_event in find metric
  perf jevents: Compress the pmu_events_table

 tools/perf/arch/arm64/util/pmu.c              |   4 +-
 tools/perf/pmu-events/Build                   |   6 +-
 .../arch/test/test_soc/cpu/metrics.json       |  64 +++
 tools/perf/pmu-events/empty-pmu-events.c      | 204 +++++++-
 tools/perf/pmu-events/jevents.py              | 478 ++++++++++++++----
 tools/perf/pmu-events/pmu-events.h            |  40 +-
 tools/perf/tests/expand-cgroup.c              |  25 +-
 tools/perf/tests/parse-metric.c               |  77 +--
 tools/perf/tests/pmu-events.c                 | 466 +++++++----------
 tools/perf/util/metricgroup.c                 | 275 ++++++----
 tools/perf/util/metricgroup.h                 |   5 +-
 tools/perf/util/pmu.c                         | 139 ++---
 tools/perf/util/pmu.h                         |   8 +-
 tools/perf/util/s390-sample-raw.c             |  50 +-
 14 files changed, 1128 insertions(+), 713 deletions(-)
 create mode 100644 tools/perf/pmu-events/arch/test/test_soc/cpu/metrics.json

-- 
2.37.0.170.g444d1eabd0-goog




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