[PATCH v2 00/18] Lazily load PMU data

From: Ian Rogers
Date: Thu Aug 24 2023 - 00:14:29 EST


Lazily load PMU data both from sysfs and json files. Reorganize
json data to be more PMU oriented to facilitate this, for
example, json data is now sorted into arrays for their PMU.

In refactoring the code some changes were made to get rid of maximum
encoding sizes for events (256 bytes), with input files being directly
passed to the lex generated code. There is also a small event parse
error message improvement.

Some results from an Intel tigerlake laptop running Debian:

Binary size reduction of 5.3% or 552,864 bytes because the PMU
name no longer appears in the string or desc field.

stat -e cpu/cycles/ minor faults reduced from 1733 to 1667, open calls reduced
from 171 to 94.

stat default minor faults reduced from 1805 to 1717, open calls reduced
from 654 to 343.

Average PMU scanning reduced from 4720.641usec to 2927.293usec.
Average core PMU scanning reduced from 1004.658usec to 232.668usec
(4.3x faster).

v2: Add error path for failing strdup when allocating a format,
suggested by Arnaldo. Rebased on top of tmp.perf-tools-next
removing 8 patches. Added "perf jevents: Don't append Unit to
desc" to save yet more encoding json event space.

Ian Rogers (18):
perf pmu: Make the loading of formats lazy
perf pmu: Abstract alias/event struct
perf pmu-events: Add extra underscore to function names
perf jevents: Group events by PMU
perf parse-events: Improve error message for double setting
perf s390 s390_cpumcfdg_dump: Don't scan all PMUs
perf pmu-events: Reduce processed events by passing PMU
perf pmu-events: Add pmu_events_table__find_event
perf pmu: Parse sysfs events directly from a file
perf pmu: Prefer passing pmu to aliases list
perf pmu: Merge json events with sysfs at load time
perf pmu: Cache json events table
perf pmu: Lazily add json events
perf pmu: Scan type early to fail an invalid PMU quickly
perf pmu: Be lazy about loading event info files from sysfs
perf pmu: Lazily load sysfs aliases
perf jevents: Sort strings in the big C string to reduce faults
perf jevents: Don't append Unit to desc

tools/perf/arch/x86/util/intel-pt.c | 2 +-
tools/perf/bench/pmu-scan.c | 8 +-
tools/perf/builtin-list.c | 13 +-
tools/perf/pmu-events/empty-pmu-events.c | 49 +-
tools/perf/pmu-events/jevents.py | 312 +++++++--
tools/perf/pmu-events/pmu-events.h | 15 +-
tools/perf/tests/parse-events.c | 2 +-
tools/perf/tests/pmu-events.c | 148 +++--
tools/perf/tests/pmu.c | 2 +-
tools/perf/util/metricgroup.c | 10 +-
tools/perf/util/parse-events.c | 87 ++-
tools/perf/util/parse-events.h | 3 +-
tools/perf/util/pmu.c | 806 +++++++++++++++--------
tools/perf/util/pmu.h | 96 ++-
tools/perf/util/pmu.y | 20 +-
tools/perf/util/pmus.c | 230 +++----
tools/perf/util/s390-sample-raw.c | 50 +-
17 files changed, 1141 insertions(+), 712 deletions(-)

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2.42.0.rc1.204.g551eb34607-goog