[PATCH v12 0/2] tools/perf: Support PERF_SAMPLE_READ with inherit

[Ben Gainey]

This revision of this change splits out the tools/perf changes requested
by Namhyung Kim for my previous work to enable PERF_SAMPLE READ with inherit (see
https://lore.kernel.org/linux-perf-users/20240730084417.7693-1-ben.gainey@xxxxxxx/ )
as the kernel side changes have been picked up by Peter Zijlstra.

Changes since v11:
 - Rebased onto perf-tools-next (b38c49d8296b9eee)

Changes since v10:
 - Fixed a formatting nit

Changes since v9:
 - Split out tools/perf patches only
 - Fixed system-wide mode in `perf record` to not set the inherit bit.

Changes since v8:
 - Rebase on v6.11-rc1

Changes since v7:
 - Rebase on v6.10-rc3
 - Respond to Peter Zijlstra's feedback:
 - Renamed nr_pending to nr_no_switch_fast and merged in nr_inherit_read
   which otherwise had overlapping use
 - Updated some of the commit messages to provide better justifications
   of usecase, behavioural changes and so on
 - Cleanup perf_event_count/_cumulative
 - Make it explicit that the sampling event decides whether or not the
   per-thread value is given in read_format for PERF_RECORD_SAMPLE and
   PERF_RECORD_READ; updated tools to account for this.

Changes since v6:
 - Rebase on v6.10-rc2
 - Make additional "perf test" tests succeed / skip based on kernel
   version as per feedback from Namhyung.

Changes since v5:
 - Rebase on v6.9
 - Cleanup feedback from Namhyung Kim

Changes since v4:
 - Rebase on v6.9-rc1
 - Removed the dependency on inherit_stat that was previously assumed
   necessary as per feedback from Namhyung Kim.
 - Fixed an incorrect use of zfree instead of free in the tools leading
   to an abort on tool shutdown.
 - Additional test coverage improvements added to perf test.
 - Cleaned up the remaining bit of irrelevant change missed between v3
   and v4.

Changes since v3:
 - Cleaned up perf test data changes incorrectly included into this
   series from elsewhere.

Changes since v2:
 - Rebase on v6.8
 - Respond to James Clarke's feedback; fixup some typos and move some
   repeated checks into a helper macro.
 - Cleaned up checkpatch lints.
 - Updated perf test; fixed evsel handling so that existing tests pass
   and added new tests to cover the new behaviour.

Changes since v1:
 - Rebase on v6.8-rc1
 - Fixed value written into sample after child exists.
 - Modified handling of switch-out so that context with these events
   take the slow path, so that the per-event/per-thread PMU state is
   correctly switched.
 - Modified perf tools to support this mode of operation.

Ben Gainey (2):
  tools/perf: Correctly calculate sample period for inherited
    SAMPLE_READ values
  tools/perf: Allow inherit + PERF_SAMPLE_READ when opening events

 tools/lib/perf/evsel.c                        | 48 ++++++++++++++
 tools/lib/perf/include/internal/evsel.h       | 63 ++++++++++++++++++-
 tools/perf/tests/attr/README                  |  2 +
 tools/perf/tests/attr/test-record-C0          |  2 +
 tools/perf/tests/attr/test-record-dummy-C0    |  2 +-
 .../tests/attr/test-record-group-sampling     |  3 +-
 .../tests/attr/test-record-group-sampling1    | 51 +++++++++++++++
 .../tests/attr/test-record-group-sampling2    | 61 ++++++++++++++++++
 tools/perf/tests/attr/test-record-group2      |  1 +
 ...{test-record-group2 => test-record-group3} | 10 +--
 tools/perf/util/evsel.c                       | 21 ++++++-
 tools/perf/util/evsel.h                       |  1 +
 tools/perf/util/session.c                     | 28 ++++++---
 13 files changed, 273 insertions(+), 20 deletions(-)
 create mode 100644 tools/perf/tests/attr/test-record-group-sampling1
 create mode 100644 tools/perf/tests/attr/test-record-group-sampling2
 copy tools/perf/tests/attr/{test-record-group2 => test-record-group3} (81%)

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2.46.1