Re: [PATCH v8 0/2] perf tests: Add uncore and x86 topdown event sorting tests

[Ian Rogers]

On Sun, May 17, 2026 at 11:29 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> A patch thread changing event sorting highlighted a lack of testing
> for the more complicated uncore and x86 perf metric event sorting:
> https://lore.kernel.org/linux-perf-users/CAP-5=fWRgDo7UnJAD4C--d=mVPRhOEWZVyU7nVM1YEp3jncAgg@xxxxxxxxxxxxxx/

Purely test changes with green analysis from Sashiko:
https://sashiko.dev/#/patchset/20260518062904.2591616-1-irogers%40google.com
It would be nice to get help landing this.

Thanks,
Ian

> v8: Simplify event_cb in the uncore event sorting test by removing the
>     unreachable dead-code else block (reported by Sashiko).
>
> v7: - Prevent double-free of m.event1 and dangling pointer access upon
>       PMU scanning loop termination or early continue in the uncore
>       event sorting test by utilizing standard perf zfree() helpers
>       (reported by Sashiko).
>     - Document Intel Hybrid CPU architectural invariants in the x86
>       topdown test to clarify why instructions correctly leads a group
>       of 2 on E-cores (cpu_atom) where slots is unsupported and
>       filtered out (reported by Sashiko).
>
> v6: - Ensure robust error initialization and resource cleanup in both
>       uncore and topdown tests by initializing evlist to NULL and
>       parse_events_error at function entry, preventing uninitialized
>       stack access or resource leaks on early return paths (reported
>       by Sashiko).
>     - Prevent double evaluation and duplicate debug logging upon test
>       assertion failure in the x86 topdown test by caching test_sort()
>       return values into local variables (reported by Sashiko).
>
> v5: - Strengthen uncore event sorting test assertions to require at
>       least 4 total events (>= 2 groups of 2 events) instead of > 0
>       events, guaranteeing that multi-PMU wildcard expansion is
>       genuinely exercised across multiple sibling PMUs (reported by Sashiko).
>     - Fix memory leaks on assertion failure across both uncore and
>       topdown test suites by replacing standard TEST_ASSERT macros
>       with local CHECK macros that correctly branch to out_err cleanup
>       handlers (reported by Sashiko).
>     - Fix test_sort() in the x86 topdown test to correctly return TEST_FAIL (-1)
>       instead of parse_events() internal error codes (e.g., -EINVAL) when event
>       parsing fails (reported by Namhyung).
>
> v4: Fix malformed event group string formatting in the uncore event
>     sorting test when running on AMD systems (where sysfs event
>     aliases lack JSON descriptions - reported by Namhyung). Added a
>     helper to strip redundant PMU prefixes and trailing slashes to
>     ensure parse_events() receives valid syntax across all
>     architectures.
>
> v3: Address sashiko nits on using evsel__name and ensuring slots is injected.
> https://lore.kernel.org/linux-perf-users/20260331185419.4085479-1-irogers@xxxxxxxxxx/
>
> v2: Address indentation and other nits from Namhyung. Add Zide Chen's
>     tested-by tags.
> https://lore.kernel.org/lkml/20260331165207.4016392-1-irogers@xxxxxxxxxx/
>
> v1: https://lore.kernel.org/lkml/20260325183045.1229502-1-irogers@xxxxxxxxxx/
>
> Ian Rogers (2):
>   perf tests: Add test for uncore event sorting
>   perf arch x86 tests: Add test for topdown event sorting
>
>  tools/perf/arch/x86/tests/topdown.c     | 166 +++++++++++++++++++++-
>  tools/perf/tests/Build                  |   1 +
>  tools/perf/tests/builtin-test.c         |   1 +
>  tools/perf/tests/tests.h                |   1 +
>  tools/perf/tests/uncore-event-sorting.c | 176 ++++++++++++++++++++++++
>  5 files changed, 344 insertions(+), 1 deletion(-)
>  create mode 100644 tools/perf/tests/uncore-event-sorting.c
>
> --
> 2.54.0.563.g4f69b47b94-goog
>