Commit 18dbcbfabfff ("perf: Fix the POLL_HUP delivery breakage") added a
direct pmu->stop() call when the refresh limit reaches zero. The change
was based on a test program [1] that reported missing POLL_HUP
notifications.However, the test program used SIGIO, which is a standard signal and can be coalesced. As a result, userspace may miss signal delivery even though the signal was generated by the kernel. This is expected behaviour for standard signals. This series adds a selftest for the PERF_EVENT_IOC_REFRESH limit using a real-time signal, which guarantees queued signal delivery and confirms that POLL_HUP notifications are delivered reliably on arm64. With that verified, the direct pmu->stop() call introduced by commit 18dbcbfabfff can be reverted, since event disabling is already handled through perf_event_disable_inatomic(). [1] https://lore.kernel.org/lkml/[email protected]/ Signed-off-by: Leo Yan <[email protected]> --- Leo Yan (2): selftests/perf_events: Add test for refresh limit signals Revert "perf: Fix the POLL_HUP delivery breakage" kernel/events/core.c | 1 - tools/testing/selftests/perf_events/.gitignore | 1 + tools/testing/selftests/perf_events/Makefile | 3 +- .../testing/selftests/perf_events/refresh_signal.c | 120 +++++++++++++++++++++ 4 files changed, 123 insertions(+), 2 deletions(-) --- base-commit: 50897c955902c93ae71c38698abb910525ebdc89 change-id: 20260429-arm_cs_clean_perf_handle-763cc339c1f5 Best regards, -- Leo Yan <[email protected]>
