perf/x86/intel: Avoid disable PMU if !cpuc->enabled in sample read

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The WARN_ON(this_cpu_read(cpu_hw_events.enabled)) in the
intel_pmu_save_and_restart_reload() is triggered, when sampling read
topdown events.

In a NMI handler, the cpu_hw_events.enabled is set and used to indicate
the status of core PMU. The generic pmu->pmu_disable_count, updated in
the perf_pmu_disable/enable pair, is not touched.
However, the perf_pmu_disable/enable pair is invoked when sampling read
in a NMI handler. The cpuc->enabled is mistakenly set by the
perf_pmu_enable().

Avoid disabling PMU if the core PMU is already disabled.
Merge the logic together.

Fixes: 7b2c05a15d ("perf/x86/intel: Generic support for hardware TopDown metrics")
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20250121152303.3128733-2-kan.liang@linux.intel.com

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This commit is contained in:

Kan Liang 2025-01-21 07:23:01 -08:00 • committed by Peter Zijlstra

parent 314dfe1057

commit f9bdf1f953

3 changed files with 25 additions and 29 deletions

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45

arch/x86/events/intel/core.c

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11

arch/x86/events/intel/ds.c

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2

arch/x86/events/perf_event.h

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