arm64: perf: Disable PMU while processing counter overflows

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The arm64 PMU updates the event counters and reprograms the
counters in the overflow IRQ handler without disabling the
PMU. This could potentially cause skews in for group counters,
where the overflowed counters may potentially loose some event
counts, while they are reprogrammed. To prevent this, disable
the PMU while we process the counter overflows and enable it
right back when we are done.

This patch also moves the PMU stop/start routines to avoid a
forward declaration.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

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Suzuki K Poulose 2018-07-10 09:58:03 +01:00 • committed by Will Deacon

parent 0c55d19c16

commit 3cce50dfec

1 changed files with 28 additions and 22 deletions

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arch/arm64/kernel/perf_event.c

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