On Thu, 2021-06-17 at 08:34 +0100, Marc Zyngier wrote:
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On Thu, 17 Jun 2021 05:51:03 +0100, Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:
On Wed, Jun 16, 2021 at 09:28:59PM +0200, Aman Priyadarshi wrote:
From: Suzuki K Poulose suzuki.poulose@arm.com
[ Upstream commit 3cce50dfec4a5b0414c974190940f47dd32c6dee ]
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 Signed-off-by: Aman Priyadarshi apeureka@amazon.de Cc: stable@vger.kernel.org
arch/arm64/kernel/perf_event.c | 50 +++++++++++++++++++-------------
1 file changed, 28 insertions(+), 22 deletions(-)
What stable tree(s) do you want this applied to?
I guess that'd be 4.14 and previous stables if the patch actually applies.
Correct. I have tested the patch on 4.14.y, can confirm that it applies cleanly on 4.9.y as well.
Thanks, Aman Priyadarshi
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