On Thu, Jun 17, 2021 at 10:57:00AM +0200, Aman Priyadarshi wrote: > On Thu, 2021-06-17 at 08:34 +0100, Marc Zyngier wrote: > > CAUTION: This email originated from outside of the organization. Do not > > click links or open attachments unless you can confirm the sender and > > know the content is safe. > > > > > > > > On Thu, 17 Jun 2021 05:51:03 +0100, > > Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > > On Wed, Jun 16, 2021 at 09:28:59PM +0200, Aman Priyadarshi wrote: > > > > From: Suzuki K Poulose <suzuki.poulose@xxxxxxx> > > > > > > > > [ 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@xxxxxxx> > > > > Cc: Will Deacon <will.deacon@xxxxxxx> > > > > Acked-by: Mark Rutland <mark.rutland@xxxxxxx> > > > > Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx> > > > > Signed-off-by: Will Deacon <will.deacon@xxxxxxx> > > > > Signed-off-by: Aman Priyadarshi <apeureka@xxxxxxxxx> > > > > Cc: stable@xxxxxxxxxxxxxxx > > > > --- > > > > 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. Now queued up, thanks. greg k-h
