All of lore.kernel.org
 help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Aman Priyadarshi <apeureka@amazon.de>
Cc: Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
	Alexander Graf <graf@amazon.de>,
	Mark Rutland <mark.rutland@arm.com>,
	stable@vger.kernel.org, Ali Saidi <alisaidi@amazon.com>
Subject: Re: [PATCH] arm64: perf: Disable PMU while processing counter overflows
Date: Thu, 17 Jun 2021 06:51:03 +0200	[thread overview]
Message-ID: <YMrUt+Vhs5exEqVt@kroah.com> (raw)
In-Reply-To: <20210616192859.21708-1-apeureka@amazon.de>

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?

thanks,

greg k-h

  reply	other threads:[~2021-06-17  4:51 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-16 11:09 [v4.14.y] 3cce50dfec4a arm64: perf: Disable PMU while processing counter overflows Aman Priyadarshi
2021-06-16 14:55 ` Greg Kroah-Hartman
2021-06-16 19:28   ` [PATCH] " Aman Priyadarshi
2021-06-17  4:51     ` Greg Kroah-Hartman [this message]
2021-06-17  7:34       ` Marc Zyngier
2021-06-17  8:57         ` Aman Priyadarshi
2021-06-25 10:22           ` Greg Kroah-Hartman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YMrUt+Vhs5exEqVt@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=alisaidi@amazon.com \
    --cc=apeureka@amazon.de \
    --cc=graf@amazon.de \
    --cc=mark.rutland@arm.com \
    --cc=maz@kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.