[PATCH 1/1] arch/arm/mm: fix major fault accounting when retrying under per-VMA lock

[Suren Baghdasaryan]

On Thu, Jan 25, 2024 at 6:04 PM Andrew Morton <akpm at linux-foundation.org> wrote:
>
> On Mon, 22 Jan 2024 22:43:05 -0800 Suren Baghdasaryan <surenb at google.com> wrote:
>
> > The change [1] missed ARM architecture when fixing major fault accounting
> > for page fault retry under per-VMA lock. Add missing code to fix ARM
> > architecture fault accounting.
> >
> > [1] 46e714c729c8 ("arch/mm/fault: fix major fault accounting when retrying under per-VMA lock")
> >
> > Fixes: 12214eba1992 ("mm: handle read faults under the VMA lock")
>
> What are the userspace-visible runtime effects of this change?

The user-visible effects is that it restores correct major fault
accounting that was broken after [2] was merged in 6.7 kernel. The
more detailed description is in [3] and this patch simply adds the
same fix to ARM architecture which I missed in [3]. I can re-send the
patch with the full description from [3] if needed.

>
> Is a cc:stable backport desirable?

Yes, I guess since [2] was merged in 6.7, cc-ing stable would be desirable.
Please let me know if you want me to re-send the patch with full
description and CC'ing stable.

[2] https://lore.kernel.org/all/20231006195318.4087158-6-willy@infradead.org/
[3] https://lore.kernel.org/all/20231226214610.109282-1-surenb@google.com/

>
> > Reported-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
> > Signed-off-by: Suren Baghdasaryan <surenb at google.com>