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From:   Suren Baghdasaryan <surenb@google.com>
Date:   Wed, 5 Jul 2023 18:16:48 -0700
Message-ID: <CAJuCfpENo+xJOFjy7geYJjH54cT6e9t-Qw18AvcwNrcE2AMicw@mail.gmail.com>
Subject: Re: [PATCH v3 2/2] mm: disable CONFIG_PER_VMA_LOCK until its fixed
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Peter Xu <peterx@redhat.com>, David Hildenbrand <david@redhat.com>,
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On Wed, Jul 5, 2023 at 5:49=E2=80=AFPM Suren Baghdasaryan <surenb@google.co=
m> wrote:
>
> On Wed, Jul 5, 2023 at 5:44=E2=80=AFPM Andrew Morton <akpm@linux-foundati=
on.org> wrote:
> >
> > On Wed, 5 Jul 2023 17:32:09 -0700 Suren Baghdasaryan <surenb@google.com=
> wrote:
> >
> > > On Wed, Jul 5, 2023 at 5:30=E2=80=AFPM Suren Baghdasaryan <surenb@goo=
gle.com> wrote:
> > > >
> > > > On Wed, Jul 5, 2023 at 5:24=E2=80=AFPM Andrew Morton <akpm@linux-fo=
undation.org> wrote:
> > > > >
> > > > > On Wed, 5 Jul 2023 13:33:26 -0700 Suren Baghdasaryan <surenb@goog=
le.com> wrote:
> > > > >
> > > > > > I was hoping we could re-enable VMA locks in 6.4 once we get mo=
re
> > > > > > confirmations that the problem is gone. Is that not possible on=
ce the
> > > > > > BROKEN dependency is merged?
> > > > >
> > > > > I think "no".  By doing this we're effectively backporting a mino=
r
> > > > > performance optimization, which isn't a thing we'd normally do.
> > > >
> > > > In that case, maybe for 6.4 we send the fix and only disable it by
> > > > default without marking BROKEN? That way we still have a way to ena=
ble
> > > > it if desired?
> > >
> > > I'm preparing the next version with Liam's corrections. If the above
> > > option I suggested is acceptable I can send a modified second patch
> > > which would not have BROKEN dependency.
> >
> > I think just mark it broken and move on.  At some later time we can
> > consider backporting the fixes into 6.4.x and reenabling, but I don't
> > think it's likely that we'll do this.
>
> Uh, ok. I'll send the next version shortly with the patch fixing the
> issue and another one marking it BROKEN. Hopefully in the next version
> we can roll it our more carefully, removing BROKEN dependency but
> keeping it disabled by default?

v4 is posted at
https://lore.kernel.org/all/20230706011400.2949242-1-surenb@google.com/
Thanks,
Suren.

>
> >