Re: [PATCH v3 2/2] mm: disable CONFIG_PER_VMA_LOCK until its fixed

[Andrew Morton]

On Wed, 5 Jul 2023 17:32:09 -0700 Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote:

> On Wed, Jul 5, 2023 at 5:30 PM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote:
> >
> > On Wed, Jul 5, 2023 at 5:24 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> > >
> > > On Wed, 5 Jul 2023 13:33:26 -0700 Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote:
> > >
> > > > I was hoping we could re-enable VMA locks in 6.4 once we get more
> > > > confirmations that the problem is gone. Is that not possible once the
> > > > BROKEN dependency is merged?
> > >
> > > I think "no".  By doing this we're effectively backporting a minor
> > > 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 enable
> > 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.