Re: [mm-unstable v4 5/5] mm: memcg: restore subtree stats flushing

[Shakeel Butt <shakeelb@google.com>]

On Tue, Dec 12, 2023 at 10:43 AM Andrew Morton
<akpm@linux-foundation.org> wrote:
>
> On Mon, 4 Dec 2023 23:58:56 +0000 Shakeel Butt <shakeelb@google.com> wrote:
>
> > On Mon, Dec 04, 2023 at 03:49:01PM -0800, Yosry Ahmed wrote:
> > [...]
> > >
> > > From 19af26e01f93cbf0806d75a234b78e48c1ce9d80 Mon Sep 17 00:00:00 2001
> > > From: Yosry Ahmed <yosryahmed@google.com>
> > > Date: Mon, 4 Dec 2023 23:43:29 +0000
> > > Subject: [PATCH] mm: memcg: remove stats flushing mutex
> > >
> > > The mutex was intended to make the waiters sleep instead of spin, and
> > > such that we can check the update thresholds again after acquiring the
> > > mutex. However, the mutex has a risk of priority inversion, especially
> > > since the underlying rstat lock can de dropped while the mutex is held.
> > >
> > > Synthetic testing with high concurrency of flushers shows no
> > > regressions without the mutex, so remove it.
> > >
> > > Suggested-by: Shakeel Butt <shakeelb@google.com>
> > > Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
> >
> > Acked-by: Shakeel Butt <shakeelb@google.com>
> >
>
> I'd like to move this series into mm-stable soon.  Are we all OK with that?

OK from me.