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

[Andrew Morton]

On Mon, 4 Dec 2023 23:58:56 +0000 Shakeel Butt <shakeelb@xxxxxxxxxx> 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@xxxxxxxxxx>
> > 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@xxxxxxxxxx>
> > Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
> 
> Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
> 

I'd like to move this series into mm-stable soon.  Are we all OK with that?