Re: [LSF/MM/BPF TOPIC] Improving MGLRU

[Shakeel Butt <shakeel.butt@linux.dev>]

On Mon, Mar 02, 2026 at 05:31:26PM -0800, Axel Rasmussen wrote:
> On Fri, Feb 27, 2026 at 9:56 AM Shakeel Butt <shakeel.butt@linux.dev> wrote:
> >
> > On Thu, Feb 26, 2026 at 03:54:22PM +0000, Matthew Wilcox wrote:
> > > On Fri, Feb 20, 2026 at 01:25:33AM +0800, Kairui Song wrote:
> > > > MGLRU has been introduced in the mainline for years, but we still have two LRUs
> > > > today. There are many reasons MGLRU is still not the only LRU implementation in
> > > > the kernel.
> > >
> > > To my mind, the biggest problem with MGLRU is that Google dumped it on us
> > > and ran away.  Commit 44958000bada claimed that it was now maintained and
> > > added three people as maintainers.  In the six months since that commit,
> > > none of those three people have any commits in mm/!  This is a shameful
> > > state of affairs.
> > >
> > > I say rip it out.
> >
> > I have very similar concerns. Though rather than ripping it out, I would like
> > we put efforts in unifying the two reclaim mechanism (traditional & MGLRU) over
> > improving MGLRU.
> 
> Shakeel, I think this is a great idea. If you have any ideas around
> low hanging fruit here, please share. I'm planning to invest much more
> time here going forward, so I'd be happy to turn some ideas into
> patches. :)

I think we can start with memcg LRU on which Chen (CCed) was working on. Also
why not propose a lsfmm discussion on the topic, I am sure many folks will be
interested.