Re: [LSF/MM/BPF TOPIC] Towards Unified and Extensible Memory Reclaim (reclaim_ext)

Shakeel Butt
2026-03-26T13:22:13Z

On Wed, Mar 25, 2026 at 07:05:47PM -0700, Andrew Morton wrote:
> On Wed, 25 Mar 2026 14:06:37 -0700 Shakeel Butt <shakeel.butt@linux.dev> wrote:
>
> > We should unify both algorithms into a single code path.
>
> I'm here to ask the questions which others fear will sound dumb.
>
> Is it indeed the plan to maintain both implementations?

I think in general the plan/wish was to have one implementation but the current
state shows that we are far from where we wish to be.

> I thought the
> long-term ambition was to knock MGLRU into shape and to drop the legacy LRU?

That might be the ambition but I don't think there was an agreement and there
weren't any efforts to do so. Traditional LRU has been battle tested for decades
and thus there were concerns/skepticisms about this ambition as well.

To me, the right way is to take step-by-step approach with clear evaluations and
comparison on unifying or selecting a component from one over the other.