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

Gregory Price
2026-03-26T20:30:50Z

On Thu, Mar 26, 2026 at 01:02:02PM -0700, Axel Rasmussen wrote:
>
> I think one thing we all agree on at least is, long term, there isn't
> really a good argument for having > 1 LRU implementation. E.g., we
> don't believe there are just irreconcilable differences, where one
> impl is better for some workloads, and another is better for others,
> and there is no way the two can be converged.
>

I absolutely believe there are irreconcilable differences - but not in
the sense that one is better or worse, but in the sense that features
from one cannot work in the other.

> - My sense is MGLRU is "close", meaning as Kairui said in "average"
> cases it is substantially better, and the gaps are both fairly narrow
> / edge-casey, and very solveable.
>

This is a really, really bold claim. So much of this is workload
dependent, and LRU has decades of battle-testing while MGLRU has barely
been around 4 years.

~Gregory