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

Gregory Price
2026-03-27T19:43:41Z

On Fri, Mar 27, 2026 at 03:12:16PM -0400, Tal Zussman wrote:
>
> It's been well-known in the academic realm for a while that there isn't
> really a "one-size-fits-all" policy that works *best* for all workloads.
> Yes, you can make a general policy that works *well*, but if you really care
> about a workload's performance and want to squeeze out the last 10-20% (or
> more) of performance, you need to be able to (1) experiment and (2) take
> advantage of application-level insights. Being able to extend reclaim (in
> our case with eBPF) enables that.
>

This just makes me think going all the way to reclaim_ext and re-writing
MGLRU as an eBPF extension in an effort to simplify the code/maintenance
and keep what works working is the least-worst option.

But this is a naive take, i'm sure making that interface stable would be
even worse than just maintaining both LRU/MGLRU.

~Gregory