Re: [LSF/MM/BPF TOPIC] Weighted interleave auto-tuning

From: Gregory Price
Date: Thu Mar 27 2025 - 08:39:33 EST


On Thu, Mar 27, 2025 at 12:11:55PM +0100, Oscar Salvador wrote:
> Hi Joshua,
>
> as discussed in the LSFMM about how you can react to nodes becoming
> memory{aware,less}, you can register a hotplug memory notifier, as
> memory-tiering currently does.
>
> The current use of the hotplug memory notifier by some consumers (e.g:
> memory-tiering, slub, etc) is a bit suboptimal, as they only care about
> nodes changing its memory state, yet they get notified for every
> {online,offline}_pages operation.
>
> I came up with [1]
>
> I did not publish it yet upstream because I wanted to discuss it a bit
> with David, but you can give it a try to see if it works for you.
> But till it is upstream, you will have to use the hotplug memory
> notifier.
>
> [1] https://github.com/leberus/linux.git numa-node-notifier
>

+CC: Yunjeong Mun and Rakie Kim

Something to consider as a follow up to your series.

Thanks Oscar, we were just discussing this. Seems there's multiple
users doing the same thing, so it seems reasonable to discuss. This
would probably deal with my race condition concerns here as well:

https://lore.kernel.org/linux-mm/20250325102804.1020-1-rakie.kim@xxxxxx/

> --
> Oscar Salvador
> SUSE Labs