Re: [PATCH 0/3] mm/mempolicy: add per-cgroup weighted interleave controls

[Gregory Price <gourry@gourry.net>]

On Wed, Nov 04, 2026 at 10:44:46AM +0800, Li Zhe wrote:
> 
> Does that distinction make the cgroup-scoped override acceptable? If not,
> could you suggest a better way to support this kind of administrative
> weight override without adding new mempolicy syscalls?
>

I'm a little confused why cgroup-anything is needed here when you could
just override the weight table / interleave functions.

I don't particularly like the idea of bpf hooks for a single mempolicy
mode as opposed to something more generally useful - and I question
how useful task-mempolicies are in general for tiered memory systems
(they also affect kernel allocation placement, which is not great).

You have many patch proposals recently trying to adjust the mempolicy
components and I think it might be helpful if we could chat a bit
about what big problems you're actually trying to solve.

I get that you want better control over task/task-groups, i think that
can be useful - but I also know that demotion immediately mucks all
this placement logic up (and we can't check vma / task policies at
demotion time) so I question how realisitic the value of these
extensions will be.

~Gregory