On Fri, Sep 25, 2026 at 05:50:47PM -0700, Ackerley Tng wrote:
> + e.g. for tmpfs,
> + Use mount page size.
> + Respect mount size limits.
> + Use guest_memfd mpol and fall back to mount mpol.
> + Gregory, now you can set mpol upfront on a mount! [3])
I haven't had time to quite give this the read it deserves yet (have
been traveling this past week), but I think this mpol/mount issue can
be solved with a new dax driver (which maybe provides this provider
interface) without needing to involve numa policy at all.
Essentially
fd = open("/dev/cxl_dev", ...); /* backed by anondax driver */
then later when a fault on that fd happens, the driver provides an
anon-memory allocation that explicitly requests the node associated
with that device - as opposed to trying to jam this into mempolicy.
If you're planning to be at LPC, happy to discuss this in person, but I
think this provider pattern is likely much cleaner without mempolicy at
all if you can just make the provider do that allocation path for you.
~Gregory
