Re: [LSF/MM/BPF TOPIC][RFC PATCH v4 00/27] Private Memory Nodes (w/ Compressed RAM)

Gregory Price
2026-02-23T16:08:46Z

On Mon, Feb 23, 2026 at 09:54:55AM -0500, Gregory Price wrote:
> On Mon, Feb 23, 2026 at 02:07:15PM +0100, David Hildenbrand (Arm) wrote:
> >
> > I'm concerned about adding more special-casing (similar to what we already
> > added for ZONE_DEVICE) all over the place.
> >
> > Like the whole folio_managed_() stuff in mprotect.c
> >
> > Having that said, sounds like a reasonable topic to discuss.
> >
>
> Another option would be to add the hook to vma_wants_writenotify()
> instead of the page table code - and mask MM_CP_TRY_CHANGE_WRITABLE.
>

scratch all this - existing hooks exist for exactly this purpose:

can_change_[pte|pmd]_writable()

Surprised I missed this.

I can clean this up to remove it from the page table walks.

Still valid to question whether we want this, but at least the hook
lives with other write-protect hooks now.

~Gregory