Re: [PATCH v22 1/4] mm: add MAP_DROPPABLE for designating always lazily freeable mappings

Jason A. Donenfeld
2024-07-11T17:54:39Z

On Thu, Jul 11, 2024 at 07:27:27PM +0200, David Hildenbrand wrote:
> > PG_owner_priv_1 maps to PG_swapcache? :)
>
> Maybe the combination !swapbacked && swapcache could be used to indicate
> such folios. (we will never set swapbacked)
>
> But likely we have to be a bit careful here. We don't want
> folio_test_swapcache() to return for folios that ... are not in the
> swapcache.

I was thinking that too, but I'm afraid it's going to be another
whack-a-mole nightmare. Even for things like task_mmu in procfs that
show stats, that's going to be wonky.

Any other flags we can overload that aren't going to be already used in
our case?

Jason