Re: [PATCH v1 2/3] mm: process_mrelease: skip LRU movement for exclusive file folios

Michal Hocko
2026-04-29T14:44:19Z

On Wed 29-04-26 15:07:04, David Hildenbrand wrote:
> On 4/29/26 12:33, Michal Hocko wrote:
> > On Wed 29-04-26 11:09:55, David Hildenbrand wrote:
> >> Unrelated stupid question: would things be clearer if we could rename
> >> MMF_UNSTABLE to MMF_OOM_REAPING once figure out whether aborting fork() still
> >> really needs it?
> >
> > While the oom is the only current kernel user of MMF_UNSTABLE (in a
> > sense it sets the flag) the flag should denote that any page faults are
> > reliable because it might fault in a fresh memory and user would lose
> > the previous content without knowing that. Not sure MMF_OOM_REAPING
> > would reflect that reality better.
>
> We use it for failed fork() as well, but that's slightly different semantics (no
> real page faults ever made sense).

The bottom line is the same. Make sure PF fails rather than silently
provide potentially corrupted data.

> Looking at the original patch here, using MMF_OOM_REAPING to modify zapping
> behavior would be clearer than MMF_UNSTABLE, I guess.

Ohh, you mean to add a new flag, right?
--
Michal Hocko
SUSE Labs