Re: [PATCH v3] mm/page_alloc: clear page->private in free_pages_prepare()

[David Hildenbrand (Arm)]

On 2/9/26 18:44, Zi Yan wrote:
> On 9 Feb 2026, at 12:36, David Hildenbrand (Arm) wrote:
>
> > On 2/9/26 17:33, Zi Yan wrote:
> > > I agree. Silently fixing non zero ->private just moves the work/responsibility
> > > from users to core mm. They could do better. :)
> > >
> > > We can have a patch or multiple patches to fix users do not zero ->private
> > > when freeing a page and add the patch below.
> >
> > Do we know roughly which ones don't zero it out?
>
> So far based on [1], I found:
>
> 1. shmem_swapin_folio() in mm/shmem.c does not zero ->swap.val (overlapping
> with private);
> 2. __free_slab() in mm/slub.c does not zero ->inuse, ->objects, ->frozen
> (overlapping with private).
>
> Mikhail found ttm_pool_unmap_and_free() in drivers/gpu/drm/ttm/ttm_pool.c
> does not zero ->private, which stores page order.

Looks doable then :) Should we take v3 as a quick fix to backport then?

--
Cheers,

David