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

[Zi Yan <ziy@nvidia.com>]

On 9 Feb 2026, at 14:39, David Hildenbrand (Arm) wrote:

> 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?

Sounds good to me.

Best Regards,
Yan, Zi