Re: [PATCH RFC 2/9] mm: page_reporting: skip redundant zeroing of host-zeroed reported pages

David Hildenbrand (Arm)
2026-04-14T15:32:27Z

On 4/14/26 12:22, Michael S. Tsirkin wrote:
> On Tue, Apr 14, 2026 at 11:18:02AM +0200, David Hildenbrand (Arm) wrote:
>> On 4/13/26 22:35, Michael S. Tsirkin wrote:
>>>
>>>
>>> So here's an only alternative I see: a page flag for when page is in
>>> buddy and a new "prezero" bool that we have to propagate everywhere
>>> else. This is a patch on top. More elegant? Please tell me if you prefer that.
>>> If yes I will squash it into the appropriate patches.
>>
>> I'd be interesting to know how this would look without the GFP flag,
>> when we don't have to leak any of this out of the buddy.
>>
>> --
>> Cheers,
>>
>> David
>
> But the zeroing takes place outside of the buddy now, it's more
> "reporting" than "leaking".

Exposing some buddy internals using questionable GFP flags, however you
want to call that hack ;)

>
> You mean, moving the zeroing into buddy?

Yes. Such that it doesn't really matter how we maintain this information
internally. A page flag is probably still nicer for that purpose.

--
Cheers,

David