Re: [PATCH RFC v3 01/19] mm: thread user_addr through page allocator for cache-friendly zeroing

David Hildenbrand (Arm)
2026-04-24T18:33:59Z

On 4/23/26 18:13, Michael S. Tsirkin wrote:
> On Thu, Apr 23, 2026 at 05:54:26PM +0200, David Hildenbrand (Arm) wrote:
>> On 4/23/26 16:46, Michael S. Tsirkin wrote:
>>>
>>> I just dislike it when things are non orthogonal.
>>> People are used to: hugetlb = same perf as THP but more predictable at the cost
>>> of being harder to use and using more resources.
>>> Here, suddenly, we have an optimization but only for THP.
>>
>> Note that we also didn't care about user_alloc_needs_zeroing() with hugetlb so far.
>
>
> You mean, that it stays because of the reserved pool?

I meant, that if we are running with init_on_free or init_on_alloc, that we end
up double-zeroing right now upstream. So nobody cared to optimize that part so far.

--
Cheers,

David