Re: [PATCH v2 1/1] mm: skip mlocked THPs that are underused early in deferred_split_scan()

Lance Yang
2025-09-08T09:28:08Z

On 2025/9/8 17:12, David Hildenbrand wrote:
> On 08.09.25 11:07, Lance Yang wrote:
>> From: Lance Yang <lance.yang@linux.dev>
>>
>> When we stumble over a fully-mapped mlocked THP in the deferred shrinker,
>> it does not make sense to try to detect whether it is underused, because
>> try_to_map_unused_to_zeropage(), called while splitting the folio,
>> will not
>> actually replace any zeroed pages by the shared zeropage.
>>
>> Splitting the folio in that case does not make any sense, so let's not
>> even
>> scan to check if the folio is underused.
>>
>> Suggested-by: David Hildenbrand <david@redhat.com>
>
> Feel free to drop that, I only tweaked you description :)

Well, I'd actually prefer to keep it. Thanks for setting me straight on
try_to_map_unused_to_zeropage() ;p

>
> Acked-by: David Hildenbrand <david@redhat.com>

Cheers,
Lance