Re: [PATCH v3 09/16] mm/rmap: use page_move_anon_rmap() when reusing a mapped PageAnon() page exclusively

[David Hildenbrand]

On 12.04.22 11:26, Vlastimil Babka wrote:
> On 3/29/22 18:04, David Hildenbrand wrote:
>> We want to mark anonymous pages exclusive, and when using
>> page_move_anon_rmap() we know that we are the exclusive user, as
>> properly documented. This is a preparation for marking anonymous pages
>> exclusive in page_move_anon_rmap().
>>
>> In both instances, we're holding page lock and are sure that we're the
>> exclusive owner (page_count() == 1). hugetlb already properly uses
>> page_move_anon_rmap() in the write fault handler.
> 
> Yeah, note that do_wp_page() used to call page_move_anon_rmap() always since
> the latter was introduced, until commit 09854ba94c6a ("mm: do_wp_page()
> simplification"). Probably not intended.

Yeah, it was buried underneath all that reuse_swap_page() complexity.


-- 
Thanks,

David / dhildenb