On 2 Jul 2023, at 21:09, Yin, Fengwei wrote: > On 7/3/2023 3:51 AM, Zi Yan wrote: >>> (3) Mapcount of first (or any other) subpage (compount+subpage): for >>> folio_estimated_sharers(). >> This is another estimation. I wonder if we can use a different estimation >> like total_mapcount() > folio_nr_pages() instead. > Considering the partial folio mapping, I suppose we should use > total_mapcount() > folio->_nr_pages_mapped > as folio_estimated_sharers(). What you propose is to get a precise check instead of estimate, and you assume no PMD mapping and still require per-page mapcount. What I am proposing is to get rid of per-page mapcount, which is my goal, and use a single mapcount to do a rough estimate. -- Best Regards, Yan, Zi
Attachment:
signature.asc
Description: OpenPGP digital signature
