On 18 Jun 2025, at 15:18, Matthew Wilcox wrote: > On Wed, Jun 18, 2025 at 03:10:10PM -0400, Zi Yan wrote: >> On 18 Jun 2025, at 13:39, David Hildenbrand wrote: >>> + /* >>> + * TODO: these pages will not be folios in the future. All >>> + * folio dependencies will have to be removed. >>> + */ >>> + struct folio *folio = page_folio(page); >>> + >>> + VM_WARN_ON_ONCE_PAGE(!PageIsolated(page), page); >>> + folio_lock(folio); >>> + /* If the page was released by it's owner, there is nothing to do. */ >>> + if (PageMovable(page)) >>> + page_movable_ops(page)->putback_page(page); >>> + ClearPageIsolated(page); >>> + folio_unlock(folio); >>> + folio_put(folio); >> >> Why not use page version of lock, unlock, and put? Especially you are >> thinking about not using folio for these pages. Just a question, >> I am OK with current patch. > > That would reintroduce unnecessary calls to compound_head(). Got it. But here page is not folio, so it cannot be a compound page. Then, we will need page versions without compound_head() for non compound pages. Could that happen in the future when only folio can be compound and page is only order-0? Best Regards, Yan, Zi
