On Mon, Nov 15, 2021 at 09:52:22PM +1100, Alistair Popple wrote: > +#ifdef CONFIG_MIGRATION > +/** > + * migration_entry_wait_on_locked - Wait for a migration entry to be removed > + * @page: page referenced by the migration entry. This should be @folio (you can test by running 'make htmldocs', or even 'make W=1' > + * @ptep: mapped pte pointer. This function will return with the ptep unmapped. > + * @ptl: already locked ptl. This function will drop the lock. > + * > + * Wait for a migration entry referencing the given page to be removed. This is > + * equivalent to put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE) except > + * this can be called without taking a reference on the page. Instead this > + * should be called while holding the ptl for the migration entry referencing > + * the page. The tool won't tell you to update these page references to be folio references ... so I will ;-) > +++ b/mm/migrate.c > @@ -305,15 +305,7 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, > page = pfn_swap_entry_to_page(entry); > page = compound_head(page); I think this whole function should be folio-based. That is: - struct page *page; + struct folio *folio; and folio = page_folio(pfn_swap_entry_to_page(entry));
