On Tue, Jul 14, 2020 at 11:46:12AM +0200, Vlastimil Babka wrote: > On 7/13/20 3:57 AM, Robbie Ko wrote: > > > > Vlastimil Babka 於 2020/7/10 下午11:31 寫道: > >> On 7/9/20 4:48 AM, robbieko wrote: > >>> From: Robbie Ko <robbieko@xxxxxxxxxxxx> > >>> > >>> When a migrate page occurs, we first create a migration entry > >>> to replace the original pte, and then go to fallback_migrate_page > >>> to execute a writeout if the migratepage is not supported. > >>> > >>> In the writeout, we will clear the dirty bit of the page and use > >>> page_mkclean to clear the dirty bit along with the corresponding pte, > >>> but page_mkclean does not support migration entry. I don't follow the scenario. When we establish migration entries with try_to_unmap(), it transfers dirty bit from PTE to the page. -- Kirill A. Shutemov
