On 18.09.20 04:29, Wei Yang wrote: > On Wed, Sep 16, 2020 at 08:34:10PM +0200, David Hildenbrand wrote: >> Page isolation doesn't actually touch the pages, it simply isolates >> pageblocks and moves all free pages to the MIGRATE_ISOLATE freelist. >> >> We already place pages to the tail of the freelists when undoing >> isolation via __putback_isolated_page(), let's do it in any case >> (e.g., if order == pageblock_order) and document the behavior. >> >> This change results in all pages getting onlined via online_pages() to >> be placed to the tail of the freelist. > > I am sorry to not follow again. unset_migratetype_isolate() is used in > __offline_pages if my understanding is correct. How does it contribute on > online_pages? See -next / -mm, that should make it clearer. -- Thanks, David / dhildenb