As we no longer shuffle via generic_online_page() and when undoing isolation, we can simplify the comment.
We now effectively shuffle only once (properly) when onlining new memory. Reviewed-by: Wei Yang <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Alexander Duyck <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Wei Yang <[email protected]> Cc: Oscar Salvador <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Pankaj Gupta <[email protected]> Signed-off-by: David Hildenbrand <[email protected]> --- mm/memory_hotplug.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 03a00cb68bf7..b44d4c7ba73b 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -858,13 +858,10 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, undo_isolate_page_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE); /* - * When exposing larger, physically contiguous memory areas to the - * buddy, shuffling in the buddy (when freeing onlined pages, putting - * them either to the head or the tail of the freelist) is only helpful - * for maintaining the shuffle, but not for creating the initial - * shuffle. Shuffle the whole zone to make sure the just onlined pages - * are properly distributed across the whole freelist. Make sure to - * shuffle once pageblocks are no longer isolated. + * Freshly onlined pages aren't shuffled (e.g., all pages are placed to + * the tail of the freelist when undoing isolation). Shuffle the whole + * zone to make sure the just onlined pages are properly distributed + * across the whole freelist - to create an initial shuffle. */ shuffle_zone(zone); -- 2.26.2
