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. Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxx> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> --- 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 9db80ee29caa..c589bd8801bb 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -859,13 +859,10 @@ 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
