[PATCH v1 5/5] mm/memory_hotplug: update comment regarding zone shuffling
From: David Hildenbrand <hidden>
Date: 2020-09-28 18:21:58
Also in:
linux-acpi, linux-mm, lkml, xen-devel
Subsystem:
memory hot(un)plug, memory management, the rest · Maintainers:
David Hildenbrand, Oscar Salvador, Andrew Morton, Linus Torvalds
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@linux-foundation.org> Cc: Alexander Duyck <redacted> Cc: Mel Gorman <redacted> Cc: Michal Hocko <mhocko@kernel.org> Cc: Dave Hansen <redacted> Cc: Vlastimil Babka <redacted> Cc: Wei Yang <redacted> Cc: Oscar Salvador <osalvador@suse.de> Cc: Mike Rapoport <rppt@kernel.org> Signed-off-by: David Hildenbrand <redacted> --- 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);
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2.26.2