Commit 2f66a68f authored by Committed by Linus Torvalds
page-allocator: change migratetype for all pageblocks within a high-order page...
page-allocator: change migratetype for all pageblocks within a high-order page during __rmqueue_fallback When there are no pages of a target migratetype free, the page allocator selects a high-order block of another migratetype to allocate from. When the order of the page taken is greater than pageblock_order, all pageblocks within that high-order page should change migratetype so that pages are later freed to the correct free-lists. The current behaviour is that pageblocks change migratetype if the order being split matches the pageblock_order. When pageblock_order < MAX_ORDER-1, ownership is not changing correct and pages are being later freed to the incorrect list and this impacts fragmentation avoidance. This patch changes all pageblocks within the high-order page being split to the correct migratetype. Without the patch, allocation success rates for hugepages under stress were about 59% of physical memory on x86-64. With the patch applied, this goes up to 65%. Signed-off-by: Mel Gorman <firstname.lastname@example.org> Cc: Andy Whitcroft <email@example.com> Cc: KOSAKI Motohiro <firstname.lastname@example.org> Cc: KAMEZAWA Hiroyuki <email@example.com> Signed-off-by: Andrew Morton <firstname.lastname@example.org> Signed-off-by: Linus Torvalds <email@example.com>
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