[PATCH 5.16 0832/1039] mm/page_isolation: unset migratetype directly for non Buddy page

[Greg Kroah-Hartman]

From: Chen Wandun <chenwandun@xxxxxxxxxx>

[ Upstream commit 721fb891ad0b3956d5c168b2931e3e5e4fb7ca40 ]

In unset_migratetype_isolate(), we can bypass the call to
move_freepages_block() for non-buddy pages.

It will save a few cpu cycles for some situations such as cma and
hugetlb when allocating continue pages, in these situation function
alloc_contig_pages will be called.

alloc_contig_pages
	__alloc_contig_migrate_range
	isolate_freepages_range ==> pages has been remove from buddy
	undo_isolate_page_range
		unset_migratetype_isolate ==> can directly set migratetype

[osalvador@xxxxxxx: changelog tweak]

Link: https://lkml.kernel.org/r/20211229033649.2760586-1-chenwandun@xxxxxxxxxx
Fixes: 3c605096d315 ("mm/page_alloc: restrict max order of merging on isolated pageblock")
Signed-off-by: Chen Wandun <chenwandun@xxxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Wang Kefeng <wangkefeng.wang@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 mm/page_isolation.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index f67c4c70f17f6..6a0ddda6b3c53 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -115,7 +115,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype)
 	 * onlining - just onlined memory won't immediately be considered for
 	 * allocation.
 	 */
-	if (!isolated_page) {
+	if (!isolated_page && PageBuddy(page)) {
 		nr_pages = move_freepages_block(zone, page, migratetype, NULL);
 		__mod_zone_freepage_state(zone, nr_pages, migratetype);
 	}
-- 
2.34.1