From: Minchan Kim <minchan@xxxxxxxxxx>
Subject: mm: remove lru_add_drain_all in alloc_contig_range
__alloc_contig_migrate_range already has lru_add_drain_all call via
migrate_prep. It's necessary to move LRU taget pages into LRU list to be
able to isolated. However, lru_add_drain_all call after
__alloc_contig_migrate_range is pointless since it has changed source page
freeing from putback_lru_pages to put_page[1].
This patch removes it.
[1] c6c919eb90e0, ("mm: use put_page() to free page instead of putback_lru_page()"
Link: https://lkml.kernel.org/r/20210303204512.2863087-1-minchan@xxxxxxxxxx
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 2 --
1 file changed, 2 deletions(-)
--- a/mm/page_alloc.c~mm-remove-lru_add_drain_all-in-alloc_contig_range
+++ a/mm/page_alloc.c
@@ -8649,8 +8649,6 @@ int alloc_contig_range(unsigned long sta
* isolated thus they won't get removed from buddy.
*/
- lru_add_drain_all();
-
order = 0;
outer_start = start;
while (!PageBuddy(pfn_to_page(outer_start))) {
_
