On 09.02.21 18:50, Minchan Kim wrote:
__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 called is pointless.This patch removes it. Signed-off-by: Minchan Kim <minc...@kernel.org> --- mm/page_alloc.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6446778cbc6b..f8fbee73dd6d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8603,8 +8603,6 @@ int alloc_contig_range(unsigned long start, unsigned long end, * 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))) {
I was expecting some magical reason why this is still required but I am not able to find a compelling one. Maybe this is really some historical artifact.
Let's see if other people know why this call here still exists. -- Thanks, David / dhildenb
