[PATCH v2 1/2] mm/page_alloc: remove unnecessary check in break_down_buddy_pages

From: Kemeng Shi
Date: Tue Sep 26 2023 - 23:17:39 EST


1. We always have target in range started with next_page and full free
range started with current_buddy.
2. The last split range size is 1 << low and low should be >= 0, then
size >= 1. So page + size != page is always true (because size > 0).
As summary, current_page will not equal to target page.

Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
Acked-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
---
mm/page_alloc.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e18e0e20eff8..bad979493dde 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6696,10 +6696,8 @@ static void break_down_buddy_pages(struct zone *zone, struct page *page,
if (set_page_guard(zone, current_buddy, high, migratetype))
continue;

- if (current_buddy != target) {
- add_to_free_list(current_buddy, zone, high, migratetype);
- set_buddy_order(current_buddy, high);
- }
+ add_to_free_list(current_buddy, zone, high, migratetype);
+ set_buddy_order(current_buddy, high);
}
}

--
2.30.0