[PATCH 12/16] mm/huge_memory: minor cleanup for split_huge_pages_all

From: Miaohe Lin
Date: Wed Jun 22 2022 - 13:07:24 EST


There is nothing to do if a zone doesn't have any pages managed by the
buddy allocator. So we should check managed_zone instead. Also if a thp
is found, there's no need to traverse the subpages again.

Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/huge_memory.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 506e7a682780..0030b4f67cd9 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2858,9 +2858,12 @@ static void split_huge_pages_all(void)
unsigned long total = 0, split = 0;

pr_debug("Split all THPs\n");
- for_each_populated_zone(zone) {
+ for_each_zone(zone) {
+ if (!managed_zone(zone))
+ continue;
max_zone_pfn = zone_end_pfn(zone);
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) {
+ int nr_pages;
if (!pfn_valid(pfn))
continue;

@@ -2876,8 +2879,10 @@ static void split_huge_pages_all(void)

total++;
lock_page(page);
+ nr_pages = thp_nr_pages(page);
if (!split_huge_page(page))
split++;
+ pfn += nr_pages - 1;
unlock_page(page);
next:
put_page(page);
--
2.23.0