[PATCH 1/2] mm/memory_hotplug: remove head page reference in do_migrate_range

From: Sidhartha Kumar
Date: Mon Jan 23 2023 - 15:25:10 EST


The head page variable is not needed as we can use folio equivalent
functions.

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
---
mm/memory_hotplug.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index a1e8c3e9ab08..ad09189786b1 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1624,7 +1624,7 @@ static int
do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long pfn;
- struct page *page, *head;
+ struct page *page;
int ret = 0;
LIST_HEAD(source);
static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL,
@@ -1637,14 +1637,13 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
continue;
page = pfn_to_page(pfn);
folio = page_folio(page);
- head = &folio->page;

- if (PageHuge(page)) {
- pfn = page_to_pfn(head) + compound_nr(head) - 1;
+ if (folio_test_hugetlb(folio)) {
+ pfn = folio_pfn(folio) + folio_nr_pages(folio) - 1;
isolate_hugetlb(folio, &source);
continue;
- } else if (PageTransHuge(page))
- pfn = page_to_pfn(head) + thp_nr_pages(page) - 1;
+ } else if (folio_test_transhuge(folio))
+ pfn = folio_pfn(folio) + thp_nr_pages(page) - 1;

/*
* HWPoison pages have elevated reference counts so the migration would
--
2.39.1