[PATCH 2/2] mm/memory_hotplug: remove head page reference in scan_movable_pages()

From: Sidhartha Kumar
Date: Mon Jan 23 2023 - 15:25:12 EST


Remove one user of the Huge Page macros which take in a page. Also remove
a reference to a head page variable by using a folio instead.

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

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index ad09189786b1..d5a0672cdf3a 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1579,7 +1579,8 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
unsigned long pfn;

for (pfn = start; pfn < end; pfn++) {
- struct page *page, *head;
+ struct page *page;
+ struct folio *folio;
unsigned long skip;

if (!pfn_valid(pfn))
@@ -1599,9 +1600,9 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
if (PageOffline(page) && page_count(page))
return -EBUSY;

- if (!PageHuge(page))
+ folio = page_folio(page);
+ if (!folio_test_hugetlb(folio))
continue;
- head = compound_head(page);
/*
* This test is racy as we hold no reference or lock. The
* hugetlb page could have been free'ed and head is no longer
@@ -1609,9 +1610,9 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
* cases false positives and negatives are possible. Calling
* code must deal with these scenarios.
*/
- if (HPageMigratable(head))
+ if (folio_test_hugetlb_migratable(folio))
goto found;
- skip = compound_nr(head) - (page - head);
+ skip = folio_nr_pages(folio) - (page - &folio->page);
pfn += skip - 1;
}
return -ENOENT;
--
2.39.1