[PATCH v2 5/9] mm/hugetlb: convert isolate_or_dissolve_huge_page to folios

Sidhartha Kumar
2022-11-01T22:32:54Z

Removes a call to compound_head() by using a folio when operating on the
head page of a hugetlb compound page.

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
---
mm/hugetlb.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 2a48feadb41c..bcc39d2613b2 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2815,7 +2815,7 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page,
int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
{
struct hstate *h;
- struct page *head;
+ struct folio *folio = page_folio(page);
int ret = -EBUSY;

/*
@@ -2824,9 +2824,8 @@ int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
* Return success when racing as if we dissolved the page ourselves.
*/
spin_lock_irq(&hugetlb_lock);
- if (PageHuge(page)) {
- head = compound_head(page);
- h = page_hstate(head);
+ if (folio_test_hugetlb(folio)) {
+ h = folio_hstate(folio);
} else {
spin_unlock_irq(&hugetlb_lock);
return 0;
@@ -2841,10 +2840,10 @@ int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
if (hstate_is_gigantic(h))
return -ENOMEM;

- if (page_count(head) && !isolate_hugetlb(head, list))
+ if (folio_ref_count(folio) && !isolate_hugetlb(&folio->page, list))
ret = 0;
- else if (!page_count(head))
- ret = alloc_and_dissolve_huge_page(h, head, list);
+ else if (!folio_ref_count(folio))
+ ret = alloc_and_dissolve_huge_page(h, &folio->page, list);

return ret;
}
--
2.31.1