mm/hugetlb: get rid of page_hstate()

Commit Message

Sidhartha Kumar July 19, 2023, 5:59 p.m. UTC

Converts the last page_hstate() user to use folio_hstate() so
page_hstate() can be safely removed.

Signed-off-by: Sidhartha Kumar <[e-mail]>
---
 include/linux/hugetlb.h | 10 ----------
 mm/hugetlb.c            |  6 +++---
 mm/page_isolation.c     |  8 ++++----
 3 files changed, 7 insertions(+), 17 deletions(-)

Comments

Matthew Wilcox July 19, 2023, 6:11 p.m. UTC | #1

On Wed, Jul 19, 2023 at 10:59:44AM -0700, Sidhartha Kumar wrote:
> -			skip_pages = compound_nr(head) - (page - head);
> +			skip_pages = folio_nr_pages(folio) - (page - &folio->page);

It turns out that you can't do (page - head) under all configs.  It
works on all common ones, but the safe way to do what you want here is:

			skip_pages = folio_nr_pages(folio) -
					folio_page_idx(folio, page);

Patch

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 57f21279c529f..3d4de9c7326bb 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -847,11 +847,6 @@  static inline struct hstate *folio_hstate(struct folio *folio)
 	return size_to_hstate(folio_size(folio));
 }
 
-static inline struct hstate *page_hstate(struct page *page)
-{
-	return folio_hstate(page_folio(page));
-}
-
 static inline unsigned hstate_index_to_shift(unsigned index)
 {
 	return hstates[index].order + PAGE_SHIFT;
@@ -1088,11 +1083,6 @@  static inline struct hstate *folio_hstate(struct folio *folio)
 	return NULL;
 }
 
-static inline struct hstate *page_hstate(struct page *page)
-{
-	return NULL;
-}
-
 static inline struct hstate *size_to_hstate(unsigned long size)
 {
 	return NULL;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 71d18bb76b4df..b15ae05819a8a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1785,10 +1785,10 @@  static void free_hpage_workfn(struct work_struct *work)
 		node = node->next;
 		page->mapping = NULL;
 		/*
-		 * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate()
-		 * is going to trigger because a previous call to
+		 * The VM_BUG_ON_FOLIO(!folio_test_hugetlb(folio), folio) in
+		 * folio_hstate() is going to trigger because a previous call to
 		 * remove_hugetlb_folio() will call folio_set_compound_dtor
-		 * (folio, NULL_COMPOUND_DTOR), so do not use page_hstate()
+		 * (folio, NULL_COMPOUND_DTOR), so do not use folio_hstate()
 		 * directly.
 		 */
 		h = size_to_hstate(page_size(page));
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 6599cc965e216..cd36b9998483d 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -79,17 +79,17 @@  static struct page *has_unmovable_pages(unsigned long start_pfn, unsigned long e
 		 * handle each tail page individually in migration.
 		 */
 		if (PageHuge(page) || PageTransCompound(page)) {
-			struct page *head = compound_head(page);
+			struct folio *folio = page_folio(page);
 			unsigned int skip_pages;
 
 			if (PageHuge(page)) {
-				if (!hugepage_migration_supported(page_hstate(head)))
+				if (!hugepage_migration_supported(folio_hstate(folio)))
 					return page;
-			} else if (!PageLRU(head) && !__PageMovable(head)) {
+			} else if (!folio_test_lru(folio) && !__folio_test_movable(folio)) {
 				return page;
 			}
 
-			skip_pages = compound_nr(head) - (page - head);
+			skip_pages = folio_nr_pages(folio) - (page - &folio->page);
 			pfn += skip_pages - 1;
 			continue;
 		}