[v13,41/72] mm: Convert huge_memory to XArray

Commit Message

Matthew Wilcox June 11, 2018, 2:06 p.m. UTC

From: Matthew Wilcox <[e-mail]>

Quite a straightforward conversion.

Signed-off-by: Matthew Wilcox <[e-mail]>
---
 mm/huge_memory.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

Patch

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index d43394fadbfd..1dfa4542fed9 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2439,13 +2439,13 @@  static void __split_huge_page(struct page *page, struct list_head *list,
 	ClearPageCompound(head);
 	/* See comment in __split_huge_page_tail() */
 	if (PageAnon(head)) {
-		/* Additional pin to radix tree of swap cache */
+		/* Additional pin to swap cache */
 		if (PageSwapCache(head))
 			page_ref_add(head, 2);
 		else
 			page_ref_inc(head);
 	} else {
-		/* Additional pin to radix tree */
+		/* Additional pin to page cache */
 		page_ref_add(head, 2);
 		xa_unlock(&head->mapping->i_pages);
 	}
@@ -2557,7 +2557,7 @@  bool can_split_huge_page(struct page *page, int *pextra_pins)
 {
 	int extra_pins;
 
-	/* Additional pins from radix tree */
+	/* Additional pins from page cache */
 	if (PageAnon(page))
 		extra_pins = PageSwapCache(page) ? HPAGE_PMD_NR : 0;
 	else
@@ -2653,17 +2653,14 @@  int split_huge_page_to_list(struct page *page, struct list_head *list)
 	spin_lock_irqsave(zone_lru_lock(page_zone(head)), flags);
 
 	if (mapping) {
-		void **pslot;
+		XA_STATE(xas, &mapping->i_pages, page_index(head));
 
-		xa_lock(&mapping->i_pages);
-		pslot = radix_tree_lookup_slot(&mapping->i_pages,
-				page_index(head));
 		/*
-		 * Check if the head page is present in radix tree.
+		 * Check if the head page is present in page cache.
 		 * We assume all tail are present too, if head is there.
 		 */
-		if (radix_tree_deref_slot_protected(pslot,
-					&mapping->i_pages.xa_lock) != head)
+		xa_lock(&mapping->i_pages);
+		if (xas_load(&xas) != head)
 			goto fail;
 	}