[PATCH v6 37/99] mm: Convert huge_memory to XArray

[Matthew Wilcox]

From: Matthew Wilcox <mawil...@microsoft.com>

Quite a straightforward conversion.

Signed-off-by: Matthew Wilcox <mawil...@microsoft.com>
---
 mm/huge_memory.c | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f71dd3e7d8cd..5c275295bbd3 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2379,7 +2379,7 @@ static void __split_huge_page_tail(struct page *head, int 
tail,
        if (PageAnon(head) && !PageSwapCache(head)) {
                page_ref_inc(page_tail);
        } else {
-               /* Additional pin to radix tree */
+               /* Additional pin to page cache */
                page_ref_add(page_tail, 2);
        }
 
@@ -2450,13 +2450,13 @@ 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->pages);
        }
@@ -2568,7 +2568,7 @@ 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
@@ -2664,17 +2664,14 @@ 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->pages, page_index(head));
 
-               xa_lock(&mapping->pages);
-               pslot = radix_tree_lookup_slot(&mapping->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->pages.xa_lock) != head)
+               xa_lock(&mapping->pages);
+               if (xas_load(&xas) != head)
                        goto fail;
        }
 
-- 
2.15.1

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