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Subject[PATCH v9 39/61] mm: Convert huge_memory to XArray
Date
From: Matthew Wilcox <mawilcox@microsoft.com>

Quite a straightforward conversion.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
mm/huge_memory.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 89737c0e0d34..354b7f768d0f 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2442,13 +2442,13 @@ 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);
}
@@ -2560,7 +2560,7 @@ 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
@@ -2656,17 +2656,14 @@ 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;
}

--
2.16.1
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