mm: Convert khugepaged_scan_shmem to XArray

Slightly shorter and easier to read code.

Signed-off-by: Matthew Wilcox <willy@infradead.org>

1 files changed, 5 insertions, 12 deletions

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 9610e8cba545..c13625c1ad5e 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1542,8 +1542,7 @@ static void khugepaged_scan_shmem(struct mm_struct *mm,
                 pgoff_t start, struct page **hpage)
 {
         struct page *page = NULL;
-        struct radix_tree_iter iter;
-        void **slot;
+        XA_STATE(xas, &mapping->i_pages, start);
         int present, swap;
         int node = NUMA_NO_NODE;
         int result = SCAN_SUCCEED;
@@ -1552,17 +1551,11 @@ static void khugepaged_scan_shmem(struct mm_struct *mm,
         swap = 0;
         memset(khugepaged_node_load, 0, sizeof(khugepaged_node_load));
         rcu_read_lock();
-        radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
-                if (iter.index >= start + HPAGE_PMD_NR)
-                        break;
-
-                page = radix_tree_deref_slot(slot);
-                if (radix_tree_deref_retry(page)) {
-                        slot = radix_tree_iter_retry(&iter);
+        xas_for_each(&xas, page, start + HPAGE_PMD_NR - 1) {
+                if (xas_retry(&xas, page))
                         continue;
-                }
 
-                if (radix_tree_exception(page)) {
+                if (xa_is_value(page)) {
                         if (++swap > khugepaged_max_ptes_swap) {
                                 result = SCAN_EXCEED_SWAP_PTE;
                                 break;
@@ -1601,7 +1594,7 @@ static void khugepaged_scan_shmem(struct mm_struct *mm,
                 present++;
 
                 if (need_resched()) {
-                        slot = radix_tree_iter_resume(slot, &iter);
+                        xas_pause(&xas);
                         cond_resched_rcu();
                 }
         }