+ if (new_ptl != old_ptl) {
+ pgtable_t pgtable;
+
+ /*
+ * Move preallocated PTE page table if new_pmd is on
+ * different PMD page table.
+ */
+ pgtable = pgtable_trans_huge_withdraw(mm, old_pmd);
+ pgtable_trans_huge_deposit(mm, new_pmd, pgtable);
+