1 files changed, 28 insertions, 3 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f5f37630c54d..5723b551c023 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -18,6 +18,7 @@
 #include <linux/freezer.h>
 #include <linux/mman.h>
 #include <linux/pagemap.h>
+#include <linux/migrate.h>
 #include <asm/tlb.h>
 #include <asm/pgalloc.h>
 #include "internal.h"
@@ -1019,17 +1020,39 @@ out:
 }
 
 /* NUMA hinting page fault entry point for trans huge pmds */
-int do_huge_pmd_numa_page(struct mm_struct *mm, unsigned long addr,
-                                pmd_t pmd, pmd_t *pmdp)
+int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
+                                unsigned long addr, pmd_t pmd, pmd_t *pmdp)
 {
-        struct page *page;
+        struct page *page = NULL;
         unsigned long haddr = addr & HPAGE_PMD_MASK;
+        int target_nid;
 
         spin_lock(&mm->page_table_lock);
         if (unlikely(!pmd_same(pmd, *pmdp)))
                 goto out_unlock;
 
         page = pmd_page(pmd);
+        get_page(page);
+        spin_unlock(&mm->page_table_lock);
+
+        target_nid = mpol_misplaced(page, vma, haddr);
+        if (target_nid == -1)
+                goto clear_pmdnuma;
+
+        /*
+         * Due to lacking code to migrate thp pages, we'll split
+         * (which preserves the special PROT_NONE) and re-take the
+         * fault on the normal pages.
+         */
+        split_huge_page(page);
+        put_page(page);
+        return 0;
+
+clear_pmdnuma:
+        spin_lock(&mm->page_table_lock);
+        if (unlikely(!pmd_same(pmd, *pmdp)))
+                goto out_unlock;
+
         pmd = pmd_mknonnuma(pmd);
         set_pmd_at(mm, haddr, pmdp, pmd);
         VM_BUG_ON(pmd_numa(*pmdp));
@@ -1037,6 +1060,8 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, unsigned long addr,
 
 out_unlock:
         spin_unlock(&mm->page_table_lock);
+        if (page)
+                put_page(page);
         return 0;
 }