Fix migration.c compilation on s390

31bit s390 doesn't have huge pages and failed with:

> mm/migrate.c: In function 'remove_migration_pte':
> mm/migrate.c:143:3: error: implicit declaration of function 'pte_mkhuge'
> mm/migrate.c:143:7: error: incompatible types when assigning to type 'pte_t' from type 'int'

Put that code into a ifdef.

Reported by Heiko Carstens

Signed-off-by: Andi Kleen <ak@linux.intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 55dbc45880c6..f8c9bccf2520 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -139,8 +139,10 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
         pte = pte_mkold(mk_pte(new, vma->vm_page_prot));
         if (is_write_migration_entry(entry))
                 pte = pte_mkwrite(pte);
+#ifdef CONFIG_HUGETLB_PAGE
         if (PageHuge(new))
                 pte = pte_mkhuge(pte);
+#endif
         flush_cache_page(vma, addr, pte_pfn(pte));
         set_pte_at(mm, addr, ptep, pte);