mm/migrate: correct failure handling if !hugepage_migration_support()

[platform/adaptation/renesas_rcar/renesas_kernel.git] / mm / migrate.c

diff --git a/mm/migrate.c b/mm/migrate.c
index f9e1635..13bedcc 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1013,7 +1013,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
 {
        int rc = 0;
        int *result = NULL;
-       struct page *new_hpage = get_new_page(hpage, private, &result);
+       struct page *new_hpage;
        struct anon_vma *anon_vma = NULL;
 
        /*
@@ -1023,9 +1023,12 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
         * tables or check whether the hugepage is pmd-based or not before
         * kicking migration.
         */
-       if (!hugepage_migration_support(page_hstate(hpage)))
+       if (!hugepage_migration_support(page_hstate(hpage))) {
+               putback_active_hugepage(hpage);
                return -ENOSYS;
+       }
 
+       new_hpage = get_new_page(hpage, private, &result);
        if (!new_hpage)
                return -ENOMEM;
 
@@ -1125,7 +1128,12 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
                                nr_succeeded++;
                                break;
                        default:
-                               /* Permanent failure */
+                               /*
+                                * Permanent failure (-EBUSY, -ENOSYS, etc.):
+                                * unlike -EAGAIN case, the failed page is
+                                * removed from migration page list and not
+                                * retried in the next outer loop.
+                                */
                                nr_failed++;
                                break;
                        }