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Diffstat (limited to 'mm/mempolicy.c')
-rw-r--r--mm/mempolicy.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 2a820600942..b21869a39f0 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -330,9 +330,19 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
int err;
struct vm_area_struct *first, *vma, *prev;
- /* Clear the LRU lists so pages can be isolated */
- if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
+ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
+ /* Must have swap device for migration */
+ if (nr_swap_pages <= 0)
+ return ERR_PTR(-ENODEV);
+
+ /*
+ * Clear the LRU lists so pages can be isolated.
+ * Note that pages may be moved off the LRU after we have
+ * drained them. Those pages will fail to migrate like other
+ * pages that may be busy.
+ */
lru_add_drain_all();
+ }
first = find_vma(mm, start);
if (!first)