Currently the migration of anonymous pages will silently fail if no swap is
setup. This patch makes page migration functions check for available swap
and fail with -ENODEV if no swap space is available.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
int err;
struct vm_area_struct *first, *vma, *prev;
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.
+ */
first = find_vma(mm, start);
if (!first)
first = find_vma(mm, start);
if (!first)