[PATCH] Allow migration of mlocked pages
Hugh clarified the role of VM_LOCKED. So we can now implement page
migration for mlocked pages.
Allow the migration of mlocked pages. This means that try_to_unmap must
unmap mlocked pages in the migration case.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/migrate.c b/mm/migrate.c
index 0576c05..3f1e0c2 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -616,15 +616,13 @@
/*
* Establish migration ptes or remove ptes
*/
- if (try_to_unmap(page, 1) != SWAP_FAIL) {
- if (!page_mapped(page))
- rc = move_to_new_page(newpage, page);
- } else
- /* A vma has VM_LOCKED set -> permanent failure */
- rc = -EPERM;
+ try_to_unmap(page, 1);
+ if (!page_mapped(page))
+ rc = move_to_new_page(newpage, page);
if (rc)
remove_migration_ptes(page, page);
+
unlock:
unlock_page(page);
diff --git a/mm/rmap.c b/mm/rmap.c
index 882a858..e76909e 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -562,9 +562,8 @@
* If it's recently referenced (perhaps page_referenced
* skipped over this mm) then we should reactivate it.
*/
- if ((vma->vm_flags & VM_LOCKED) ||
- (ptep_clear_flush_young(vma, address, pte)
- && !migration)) {
+ if (!migration && ((vma->vm_flags & VM_LOCKED) ||
+ (ptep_clear_flush_young(vma, address, pte)))) {
ret = SWAP_FAIL;
goto out_unmap;
}
@@ -771,7 +770,7 @@
list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
shared.vm_set.list) {
- if (vma->vm_flags & VM_LOCKED)
+ if ((vma->vm_flags & VM_LOCKED) && !migration)
continue;
cursor = (unsigned long) vma->vm_private_data;
if (cursor > max_nl_cursor)
@@ -805,7 +804,7 @@
do {
list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
shared.vm_set.list) {
- if (vma->vm_flags & VM_LOCKED)
+ if ((vma->vm_flags & VM_LOCKED) && !migration)
continue;
cursor = (unsigned long) vma->vm_private_data;
while ( cursor < max_nl_cursor &&