Commit e6a1530d authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds

[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: default avatarChristoph Lameter <clameter@sgi.com>
Acked-by: default avatarHugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7b2259b3
......@@ -616,15 +616,13 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
/*
* 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);
......
......@@ -562,9 +562,8 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
* 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 @@ static int try_to_unmap_file(struct page *page, int migration)
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 @@ static int try_to_unmap_file(struct page *page, int migration)
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 &&
......
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