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

[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

mm/migrate.c

+4 −6
Original line number Diff line number Diff line
@@ -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) {

	try_to_unmap(page, 1);

	if (!page_mapped(page))

		rc = move_to_new_page(newpage, page);

	} else

		/* A vma has VM_LOCKED set -> permanent failure */

		rc = -EPERM;



	if (rc)

		remove_migration_ptes(page, page);



unlock:

	unlock_page(page);

mm/rmap.c

+4 −5
Original line number Diff line number Diff line
@@ -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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