mm: make remove_migration_ptes() beyond mm/migration.c
Make remove_migration_ptes() available to be used in split_huge_page().
New parameter 'locked' added: as with try_to_umap() we need a way to
indicate that caller holds rmap lock.
We also shouldn't try to mlock() pte-mapped huge pages: pte-mapeed THP
pages are never mlocked.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/migrate.c b/mm/migrate.c
index 577c94b..6c822a7 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -172,7 +172,7 @@
else
page_add_file_rmap(new);
- if (vma->vm_flags & VM_LOCKED)
+ if (vma->vm_flags & VM_LOCKED && !PageTransCompound(new))
mlock_vma_page(new);
/* No need to invalidate - it was non-present before */
@@ -187,14 +187,17 @@
* Get rid of all migration entries and replace them by
* references to the indicated page.
*/
-static void remove_migration_ptes(struct page *old, struct page *new)
+void remove_migration_ptes(struct page *old, struct page *new, bool locked)
{
struct rmap_walk_control rwc = {
.rmap_one = remove_migration_pte,
.arg = old,
};
- rmap_walk(new, &rwc);
+ if (locked)
+ rmap_walk_locked(new, &rwc);
+ else
+ rmap_walk(new, &rwc);
}
/*
@@ -702,7 +705,7 @@
* At this point we know that the migration attempt cannot
* be successful.
*/
- remove_migration_ptes(page, page);
+ remove_migration_ptes(page, page, false);
rc = mapping->a_ops->writepage(page, &wbc);
@@ -900,7 +903,7 @@
if (page_was_mapped)
remove_migration_ptes(page,
- rc == MIGRATEPAGE_SUCCESS ? newpage : page);
+ rc == MIGRATEPAGE_SUCCESS ? newpage : page, false);
out_unlock_both:
unlock_page(newpage);
@@ -1070,7 +1073,7 @@
if (page_was_mapped)
remove_migration_ptes(hpage,
- rc == MIGRATEPAGE_SUCCESS ? new_hpage : hpage);
+ rc == MIGRATEPAGE_SUCCESS ? new_hpage : hpage, false);
unlock_page(new_hpage);
