The patch makes 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@xxxxxxxxxxxxxxx>
---
include/linux/rmap.h | 2 ++
mm/migrate.c | 15 +++++++++------
2 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 3d975e2252d4..49eb4f8ebac9 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -243,6 +243,8 @@ int page_mkclean(struct page *);
*/
int try_to_munlock(struct page *);
+void remove_migration_ptes(struct page *old, struct page *new, bool locked);
+
/*
* Called by memory-failure.c to kill processes.
*/
diff --git a/mm/migrate.c b/mm/migrate.c
index 577c94b8e959..6c822a7b27e0 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -172,7 +172,7 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
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 @@ out:
* 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 @@ static int writeout(struct address_space *mapping, struct page *page)
* 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 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
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 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
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);
--
2.7.0
--
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