[PATCH] mm/swap: Fix release_pages() when releasing devmap pages

From: ira . weiny
Date: Thu May 23 2019 - 18:40:07 EST


From: Ira Weiny <ira.weiny@xxxxxxxxx>

Device pages can be more than type MEMORY_DEVICE_PUBLIC.

Handle all device pages within release_pages()

This was found via code inspection while determining if release_pages()
and the new put_user_pages() could be interchangeable.

Cc: JÃrÃme Glisse <jglisse@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
---
mm/swap.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/swap.c b/mm/swap.c
index 3a75722e68a9..d1e8122568d0 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -739,15 +739,14 @@ void release_pages(struct page **pages, int nr)
if (is_huge_zero_page(page))
continue;

- /* Device public page can not be huge page */
- if (is_device_public_page(page)) {
+ if (is_zone_device_page(page)) {
if (locked_pgdat) {
spin_unlock_irqrestore(&locked_pgdat->lru_lock,
flags);
locked_pgdat = NULL;
}
- put_devmap_managed_page(page);
- continue;
+ if (put_devmap_managed_page(page))
+ continue;
}

page = compound_head(page);
--
2.20.1