[RFC 24/43] mm: shmem: prevent swapping of PKRAM-enabled tmpfs pages

[Anthony Yznaga]

Workaround the limitation that shmem pages must be in memory in order
to be preserved by preventing them from being swapped out in the first
place.  Do this by marking shmem pages associated with a PKRAM node
as unevictable.

Signed-off-by: Anthony Yznaga <anthony.yznaga@xxxxxxxxxx>
---
 mm/shmem.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/shmem.c b/mm/shmem.c
index 9c28ef657cd1..13475073fb52 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2360,6 +2360,8 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
 		INIT_LIST_HEAD(&info->swaplist);
 		simple_xattrs_init(&info->xattrs);
 		cache_no_acl(inode);
+		if (sbinfo->pkram)
+			mapping_set_unevictable(inode->i_mapping);
 
 		switch (mode & S_IFMT) {
 		default:
-- 
2.13.3