The field is only used in swap code.
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---
include/linux/mm_types.h | 2 ++
1 file changed, 2 insertions(+)
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -326,7 +326,9 @@ struct vm_area_struct {
struct file * vm_file; /* File we map to (can be NULL). */
void * vm_private_data; /* was vm_pte (shared mem) */
+#ifdef CONFIG_SWAP
atomic_long_t swap_readahead_info;
+#endif
#ifndef CONFIG_MMU
struct vm_region *vm_region; /* NOMMU mapping region */
#endif
