As preparation to using write rare on the nodes of various types of
lists, specify that the fields in the basic data structures must be
aligned to sizeof(void *)
It is meant to ensure that any static allocation will not cross a page
boundary, to allow pointers to be updated in one step.
Signed-off-by: Igor Stoppa <igor.stoppa@xxxxxxxxxx>
CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
CC: Alexey Dobriyan <adobriyan@xxxxxxxxx>
CC: Pekka Enberg <penberg@xxxxxxxxxx>
CC: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
CC: Lihao Liang <lianglihao@xxxxxxxxxx>
CC: linux-kernel@xxxxxxxxxxxxxxx
---
include/linux/types.h | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/include/linux/types.h b/include/linux/types.h
index 9834e90aa010..53609bbdcf0f 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -183,17 +183,29 @@ typedef struct {
} atomic64_t;
#endif
+#ifdef CONFIG_PRMEM
struct list_head {
- struct list_head *next, *prev;
-};
+ struct list_head *next __aligned(sizeof(void *));
+ struct list_head *prev __aligned(sizeof(void *));
+} __aligned(sizeof(void *));
-struct hlist_head {
- struct hlist_node *first;
+struct hlist_node {
+ struct hlist_node *next __aligned(sizeof(void *));
+ struct hlist_node **pprev __aligned(sizeof(void *));
+} __aligned(sizeof(void *));
+#else
+struct list_head {
+ struct list_head *next, *prev;
};
struct hlist_node {
struct hlist_node *next, **pprev;
};
+#endif
+
+struct hlist_head {
+ struct hlist_node *first;
+};
struct ustat {
__kernel_daddr_t f_tfree;
--
2.17.1
