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 <[email protected]> CC: Greg Kroah-Hartman <[email protected]> CC: Andrew Morton <[email protected]> CC: Masahiro Yamada <[email protected]> CC: Alexey Dobriyan <[email protected]> CC: Pekka Enberg <[email protected]> CC: "Paul E. McKenney" <[email protected]> CC: Lihao Liang <[email protected]> CC: [email protected] --- 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
