From 71a9b26963f8c2d0df6f782e2b29ccefc22d4fba Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 31 Mar 2014 13:13:02 -0700 Subject: [PATCH] rcu: Document RCU_INIT_POINTER()'s lack of ordering guarantees Although rcu_assign_pointer() provides ordering guarantees, RCU_INIT_POINTER() does not. This commit makes that explicit in the docbook comment header. Reported-by: Lai Jiangshan Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- include/linux/rcupdate.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index fdc422f3d61d..3c5ef02ea580 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -949,6 +949,9 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) * pointers, but you must use rcu_assign_pointer() to initialize the * external-to-structure pointer -after- you have completely initialized * the reader-accessible portions of the linked structure. + * + * Note that unlike rcu_assign_pointer(), RCU_INIT_POINTER() provides no + * ordering guarantees for either the CPU or the compiler. */ #define RCU_INIT_POINTER(p, v) \ do { \ -- 2.39.2