From 3a518b76af7bb411efe6dd090fbf098e29accb2e Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 21 Aug 2015 19:42:50 +0200 Subject: rcu_sync: Add CONFIG_PROVE_RCU checks This commit validates that the caller of rcu_sync_is_idle() holds the corresponding type of RCU read-side lock, but only in kernels built with CONFIG_PROVE_RCU=y. This validation is carried out via a new rcu_sync_ops->held() method that is checked within rcu_sync_is_idle(). Note that although this does add code to the fast path, it only does so in kernels built with CONFIG_PROVE_RCU=y. Suggested-by: "Paul E. McKenney" Signed-off-by: Oleg Nesterov Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- include/linux/rcu_sync.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/rcu_sync.h') diff --git a/include/linux/rcu_sync.h b/include/linux/rcu_sync.h index c6d2272c4459..1f2d4fc30b04 100644 --- a/include/linux/rcu_sync.h +++ b/include/linux/rcu_sync.h @@ -40,6 +40,8 @@ struct rcu_sync { enum rcu_sync_type gp_type; }; +extern bool __rcu_sync_is_idle(struct rcu_sync *); + /** * rcu_sync_is_idle() - Are readers permitted to use their fastpaths? * @rsp: Pointer to rcu_sync structure to use for synchronization @@ -50,7 +52,11 @@ struct rcu_sync { */ static inline bool rcu_sync_is_idle(struct rcu_sync *rsp) { +#ifdef CONFIG_PROVE_RCU + return __rcu_sync_is_idle(rsp); +#else return !rsp->gp_state; /* GP_IDLE */ +#endif } extern void rcu_sync_init(struct rcu_sync *, enum rcu_sync_type); -- cgit v1.2.3-59-g8ed1b