From ec90a194ae2cb8b8e9fe4f6f70dd3d4dc0269b4b Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 10 Jun 2015 12:53:06 -0700 Subject: rcu: Create a synchronize_rcu_mult() There have been several requests for a primitive that waits for grace periods for several RCU flavors concurrently, so this commit creates it. This is a variadic macro, and you pass in the call_rcu() functions of the flavors of RCU that you wish to wait for. Note that you cannot pass in call_srcu() for two reasons: (1) This would result in a type mismatch and (2) You need to specify which srcu_struct you want to use. Handle this by creating a wrapper function for your SRCU domain, for example: void call_srcu_mine(struct rcu_head *head, rcu_callback_t func) { call_srcu(&ss_mine, head, func); } You can then do something like this: synchronize_rcu_mult(call_srcu_mine, call_rcu, call_rcu_sched); Signed-off-by: Paul E. McKenney --- include/linux/rcupdate.h | 35 +++++++++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-) (limited to 'include/linux/rcupdate.h') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index c63428c..33ec16b 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -226,6 +226,37 @@ struct rcu_synchronize { }; void wakeme_after_rcu(struct rcu_head *head); +void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array, + struct rcu_synchronize *rs_array); + +#define _wait_rcu_gp(checktiny, ...) \ +do { \ + call_rcu_func_t __crcu_array[] = { __VA_ARGS__ }; \ + const int __n = ARRAY_SIZE(__crcu_array); \ + struct rcu_synchronize __rs_array[__n]; \ + \ + __wait_rcu_gp(checktiny, __n, __crcu_array, __rs_array); \ +} while (0) + +#define wait_rcu_gp(...) _wait_rcu_gp(false, __VA_ARGS__) + +/** + * synchronize_rcu_mult - Wait concurrently for multiple grace periods + * @...: List of call_rcu() functions for the flavors to wait on. + * + * This macro waits concurrently for multiple flavors of RCU grace periods. + * For example, synchronize_rcu_mult(call_rcu, call_rcu_bh) would wait + * on concurrent RCU and RCU-bh grace periods. Waiting on a give SRCU + * domain requires you to write a wrapper function for that SRCU domain's + * call_srcu() function, supplying the corresponding srcu_struct. + * + * If Tiny RCU, tell _wait_rcu_gp() not to bother waiting for RCU + * or RCU-bh, given that anywhere synchronize_rcu_mult() can be called + * is automatically a grace period. + */ +#define synchronize_rcu_mult(...) \ + _wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__) + /** * call_rcu_tasks() - Queue an RCU for invocation task-based grace period * @head: structure to be used for queueing the RCU updates. @@ -392,10 +423,6 @@ bool __rcu_is_watching(void); * TREE_RCU and rcu_barrier_() primitives in TINY_RCU. */ -typedef void call_rcu_func_t(struct rcu_head *head, - void (*func)(struct rcu_head *head)); -void wait_rcu_gp(call_rcu_func_t crf); - #if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU) #include #elif defined(CONFIG_TINY_RCU) -- cgit v1.1