From b3d73156b075014ce5b2609f4f47723d6c0c23d6 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 6 Mar 2020 13:58:27 -0800 Subject: rcu: Reinstate synchronize_rcu_mult() With the advent and likely usage of synchronize_rcu_rude(), there is again a need to wait on multiple types of RCU grace periods, for example, call_rcu_tasks() and call_rcu_tasks_rude(). This commit therefore reinstates synchronize_rcu_mult() in order to allow these grace periods to be straightforwardly waited on concurrently. Signed-off-by: Paul E. McKenney --- include/linux/rcupdate_wait.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'include/linux/rcupdate_wait.h') diff --git a/include/linux/rcupdate_wait.h b/include/linux/rcupdate_wait.h index c0578ba23c1a..699b938358bf 100644 --- a/include/linux/rcupdate_wait.h +++ b/include/linux/rcupdate_wait.h @@ -31,4 +31,23 @@ do { \ #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 different grace periods to wait on + * + * This macro waits concurrently for multiple types of RCU grace periods. + * For example, synchronize_rcu_mult(call_rcu, call_rcu_tasks) would wait + * on concurrent RCU and RCU-tasks grace periods. Waiting on a given SRCU + * domain requires you to write a wrapper function for that SRCU domain's + * call_srcu() function, with this wrapper supplying the pointer to the + * corresponding srcu_struct. + * + * The first argument tells Tiny RCU's _wait_rcu_gp() not to + * bother waiting for RCU. The reason for this is because anywhere + * synchronize_rcu_mult() can be called is automatically already a full + * grace period. + */ +#define synchronize_rcu_mult(...) \ + _wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__) + #endif /* _LINUX_SCHED_RCUPDATE_WAIT_H */ -- cgit v1.2.3