forked from mirrors/linux
		
	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 <paulmck@kernel.org>
		
			
				
	
	
		
			53 lines
		
	
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			53 lines
		
	
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_SCHED_RCUPDATE_WAIT_H
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#define _LINUX_SCHED_RCUPDATE_WAIT_H
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/*
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 * RCU synchronization types and methods:
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 */
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#include <linux/rcupdate.h>
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#include <linux/completion.h>
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/*
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 * Structure allowing asynchronous waiting on RCU.
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 */
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struct rcu_synchronize {
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	struct rcu_head head;
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	struct completion completion;
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};
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void wakeme_after_rcu(struct rcu_head *head);
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void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array,
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		   struct rcu_synchronize *rs_array);
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#define _wait_rcu_gp(checktiny, ...) \
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do {									\
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	call_rcu_func_t __crcu_array[] = { __VA_ARGS__ };		\
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	struct rcu_synchronize __rs_array[ARRAY_SIZE(__crcu_array)];	\
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	__wait_rcu_gp(checktiny, ARRAY_SIZE(__crcu_array),		\
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			__crcu_array, __rs_array);			\
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} while (0)
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#define wait_rcu_gp(...) _wait_rcu_gp(false, __VA_ARGS__)
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/**
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 * synchronize_rcu_mult - Wait concurrently for multiple grace periods
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 * @...: List of call_rcu() functions for different grace periods to wait on
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 *
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 * This macro waits concurrently for multiple types of RCU grace periods.
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 * For example, synchronize_rcu_mult(call_rcu, call_rcu_tasks) would wait
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 * on concurrent RCU and RCU-tasks grace periods.  Waiting on a given SRCU
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 * domain requires you to write a wrapper function for that SRCU domain's
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 * call_srcu() function, with this wrapper supplying the pointer to the
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 * corresponding srcu_struct.
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 *
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 * The first argument tells Tiny RCU's _wait_rcu_gp() not to
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 * bother waiting for RCU.  The reason for this is because anywhere
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 * synchronize_rcu_mult() can be called is automatically already a full
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 * grace period.
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 */
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#define synchronize_rcu_mult(...) \
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	_wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__)
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#endif /* _LINUX_SCHED_RCUPDATE_WAIT_H */
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