Commit 309ba859 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Paul E. McKenney
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rcu: Eliminate synchronize_rcu_mult() 



Now that synchronize_rcu() waits for both RCU read-side critical
sections and preempt-disabled regions of code, the sole caller of
synchronize_rcu_mult() can be replaced by synchronize_rcu().
This patch makes this change and removes synchronize_rcu_mult().
Note that _wait_rcu_gp() still supports synchronize_rcu_mult(),
and thus might be simplified in the future to take only take
a single call_rcu() function rather than the current list of them.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent adbccddb

include/linux/rcupdate_wait.h

+0 −17
Original line number Diff line number Diff line
@@ -31,21 +31,4 @@ 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 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() does not bother waiting for RCU,

 * 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__)



#endif /* _LINUX_SCHED_RCUPDATE_WAIT_H */

kernel/rcu/update.c

+2 −4
Original line number Diff line number Diff line
@@ -335,8 +335,7 @@ void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array, 
	/* Initialize and register callbacks for each crcu_array element. */

	for (i = 0; i < n; i++) {

		if (checktiny &&

		    (crcu_array[i] == call_rcu ||

		     crcu_array[i] == call_rcu_bh)) {

		    (crcu_array[i] == call_rcu)) {

			might_sleep();

			continue;

		}
@@ -352,8 +351,7 @@ void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array, 
	/* Wait for all callbacks to be invoked. */

	for (i = 0; i < n; i++) {

		if (checktiny &&

		    (crcu_array[i] == call_rcu ||

		     crcu_array[i] == call_rcu_bh))

		    (crcu_array[i] == call_rcu))

			continue;

		for (j = 0; j < i; j++)

			if (crcu_array[j] == crcu_array[i])

kernel/sched/core.c

+1 −1
Original line number Diff line number Diff line
@@ -5788,7 +5788,7 @@ int sched_cpu_deactivate(unsigned int cpu) 
	 *

	 * Do sync before park smpboot threads to take care the rcu boost case.

	 */

	synchronize_rcu_mult(call_rcu, call_rcu_sched);

	synchronize_rcu();



	if (!sched_smp_initialized)

		return 0;

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