mirror_ubuntu-kernels/include/linux/rcupdate_wait.h

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2024-07-02 00:48:40 +03:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_SCHED_RCUPDATE_WAIT_H
#define _LINUX_SCHED_RCUPDATE_WAIT_H
/*
* RCU synchronization types and methods:
*/
#include <linux/rcupdate.h>
#include <linux/completion.h>
#include <linux/sched.h>
/*
* Structure allowing asynchronous waiting on RCU.
*/
struct rcu_synchronize {
struct rcu_head head;
struct completion completion;
};
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__ }; \
struct rcu_synchronize __rs_array[ARRAY_SIZE(__crcu_array)]; \
__wait_rcu_gp(checktiny, ARRAY_SIZE(__crcu_array), \
__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 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.
*
* Note that call_rcu_hurry() should be used instead of call_rcu()
* because in kernels built with CONFIG_RCU_LAZY=y the delay between the
* invocation of call_rcu() and that of the corresponding RCU callback
* can be multiple seconds.
*
* 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__)
static inline void cond_resched_rcu(void)
{
#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
rcu_read_unlock();
cond_resched();
rcu_read_lock();
#endif
}
#endif /* _LINUX_SCHED_RCUPDATE_WAIT_H */