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/*
* Read-Copy Update mechanism for mutual exclusion (tree-based version)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright IBM Corporation, 2008
*
* Author: Dipankar Sarma <dipankar@in.ibm.com>
* Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical algorithm
*
* Based on the original work by Paul McKenney <paulmck@us.ibm.com>
* and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
*
* For detailed explanation of Read-Copy Update mechanism see -
* Documentation/RCU
*/
#ifndef __LINUX_RCUTREE_H
#define __LINUX_RCUTREE_H
struct notifier_block;
extern void rcu_sched_qs(int cpu);
extern void rcu_bh_qs(int cpu);
extern int rcu_needs_cpu(int cpu);
#ifdef CONFIG_TREE_PREEMPT_RCU
extern void __rcu_read_lock(void);
extern void __rcu_read_unlock(void);
extern void synchronize_rcu(void);
extern void exit_rcu(void);
/*
* Defined as macro as it is a very low level header
* included from areas that don't even know about current
*/
#define rcu_preempt_depth() (current->rcu_read_lock_nesting)
#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
static inline void __rcu_read_lock(void)
{
preempt_disable();
}
static inline void __rcu_read_unlock(void)
{
preempt_enable();
}
#define synchronize_rcu synchronize_sched
static inline void exit_rcu(void)
{
}
static inline int rcu_preempt_depth(void)
{
return 0;
}
#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
static inline void __rcu_read_lock_bh(void)
{
local_bh_disable();
}
static inline void __rcu_read_unlock_bh(void)
{
local_bh_enable();
}
extern void call_rcu_sched(struct rcu_head *head,
void (*func)(struct rcu_head *rcu));
extern void synchronize_rcu_expedited(void);
static inline void synchronize_rcu_bh_expedited(void)
{
synchronize_sched_expedited();
}
extern void rcu_check_callbacks(int cpu, int user);
extern long rcu_batches_completed(void);
extern long rcu_batches_completed_bh(void);
extern long rcu_batches_completed_sched(void);
extern void rcu_force_quiescent_state(void);
extern void rcu_bh_force_quiescent_state(void);
extern void rcu_sched_force_quiescent_state(void);
#ifdef CONFIG_NO_HZ
void rcu_enter_nohz(void);
void rcu_exit_nohz(void);
#else /* CONFIG_NO_HZ */
static inline void rcu_enter_nohz(void)
{
}
static inline void rcu_exit_nohz(void)
{
}
#endif /* CONFIG_NO_HZ */
/* A context switch is a grace period for RCU-sched and RCU-bh. */
static inline int rcu_blocking_is_gp(void)
{
return num_online_cpus() == 1;
}
#endif /* __LINUX_RCUTREE_H */
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