rcutree.h 2.7 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
/*
 * 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 -
27
 *	Documentation/RCU
28 29 30 31 32
 */

#ifndef __LINUX_RCUTREE_H
#define __LINUX_RCUTREE_H

33
extern void rcu_init(void);
34
extern void rcu_note_context_switch(int cpu);
35
extern int rcu_needs_cpu(int cpu);
36
extern void rcu_cpu_stall_reset(void);
37

38 39 40 41 42 43 44 45 46 47
/*
 * Note a virtualization-based context switch.  This is simply a
 * wrapper around rcu_note_context_switch(), which allows TINY_RCU
 * to save a few bytes.
 */
static inline void rcu_virt_note_context_switch(int cpu)
{
	rcu_note_context_switch(cpu);
}

48 49 50 51 52 53 54 55 56 57 58 59
#ifdef CONFIG_TREE_PREEMPT_RCU

extern void exit_rcu(void);

#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */

static inline void exit_rcu(void)
{
}

#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */

60
extern void synchronize_rcu_bh(void);
61
extern void synchronize_sched_expedited(void);
62
extern void synchronize_rcu_expedited(void);
63 64

static inline void synchronize_rcu_bh_expedited(void)
65
{
66
	synchronize_sched_expedited();
67 68
}

P
Paul E. McKenney 已提交
69
extern void rcu_barrier(void);
70 71
extern void rcu_barrier_bh(void);
extern void rcu_barrier_sched(void);
P
Paul E. McKenney 已提交
72

73 74
extern unsigned long rcutorture_testseq;
extern unsigned long rcutorture_vernum;
75 76
extern long rcu_batches_completed(void);
extern long rcu_batches_completed_bh(void);
77
extern long rcu_batches_completed_sched(void);
78

79 80 81
extern void rcu_force_quiescent_state(void);
extern void rcu_bh_force_quiescent_state(void);
extern void rcu_sched_force_quiescent_state(void);
82

83
/* A context switch is a grace period for RCU-sched and RCU-bh. */
84 85 86 87 88
static inline int rcu_blocking_is_gp(void)
{
	return num_online_cpus() == 1;
}

89 90 91
extern void rcu_scheduler_starting(void);
extern int rcu_scheduler_active __read_mostly;

92
#endif /* __LINUX_RCUTREE_H */