Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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1/*
2 * Read-Copy Update mechanism for mutual exclusion (tree-based version)
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 * Copyright IBM Corporation, 2008
19 *
20 * Author: Dipankar Sarma <dipankar@in.ibm.com>
21 * Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical algorithm
22 *
23 * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
24 * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
25 *
26 * For detailed explanation of Read-Copy Update mechanism see -
27 * Documentation/RCU
28 */
29
30#ifndef __LINUX_RCUTREE_H
31#define __LINUX_RCUTREE_H
32
33extern void rcu_init(void);
34extern void rcu_note_context_switch(int cpu);
35extern int rcu_needs_cpu(int cpu);
36extern void rcu_cpu_stall_reset(void);
37
38/*
39 * Note a virtualization-based context switch. This is simply a
40 * wrapper around rcu_note_context_switch(), which allows TINY_RCU
41 * to save a few bytes.
42 */
43static inline void rcu_virt_note_context_switch(int cpu)
44{
45 rcu_note_context_switch(cpu);
46}
47
48#ifdef CONFIG_TREE_PREEMPT_RCU
49
50extern void exit_rcu(void);
51
52#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
53
54static inline void exit_rcu(void)
55{
56}
57
58#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
59
60extern void synchronize_rcu_bh(void);
61extern void synchronize_sched_expedited(void);
62extern void synchronize_rcu_expedited(void);
63
64static inline void synchronize_rcu_bh_expedited(void)
65{
66 synchronize_sched_expedited();
67}
68
69extern void rcu_barrier(void);
70extern void rcu_barrier_bh(void);
71extern void rcu_barrier_sched(void);
72
73extern unsigned long rcutorture_testseq;
74extern unsigned long rcutorture_vernum;
75extern long rcu_batches_completed(void);
76extern long rcu_batches_completed_bh(void);
77extern long rcu_batches_completed_sched(void);
78
79extern void rcu_force_quiescent_state(void);
80extern void rcu_bh_force_quiescent_state(void);
81extern void rcu_sched_force_quiescent_state(void);
82
83/* A context switch is a grace period for RCU-sched and RCU-bh. */
84static inline int rcu_blocking_is_gp(void)
85{
86 return num_online_cpus() == 1;
87}
88
89extern void rcu_scheduler_starting(void);
90extern int rcu_scheduler_active __read_mostly;
91
92#endif /* __LINUX_RCUTREE_H */