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-rw-r--r--kernel/rcupdate.c122
1 files changed, 0 insertions, 122 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 400183346ad2..9b7fd4723878 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -44,7 +44,6 @@
44#include <linux/cpu.h> 44#include <linux/cpu.h>
45#include <linux/mutex.h> 45#include <linux/mutex.h>
46#include <linux/module.h> 46#include <linux/module.h>
47#include <linux/kernel_stat.h>
48 47
49#ifdef CONFIG_DEBUG_LOCK_ALLOC 48#ifdef CONFIG_DEBUG_LOCK_ALLOC
50static struct lock_class_key rcu_lock_key; 49static struct lock_class_key rcu_lock_key;
@@ -53,8 +52,6 @@ struct lockdep_map rcu_lock_map =
53EXPORT_SYMBOL_GPL(rcu_lock_map); 52EXPORT_SYMBOL_GPL(rcu_lock_map);
54#endif 53#endif
55 54
56int rcu_scheduler_active __read_mostly;
57
58/* 55/*
59 * Awaken the corresponding synchronize_rcu() instance now that a 56 * Awaken the corresponding synchronize_rcu() instance now that a
60 * grace period has elapsed. 57 * grace period has elapsed.
@@ -66,122 +63,3 @@ void wakeme_after_rcu(struct rcu_head *head)
66 rcu = container_of(head, struct rcu_synchronize, head); 63 rcu = container_of(head, struct rcu_synchronize, head);
67 complete(&rcu->completion); 64 complete(&rcu->completion);
68} 65}
69
70#ifdef CONFIG_TREE_PREEMPT_RCU
71
72/**
73 * synchronize_rcu - wait until a grace period has elapsed.
74 *
75 * Control will return to the caller some time after a full grace
76 * period has elapsed, in other words after all currently executing RCU
77 * read-side critical sections have completed. RCU read-side critical
78 * sections are delimited by rcu_read_lock() and rcu_read_unlock(),
79 * and may be nested.
80 */
81void synchronize_rcu(void)
82{
83 struct rcu_synchronize rcu;
84
85 if (!rcu_scheduler_active)
86 return;
87
88 init_completion(&rcu.completion);
89 /* Will wake me after RCU finished. */
90 call_rcu(&rcu.head, wakeme_after_rcu);
91 /* Wait for it. */
92 wait_for_completion(&rcu.completion);
93}
94EXPORT_SYMBOL_GPL(synchronize_rcu);
95
96#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
97
98/**
99 * synchronize_sched - wait until an rcu-sched grace period has elapsed.
100 *
101 * Control will return to the caller some time after a full rcu-sched
102 * grace period has elapsed, in other words after all currently executing
103 * rcu-sched read-side critical sections have completed. These read-side
104 * critical sections are delimited by rcu_read_lock_sched() and
105 * rcu_read_unlock_sched(), and may be nested. Note that preempt_disable(),
106 * local_irq_disable(), and so on may be used in place of
107 * rcu_read_lock_sched().
108 *
109 * This means that all preempt_disable code sequences, including NMI and
110 * hardware-interrupt handlers, in progress on entry will have completed
111 * before this primitive returns. However, this does not guarantee that
112 * softirq handlers will have completed, since in some kernels, these
113 * handlers can run in process context, and can block.
114 *
115 * This primitive provides the guarantees made by the (now removed)
116 * synchronize_kernel() API. In contrast, synchronize_rcu() only
117 * guarantees that rcu_read_lock() sections will have completed.
118 * In "classic RCU", these two guarantees happen to be one and
119 * the same, but can differ in realtime RCU implementations.
120 */
121void synchronize_sched(void)
122{
123 struct rcu_synchronize rcu;
124
125 if (rcu_blocking_is_gp())
126 return;
127
128 init_completion(&rcu.completion);
129 /* Will wake me after RCU finished. */
130 call_rcu_sched(&rcu.head, wakeme_after_rcu);
131 /* Wait for it. */
132 wait_for_completion(&rcu.completion);
133}
134EXPORT_SYMBOL_GPL(synchronize_sched);
135
136/**
137 * synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed.
138 *
139 * Control will return to the caller some time after a full rcu_bh grace
140 * period has elapsed, in other words after all currently executing rcu_bh
141 * read-side critical sections have completed. RCU read-side critical
142 * sections are delimited by rcu_read_lock_bh() and rcu_read_unlock_bh(),
143 * and may be nested.
144 */
145void synchronize_rcu_bh(void)
146{
147 struct rcu_synchronize rcu;
148
149 if (rcu_blocking_is_gp())
150 return;
151
152 init_completion(&rcu.completion);
153 /* Will wake me after RCU finished. */
154 call_rcu_bh(&rcu.head, wakeme_after_rcu);
155 /* Wait for it. */
156 wait_for_completion(&rcu.completion);
157}
158EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
159
160static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self,
161 unsigned long action, void *hcpu)
162{
163 return rcu_cpu_notify(self, action, hcpu);
164}
165
166void __init rcu_init(void)
167{
168 int i;
169
170 __rcu_init();
171 cpu_notifier(rcu_barrier_cpu_hotplug, 0);
172
173 /*
174 * We don't need protection against CPU-hotplug here because
175 * this is called early in boot, before either interrupts
176 * or the scheduler are operational.
177 */
178 for_each_online_cpu(i)
179 rcu_barrier_cpu_hotplug(NULL, CPU_UP_PREPARE, (void *)(long)i);
180}
181
182void rcu_scheduler_starting(void)
183{
184 WARN_ON(num_online_cpus() != 1);
185 WARN_ON(nr_context_switches() > 0);
186 rcu_scheduler_active = 1;
187}