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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-12-06 12:00:33 -0500 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-12-06 12:00:33 -0500 |
| commit | 3d14b5beba35250c548d3851a2b84fce742d8311 (patch) | |
| tree | 065e3d93c3fcbc5ee4c44fa78662393cddbdf6de /kernel/rcupdate.c | |
| parent | 0719dc341389882cc834ed18fc9b7fc6006b2b85 (diff) | |
| parent | 1bf8e6219552d5dd27012d567ec8c4bb9c2d86b4 (diff) | |
Merge branch 'sa1100' into devel
Diffstat (limited to 'kernel/rcupdate.c')
| -rw-r--r-- | kernel/rcupdate.c | 122 |
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 |
| 50 | static struct lock_class_key rcu_lock_key; | 49 | static struct lock_class_key rcu_lock_key; |
| @@ -53,8 +52,6 @@ struct lockdep_map rcu_lock_map = | |||
| 53 | EXPORT_SYMBOL_GPL(rcu_lock_map); | 52 | EXPORT_SYMBOL_GPL(rcu_lock_map); |
| 54 | #endif | 53 | #endif |
| 55 | 54 | ||
| 56 | int 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 | */ | ||
| 81 | void 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 | } | ||
| 94 | EXPORT_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 | */ | ||
| 121 | void 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 | } | ||
| 134 | EXPORT_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 | */ | ||
| 145 | void 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 | } | ||
| 158 | EXPORT_SYMBOL_GPL(synchronize_rcu_bh); | ||
| 159 | |||
| 160 | static 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 | |||
| 166 | void __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 | |||
| 182 | void 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 | } | ||
