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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-05 12:52:14 -0500 | 
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-05 12:52:14 -0500 | 
| commit | 607781762e7aae9c976f0a9a8829d4ba3e2da4ab (patch) | |
| tree | 933dad6ecb0be49e9b1ef41b69d5aa256510720e /kernel/rcupdate.c | |
| parent | d0b093a8b5ae34ee8be1f7e0dd197fe4788fa1d5 (diff) | |
| parent | 8bfb2f8e655b9d0c45fde679fcd5fd97e34513db (diff) | |
Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits)
  rcu: Make RCU's CPU-stall detector be default
  rcu: Add expedited grace-period support for preemptible RCU
  rcu: Enable fourth level of TREE_RCU hierarchy
  rcu: Rename "quiet" functions
  rcu: Re-arrange code to reduce #ifdef pain
  rcu: Eliminate unneeded function wrapping
  rcu: Fix grace-period-stall bug on large systems with CPU hotplug
  rcu: Eliminate __rcu_pending() false positives
  rcu: Further cleanups of use of lastcomp
  rcu: Simplify association of forced quiescent states with grace periods
  rcu: Accelerate callback processing on CPUs not detecting GP end
  rcu: Mark init-time-only rcu_bootup_announce() as __init
  rcu: Simplify association of quiescent states with grace periods
  rcu: Rename dynticks_completed to completed_fqs
  rcu: Enable synchronize_sched_expedited() fastpath
  rcu: Remove inline from forward-referenced functions
  rcu: Fix note_new_gpnum() uses of ->gpnum
  rcu: Fix synchronization for rcu_process_gp_end() uses of ->completed counter
  rcu: Prepare for synchronization fixes: clean up for non-NO_HZ handling of ->completed counter
  rcu: Cleanup: balance rcu_irq_enter()/rcu_irq_exit() calls
  ...
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 | } | ||
