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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2009-08-15 09:53:48 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-15 19:02:08 +0200 |
| commit | 2e597558086dec36d5c33521a36e0f6b1bc3f3a7 (patch) | |
| tree | ce8c6ced1c8a3b6bf6170a5894e1d7102e6ee9d4 /kernel/rcupdate.c | |
| parent | 799e64f05f4bfaad2bb3165cab95c8c992a1c296 (diff) | |
| download | lwn-2e597558086dec36d5c33521a36e0f6b1bc3f3a7.tar.gz lwn-2e597558086dec36d5c33521a36e0f6b1bc3f3a7.zip | |
rcu: Simplify RCU CPU-hotplug notification
Use the new cpu_notifier() API to simplify RCU's CPU-hotplug
notifiers, collapsing down to a single such notifier.
This makes it trivial to provide the notifier-ordering
guarantee that rcu_barrier() depends on.
Also remove redundant open_softirq() calls from Hierarchical
RCU notifier.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: josht@linux.vnet.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: hugh.dickins@tiscali.co.uk
Cc: benh@kernel.crashing.org
LKML-Reference: <12503552312510-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/rcupdate.c')
| -rw-r--r-- | kernel/rcupdate.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index eae29c25fb14..8df115600c2d 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -217,9 +217,13 @@ static void rcu_migrate_callback(struct rcu_head *notused) wake_up(&rcu_migrate_wq); } +extern int rcu_cpu_notify(struct notifier_block *self, + unsigned long action, void *hcpu); + static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self, unsigned long action, void *hcpu) { + rcu_cpu_notify(self, action, hcpu); if (action == CPU_DYING) { /* * preempt_disable() in on_each_cpu() prevents stop_machine(), @@ -244,8 +248,18 @@ static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self, void __init rcu_init(void) { + int i; + __rcu_init(); - hotcpu_notifier(rcu_barrier_cpu_hotplug, 0); + cpu_notifier(rcu_barrier_cpu_hotplug, 0); + + /* + * We don't need protection against CPU-hotplug here because + * this is called early in boot, before either interrupts + * or the scheduler are operational. + */ + for_each_online_cpu(i) + rcu_barrier_cpu_hotplug(NULL, CPU_UP_PREPARE, (void *)(long)i); } void rcu_scheduler_starting(void) |