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authorChandra Seetharaman <sekharan@us.ibm.com>2006-06-27 02:54:08 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-27 17:32:41 -0700
commit65edc68c345cbe21d0b0375c3452a3ed5e322868 (patch)
tree07961d63cdacf95355a8db471c6ff4e321ca94fd
parent054cc8a2d808822dadf488a61729e3e550f114c4 (diff)
[PATCH] cpu hotplug: make [un]register_cpu_notifier init time only
CPUs come online only at init time (unless CONFIG_HOTPLUG_CPU is defined). So, cpu_notifier functionality need to be available only at init time. This patch makes register_cpu_notifier() available only at init time, unless CONFIG_HOTPLUG_CPU is defined. This patch exports register_cpu_notifier() and unregister_cpu_notifier() only if CONFIG_HOTPLUG_CPU is defined. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--drivers/cpufreq/cpufreq.c8
-rw-r--r--drivers/cpufreq/cpufreq_stats.c4
-rw-r--r--include/linux/cpu.h6
-rw-r--r--kernel/cpu.c8
4 files changed, 18 insertions, 8 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 486ef666470..3533e26f837 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1497,7 +1497,8 @@ int cpufreq_update_policy(unsigned int cpu)
}
EXPORT_SYMBOL(cpufreq_update_policy);
-static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb,
+#ifdef CONFIG_HOTPLUG_CPU
+static int cpufreq_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
@@ -1536,6 +1537,7 @@ static struct notifier_block cpufreq_cpu_notifier =
{
.notifier_call = cpufreq_cpu_callback,
};
+#endif /* CONFIG_HOTPLUG_CPU */
/*********************************************************************
* REGISTER / UNREGISTER CPUFREQ DRIVER *
@@ -1596,7 +1598,7 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
}
if (!ret) {
- register_cpu_notifier(&cpufreq_cpu_notifier);
+ register_hotcpu_notifier(&cpufreq_cpu_notifier);
dprintk("driver %s up and running\n", driver_data->name);
cpufreq_debug_enable_ratelimit();
}
@@ -1628,7 +1630,7 @@ int cpufreq_unregister_driver(struct cpufreq_driver *driver)
dprintk("unregistering driver %s\n", driver->name);
sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
- unregister_cpu_notifier(&cpufreq_cpu_notifier);
+ unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
spin_lock_irqsave(&cpufreq_driver_lock, flags);
cpufreq_driver = NULL;
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index c576c0b3f45..145061b8472 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -350,7 +350,7 @@ __init cpufreq_stats_init(void)
return ret;
}
- register_cpu_notifier(&cpufreq_stat_cpu_notifier);
+ register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
lock_cpu_hotplug();
for_each_online_cpu(cpu) {
cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_ONLINE,
@@ -368,7 +368,7 @@ __exit cpufreq_stats_exit(void)
CPUFREQ_POLICY_NOTIFIER);
cpufreq_unregister_notifier(&notifier_trans_block,
CPUFREQ_TRANSITION_NOTIFIER);
- unregister_cpu_notifier(&cpufreq_stat_cpu_notifier);
+ unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
lock_cpu_hotplug();
for_each_online_cpu(cpu) {
cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_DEAD,
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index b23bf1c8add..cdfe471a70a 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -41,7 +41,13 @@ struct notifier_block;
#ifdef CONFIG_SMP
/* Need to know about CPUs going up/down? */
extern int register_cpu_notifier(struct notifier_block *nb);
+#ifdef CONFIG_HOTPLUG_CPU
extern void unregister_cpu_notifier(struct notifier_block *nb);
+#else
+static inline void unregister_cpu_notifier(struct notifier_block *nb)
+{
+}
+#endif
extern int current_in_cpu_hotplug(void);
int cpu_up(unsigned int cpu);
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 03dcd981846..70fbf2e8376 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -18,7 +18,7 @@
/* This protects CPUs going up and down... */
static DEFINE_MUTEX(cpucontrol);
-static BLOCKING_NOTIFIER_HEAD(cpu_chain);
+static __cpuinitdata BLOCKING_NOTIFIER_HEAD(cpu_chain);
#ifdef CONFIG_HOTPLUG_CPU
static struct task_struct *lock_cpu_hotplug_owner;
@@ -69,10 +69,13 @@ EXPORT_SYMBOL_GPL(lock_cpu_hotplug_interruptible);
#endif /* CONFIG_HOTPLUG_CPU */
/* Need to know about CPUs going up/down? */
-int register_cpu_notifier(struct notifier_block *nb)
+int __cpuinit register_cpu_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&cpu_chain, nb);
}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
EXPORT_SYMBOL(register_cpu_notifier);
void unregister_cpu_notifier(struct notifier_block *nb)
@@ -81,7 +84,6 @@ void unregister_cpu_notifier(struct notifier_block *nb)
}
EXPORT_SYMBOL(unregister_cpu_notifier);
-#ifdef CONFIG_HOTPLUG_CPU
static inline void check_for_tasks(int cpu)
{
struct task_struct *p;