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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2013-11-14 17:38:05 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2013-11-14 17:38:05 -0800
commit42249094f79422fbf5ed4b54eeb48ff096809b8f (patch)
tree91e6850c8c7e8cc284cf8bb6363f8662f84011f4 /kernel/cpu.c
parent936816161978ca716a56c5e553c68f25972b1e3a (diff)
parent2c027b7c48a888ab173ba45babb4525e278375d9 (diff)
Merge branch 'next' into for-linus
Merge first round of changes for 3.13 merge window.
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r--kernel/cpu.c70
1 files changed, 29 insertions, 41 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index b5e4ab2d427e..d7f07a2da5a6 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -113,7 +113,7 @@ EXPORT_SYMBOL_GPL(put_online_cpus);
* get_online_cpus() not an api which is called all that often.
*
*/
-static void cpu_hotplug_begin(void)
+void cpu_hotplug_begin(void)
{
cpu_hotplug.active_writer = current;
@@ -127,16 +127,34 @@ static void cpu_hotplug_begin(void)
}
}
-static void cpu_hotplug_done(void)
+void cpu_hotplug_done(void)
{
cpu_hotplug.active_writer = NULL;
mutex_unlock(&cpu_hotplug.lock);
}
-#else /* #if CONFIG_HOTPLUG_CPU */
-static void cpu_hotplug_begin(void) {}
-static void cpu_hotplug_done(void) {}
-#endif /* #else #if CONFIG_HOTPLUG_CPU */
+/*
+ * Wait for currently running CPU hotplug operations to complete (if any) and
+ * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects
+ * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the
+ * hotplug path before performing hotplug operations. So acquiring that lock
+ * guarantees mutual exclusion from any currently running hotplug operations.
+ */
+void cpu_hotplug_disable(void)
+{
+ cpu_maps_update_begin();
+ cpu_hotplug_disabled = 1;
+ cpu_maps_update_done();
+}
+
+void cpu_hotplug_enable(void)
+{
+ cpu_maps_update_begin();
+ cpu_hotplug_disabled = 0;
+ cpu_maps_update_done();
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
/* Need to know about CPUs going up/down? */
int __ref register_cpu_notifier(struct notifier_block *nb)
@@ -345,7 +363,7 @@ EXPORT_SYMBOL(cpu_down);
#endif /*CONFIG_HOTPLUG_CPU*/
/* Requires cpu_add_remove_lock to be held */
-static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
+static int _cpu_up(unsigned int cpu, int tasks_frozen)
{
int ret, nr_calls = 0;
void *hcpu = (void *)(long)cpu;
@@ -398,7 +416,7 @@ out:
return ret;
}
-int __cpuinit cpu_up(unsigned int cpu)
+int cpu_up(unsigned int cpu)
{
int err = 0;
@@ -541,36 +559,6 @@ static int __init alloc_frozen_cpus(void)
core_initcall(alloc_frozen_cpus);
/*
- * Prevent regular CPU hotplug from racing with the freezer, by disabling CPU
- * hotplug when tasks are about to be frozen. Also, don't allow the freezer
- * to continue until any currently running CPU hotplug operation gets
- * completed.
- * To modify the 'cpu_hotplug_disabled' flag, we need to acquire the
- * 'cpu_add_remove_lock'. And this same lock is also taken by the regular
- * CPU hotplug path and released only after it is complete. Thus, we
- * (and hence the freezer) will block here until any currently running CPU
- * hotplug operation gets completed.
- */
-void cpu_hotplug_disable_before_freeze(void)
-{
- cpu_maps_update_begin();
- cpu_hotplug_disabled = 1;
- cpu_maps_update_done();
-}
-
-
-/*
- * When tasks have been thawed, re-enable regular CPU hotplug (which had been
- * disabled while beginning to freeze tasks).
- */
-void cpu_hotplug_enable_after_thaw(void)
-{
- cpu_maps_update_begin();
- cpu_hotplug_disabled = 0;
- cpu_maps_update_done();
-}
-
-/*
* When callbacks for CPU hotplug notifications are being executed, we must
* ensure that the state of the system with respect to the tasks being frozen
* or not, as reported by the notification, remains unchanged *throughout the
@@ -589,12 +577,12 @@ cpu_hotplug_pm_callback(struct notifier_block *nb,
case PM_SUSPEND_PREPARE:
case PM_HIBERNATION_PREPARE:
- cpu_hotplug_disable_before_freeze();
+ cpu_hotplug_disable();
break;
case PM_POST_SUSPEND:
case PM_POST_HIBERNATION:
- cpu_hotplug_enable_after_thaw();
+ cpu_hotplug_enable();
break;
default:
@@ -627,7 +615,7 @@ core_initcall(cpu_hotplug_pm_sync_init);
* It must be called by the arch code on the new cpu, before the new cpu
* enables interrupts and before the "boot" cpu returns from __cpu_up().
*/
-void __cpuinit notify_cpu_starting(unsigned int cpu)
+void notify_cpu_starting(unsigned int cpu)
{
unsigned long val = CPU_STARTING;