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Diffstat (limited to 'kernel/cpu.c')
-rw-r--r--kernel/cpu.c80
1 files changed, 59 insertions, 21 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index deff2e69376..a343bde710b 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -19,6 +19,8 @@
#include <linux/mutex.h>
#include <linux/gfp.h>
#include <linux/suspend.h>
+#include <linux/lockdep.h>
+#include <trace/events/power.h>
#include "smpboot.h"
@@ -27,18 +29,23 @@
static DEFINE_MUTEX(cpu_add_remove_lock);
/*
- * The following two API's must be used when attempting
- * to serialize the updates to cpu_online_mask, cpu_present_mask.
+ * The following two APIs (cpu_maps_update_begin/done) must be used when
+ * attempting to serialize the updates to cpu_online_mask & cpu_present_mask.
+ * The APIs cpu_notifier_register_begin/done() must be used to protect CPU
+ * hotplug callback (un)registration performed using __register_cpu_notifier()
+ * or __unregister_cpu_notifier().
*/
void cpu_maps_update_begin(void)
{
mutex_lock(&cpu_add_remove_lock);
}
+EXPORT_SYMBOL(cpu_notifier_register_begin);
void cpu_maps_update_done(void)
{
mutex_unlock(&cpu_add_remove_lock);
}
+EXPORT_SYMBOL(cpu_notifier_register_done);
static RAW_NOTIFIER_HEAD(cpu_chain);
@@ -57,17 +64,30 @@ static struct {
* an ongoing cpu hotplug operation.
*/
int refcount;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
} cpu_hotplug = {
.active_writer = NULL,
.lock = __MUTEX_INITIALIZER(cpu_hotplug.lock),
.refcount = 0,
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ .dep_map = {.name = "cpu_hotplug.lock" },
+#endif
};
+/* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */
+#define cpuhp_lock_acquire_read() lock_map_acquire_read(&cpu_hotplug.dep_map)
+#define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map)
+#define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map)
+
void get_online_cpus(void)
{
might_sleep();
if (cpu_hotplug.active_writer == current)
return;
+ cpuhp_lock_acquire_read();
mutex_lock(&cpu_hotplug.lock);
cpu_hotplug.refcount++;
mutex_unlock(&cpu_hotplug.lock);
@@ -87,6 +107,7 @@ void put_online_cpus(void)
if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer))
wake_up_process(cpu_hotplug.active_writer);
mutex_unlock(&cpu_hotplug.lock);
+ cpuhp_lock_release();
}
EXPORT_SYMBOL_GPL(put_online_cpus);
@@ -117,6 +138,7 @@ void cpu_hotplug_begin(void)
{
cpu_hotplug.active_writer = current;
+ cpuhp_lock_acquire();
for (;;) {
mutex_lock(&cpu_hotplug.lock);
if (likely(!cpu_hotplug.refcount))
@@ -131,6 +153,7 @@ void cpu_hotplug_done(void)
{
cpu_hotplug.active_writer = NULL;
mutex_unlock(&cpu_hotplug.lock);
+ cpuhp_lock_release();
}
/*
@@ -166,6 +189,11 @@ int __ref register_cpu_notifier(struct notifier_block *nb)
return ret;
}
+int __ref __register_cpu_notifier(struct notifier_block *nb)
+{
+ return raw_notifier_chain_register(&cpu_chain, nb);
+}
+
static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
int *nr_calls)
{
@@ -189,6 +217,7 @@ static void cpu_notify_nofail(unsigned long val, void *v)
BUG_ON(cpu_notify(val, v));
}
EXPORT_SYMBOL(register_cpu_notifier);
+EXPORT_SYMBOL(__register_cpu_notifier);
void __ref unregister_cpu_notifier(struct notifier_block *nb)
{
@@ -198,6 +227,12 @@ void __ref unregister_cpu_notifier(struct notifier_block *nb)
}
EXPORT_SYMBOL(unregister_cpu_notifier);
+void __ref __unregister_cpu_notifier(struct notifier_block *nb)
+{
+ raw_notifier_chain_unregister(&cpu_chain, nb);
+}
+EXPORT_SYMBOL(__unregister_cpu_notifier);
+
/**
* clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
* @cpu: a CPU id
@@ -249,8 +284,7 @@ static inline void check_for_tasks(int cpu)
task_cputime(p, &utime, &stime);
if (task_cpu(p) == cpu && p->state == TASK_RUNNING &&
(utime || stime))
- printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d "
- "(state = %ld, flags = %x)\n",
+ pr_warn("Task %s (pid = %d) is on cpu %d (state = %ld, flags = %x)\n",
p->comm, task_pid_nr(p), cpu,
p->state, p->flags);
}
@@ -302,8 +336,8 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
if (err) {
nr_calls--;
__cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
- printk("%s: attempt to take down CPU %u failed\n",
- __func__, cpu);
+ pr_warn("%s: attempt to take down CPU %u failed\n",
+ __func__, cpu);
goto out_release;
}
@@ -410,8 +444,8 @@ static int _cpu_up(unsigned int cpu, int tasks_frozen)
ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
if (ret) {
nr_calls--;
- printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n",
- __func__, cpu);
+ pr_warn("%s: attempt to bring up CPU %u failed\n",
+ __func__, cpu);
goto out_notify;
}
@@ -441,11 +475,10 @@ int cpu_up(unsigned int cpu)
int err = 0;
if (!cpu_possible(cpu)) {
- printk(KERN_ERR "can't online cpu %d because it is not "
- "configured as may-hotadd at boot time\n", cpu);
+ pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n",
+ cpu);
#if defined(CONFIG_IA64)
- printk(KERN_ERR "please check additional_cpus= boot "
- "parameter\n");
+ pr_err("please check additional_cpus= boot parameter\n");
#endif
return -EINVAL;
}
@@ -484,16 +517,17 @@ int disable_nonboot_cpus(void)
*/
cpumask_clear(frozen_cpus);
- printk("Disabling non-boot CPUs ...\n");
+ pr_info("Disabling non-boot CPUs ...\n");
for_each_online_cpu(cpu) {
if (cpu == first_cpu)
continue;
+ trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
error = _cpu_down(cpu, 1);
+ trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
if (!error)
cpumask_set_cpu(cpu, frozen_cpus);
else {
- printk(KERN_ERR "Error taking CPU%d down: %d\n",
- cpu, error);
+ pr_err("Error taking CPU%d down: %d\n", cpu, error);
break;
}
}
@@ -503,7 +537,7 @@ int disable_nonboot_cpus(void)
/* Make sure the CPUs won't be enabled by someone else */
cpu_hotplug_disabled = 1;
} else {
- printk(KERN_ERR "Non-boot CPUs are not disabled\n");
+ pr_err("Non-boot CPUs are not disabled\n");
}
cpu_maps_update_done();
return error;
@@ -527,17 +561,19 @@ void __ref enable_nonboot_cpus(void)
if (cpumask_empty(frozen_cpus))
goto out;
- printk(KERN_INFO "Enabling non-boot CPUs ...\n");
+ pr_info("Enabling non-boot CPUs ...\n");
arch_enable_nonboot_cpus_begin();
for_each_cpu(cpu, frozen_cpus) {
+ trace_suspend_resume(TPS("CPU_ON"), cpu, true);
error = _cpu_up(cpu, 1);
+ trace_suspend_resume(TPS("CPU_ON"), cpu, false);
if (!error) {
- printk(KERN_INFO "CPU%d is up\n", cpu);
+ pr_info("CPU%d is up\n", cpu);
continue;
}
- printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error);
+ pr_warn("Error taking CPU%d up: %d\n", cpu, error);
}
arch_enable_nonboot_cpus_end();
@@ -692,10 +728,12 @@ void set_cpu_present(unsigned int cpu, bool present)
void set_cpu_online(unsigned int cpu, bool online)
{
- if (online)
+ if (online) {
cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits));
- else
+ cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits));
+ } else {
cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits));
+ }
}
void set_cpu_active(unsigned int cpu, bool active)
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 00:55:20 +0000