#include <linux/kthread.h>
#include <linux/stop_machine.h>
#include <linux/mutex.h>
+#include <linux/gfp.h>
#ifdef CONFIG_SMP
/* Serializes the updates to cpu_online_mask, cpu_present_mask */
static DEFINE_MUTEX(cpu_add_remove_lock);
-static __cpuinitdata RAW_NOTIFIER_HEAD(cpu_chain);
+/*
+ * The following two API's must be used when attempting
+ * to serialize the updates to cpu_online_mask, cpu_present_mask.
+ */
+void cpu_maps_update_begin(void)
+{
+ mutex_lock(&cpu_add_remove_lock);
+}
+
+void cpu_maps_update_done(void)
+{
+ mutex_unlock(&cpu_add_remove_lock);
+}
+
+static RAW_NOTIFIER_HEAD(cpu_chain);
/* If set, cpu_up and cpu_down will return -EBUSY and do nothing.
* Should always be manipulated under cpu_add_remove_lock
*/
static int cpu_hotplug_disabled;
+#ifdef CONFIG_HOTPLUG_CPU
+
static struct {
struct task_struct *active_writer;
struct mutex lock; /* Synchronizes accesses to refcount, */
.refcount = 0,
};
-#ifdef CONFIG_HOTPLUG_CPU
-
void get_online_cpus(void)
{
might_sleep();
}
EXPORT_SYMBOL_GPL(put_online_cpus);
-#endif /* CONFIG_HOTPLUG_CPU */
-
-/*
- * The following two API's must be used when attempting
- * to serialize the updates to cpu_online_mask, cpu_present_mask.
- */
-void cpu_maps_update_begin(void)
-{
- mutex_lock(&cpu_add_remove_lock);
-}
-
-void cpu_maps_update_done(void)
-{
- mutex_unlock(&cpu_add_remove_lock);
-}
-
/*
* This ensures that the hotplug operation can begin only when the
* refcount goes to zero.
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 /* #esle #if CONFIG_HOTPLUG_CPU */
+
/* Need to know about CPUs going up/down? */
int __ref register_cpu_notifier(struct notifier_block *nb)
{
return ret;
}
+static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
+ int *nr_calls)
+{
+ int ret;
+
+ ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call,
+ nr_calls);
+
+ return notifier_to_errno(ret);
+}
+
+static int cpu_notify(unsigned long val, void *v)
+{
+ return __cpu_notify(val, v, -1, NULL);
+}
+
#ifdef CONFIG_HOTPLUG_CPU
+static void cpu_notify_nofail(unsigned long val, void *v)
+{
+ BUG_ON(cpu_notify(val, v));
+}
+
EXPORT_SYMBOL(register_cpu_notifier);
void __ref unregister_cpu_notifier(struct notifier_block *nb)
write_lock_irq(&tasklist_lock);
for_each_process(p) {
- if (task_cpu(p) == cpu &&
+ if (task_cpu(p) == cpu && p->state == TASK_RUNNING &&
(!cputime_eq(p->utime, cputime_zero) ||
!cputime_eq(p->stime, cputime_zero)))
- printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d\
- (state = %ld, flags = %x) \n",
- p->comm, task_pid_nr(p), cpu,
- p->state, p->flags);
+ printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d "
+ "(state = %ld, flags = %x)\n",
+ p->comm, task_pid_nr(p), cpu,
+ p->state, p->flags);
}
write_unlock_irq(&tasklist_lock);
}
struct take_cpu_down_param {
+ struct task_struct *caller;
unsigned long mod;
void *hcpu;
};
static int __ref take_cpu_down(void *_param)
{
struct take_cpu_down_param *param = _param;
+ unsigned int cpu = (unsigned long)param->hcpu;
int err;
/* Ensure this CPU doesn't handle any more interrupts. */
if (err < 0)
return err;
- raw_notifier_call_chain(&cpu_chain, CPU_DYING | param->mod,
- param->hcpu);
+ cpu_notify(CPU_DYING | param->mod, param->hcpu);
+ if (task_cpu(param->caller) == cpu)
+ move_task_off_dead_cpu(cpu, param->caller);
/* Force idle task to run as soon as we yield: it should
immediately notice cpu is offline and die quickly. */
sched_idle_next();
static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
{
int err, nr_calls = 0;
- cpumask_var_t old_allowed;
void *hcpu = (void *)(long)cpu;
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct take_cpu_down_param tcd_param = {
+ .caller = current,
.mod = mod,
.hcpu = hcpu,
};
if (!cpu_online(cpu))
return -EINVAL;
- if (!alloc_cpumask_var(&old_allowed, GFP_KERNEL))
- return -ENOMEM;
-
cpu_hotplug_begin();
- err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
- hcpu, -1, &nr_calls);
- if (err == NOTIFY_BAD) {
+ set_cpu_active(cpu, false);
+ err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
+ if (err) {
+ set_cpu_active(cpu, true);
+
nr_calls--;
- __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
- hcpu, nr_calls, NULL);
+ __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
printk("%s: attempt to take down CPU %u failed\n",
__func__, cpu);
- err = -EINVAL;
goto out_release;
}
- /* Ensure that we are not runnable on dying cpu */
- cpumask_copy(old_allowed, ¤t->cpus_allowed);
- set_cpus_allowed_ptr(current,
- cpumask_of(cpumask_any_but(cpu_online_mask, cpu)));
-
err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
if (err) {
+ set_cpu_active(cpu, true);
/* CPU didn't die: tell everyone. Can't complain. */
- if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
- hcpu) == NOTIFY_BAD)
- BUG();
+ cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
- goto out_allowed;
+ goto out_release;
}
BUG_ON(cpu_online(cpu));
__cpu_die(cpu);
/* CPU is completely dead: tell everyone. Too late to complain. */
- if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD | mod,
- hcpu) == NOTIFY_BAD)
- BUG();
+ cpu_notify_nofail(CPU_DEAD | mod, hcpu);
check_for_tasks(cpu);
-out_allowed:
- set_cpus_allowed_ptr(current, old_allowed);
out_release:
cpu_hotplug_done();
- if (!err) {
- if (raw_notifier_call_chain(&cpu_chain, CPU_POST_DEAD | mod,
- hcpu) == NOTIFY_BAD)
- BUG();
- }
- free_cpumask_var(old_allowed);
+ if (!err)
+ cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
return err;
}
{
int err;
- err = stop_machine_create();
- if (err)
- return err;
cpu_maps_update_begin();
if (cpu_hotplug_disabled) {
goto out;
}
- set_cpu_active(cpu, false);
-
- /*
- * Make sure the all cpus did the reschedule and are not
- * using stale version of the cpu_active_mask.
- * This is not strictly necessary becuase stop_machine()
- * that we run down the line already provides the required
- * synchronization. But it's really a side effect and we do not
- * want to depend on the innards of the stop_machine here.
- */
- synchronize_sched();
-
err = _cpu_down(cpu, 0);
- if (cpu_online(cpu))
- set_cpu_active(cpu, true);
-
out:
cpu_maps_update_done();
- stop_machine_destroy();
return err;
}
EXPORT_SYMBOL(cpu_down);
return -EINVAL;
cpu_hotplug_begin();
- ret = __raw_notifier_call_chain(&cpu_chain, CPU_UP_PREPARE | mod, hcpu,
- -1, &nr_calls);
- if (ret == NOTIFY_BAD) {
+ ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
+ if (ret) {
nr_calls--;
printk("%s: attempt to bring up CPU %u failed\n",
__func__, cpu);
- ret = -EINVAL;
goto out_notify;
}
set_cpu_active(cpu, true);
/* Now call notifier in preparation. */
- raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu);
+ cpu_notify(CPU_ONLINE | mod, hcpu);
out_notify:
if (ret != 0)
- __raw_notifier_call_chain(&cpu_chain,
- CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
+ __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
cpu_hotplug_done();
return ret;
int __cpuinit cpu_up(unsigned int cpu)
{
int err = 0;
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+ int nid;
+ pg_data_t *pgdat;
+#endif
+
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);
-#if defined(CONFIG_IA64) || defined(CONFIG_X86_64)
+#if defined(CONFIG_IA64)
printk(KERN_ERR "please check additional_cpus= boot "
"parameter\n");
#endif
return -EINVAL;
}
+#ifdef CONFIG_MEMORY_HOTPLUG
+ nid = cpu_to_node(cpu);
+ if (!node_online(nid)) {
+ err = mem_online_node(nid);
+ if (err)
+ return err;
+ }
+
+ pgdat = NODE_DATA(nid);
+ if (!pgdat) {
+ printk(KERN_ERR
+ "Can't online cpu %d due to NULL pgdat\n", cpu);
+ return -ENOMEM;
+ }
+
+ if (pgdat->node_zonelists->_zonerefs->zone == NULL) {
+ mutex_lock(&zonelists_mutex);
+ build_all_zonelists(NULL);
+ mutex_unlock(&zonelists_mutex);
+ }
+#endif
+
cpu_maps_update_begin();
if (cpu_hotplug_disabled) {
int disable_nonboot_cpus(void)
{
- int cpu, first_cpu, error;
+ int cpu, first_cpu, error = 0;
- error = stop_machine_create();
- if (error)
- return error;
cpu_maps_update_begin();
first_cpu = cpumask_first(cpu_online_mask);
- /* We take down all of the non-boot CPUs in one shot to avoid races
+ /*
+ * We take down all of the non-boot CPUs in one shot to avoid races
* with the userspace trying to use the CPU hotplug at the same time
*/
cpumask_clear(frozen_cpus);
+
printk("Disabling non-boot CPUs ...\n");
for_each_online_cpu(cpu) {
if (cpu == first_cpu)
continue;
error = _cpu_down(cpu, 1);
- if (!error) {
+ if (!error)
cpumask_set_cpu(cpu, frozen_cpus);
- printk("CPU%d is down\n", cpu);
- } else {
+ else {
printk(KERN_ERR "Error taking CPU%d down: %d\n",
cpu, error);
break;
}
}
+
if (!error) {
BUG_ON(num_online_cpus() > 1);
/* Make sure the CPUs won't be enabled by someone else */
printk(KERN_ERR "Non-boot CPUs are not disabled\n");
}
cpu_maps_update_done();
- stop_machine_destroy();
return error;
}
if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus))
val = CPU_STARTING_FROZEN;
#endif /* CONFIG_PM_SLEEP_SMP */
- raw_notifier_call_chain(&cpu_chain, val, (void *)(long)cpu);
+ cpu_notify(val, (void *)(long)cpu);
}
#endif /* CONFIG_SMP */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff