#include <linux/kthread.h>
#include <linux/stop_machine.h>
#include <linux/mutex.h>
+#include <linux/gfp.h>
-/*
- * Represents all cpu's present in the system
- * In systems capable of hotplug, this map could dynamically grow
- * as new cpu's are detected in the system via any platform specific
- * method, such as ACPI for e.g.
- */
-cpumask_t cpu_present_map __read_mostly;
-EXPORT_SYMBOL(cpu_present_map);
-
-#ifndef CONFIG_SMP
+#ifdef CONFIG_SMP
+/* Serializes the updates to cpu_online_mask, cpu_present_mask */
+static DEFINE_MUTEX(cpu_add_remove_lock);
/*
- * Represents all cpu's that are currently online.
+ * The following two API's must be used when attempting
+ * to serialize the updates to cpu_online_mask, cpu_present_mask.
*/
-cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL;
-EXPORT_SYMBOL(cpu_online_map);
-
-cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;
-EXPORT_SYMBOL(cpu_possible_map);
-
-#else /* CONFIG_SMP */
+void cpu_maps_update_begin(void)
+{
+ mutex_lock(&cpu_add_remove_lock);
+}
-/* Serializes the updates to cpu_online_map, cpu_present_map */
-static DEFINE_MUTEX(cpu_add_remove_lock);
+void cpu_maps_update_done(void)
+{
+ mutex_unlock(&cpu_add_remove_lock);
+}
-static __cpuinitdata RAW_NOTIFIER_HEAD(cpu_chain);
+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, */
* an ongoing cpu hotplug operation.
*/
int refcount;
-} cpu_hotplug;
-
-void __init cpu_hotplug_init(void)
-{
- cpu_hotplug.active_writer = NULL;
- mutex_init(&cpu_hotplug.lock);
- cpu_hotplug.refcount = 0;
-}
-
-cpumask_t cpu_active_map;
-
-#ifdef CONFIG_HOTPLUG_CPU
+} cpu_hotplug = {
+ .active_writer = NULL,
+ .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock),
+ .refcount = 0,
+};
void get_online_cpus(void)
{
}
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_map, cpu_present_map.
- */
-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 /* #else #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 *param = _param;
int err;
- raw_notifier_call_chain(&cpu_chain, CPU_DYING | param->mod,
- param->hcpu);
/* Ensure this CPU doesn't handle any more interrupts. */
err = __cpu_disable();
if (err < 0)
return err;
- /* Force idle task to run as soon as we yield: it should
- immediately notice cpu is offline and die quickly. */
- sched_idle_next();
+ cpu_notify(CPU_DYING | param->mod, param->hcpu);
return 0;
}
static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
{
int err, nr_calls = 0;
- struct task_struct *p;
- cpumask_t old_allowed, tmp;
void *hcpu = (void *)(long)cpu;
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct take_cpu_down_param tcd_param = {
return -EINVAL;
cpu_hotplug_begin();
- err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
- hcpu, -1, &nr_calls);
- if (err == NOTIFY_BAD) {
+
+ err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
+ if (err) {
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 */
- old_allowed = current->cpus_allowed;
- cpus_setall(tmp);
- cpu_clear(cpu, tmp);
- set_cpus_allowed_ptr(current, &tmp);
-
- p = __stop_machine_run(take_cpu_down, &tcd_param, cpu);
-
- if (IS_ERR(p) || cpu_online(cpu)) {
+ err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
+ if (err) {
/* 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);
- if (IS_ERR(p)) {
- err = PTR_ERR(p);
- goto out_allowed;
- }
- goto out_thread;
+ goto out_release;
}
+ BUG_ON(cpu_online(cpu));
- /* Wait for it to sleep (leaving idle task). */
+ /*
+ * The migration_call() CPU_DYING callback will have removed all
+ * runnable tasks from the cpu, there's only the idle task left now
+ * that the migration thread is done doing the stop_machine thing.
+ *
+ * Wait for the stop thread to go away.
+ */
while (!idle_cpu(cpu))
- yield();
+ cpu_relax();
/* This actually kills the 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_thread:
- err = kthread_stop(p);
-out_allowed:
- set_cpus_allowed_ptr(current, &old_allowed);
out_release:
cpu_hotplug_done();
+ if (!err)
+ cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
return err;
}
int __ref cpu_down(unsigned int cpu)
{
- int err = 0;
+ int err;
cpu_maps_update_begin();
goto out;
}
- cpu_clear(cpu, cpu_active_map);
-
- /*
- * Make sure the all cpus did the reschedule and are not
- * using stale version of the cpu_active_map.
- * 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))
- cpu_set(cpu, cpu_active_map);
-
out:
cpu_maps_update_done();
return err;
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",
+ printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n",
__func__, cpu);
- ret = -EINVAL;
goto out_notify;
}
BUG_ON(!cpu_online(cpu));
/* 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;
- if (!cpu_isset(cpu, cpu_possible_map)) {
+
+#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) || defined(CONFIG_S390)
+#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) {
err = _cpu_up(cpu, 0);
- if (cpu_online(cpu))
- cpu_set(cpu, cpu_active_map);
-
out:
cpu_maps_update_done();
return err;
}
#ifdef CONFIG_PM_SLEEP_SMP
-static cpumask_t frozen_cpus;
+static cpumask_var_t frozen_cpus;
+
+void __weak arch_disable_nonboot_cpus_begin(void)
+{
+}
+
+void __weak arch_disable_nonboot_cpus_end(void)
+{
+}
int disable_nonboot_cpus(void)
{
int cpu, first_cpu, error = 0;
cpu_maps_update_begin();
- first_cpu = first_cpu(cpu_online_map);
- /* We take down all of the non-boot CPUs in one shot to avoid races
+ first_cpu = cpumask_first(cpu_online_mask);
+ /*
+ * 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
*/
- cpus_clear(frozen_cpus);
+ cpumask_clear(frozen_cpus);
+ arch_disable_nonboot_cpus_begin();
+
printk("Disabling non-boot CPUs ...\n");
for_each_online_cpu(cpu) {
if (cpu == first_cpu)
continue;
error = _cpu_down(cpu, 1);
- if (!error) {
- cpu_set(cpu, frozen_cpus);
- printk("CPU%d is down\n", cpu);
- } else {
+ if (!error)
+ cpumask_set_cpu(cpu, frozen_cpus);
+ else {
printk(KERN_ERR "Error taking CPU%d down: %d\n",
cpu, error);
break;
}
}
+
+ arch_disable_nonboot_cpus_end();
+
if (!error) {
BUG_ON(num_online_cpus() > 1);
/* Make sure the CPUs won't be enabled by someone else */
return error;
}
+void __weak arch_enable_nonboot_cpus_begin(void)
+{
+}
+
+void __weak arch_enable_nonboot_cpus_end(void)
+{
+}
+
void __ref enable_nonboot_cpus(void)
{
int cpu, error;
/* Allow everyone to use the CPU hotplug again */
cpu_maps_update_begin();
cpu_hotplug_disabled = 0;
- if (cpus_empty(frozen_cpus))
+ if (cpumask_empty(frozen_cpus))
goto out;
- printk("Enabling non-boot CPUs ...\n");
- for_each_cpu_mask(cpu, frozen_cpus) {
+ printk(KERN_INFO "Enabling non-boot CPUs ...\n");
+
+ arch_enable_nonboot_cpus_begin();
+
+ for_each_cpu(cpu, frozen_cpus) {
error = _cpu_up(cpu, 1);
if (!error) {
- printk("CPU%d is up\n", cpu);
+ printk(KERN_INFO "CPU%d is up\n", cpu);
continue;
}
printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error);
}
- cpus_clear(frozen_cpus);
+
+ arch_enable_nonboot_cpus_end();
+
+ cpumask_clear(frozen_cpus);
out:
cpu_maps_update_done();
}
+
+static int alloc_frozen_cpus(void)
+{
+ if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO))
+ return -ENOMEM;
+ return 0;
+}
+core_initcall(alloc_frozen_cpus);
+#endif /* CONFIG_PM_SLEEP_SMP */
+
+/**
+ * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
+ * @cpu: cpu that just started
+ *
+ * This function calls the cpu_chain notifiers with CPU_STARTING.
+ * 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)
+{
+ unsigned long val = CPU_STARTING;
+
+#ifdef CONFIG_PM_SLEEP_SMP
+ if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus))
+ val = CPU_STARTING_FROZEN;
#endif /* CONFIG_PM_SLEEP_SMP */
+ cpu_notify(val, (void *)(long)cpu);
+}
#endif /* CONFIG_SMP */
+
+/*
+ * cpu_bit_bitmap[] is a special, "compressed" data structure that
+ * represents all NR_CPUS bits binary values of 1<<nr.
+ *
+ * It is used by cpumask_of() to get a constant address to a CPU
+ * mask value that has a single bit set only.
+ */
+
+/* cpu_bit_bitmap[0] is empty - so we can back into it */
+#define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x))
+#define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1)
+#define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2)
+#define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4)
+
+const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = {
+
+ MASK_DECLARE_8(0), MASK_DECLARE_8(8),
+ MASK_DECLARE_8(16), MASK_DECLARE_8(24),
+#if BITS_PER_LONG > 32
+ MASK_DECLARE_8(32), MASK_DECLARE_8(40),
+ MASK_DECLARE_8(48), MASK_DECLARE_8(56),
+#endif
+};
+EXPORT_SYMBOL_GPL(cpu_bit_bitmap);
+
+const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL;
+EXPORT_SYMBOL(cpu_all_bits);
+
+#ifdef CONFIG_INIT_ALL_POSSIBLE
+static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly
+ = CPU_BITS_ALL;
+#else
+static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly;
+#endif
+const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits);
+EXPORT_SYMBOL(cpu_possible_mask);
+
+static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly;
+const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits);
+EXPORT_SYMBOL(cpu_online_mask);
+
+static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly;
+const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits);
+EXPORT_SYMBOL(cpu_present_mask);
+
+static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly;
+const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits);
+EXPORT_SYMBOL(cpu_active_mask);
+
+void set_cpu_possible(unsigned int cpu, bool possible)
+{
+ if (possible)
+ cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits));
+ else
+ cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits));
+}
+
+void set_cpu_present(unsigned int cpu, bool present)
+{
+ if (present)
+ cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits));
+ else
+ cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits));
+}
+
+void set_cpu_online(unsigned int cpu, bool online)
+{
+ if (online)
+ cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits));
+ else
+ cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits));
+}
+
+void set_cpu_active(unsigned int cpu, bool active)
+{
+ if (active)
+ cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits));
+ else
+ cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits));
+}
+
+void init_cpu_present(const struct cpumask *src)
+{
+ cpumask_copy(to_cpumask(cpu_present_bits), src);
+}
+
+void init_cpu_possible(const struct cpumask *src)
+{
+ cpumask_copy(to_cpumask(cpu_possible_bits), src);
+}
+
+void init_cpu_online(const struct cpumask *src)
+{
+ cpumask_copy(to_cpumask(cpu_online_bits), src);
+}
Code Review / linux-2.6.git / blobdiff