diff options
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r-- | kernel/cpu.c | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 9c9c9fab16cc..3612e744006f 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -21,6 +21,7 @@ #include <linux/suspend.h> #include <linux/lockdep.h> #include <linux/tick.h> +#include <linux/irq.h> #include <trace/events/power.h> #include "smpboot.h" @@ -392,13 +393,19 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) smpboot_park_threads(cpu); /* - * So now all preempt/rcu users must observe !cpu_active(). + * Prevent irq alloc/free while the dying cpu reorganizes the + * interrupt affinities. */ + irq_lock_sparse(); + /* + * So now all preempt/rcu users must observe !cpu_active(). + */ err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); if (err) { /* CPU didn't die: tell everyone. Can't complain. */ cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); + irq_unlock_sparse(); goto out_release; } BUG_ON(cpu_online(cpu)); @@ -415,6 +422,9 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */ per_cpu(cpu_dead_idle, cpu) = false; + /* Interrupts are moved away from the dying cpu, reenable alloc/free */ + irq_unlock_sparse(); + hotplug_cpu__broadcast_tick_pull(cpu); /* This actually kills the CPU. */ __cpu_die(cpu); @@ -519,6 +529,7 @@ static int _cpu_up(unsigned int cpu, int tasks_frozen) /* Arch-specific enabling code. */ ret = __cpu_up(cpu, idle); + if (ret != 0) goto out_notify; BUG_ON(!cpu_online(cpu)); @@ -823,3 +834,23 @@ void init_cpu_online(const struct cpumask *src) { cpumask_copy(to_cpumask(cpu_online_bits), src); } + +static ATOMIC_NOTIFIER_HEAD(idle_notifier); + +void idle_notifier_register(struct notifier_block *n) +{ + atomic_notifier_chain_register(&idle_notifier, n); +} +EXPORT_SYMBOL_GPL(idle_notifier_register); + +void idle_notifier_unregister(struct notifier_block *n) +{ + atomic_notifier_chain_unregister(&idle_notifier, n); +} +EXPORT_SYMBOL_GPL(idle_notifier_unregister); + +void idle_notifier_call_chain(unsigned long val) +{ + atomic_notifier_call_chain(&idle_notifier, val, NULL); +} +EXPORT_SYMBOL_GPL(idle_notifier_call_chain); |