diff options
Diffstat (limited to 'kernel/cpu.c')
| -rw-r--r-- | kernel/cpu.c | 38 |
1 files changed, 23 insertions, 15 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 14d32588ccc..3046a503242 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -80,6 +80,10 @@ void put_online_cpus(void) if (cpu_hotplug.active_writer == current) return; mutex_lock(&cpu_hotplug.lock); + + if (WARN_ON(!cpu_hotplug.refcount)) + cpu_hotplug.refcount++; /* try to fix things up */ + if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer)) wake_up_process(cpu_hotplug.active_writer); mutex_unlock(&cpu_hotplug.lock); @@ -280,12 +284,13 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) __func__, cpu); goto out_release; } + smpboot_park_threads(cpu); err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); if (err) { /* CPU didn't die: tell everyone. Can't complain. */ + smpboot_unpark_threads(cpu); cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); - goto out_release; } BUG_ON(cpu_online(cpu)); @@ -343,17 +348,23 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; struct task_struct *idle; - if (cpu_online(cpu) || !cpu_present(cpu)) - return -EINVAL; - cpu_hotplug_begin(); + if (cpu_online(cpu) || !cpu_present(cpu)) { + ret = -EINVAL; + goto out; + } + idle = idle_thread_get(cpu); if (IS_ERR(idle)) { ret = PTR_ERR(idle); goto out; } + ret = smpboot_create_threads(cpu); + if (ret) + goto out; + ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls); if (ret) { nr_calls--; @@ -368,6 +379,9 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) goto out_notify; BUG_ON(!cpu_online(cpu)); + /* Wake the per cpu threads */ + smpboot_unpark_threads(cpu); + /* Now call notifier in preparation. */ cpu_notify(CPU_ONLINE | mod, hcpu); @@ -439,14 +453,6 @@ EXPORT_SYMBOL_GPL(cpu_up); #ifdef CONFIG_PM_SLEEP_SMP 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; @@ -458,7 +464,6 @@ int disable_nonboot_cpus(void) * with the userspace trying to use the CPU hotplug at the same time */ cpumask_clear(frozen_cpus); - arch_disable_nonboot_cpus_begin(); printk("Disabling non-boot CPUs ...\n"); for_each_online_cpu(cpu) { @@ -474,8 +479,6 @@ int disable_nonboot_cpus(void) } } - arch_disable_nonboot_cpus_end(); - if (!error) { BUG_ON(num_online_cpus() > 1); /* Make sure the CPUs won't be enabled by someone else */ @@ -600,6 +603,11 @@ cpu_hotplug_pm_callback(struct notifier_block *nb, static int __init cpu_hotplug_pm_sync_init(void) { + /* + * cpu_hotplug_pm_callback has higher priority than x86 + * bsp_pm_callback which depends on cpu_hotplug_pm_callback + * to disable cpu hotplug to avoid cpu hotplug race. + */ pm_notifier(cpu_hotplug_pm_callback, 0); return 0; } |