diff options
Diffstat (limited to 'kernel/cpu.c')
| -rw-r--r-- | kernel/cpu.c | 170 |
1 files changed, 98 insertions, 72 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 1c8ddd6..8b92539 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -14,11 +14,26 @@ #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); +/* + * 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 __cpuinitdata RAW_NOTIFIER_HEAD(cpu_chain); /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. @@ -26,6 +41,8 @@ static __cpuinitdata RAW_NOTIFIER_HEAD(cpu_chain); */ static int cpu_hotplug_disabled; +#ifdef CONFIG_HOTPLUG_CPU + static struct { struct task_struct *active_writer; struct mutex lock; /* Synchronizes accesses to refcount, */ @@ -40,8 +57,6 @@ static struct { .refcount = 0, }; -#ifdef CONFIG_HOTPLUG_CPU - void get_online_cpus(void) { might_sleep(); @@ -66,22 +81,6 @@ void put_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_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. @@ -123,6 +122,12 @@ static void cpu_hotplug_done(void) 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) { @@ -133,8 +138,29 @@ 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) @@ -151,18 +177,19 @@ static inline void check_for_tasks(int cpu) 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; }; @@ -171,6 +198,7 @@ struct take_cpu_down_param { 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. */ @@ -178,9 +206,10 @@ static int __ref take_cpu_down(void *_param) 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(); @@ -191,10 +220,10 @@ static int __ref take_cpu_down(void *_param) 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, }; @@ -205,38 +234,26 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) if (!cpu_online(cpu)) return -EINVAL; - if (!alloc_cpumask_var(&old_allowed, GFP_KERNEL)) - return -ENOMEM; - cpu_hotplug_begin(); set_cpu_active(cpu, false); - 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) { 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, cpu_active_mask); - 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)); @@ -248,22 +265,14 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) __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; } @@ -271,9 +280,6 @@ int __ref cpu_down(unsigned int cpu) { int err; - err = stop_machine_create(); - if (err) - return err; cpu_maps_update_begin(); if (cpu_hotplug_disabled) { @@ -285,7 +291,6 @@ int __ref cpu_down(unsigned int cpu) out: cpu_maps_update_done(); - stop_machine_destroy(); return err; } EXPORT_SYMBOL(cpu_down); @@ -302,13 +307,11 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) 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; } @@ -321,12 +324,11 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) 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; @@ -335,16 +337,44 @@ out_notify: 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) { @@ -364,11 +394,8 @@ static cpumask_var_t frozen_cpus; 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); /* @@ -399,7 +426,6 @@ int disable_nonboot_cpus(void) printk(KERN_ERR "Non-boot CPUs are not disabled\n"); } cpu_maps_update_done(); - stop_machine_destroy(); return error; } @@ -466,7 +492,7 @@ void __cpuinit notify_cpu_starting(unsigned int cpu) 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 */ |