X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fcpu.c;h=7c4e2713df0a9b12eb31c47b176134516968f6a2;hb=60d8ce2cd6c283132928c11f3fd57ff4187287e0;hp=e202a68d1cc180cf62ade78b025ec2329c8aabcd;hpb=9e3ee1c39c0cc71222f9980ccbf87fe072897eef;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/cpu.c b/kernel/cpu.c index e202a68..7c4e271 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -15,29 +15,8 @@ #include #include -/* - * 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 - -/* - * Represents all cpu's that are currently online. - */ -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 */ - -/* Serializes the updates to cpu_online_map, cpu_present_map */ +#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); @@ -55,16 +34,11 @@ static struct { * 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; +} cpu_hotplug = { + .active_writer = NULL, + .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), + .refcount = 0, +}; #ifdef CONFIG_HOTPLUG_CPU @@ -96,7 +70,7 @@ EXPORT_SYMBOL_GPL(put_online_cpus); /* * The following two API's must be used when attempting - * to serialize the updates to cpu_online_map, cpu_present_map. + * to serialize the updates to cpu_online_mask, cpu_present_mask. */ void cpu_maps_update_begin(void) { @@ -199,13 +173,14 @@ static int __ref take_cpu_down(void *_param) 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; + raw_notifier_call_chain(&cpu_chain, CPU_DYING | param->mod, + param->hcpu); + /* Force idle task to run as soon as we yield: it should immediately notice cpu is offline and die quickly. */ sched_idle_next(); @@ -216,7 +191,7 @@ 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_t old_allowed, tmp; + 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 = { @@ -230,6 +205,9 @@ 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(); err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls); @@ -244,13 +222,11 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) } /* 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); - tmp = cpumask_of_cpu(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, &tmp); + 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, @@ -276,7 +252,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) check_for_tasks(cpu); out_allowed: - set_cpus_allowed_ptr(current, &old_allowed); + set_cpus_allowed_ptr(current, old_allowed); out_release: cpu_hotplug_done(); if (!err) { @@ -284,13 +260,17 @@ out_release: hcpu) == NOTIFY_BAD) BUG(); } + free_cpumask_var(old_allowed); return err; } int __ref cpu_down(unsigned int cpu) { - int err = 0; + int err; + err = stop_machine_create(); + if (err) + return err; cpu_maps_update_begin(); if (cpu_hotplug_disabled) { @@ -298,11 +278,11 @@ int __ref cpu_down(unsigned int cpu) goto out; } - cpu_clear(cpu, cpu_active_map); + set_cpu_active(cpu, false); /* * Make sure the all cpus did the reschedule and are not - * using stale version of the cpu_active_map. + * 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 @@ -313,10 +293,11 @@ int __ref cpu_down(unsigned int cpu) err = _cpu_down(cpu, 0); if (cpu_online(cpu)) - cpu_set(cpu, cpu_active_map); + set_cpu_active(cpu, true); out: cpu_maps_update_done(); + stop_machine_destroy(); return err; } EXPORT_SYMBOL(cpu_down); @@ -349,6 +330,8 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) goto out_notify; BUG_ON(!cpu_online(cpu)); + set_cpu_active(cpu, true); + /* Now call notifier in preparation. */ raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu); @@ -364,10 +347,10 @@ out_notify: int __cpuinit cpu_up(unsigned int cpu) { int err = 0; - if (!cpu_isset(cpu, cpu_possible_map)) { + 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) || defined(CONFIG_X86_64) printk(KERN_ERR "please check additional_cpus= boot " "parameter\n"); #endif @@ -383,41 +366,41 @@ int __cpuinit cpu_up(unsigned int cpu) 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; int disable_nonboot_cpus(void) { - int cpu, first_cpu, error = 0; + int cpu, first_cpu, error; + error = stop_machine_create(); + if (error) + return error; cpu_maps_update_begin(); - first_cpu = first_cpu(cpu_online_map); + 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); 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; } } + if (!error) { BUG_ON(num_online_cpus() > 1); /* Make sure the CPUs won't be enabled by someone else */ @@ -426,9 +409,18 @@ int disable_nonboot_cpus(void) printk(KERN_ERR "Non-boot CPUs are not disabled\n"); } cpu_maps_update_done(); + stop_machine_destroy(); 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; @@ -436,11 +428,14 @@ void __ref enable_nonboot_cpus(void) /* 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_nr(cpu, frozen_cpus) { + + 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); @@ -448,11 +443,41 @@ void __ref enable_nonboot_cpus(void) } 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 */ + raw_notifier_call_chain(&cpu_chain, val, (void *)(long)cpu); +} #endif /* CONFIG_SMP */ @@ -460,7 +485,7 @@ out: * cpu_bit_bitmap[] is a special, "compressed" data structure that * represents all NR_CPUS bits binary values of 1<