-/* Copyright 2005 Rusty Russell rusty@rustcorp.com.au IBM Corporation.
- * GPL v2 and any later version.
+/*
+ * kernel/stop_machine.c
+ *
+ * Copyright (C) 2008, 2005 IBM Corporation.
+ * Copyright (C) 2008, 2005 Rusty Russell rusty@rustcorp.com.au
+ * Copyright (C) 2010 SUSE Linux Products GmbH
+ * Copyright (C) 2010 Tejun Heo <tj@kernel.org>
+ *
+ * This file is released under the GPLv2 and any later version.
*/
+#include <linux/completion.h>
#include <linux/cpu.h>
-#include <linux/err.h>
+#include <linux/init.h>
#include <linux/kthread.h>
#include <linux/module.h>
+#include <linux/percpu.h>
#include <linux/sched.h>
#include <linux/stop_machine.h>
-#include <linux/syscalls.h>
#include <linux/interrupt.h>
+#include <linux/kallsyms.h>
-#include <asm/atomic.h>
-#include <asm/uaccess.h>
+#include <linux/atomic.h>
-/* Since we effect priority and affinity (both of which are visible
- * to, and settable by outside processes) we do indirection via a
- * kthread. */
+/*
+ * Structure to determine completion condition and record errors. May
+ * be shared by works on different cpus.
+ */
+struct cpu_stop_done {
+ atomic_t nr_todo; /* nr left to execute */
+ bool executed; /* actually executed? */
+ int ret; /* collected return value */
+ struct completion completion; /* fired if nr_todo reaches 0 */
+};
-/* Thread to stop each CPU in user context. */
-enum stopmachine_state {
- STOPMACHINE_WAIT,
- STOPMACHINE_PREPARE,
- STOPMACHINE_DISABLE_IRQ,
- STOPMACHINE_EXIT,
+/* the actual stopper, one per every possible cpu, enabled on online cpus */
+struct cpu_stopper {
+ spinlock_t lock;
+ bool enabled; /* is this stopper enabled? */
+ struct list_head works; /* list of pending works */
+ struct task_struct *thread; /* stopper thread */
};
-static enum stopmachine_state stopmachine_state;
-static unsigned int stopmachine_num_threads;
-static atomic_t stopmachine_thread_ack;
+static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper);
-static int stopmachine(void *cpu)
+static void cpu_stop_init_done(struct cpu_stop_done *done, unsigned int nr_todo)
{
- int irqs_disabled = 0;
- int prepared = 0;
-
- set_cpus_allowed_ptr(current, &cpumask_of_cpu((int)(long)cpu));
-
- /* Ack: we are alive */
- smp_mb(); /* Theoretically the ack = 0 might not be on this CPU yet. */
- atomic_inc(&stopmachine_thread_ack);
+ memset(done, 0, sizeof(*done));
+ atomic_set(&done->nr_todo, nr_todo);
+ init_completion(&done->completion);
+}
- /* Simple state machine */
- while (stopmachine_state != STOPMACHINE_EXIT) {
- if (stopmachine_state == STOPMACHINE_DISABLE_IRQ
- && !irqs_disabled) {
- local_irq_disable();
- hard_irq_disable();
- irqs_disabled = 1;
- /* Ack: irqs disabled. */
- smp_mb(); /* Must read state first. */
- atomic_inc(&stopmachine_thread_ack);
- } else if (stopmachine_state == STOPMACHINE_PREPARE
- && !prepared) {
- /* Everyone is in place, hold CPU. */
- preempt_disable();
- prepared = 1;
- smp_mb(); /* Must read state first. */
- atomic_inc(&stopmachine_thread_ack);
- }
- /* Yield in first stage: migration threads need to
- * help our sisters onto their CPUs. */
- if (!prepared && !irqs_disabled)
- yield();
- else
- cpu_relax();
+/* signal completion unless @done is NULL */
+static void cpu_stop_signal_done(struct cpu_stop_done *done, bool executed)
+{
+ if (done) {
+ if (executed)
+ done->executed = true;
+ if (atomic_dec_and_test(&done->nr_todo))
+ complete(&done->completion);
}
+}
+
+/* queue @work to @stopper. if offline, @work is completed immediately */
+static void cpu_stop_queue_work(struct cpu_stopper *stopper,
+ struct cpu_stop_work *work)
+{
+ unsigned long flags;
- /* Ack: we are exiting. */
- smp_mb(); /* Must read state first. */
- atomic_inc(&stopmachine_thread_ack);
+ spin_lock_irqsave(&stopper->lock, flags);
- if (irqs_disabled)
- local_irq_enable();
- if (prepared)
- preempt_enable();
+ if (stopper->enabled) {
+ list_add_tail(&work->list, &stopper->works);
+ wake_up_process(stopper->thread);
+ } else
+ cpu_stop_signal_done(work->done, false);
- return 0;
+ spin_unlock_irqrestore(&stopper->lock, flags);
}
-/* Change the thread state */
-static void stopmachine_set_state(enum stopmachine_state state)
+/**
+ * stop_one_cpu - stop a cpu
+ * @cpu: cpu to stop
+ * @fn: function to execute
+ * @arg: argument to @fn
+ *
+ * Execute @fn(@arg) on @cpu. @fn is run in a process context with
+ * the highest priority preempting any task on the cpu and
+ * monopolizing it. This function returns after the execution is
+ * complete.
+ *
+ * This function doesn't guarantee @cpu stays online till @fn
+ * completes. If @cpu goes down in the middle, execution may happen
+ * partially or fully on different cpus. @fn should either be ready
+ * for that or the caller should ensure that @cpu stays online until
+ * this function completes.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * -ENOENT if @fn(@arg) was not executed because @cpu was offline;
+ * otherwise, the return value of @fn.
+ */
+int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
{
- atomic_set(&stopmachine_thread_ack, 0);
- smp_wmb();
- stopmachine_state = state;
- while (atomic_read(&stopmachine_thread_ack) != stopmachine_num_threads)
- cpu_relax();
+ struct cpu_stop_done done;
+ struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done };
+
+ cpu_stop_init_done(&done, 1);
+ cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), &work);
+ wait_for_completion(&done.completion);
+ return done.executed ? done.ret : -ENOENT;
}
-static int stop_machine(void)
+/**
+ * stop_one_cpu_nowait - stop a cpu but don't wait for completion
+ * @cpu: cpu to stop
+ * @fn: function to execute
+ * @arg: argument to @fn
+ *
+ * Similar to stop_one_cpu() but doesn't wait for completion. The
+ * caller is responsible for ensuring @work_buf is currently unused
+ * and will remain untouched until stopper starts executing @fn.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
+ struct cpu_stop_work *work_buf)
{
- int i, ret = 0;
-
- atomic_set(&stopmachine_thread_ack, 0);
- stopmachine_num_threads = 0;
- stopmachine_state = STOPMACHINE_WAIT;
-
- for_each_online_cpu(i) {
- if (i == raw_smp_processor_id())
- continue;
- ret = kernel_thread(stopmachine, (void *)(long)i,CLONE_KERNEL);
- if (ret < 0)
- break;
- stopmachine_num_threads++;
- }
+ *work_buf = (struct cpu_stop_work){ .fn = fn, .arg = arg, };
+ cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), work_buf);
+}
- /* Wait for them all to come to life. */
- while (atomic_read(&stopmachine_thread_ack) != stopmachine_num_threads)
- yield();
+/* static data for stop_cpus */
+static DEFINE_MUTEX(stop_cpus_mutex);
+static DEFINE_PER_CPU(struct cpu_stop_work, stop_cpus_work);
- /* If some failed, kill them all. */
- if (ret < 0) {
- stopmachine_set_state(STOPMACHINE_EXIT);
- return ret;
+static void queue_stop_cpus_work(const struct cpumask *cpumask,
+ cpu_stop_fn_t fn, void *arg,
+ struct cpu_stop_done *done)
+{
+ struct cpu_stop_work *work;
+ unsigned int cpu;
+
+ /* initialize works and done */
+ for_each_cpu(cpu, cpumask) {
+ work = &per_cpu(stop_cpus_work, cpu);
+ work->fn = fn;
+ work->arg = arg;
+ work->done = done;
}
- /* Now they are all started, make them hold the CPUs, ready. */
+ /*
+ * Disable preemption while queueing to avoid getting
+ * preempted by a stopper which might wait for other stoppers
+ * to enter @fn which can lead to deadlock.
+ */
preempt_disable();
- stopmachine_set_state(STOPMACHINE_PREPARE);
+ for_each_cpu(cpu, cpumask)
+ cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu),
+ &per_cpu(stop_cpus_work, cpu));
+ preempt_enable();
+}
- /* Make them disable irqs. */
- local_irq_disable();
- hard_irq_disable();
- stopmachine_set_state(STOPMACHINE_DISABLE_IRQ);
+static int __stop_cpus(const struct cpumask *cpumask,
+ cpu_stop_fn_t fn, void *arg)
+{
+ struct cpu_stop_done done;
- return 0;
+ cpu_stop_init_done(&done, cpumask_weight(cpumask));
+ queue_stop_cpus_work(cpumask, fn, arg, &done);
+ wait_for_completion(&done.completion);
+ return done.executed ? done.ret : -ENOENT;
}
-static void restart_machine(void)
+/**
+ * stop_cpus - stop multiple cpus
+ * @cpumask: cpus to stop
+ * @fn: function to execute
+ * @arg: argument to @fn
+ *
+ * Execute @fn(@arg) on online cpus in @cpumask. On each target cpu,
+ * @fn is run in a process context with the highest priority
+ * preempting any task on the cpu and monopolizing it. This function
+ * returns after all executions are complete.
+ *
+ * This function doesn't guarantee the cpus in @cpumask stay online
+ * till @fn completes. If some cpus go down in the middle, execution
+ * on the cpu may happen partially or fully on different cpus. @fn
+ * should either be ready for that or the caller should ensure that
+ * the cpus stay online until this function completes.
+ *
+ * All stop_cpus() calls are serialized making it safe for @fn to wait
+ * for all cpus to start executing it.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * -ENOENT if @fn(@arg) was not executed at all because all cpus in
+ * @cpumask were offline; otherwise, 0 if all executions of @fn
+ * returned 0, any non zero return value if any returned non zero.
+ */
+int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
{
- stopmachine_set_state(STOPMACHINE_EXIT);
- local_irq_enable();
- preempt_enable_no_resched();
+ int ret;
+
+ /* static works are used, process one request at a time */
+ mutex_lock(&stop_cpus_mutex);
+ ret = __stop_cpus(cpumask, fn, arg);
+ mutex_unlock(&stop_cpus_mutex);
+ return ret;
}
-struct stop_machine_data
+/**
+ * try_stop_cpus - try to stop multiple cpus
+ * @cpumask: cpus to stop
+ * @fn: function to execute
+ * @arg: argument to @fn
+ *
+ * Identical to stop_cpus() except that it fails with -EAGAIN if
+ * someone else is already using the facility.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * -EAGAIN if someone else is already stopping cpus, -ENOENT if
+ * @fn(@arg) was not executed at all because all cpus in @cpumask were
+ * offline; otherwise, 0 if all executions of @fn returned 0, any non
+ * zero return value if any returned non zero.
+ */
+int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
{
- int (*fn)(void *);
- void *data;
- struct completion done;
-};
+ int ret;
-static int do_stop(void *_smdata)
+ /* static works are used, process one request at a time */
+ if (!mutex_trylock(&stop_cpus_mutex))
+ return -EAGAIN;
+ ret = __stop_cpus(cpumask, fn, arg);
+ mutex_unlock(&stop_cpus_mutex);
+ return ret;
+}
+
+static int cpu_stopper_thread(void *data)
{
- struct stop_machine_data *smdata = _smdata;
+ struct cpu_stopper *stopper = data;
+ struct cpu_stop_work *work;
int ret;
- ret = stop_machine();
- if (ret == 0) {
- ret = smdata->fn(smdata->data);
- restart_machine();
+repeat:
+ set_current_state(TASK_INTERRUPTIBLE); /* mb paired w/ kthread_stop */
+
+ if (kthread_should_stop()) {
+ __set_current_state(TASK_RUNNING);
+ return 0;
}
- /* We're done: you can kthread_stop us now */
- complete(&smdata->done);
+ work = NULL;
+ spin_lock_irq(&stopper->lock);
+ if (!list_empty(&stopper->works)) {
+ work = list_first_entry(&stopper->works,
+ struct cpu_stop_work, list);
+ list_del_init(&work->list);
+ }
+ spin_unlock_irq(&stopper->lock);
- /* Wait for kthread_stop */
- set_current_state(TASK_INTERRUPTIBLE);
- while (!kthread_should_stop()) {
+ if (work) {
+ cpu_stop_fn_t fn = work->fn;
+ void *arg = work->arg;
+ struct cpu_stop_done *done = work->done;
+ char ksym_buf[KSYM_NAME_LEN] __maybe_unused;
+
+ __set_current_state(TASK_RUNNING);
+
+ /* cpu stop callbacks are not allowed to sleep */
+ preempt_disable();
+
+ ret = fn(arg);
+ if (ret)
+ done->ret = ret;
+
+ /* restore preemption and check it's still balanced */
+ preempt_enable();
+ WARN_ONCE(preempt_count(),
+ "cpu_stop: %s(%p) leaked preempt count\n",
+ kallsyms_lookup((unsigned long)fn, NULL, NULL, NULL,
+ ksym_buf), arg);
+
+ cpu_stop_signal_done(done, true);
+ } else
schedule();
- set_current_state(TASK_INTERRUPTIBLE);
- }
- __set_current_state(TASK_RUNNING);
- return ret;
+
+ goto repeat;
}
-struct task_struct *__stop_machine_run(int (*fn)(void *), void *data,
- unsigned int cpu)
+extern void sched_set_stop_task(int cpu, struct task_struct *stop);
+
+/* manage stopper for a cpu, mostly lifted from sched migration thread mgmt */
+static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
{
- static DEFINE_MUTEX(stopmachine_mutex);
- struct stop_machine_data smdata;
+ unsigned int cpu = (unsigned long)hcpu;
+ struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
struct task_struct *p;
- smdata.fn = fn;
- smdata.data = data;
- init_completion(&smdata.done);
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_UP_PREPARE:
+ BUG_ON(stopper->thread || stopper->enabled ||
+ !list_empty(&stopper->works));
+ p = kthread_create_on_node(cpu_stopper_thread,
+ stopper,
+ cpu_to_node(cpu),
+ "migration/%d", cpu);
+ if (IS_ERR(p))
+ return notifier_from_errno(PTR_ERR(p));
+ get_task_struct(p);
+ kthread_bind(p, cpu);
+ sched_set_stop_task(cpu, p);
+ stopper->thread = p;
+ break;
+
+ case CPU_ONLINE:
+ /* strictly unnecessary, as first user will wake it */
+ wake_up_process(stopper->thread);
+ /* mark enabled */
+ spin_lock_irq(&stopper->lock);
+ stopper->enabled = true;
+ spin_unlock_irq(&stopper->lock);
+ break;
+
+#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_UP_CANCELED:
+ case CPU_POST_DEAD:
+ {
+ struct cpu_stop_work *work;
+
+ sched_set_stop_task(cpu, NULL);
+ /* kill the stopper */
+ kthread_stop(stopper->thread);
+ /* drain remaining works */
+ spin_lock_irq(&stopper->lock);
+ list_for_each_entry(work, &stopper->works, list)
+ cpu_stop_signal_done(work->done, false);
+ stopper->enabled = false;
+ spin_unlock_irq(&stopper->lock);
+ /* release the stopper */
+ put_task_struct(stopper->thread);
+ stopper->thread = NULL;
+ break;
+ }
+#endif
+ }
- mutex_lock(&stopmachine_mutex);
+ return NOTIFY_OK;
+}
- /* If they don't care which CPU fn runs on, bind to any online one. */
- if (cpu == NR_CPUS)
- cpu = raw_smp_processor_id();
+/*
+ * Give it a higher priority so that cpu stopper is available to other
+ * cpu notifiers. It currently shares the same priority as sched
+ * migration_notifier.
+ */
+static struct notifier_block __cpuinitdata cpu_stop_cpu_notifier = {
+ .notifier_call = cpu_stop_cpu_callback,
+ .priority = 10,
+};
- p = kthread_create(do_stop, &smdata, "kstopmachine");
- if (!IS_ERR(p)) {
- struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
+static int __init cpu_stop_init(void)
+{
+ void *bcpu = (void *)(long)smp_processor_id();
+ unsigned int cpu;
+ int err;
- /* One high-prio thread per cpu. We'll do this one. */
- sched_setscheduler(p, SCHED_FIFO, ¶m);
- kthread_bind(p, cpu);
- wake_up_process(p);
- wait_for_completion(&smdata.done);
+ for_each_possible_cpu(cpu) {
+ struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
+
+ spin_lock_init(&stopper->lock);
+ INIT_LIST_HEAD(&stopper->works);
}
- mutex_unlock(&stopmachine_mutex);
- return p;
+
+ /* start one for the boot cpu */
+ err = cpu_stop_cpu_callback(&cpu_stop_cpu_notifier, CPU_UP_PREPARE,
+ bcpu);
+ BUG_ON(err != NOTIFY_OK);
+ cpu_stop_cpu_callback(&cpu_stop_cpu_notifier, CPU_ONLINE, bcpu);
+ register_cpu_notifier(&cpu_stop_cpu_notifier);
+
+ return 0;
}
+early_initcall(cpu_stop_init);
-int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
+#ifdef CONFIG_STOP_MACHINE
+
+/* This controls the threads on each CPU. */
+enum stopmachine_state {
+ /* Dummy starting state for thread. */
+ STOPMACHINE_NONE,
+ /* Awaiting everyone to be scheduled. */
+ STOPMACHINE_PREPARE,
+ /* Disable interrupts. */
+ STOPMACHINE_DISABLE_IRQ,
+ /* Run the function */
+ STOPMACHINE_RUN,
+ /* Exit */
+ STOPMACHINE_EXIT,
+};
+
+struct stop_machine_data {
+ int (*fn)(void *);
+ void *data;
+ /* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */
+ unsigned int num_threads;
+ const struct cpumask *active_cpus;
+
+ enum stopmachine_state state;
+ atomic_t thread_ack;
+};
+
+static void set_state(struct stop_machine_data *smdata,
+ enum stopmachine_state newstate)
+{
+ /* Reset ack counter. */
+ atomic_set(&smdata->thread_ack, smdata->num_threads);
+ smp_wmb();
+ smdata->state = newstate;
+}
+
+/* Last one to ack a state moves to the next state. */
+static void ack_state(struct stop_machine_data *smdata)
+{
+ if (atomic_dec_and_test(&smdata->thread_ack))
+ set_state(smdata, smdata->state + 1);
+}
+
+/* This is the cpu_stop function which stops the CPU. */
+static int stop_machine_cpu_stop(void *data)
+{
+ struct stop_machine_data *smdata = data;
+ enum stopmachine_state curstate = STOPMACHINE_NONE;
+ int cpu = smp_processor_id(), err = 0;
+ unsigned long flags;
+ bool is_active;
+
+ /*
+ * When called from stop_machine_from_inactive_cpu(), irq might
+ * already be disabled. Save the state and restore it on exit.
+ */
+ local_save_flags(flags);
+
+ if (!smdata->active_cpus)
+ is_active = cpu == cpumask_first(cpu_online_mask);
+ else
+ is_active = cpumask_test_cpu(cpu, smdata->active_cpus);
+
+ /* Simple state machine */
+ do {
+ /* Chill out and ensure we re-read stopmachine_state. */
+ cpu_relax();
+ if (smdata->state != curstate) {
+ curstate = smdata->state;
+ switch (curstate) {
+ case STOPMACHINE_DISABLE_IRQ:
+ local_irq_disable();
+ hard_irq_disable();
+ break;
+ case STOPMACHINE_RUN:
+ if (is_active)
+ err = smdata->fn(smdata->data);
+ break;
+ default:
+ break;
+ }
+ ack_state(smdata);
+ }
+ } while (curstate != STOPMACHINE_EXIT);
+
+ local_irq_restore(flags);
+ return err;
+}
+
+int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
+{
+ struct stop_machine_data smdata = { .fn = fn, .data = data,
+ .num_threads = num_online_cpus(),
+ .active_cpus = cpus };
+
+ /* Set the initial state and stop all online cpus. */
+ set_state(&smdata, STOPMACHINE_PREPARE);
+ return stop_cpus(cpu_online_mask, stop_machine_cpu_stop, &smdata);
+}
+
+int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
{
- struct task_struct *p;
int ret;
/* No CPUs can come up or down during this. */
get_online_cpus();
- p = __stop_machine_run(fn, data, cpu);
- if (!IS_ERR(p))
- ret = kthread_stop(p);
- else
- ret = PTR_ERR(p);
+ ret = __stop_machine(fn, data, cpus);
put_online_cpus();
-
return ret;
}
-EXPORT_SYMBOL_GPL(stop_machine_run);
+EXPORT_SYMBOL_GPL(stop_machine);
+
+/**
+ * stop_machine_from_inactive_cpu - stop_machine() from inactive CPU
+ * @fn: the function to run
+ * @data: the data ptr for the @fn()
+ * @cpus: the cpus to run the @fn() on (NULL = any online cpu)
+ *
+ * This is identical to stop_machine() but can be called from a CPU which
+ * is not active. The local CPU is in the process of hotplug (so no other
+ * CPU hotplug can start) and not marked active and doesn't have enough
+ * context to sleep.
+ *
+ * This function provides stop_machine() functionality for such state by
+ * using busy-wait for synchronization and executing @fn directly for local
+ * CPU.
+ *
+ * CONTEXT:
+ * Local CPU is inactive. Temporarily stops all active CPUs.
+ *
+ * RETURNS:
+ * 0 if all executions of @fn returned 0, any non zero return value if any
+ * returned non zero.
+ */
+int stop_machine_from_inactive_cpu(int (*fn)(void *), void *data,
+ const struct cpumask *cpus)
+{
+ struct stop_machine_data smdata = { .fn = fn, .data = data,
+ .active_cpus = cpus };
+ struct cpu_stop_done done;
+ int ret;
+
+ /* Local CPU must be inactive and CPU hotplug in progress. */
+ BUG_ON(cpu_active(raw_smp_processor_id()));
+ smdata.num_threads = num_active_cpus() + 1; /* +1 for local */
+
+ /* No proper task established and can't sleep - busy wait for lock. */
+ while (!mutex_trylock(&stop_cpus_mutex))
+ cpu_relax();
+
+ /* Schedule work on other CPUs and execute directly for local CPU */
+ set_state(&smdata, STOPMACHINE_PREPARE);
+ cpu_stop_init_done(&done, num_active_cpus());
+ queue_stop_cpus_work(cpu_active_mask, stop_machine_cpu_stop, &smdata,
+ &done);
+ ret = stop_machine_cpu_stop(&smdata);
+
+ /* Busy wait for completion. */
+ while (!completion_done(&done.completion))
+ cpu_relax();
+
+ mutex_unlock(&stop_cpus_mutex);
+ return ret ?: done.ret;
+}
+
+#endif /* CONFIG_STOP_MACHINE */
Code Review / linux-2.6.git / blobdiff