* Derived from the taskqueue/keventd code by:
*
* David Woodhouse <dwmw2@infradead.org>
- * Andrew Morton <andrewm@uow.edu.au>
+ * Andrew Morton
* Kai Petzke <wpp@marie.physik.tu-berlin.de>
* Theodore Ts'o <tytso@mit.edu>
*
const char *name;
int singlethread;
int freezeable; /* Freeze threads during suspend */
+ int rt;
#ifdef CONFIG_LOCKDEP
struct lockdep_map lockdep_map;
#endif
static LIST_HEAD(workqueues);
static int singlethread_cpu __read_mostly;
-static cpumask_t cpu_singlethread_map __read_mostly;
+static const struct cpumask *cpu_singlethread_map __read_mostly;
/*
* _cpu_down() first removes CPU from cpu_online_map, then CPU_DEAD
* flushes cwq->worklist. This means that flush_workqueue/wait_on_work
* use cpu_possible_map, the cpumask below is more a documentation
* than optimization.
*/
-static cpumask_t cpu_populated_map __read_mostly;
+static cpumask_var_t cpu_populated_map __read_mostly;
/* If it's single threaded, it isn't in the list of workqueues. */
-static inline int is_single_threaded(struct workqueue_struct *wq)
+static inline int is_wq_single_threaded(struct workqueue_struct *wq)
{
return wq->singlethread;
}
-static const cpumask_t *wq_cpu_map(struct workqueue_struct *wq)
+static const struct cpumask *wq_cpu_map(struct workqueue_struct *wq)
{
- return is_single_threaded(wq)
- ? &cpu_singlethread_map : &cpu_populated_map;
+ return is_wq_single_threaded(wq)
+ ? cpu_singlethread_map : cpu_populated_map;
}
static
struct cpu_workqueue_struct *wq_per_cpu(struct workqueue_struct *wq, int cpu)
{
- if (unlikely(is_single_threaded(wq)))
+ if (unlikely(is_wq_single_threaded(wq)))
cpu = singlethread_cpu;
return per_cpu_ptr(wq->cpu_wq, cpu);
}
*/
int queue_work(struct workqueue_struct *wq, struct work_struct *work)
{
- int ret = 0;
+ int ret;
+
+ ret = queue_work_on(get_cpu(), wq, work);
+ put_cpu();
- if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
- BUG_ON(!list_empty(&work->entry));
- __queue_work(wq_per_cpu(wq, get_cpu()), work);
- put_cpu();
- ret = 1;
- }
return ret;
}
EXPORT_SYMBOL_GPL(queue_work);
BUG_ON(get_wq_data(work) != cwq);
work_clear_pending(work);
- lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
- lock_acquire(&lockdep_map, 0, 0, 0, 2, _THIS_IP_);
+ lock_map_acquire(&cwq->wq->lockdep_map);
+ lock_map_acquire(&lockdep_map);
f(work);
- lock_release(&lockdep_map, 1, _THIS_IP_);
- lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_);
+ lock_map_release(&lockdep_map);
+ lock_map_release(&cwq->wq->lockdep_map);
if (unlikely(in_atomic() || lockdep_depth(current) > 0)) {
printk(KERN_ERR "BUG: workqueue leaked lock or atomic: "
*/
void flush_workqueue(struct workqueue_struct *wq)
{
- const cpumask_t *cpu_map = wq_cpu_map(wq);
+ const struct cpumask *cpu_map = wq_cpu_map(wq);
int cpu;
might_sleep();
- lock_acquire(&wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
- lock_release(&wq->lockdep_map, 1, _THIS_IP_);
+ lock_map_acquire(&wq->lockdep_map);
+ lock_map_release(&wq->lockdep_map);
for_each_cpu_mask_nr(cpu, *cpu_map)
flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu));
}
* flush_work - block until a work_struct's callback has terminated
* @work: the work which is to be flushed
*
+ * Returns false if @work has already terminated.
+ *
* It is expected that, prior to calling flush_work(), the caller has
* arranged for the work to not be requeued, otherwise it doesn't make
* sense to use this function.
if (!cwq)
return 0;
+ lock_map_acquire(&cwq->wq->lockdep_map);
+ lock_map_release(&cwq->wq->lockdep_map);
+
prev = NULL;
spin_lock_irq(&cwq->lock);
if (!list_empty(&work->entry)) {
{
struct cpu_workqueue_struct *cwq;
struct workqueue_struct *wq;
- const cpumask_t *cpu_map;
+ const struct cpumask *cpu_map;
int cpu;
might_sleep();
- lock_acquire(&work->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
- lock_release(&work->lockdep_map, 1, _THIS_IP_);
+ lock_map_acquire(&work->lockdep_map);
+ lock_map_release(&work->lockdep_map);
cwq = get_wq_data(work);
if (!cwq)
struct work_struct *work = per_cpu_ptr(works, cpu);
INIT_WORK(work, func);
- set_bit(WORK_STRUCT_PENDING, work_data_bits(work));
- __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), work);
+ schedule_work_on(cpu, work);
}
- flush_workqueue(keventd_wq);
+ for_each_online_cpu(cpu)
+ flush_work(per_cpu_ptr(works, cpu));
put_online_cpus();
free_percpu(works);
return 0;
static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
{
+ struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
struct workqueue_struct *wq = cwq->wq;
- const char *fmt = is_single_threaded(wq) ? "%s" : "%s/%d";
+ const char *fmt = is_wq_single_threaded(wq) ? "%s" : "%s/%d";
struct task_struct *p;
p = kthread_create(worker_thread, cwq, fmt, wq->name, cpu);
*/
if (IS_ERR(p))
return PTR_ERR(p);
-
+ if (cwq->wq->rt)
+ sched_setscheduler_nocheck(p, SCHED_FIFO, ¶m);
cwq->thread = p;
return 0;
struct workqueue_struct *__create_workqueue_key(const char *name,
int singlethread,
int freezeable,
+ int rt,
struct lock_class_key *key,
const char *lock_name)
{
lockdep_init_map(&wq->lockdep_map, lock_name, key, 0);
wq->singlethread = singlethread;
wq->freezeable = freezeable;
+ wq->rt = rt;
INIT_LIST_HEAD(&wq->list);
if (singlethread) {
err = create_workqueue_thread(cwq, singlethread_cpu);
start_workqueue_thread(cwq, -1);
} else {
- get_online_cpus();
+ cpu_maps_update_begin();
+ /*
+ * We must place this wq on list even if the code below fails.
+ * cpu_down(cpu) can remove cpu from cpu_populated_map before
+ * destroy_workqueue() takes the lock, in that case we leak
+ * cwq[cpu]->thread.
+ */
spin_lock(&workqueue_lock);
list_add(&wq->list, &workqueues);
spin_unlock(&workqueue_lock);
-
+ /*
+ * We must initialize cwqs for each possible cpu even if we
+ * are going to call destroy_workqueue() finally. Otherwise
+ * cpu_up() can hit the uninitialized cwq once we drop the
+ * lock.
+ */
for_each_possible_cpu(cpu) {
cwq = init_cpu_workqueue(wq, cpu);
if (err || !cpu_online(cpu))
err = create_workqueue_thread(cwq, cpu);
start_workqueue_thread(cwq, cpu);
}
- put_online_cpus();
+ cpu_maps_update_done();
}
if (err) {
static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq)
{
/*
- * Our caller is either destroy_workqueue() or CPU_DEAD,
- * get_online_cpus() protects cwq->thread.
+ * Our caller is either destroy_workqueue() or CPU_POST_DEAD,
+ * cpu_add_remove_lock protects cwq->thread.
*/
if (cwq->thread == NULL)
return;
- lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
- lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_);
+ lock_map_acquire(&cwq->wq->lockdep_map);
+ lock_map_release(&cwq->wq->lockdep_map);
flush_cpu_workqueue(cwq);
/*
- * If the caller is CPU_DEAD and cwq->worklist was not empty,
+ * If the caller is CPU_POST_DEAD and cwq->worklist was not empty,
* a concurrent flush_workqueue() can insert a barrier after us.
* However, in that case run_workqueue() won't return and check
* kthread_should_stop() until it flushes all work_struct's.
*/
void destroy_workqueue(struct workqueue_struct *wq)
{
- const cpumask_t *cpu_map = wq_cpu_map(wq);
+ const struct cpumask *cpu_map = wq_cpu_map(wq);
int cpu;
- get_online_cpus();
+ cpu_maps_update_begin();
spin_lock(&workqueue_lock);
list_del(&wq->list);
spin_unlock(&workqueue_lock);
for_each_cpu_mask_nr(cpu, *cpu_map)
cleanup_workqueue_thread(per_cpu_ptr(wq->cpu_wq, cpu));
- put_online_cpus();
+ cpu_maps_update_done();
free_percpu(wq->cpu_wq);
kfree(wq);
unsigned int cpu = (unsigned long)hcpu;
struct cpu_workqueue_struct *cwq;
struct workqueue_struct *wq;
+ int ret = NOTIFY_OK;
action &= ~CPU_TASKS_FROZEN;
switch (action) {
case CPU_UP_PREPARE:
- cpu_set(cpu, cpu_populated_map);
+ cpumask_set_cpu(cpu, cpu_populated_map);
}
-
+undo:
list_for_each_entry(wq, &workqueues, list) {
cwq = per_cpu_ptr(wq->cpu_wq, cpu);
break;
printk(KERN_ERR "workqueue [%s] for %i failed\n",
wq->name, cpu);
- return NOTIFY_BAD;
+ action = CPU_UP_CANCELED;
+ ret = NOTIFY_BAD;
+ goto undo;
case CPU_ONLINE:
start_workqueue_thread(cwq, cpu);
case CPU_UP_CANCELED:
start_workqueue_thread(cwq, -1);
- case CPU_DEAD:
+ case CPU_POST_DEAD:
cleanup_workqueue_thread(cwq);
break;
}
switch (action) {
case CPU_UP_CANCELED:
- case CPU_DEAD:
- cpu_clear(cpu, cpu_populated_map);
+ case CPU_POST_DEAD:
+ cpumask_clear_cpu(cpu, cpu_populated_map);
}
- return NOTIFY_OK;
+ return ret;
+}
+
+#ifdef CONFIG_SMP
+struct work_for_cpu {
+ struct work_struct work;
+ long (*fn)(void *);
+ void *arg;
+ long ret;
+};
+
+static void do_work_for_cpu(struct work_struct *w)
+{
+ struct work_for_cpu *wfc = container_of(w, struct work_for_cpu, work);
+
+ wfc->ret = wfc->fn(wfc->arg);
}
+/**
+ * work_on_cpu - run a function in user context on a particular cpu
+ * @cpu: the cpu to run on
+ * @fn: the function to run
+ * @arg: the function arg
+ *
+ * This will return -EINVAL in the cpu is not online, or the return value
+ * of @fn otherwise.
+ */
+long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
+{
+ struct work_for_cpu wfc;
+
+ INIT_WORK(&wfc.work, do_work_for_cpu);
+ wfc.fn = fn;
+ wfc.arg = arg;
+ get_online_cpus();
+ if (unlikely(!cpu_online(cpu)))
+ wfc.ret = -EINVAL;
+ else {
+ schedule_work_on(cpu, &wfc.work);
+ flush_work(&wfc.work);
+ }
+ put_online_cpus();
+
+ return wfc.ret;
+}
+EXPORT_SYMBOL_GPL(work_on_cpu);
+#endif /* CONFIG_SMP */
+
void __init init_workqueues(void)
{
- cpu_populated_map = cpu_online_map;
- singlethread_cpu = first_cpu(cpu_possible_map);
- cpu_singlethread_map = cpumask_of_cpu(singlethread_cpu);
+ alloc_cpumask_var(&cpu_populated_map, GFP_KERNEL);
+
+ cpumask_copy(cpu_populated_map, cpu_online_mask);
+ singlethread_cpu = cpumask_first(cpu_possible_mask);
+ cpu_singlethread_map = cpumask_of(singlethread_cpu);
hotcpu_notifier(workqueue_cpu_callback, 0);
keventd_wq = create_workqueue("events");
BUG_ON(!keventd_wq);