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Diffstat (limited to 'kernel/workqueue.c')
-rw-r--r--kernel/workqueue.c91
1 files changed, 75 insertions, 16 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index eebb1d839235..835fe28b87a8 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -68,7 +68,7 @@ struct workqueue_struct {
/* All the per-cpu workqueues on the system, for hotplug cpu to add/remove
threads to each one as cpus come/go. */
-static DEFINE_SPINLOCK(workqueue_lock);
+static DEFINE_MUTEX(workqueue_mutex);
static LIST_HEAD(workqueues);
static int singlethread_cpu;
@@ -93,9 +93,12 @@ static void __queue_work(struct cpu_workqueue_struct *cwq,
spin_unlock_irqrestore(&cwq->lock, flags);
}
-/*
- * Queue work on a workqueue. Return non-zero if it was successfully
- * added.
+/**
+ * queue_work - queue work on a workqueue
+ * @wq: workqueue to use
+ * @work: work to queue
+ *
+ * Returns non-zero if it was successfully added.
*
* We queue the work to the CPU it was submitted, but there is no
* guarantee that it will be processed by that CPU.
@@ -128,6 +131,14 @@ static void delayed_work_timer_fn(unsigned long __data)
__queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work);
}
+/**
+ * queue_delayed_work - queue work on a workqueue after delay
+ * @wq: workqueue to use
+ * @work: work to queue
+ * @delay: number of jiffies to wait before queueing
+ *
+ * Returns non-zero if it was successfully added.
+ */
int fastcall queue_delayed_work(struct workqueue_struct *wq,
struct work_struct *work, unsigned long delay)
{
@@ -150,6 +161,15 @@ int fastcall queue_delayed_work(struct workqueue_struct *wq,
}
EXPORT_SYMBOL_GPL(queue_delayed_work);
+/**
+ * queue_delayed_work_on - queue work on specific CPU after delay
+ * @cpu: CPU number to execute work on
+ * @wq: workqueue to use
+ * @work: work to queue
+ * @delay: number of jiffies to wait before queueing
+ *
+ * Returns non-zero if it was successfully added.
+ */
int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
struct work_struct *work, unsigned long delay)
{
@@ -275,8 +295,9 @@ static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq)
}
}
-/*
+/**
* flush_workqueue - ensure that any scheduled work has run to completion.
+ * @wq: workqueue to flush
*
* Forces execution of the workqueue and blocks until its completion.
* This is typically used in driver shutdown handlers.
@@ -299,10 +320,10 @@ void fastcall flush_workqueue(struct workqueue_struct *wq)
} else {
int cpu;
- lock_cpu_hotplug();
+ mutex_lock(&workqueue_mutex);
for_each_online_cpu(cpu)
flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu));
- unlock_cpu_hotplug();
+ mutex_unlock(&workqueue_mutex);
}
}
EXPORT_SYMBOL_GPL(flush_workqueue);
@@ -350,8 +371,7 @@ struct workqueue_struct *__create_workqueue(const char *name,
}
wq->name = name;
- /* We don't need the distraction of CPUs appearing and vanishing. */
- lock_cpu_hotplug();
+ mutex_lock(&workqueue_mutex);
if (singlethread) {
INIT_LIST_HEAD(&wq->list);
p = create_workqueue_thread(wq, singlethread_cpu);
@@ -360,9 +380,7 @@ struct workqueue_struct *__create_workqueue(const char *name,
else
wake_up_process(p);
} else {
- spin_lock(&workqueue_lock);
list_add(&wq->list, &workqueues);
- spin_unlock(&workqueue_lock);
for_each_online_cpu(cpu) {
p = create_workqueue_thread(wq, cpu);
if (p) {
@@ -372,7 +390,7 @@ struct workqueue_struct *__create_workqueue(const char *name,
destroy = 1;
}
}
- unlock_cpu_hotplug();
+ mutex_unlock(&workqueue_mutex);
/*
* Was there any error during startup? If yes then clean up:
@@ -400,6 +418,12 @@ static void cleanup_workqueue_thread(struct workqueue_struct *wq, int cpu)
kthread_stop(p);
}
+/**
+ * destroy_workqueue - safely terminate a workqueue
+ * @wq: target workqueue
+ *
+ * Safely destroy a workqueue. All work currently pending will be done first.
+ */
void destroy_workqueue(struct workqueue_struct *wq)
{
int cpu;
@@ -407,17 +431,15 @@ void destroy_workqueue(struct workqueue_struct *wq)
flush_workqueue(wq);
/* We don't need the distraction of CPUs appearing and vanishing. */
- lock_cpu_hotplug();
+ mutex_lock(&workqueue_mutex);
if (is_single_threaded(wq))
cleanup_workqueue_thread(wq, singlethread_cpu);
else {
for_each_online_cpu(cpu)
cleanup_workqueue_thread(wq, cpu);
- spin_lock(&workqueue_lock);
list_del(&wq->list);
- spin_unlock(&workqueue_lock);
}
- unlock_cpu_hotplug();
+ mutex_unlock(&workqueue_mutex);
free_percpu(wq->cpu_wq);
kfree(wq);
}
@@ -425,18 +447,41 @@ EXPORT_SYMBOL_GPL(destroy_workqueue);
static struct workqueue_struct *keventd_wq;
+/**
+ * schedule_work - put work task in global workqueue
+ * @work: job to be done
+ *
+ * This puts a job in the kernel-global workqueue.
+ */
int fastcall schedule_work(struct work_struct *work)
{
return queue_work(keventd_wq, work);
}
EXPORT_SYMBOL(schedule_work);
+/**
+ * schedule_delayed_work - put work task in global workqueue after delay
+ * @work: job to be done
+ * @delay: number of jiffies to wait
+ *
+ * After waiting for a given time this puts a job in the kernel-global
+ * workqueue.
+ */
int fastcall schedule_delayed_work(struct work_struct *work, unsigned long delay)
{
return queue_delayed_work(keventd_wq, work, delay);
}
EXPORT_SYMBOL(schedule_delayed_work);
+/**
+ * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
+ * @cpu: cpu to use
+ * @work: job to be done
+ * @delay: number of jiffies to wait
+ *
+ * After waiting for a given time this puts a job in the kernel-global
+ * workqueue on the specified CPU.
+ */
int schedule_delayed_work_on(int cpu,
struct work_struct *work, unsigned long delay)
{
@@ -465,11 +510,13 @@ int schedule_on_each_cpu(void (*func)(void *info), void *info)
if (!works)
return -ENOMEM;
+ mutex_lock(&workqueue_mutex);
for_each_online_cpu(cpu) {
INIT_WORK(per_cpu_ptr(works, cpu), func, info);
__queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu),
per_cpu_ptr(works, cpu));
}
+ mutex_unlock(&workqueue_mutex);
flush_workqueue(keventd_wq);
free_percpu(works);
return 0;
@@ -585,6 +632,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
switch (action) {
case CPU_UP_PREPARE:
+ mutex_lock(&workqueue_mutex);
/* Create a new workqueue thread for it. */
list_for_each_entry(wq, &workqueues, list) {
if (!create_workqueue_thread(wq, hotcpu)) {
@@ -603,6 +651,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
kthread_bind(cwq->thread, hotcpu);
wake_up_process(cwq->thread);
}
+ mutex_unlock(&workqueue_mutex);
break;
case CPU_UP_CANCELED:
@@ -614,6 +663,15 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
any_online_cpu(cpu_online_map));
cleanup_workqueue_thread(wq, hotcpu);
}
+ mutex_unlock(&workqueue_mutex);
+ break;
+
+ case CPU_DOWN_PREPARE:
+ mutex_lock(&workqueue_mutex);
+ break;
+
+ case CPU_DOWN_FAILED:
+ mutex_unlock(&workqueue_mutex);
break;
case CPU_DEAD:
@@ -621,6 +679,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
cleanup_workqueue_thread(wq, hotcpu);
list_for_each_entry(wq, &workqueues, list)
take_over_work(wq, hotcpu);
+ mutex_unlock(&workqueue_mutex);
break;
}