*
* Derived from the taskqueue/keventd code by:
*
- * David Woodhouse <dwmw2@redhat.com>
+ * David Woodhouse <dwmw2@infradead.org>
* Andrew Morton <andrewm@uow.edu.au>
* Kai Petzke <wpp@marie.physik.tu-berlin.de>
* Theodore Ts'o <tytso@mit.edu>
+ *
+ * Made to use alloc_percpu by Christoph Lameter <clameter@sgi.com>.
*/
#include <linux/module.h>
#include <linux/cpu.h>
#include <linux/notifier.h>
#include <linux/kthread.h>
+#include <linux/hardirq.h>
/*
- * The per-CPU workqueue (if single thread, we always use cpu 0's).
+ * The per-CPU workqueue (if single thread, we always use the first
+ * possible cpu).
*
* The sequence counters are for flush_scheduled_work(). It wants to wait
* until until all currently-scheduled works are completed, but it doesn't
wait_queue_head_t work_done;
struct workqueue_struct *wq;
- task_t *thread;
+ struct task_struct *thread;
int run_depth; /* Detect run_workqueue() recursion depth */
} ____cacheline_aligned;
* per-CPU workqueues:
*/
struct workqueue_struct {
- struct cpu_workqueue_struct cpu_wq[NR_CPUS];
+ struct cpu_workqueue_struct *cpu_wq;
const char *name;
struct list_head list; /* Empty if single thread */
};
/* All the per-cpu workqueues on the system, for hotplug cpu to add/remove
threads to each one as cpus come/go. */
-static spinlock_t workqueue_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_MUTEX(workqueue_mutex);
static LIST_HEAD(workqueues);
+static int singlethread_cpu;
+
/* If it's single threaded, it isn't in the list of workqueues. */
static inline int is_single_threaded(struct workqueue_struct *wq)
{
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.
if (!test_and_set_bit(0, &work->pending)) {
if (unlikely(is_single_threaded(wq)))
- cpu = 0;
+ cpu = singlethread_cpu;
BUG_ON(!list_empty(&work->entry));
- __queue_work(wq->cpu_wq + cpu, work);
+ __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work);
ret = 1;
}
put_cpu();
return ret;
}
+EXPORT_SYMBOL_GPL(queue_work);
static void delayed_work_timer_fn(unsigned long __data)
{
int cpu = smp_processor_id();
if (unlikely(is_single_threaded(wq)))
- cpu = 0;
+ cpu = singlethread_cpu;
- __queue_work(wq->cpu_wq + cpu, work);
+ __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)
{
}
return ret;
}
+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)
+{
+ int ret = 0;
+ struct timer_list *timer = &work->timer;
+
+ if (!test_and_set_bit(0, &work->pending)) {
+ BUG_ON(timer_pending(timer));
+ BUG_ON(!list_empty(&work->entry));
+
+ /* This stores wq for the moment, for the timer_fn */
+ work->wq_data = wq;
+ timer->expires = jiffies + delay;
+ timer->data = (unsigned long)work;
+ timer->function = delayed_work_timer_fn;
+ add_timer_on(timer, cpu);
+ ret = 1;
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(queue_delayed_work_on);
-static inline void run_workqueue(struct cpu_workqueue_struct *cwq)
+static void run_workqueue(struct cpu_workqueue_struct *cwq)
{
unsigned long flags;
current->flags |= PF_NOFREEZE;
- set_user_nice(current, -10);
+ set_user_nice(current, -5);
/* Block and flush all signals */
sigfillset(&blocked);
}
}
-/*
+/**
* 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.
might_sleep();
if (is_single_threaded(wq)) {
- /* Always use cpu 0's area. */
- flush_cpu_workqueue(wq->cpu_wq + 0);
+ /* Always use first cpu's area. */
+ flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, singlethread_cpu));
} else {
int cpu;
- lock_cpu_hotplug();
+ mutex_lock(&workqueue_mutex);
for_each_online_cpu(cpu)
- flush_cpu_workqueue(wq->cpu_wq + cpu);
- unlock_cpu_hotplug();
+ flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu));
+ mutex_unlock(&workqueue_mutex);
}
}
+EXPORT_SYMBOL_GPL(flush_workqueue);
static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq,
int cpu)
{
- struct cpu_workqueue_struct *cwq = wq->cpu_wq + cpu;
+ struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu);
struct task_struct *p;
spin_lock_init(&cwq->lock);
struct workqueue_struct *wq;
struct task_struct *p;
- BUG_ON(strlen(name) > 10);
-
- wq = kmalloc(sizeof(*wq), GFP_KERNEL);
+ wq = kzalloc(sizeof(*wq), GFP_KERNEL);
if (!wq)
return NULL;
- memset(wq, 0, sizeof(*wq));
+
+ wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct);
+ if (!wq->cpu_wq) {
+ kfree(wq);
+ return NULL;
+ }
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, 0);
+ p = create_workqueue_thread(wq, singlethread_cpu);
if (!p)
destroy = 1;
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) {
destroy = 1;
}
}
- unlock_cpu_hotplug();
+ mutex_unlock(&workqueue_mutex);
/*
* Was there any error during startup? If yes then clean up:
}
return wq;
}
+EXPORT_SYMBOL_GPL(__create_workqueue);
static void cleanup_workqueue_thread(struct workqueue_struct *wq, int cpu)
{
unsigned long flags;
struct task_struct *p;
- cwq = wq->cpu_wq + cpu;
+ cwq = per_cpu_ptr(wq->cpu_wq, cpu);
spin_lock_irqsave(&cwq->lock, flags);
p = cwq->thread;
cwq->thread = NULL;
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;
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, 0);
+ 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);
}
+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)
{
- int ret = 0;
- struct timer_list *timer = &work->timer;
+ return queue_delayed_work_on(cpu, keventd_wq, work, delay);
+}
+EXPORT_SYMBOL(schedule_delayed_work_on);
- if (!test_and_set_bit(0, &work->pending)) {
- BUG_ON(timer_pending(timer));
- BUG_ON(!list_empty(&work->entry));
- /* This stores keventd_wq for the moment, for the timer_fn */
- work->wq_data = keventd_wq;
- timer->expires = jiffies + delay;
- timer->data = (unsigned long)work;
- timer->function = delayed_work_timer_fn;
- add_timer_on(timer, cpu);
- ret = 1;
+/**
+ * schedule_on_each_cpu - call a function on each online CPU from keventd
+ * @func: the function to call
+ * @info: a pointer to pass to func()
+ *
+ * Returns zero on success.
+ * Returns -ve errno on failure.
+ *
+ * Appears to be racy against CPU hotplug.
+ *
+ * schedule_on_each_cpu() is very slow.
+ */
+int schedule_on_each_cpu(void (*func)(void *info), void *info)
+{
+ int cpu;
+ struct work_struct *works;
+
+ works = alloc_percpu(struct work_struct);
+ 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));
}
- return ret;
+ mutex_unlock(&workqueue_mutex);
+ flush_workqueue(keventd_wq);
+ free_percpu(works);
+ return 0;
}
void flush_scheduled_work(void)
{
flush_workqueue(keventd_wq);
}
+EXPORT_SYMBOL(flush_scheduled_work);
+
+/**
+ * cancel_rearming_delayed_workqueue - reliably kill off a delayed
+ * work whose handler rearms the delayed work.
+ * @wq: the controlling workqueue structure
+ * @work: the delayed work struct
+ */
+void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
+ struct work_struct *work)
+{
+ while (!cancel_delayed_work(work))
+ flush_workqueue(wq);
+}
+EXPORT_SYMBOL(cancel_rearming_delayed_workqueue);
+
+/**
+ * cancel_rearming_delayed_work - reliably kill off a delayed keventd
+ * work whose handler rearms the delayed work.
+ * @work: the delayed work struct
+ */
+void cancel_rearming_delayed_work(struct work_struct *work)
+{
+ cancel_rearming_delayed_workqueue(keventd_wq, work);
+}
+EXPORT_SYMBOL(cancel_rearming_delayed_work);
+
+/**
+ * execute_in_process_context - reliably execute the routine with user context
+ * @fn: the function to execute
+ * @data: data to pass to the function
+ * @ew: guaranteed storage for the execute work structure (must
+ * be available when the work executes)
+ *
+ * Executes the function immediately if process context is available,
+ * otherwise schedules the function for delayed execution.
+ *
+ * Returns: 0 - function was executed
+ * 1 - function was scheduled for execution
+ */
+int execute_in_process_context(void (*fn)(void *data), void *data,
+ struct execute_work *ew)
+{
+ if (!in_interrupt()) {
+ fn(data);
+ return 0;
+ }
+
+ INIT_WORK(&ew->work, fn, data);
+ schedule_work(&ew->work);
+
+ return 1;
+}
+EXPORT_SYMBOL_GPL(execute_in_process_context);
int keventd_up(void)
{
BUG_ON(!keventd_wq);
- cwq = keventd_wq->cpu_wq + cpu;
+ cwq = per_cpu_ptr(keventd_wq->cpu_wq, cpu);
if (current == cwq->thread)
ret = 1;
/* Take the work from this (downed) CPU. */
static void take_over_work(struct workqueue_struct *wq, unsigned int cpu)
{
- struct cpu_workqueue_struct *cwq = wq->cpu_wq + cpu;
- LIST_HEAD(list);
+ struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu);
+ struct list_head list;
struct work_struct *work;
spin_lock_irq(&cwq->lock);
- list_splice_init(&cwq->worklist, &list);
+ list_replace_init(&cwq->worklist, &list);
while (!list_empty(&list)) {
printk("Taking work for %s\n", wq->name);
work = list_entry(list.next,struct work_struct,entry);
list_del(&work->entry);
- __queue_work(wq->cpu_wq + smp_processor_id(), work);
+ __queue_work(per_cpu_ptr(wq->cpu_wq, smp_processor_id()), work);
}
spin_unlock_irq(&cwq->lock);
}
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) < 0) {
+ if (!create_workqueue_thread(wq, hotcpu)) {
printk("workqueue for %i failed\n", hotcpu);
return NOTIFY_BAD;
}
case CPU_ONLINE:
/* Kick off worker threads. */
- list_for_each_entry(wq, &workqueues, list)
- wake_up_process(wq->cpu_wq[hotcpu].thread);
+ list_for_each_entry(wq, &workqueues, list) {
+ struct cpu_workqueue_struct *cwq;
+
+ cwq = per_cpu_ptr(wq->cpu_wq, hotcpu);
+ kthread_bind(cwq->thread, hotcpu);
+ wake_up_process(cwq->thread);
+ }
+ mutex_unlock(&workqueue_mutex);
break;
case CPU_UP_CANCELED:
list_for_each_entry(wq, &workqueues, list) {
+ if (!per_cpu_ptr(wq->cpu_wq, hotcpu)->thread)
+ continue;
/* Unbind so it can run. */
- kthread_bind(wq->cpu_wq[hotcpu].thread,
- smp_processor_id());
+ kthread_bind(per_cpu_ptr(wq->cpu_wq, hotcpu)->thread,
+ 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:
cleanup_workqueue_thread(wq, hotcpu);
list_for_each_entry(wq, &workqueues, list)
take_over_work(wq, hotcpu);
+ mutex_unlock(&workqueue_mutex);
break;
}
void init_workqueues(void)
{
+ singlethread_cpu = first_cpu(cpu_possible_map);
hotcpu_notifier(workqueue_cpu_callback, 0);
keventd_wq = create_workqueue("events");
BUG_ON(!keventd_wq);
}
-EXPORT_SYMBOL_GPL(__create_workqueue);
-EXPORT_SYMBOL_GPL(queue_work);
-EXPORT_SYMBOL_GPL(queue_delayed_work);
-EXPORT_SYMBOL_GPL(flush_workqueue);
-EXPORT_SYMBOL_GPL(destroy_workqueue);
-
-EXPORT_SYMBOL(schedule_work);
-EXPORT_SYMBOL(schedule_delayed_work);
-EXPORT_SYMBOL(schedule_delayed_work_on);
-EXPORT_SYMBOL(flush_scheduled_work);
git://git.onelab.eu / linux-2.6.git / blobdiff