#include <linux/kthread.h>
#include <linux/hardirq.h>
#include <linux/mempolicy.h>
+#include <linux/freezer.h>
+#include <linux/kallsyms.h>
+#include <linux/debug_locks.h>
/*
* The per-CPU workqueue (if single thread, we always use the first
struct task_struct *thread;
int run_depth; /* Detect run_workqueue() recursion depth */
+
+ int freezeable; /* Freeze the thread during suspend */
} ____cacheline_aligned;
/*
return list_empty(&wq->list);
}
+/*
+ * Set the workqueue on which a work item is to be run
+ * - Must *only* be called if the pending flag is set
+ */
static inline void set_wq_data(struct work_struct *work, void *wq)
{
- unsigned long new, old, res;
+ unsigned long new;
+
+ BUG_ON(!work_pending(work));
- /* assume the pending flag is already set and that the task has already
- * been queued on this workqueue */
new = (unsigned long) wq | (1UL << WORK_STRUCT_PENDING);
- res = work->management;
- if (res != new) {
- do {
- old = res;
- new = (unsigned long) wq;
- new |= (old & WORK_STRUCT_FLAG_MASK);
- res = cmpxchg(&work->management, old, new);
- } while (res != old);
- }
+ new |= WORK_STRUCT_FLAG_MASK & *work_data_bits(work);
+ atomic_long_set(&work->data, new);
}
static inline void *get_wq_data(struct work_struct *work)
{
- return (void *) (work->management & WORK_STRUCT_WQ_DATA_MASK);
+ return (void *) (atomic_long_read(&work->data) & WORK_STRUCT_WQ_DATA_MASK);
+}
+
+static int __run_work(struct cpu_workqueue_struct *cwq, struct work_struct *work)
+{
+ int ret = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cwq->lock, flags);
+ /*
+ * We need to re-validate the work info after we've gotten
+ * the cpu_workqueue lock. We can run the work now iff:
+ *
+ * - the wq_data still matches the cpu_workqueue_struct
+ * - AND the work is still marked pending
+ * - AND the work is still on a list (which will be this
+ * workqueue_struct list)
+ *
+ * All these conditions are important, because we
+ * need to protect against the work being run right
+ * now on another CPU (all but the last one might be
+ * true if it's currently running and has not been
+ * released yet, for example).
+ */
+ if (get_wq_data(work) == cwq
+ && work_pending(work)
+ && !list_empty(&work->entry)) {
+ work_func_t f = work->func;
+ list_del_init(&work->entry);
+ spin_unlock_irqrestore(&cwq->lock, flags);
+
+ if (!test_bit(WORK_STRUCT_NOAUTOREL, work_data_bits(work)))
+ work_release(work);
+ f(work);
+
+ spin_lock_irqsave(&cwq->lock, flags);
+ cwq->remove_sequence++;
+ wake_up(&cwq->work_done);
+ ret = 1;
+ }
+ spin_unlock_irqrestore(&cwq->lock, flags);
+ return ret;
+}
+
+/**
+ * run_scheduled_work - run scheduled work synchronously
+ * @work: work to run
+ *
+ * This checks if the work was pending, and runs it
+ * synchronously if so. It returns a boolean to indicate
+ * whether it had any scheduled work to run or not.
+ *
+ * NOTE! This _only_ works for normal work_structs. You
+ * CANNOT use this for delayed work, because the wq data
+ * for delayed work will not point properly to the per-
+ * CPU workqueue struct, but will change!
+ */
+int fastcall run_scheduled_work(struct work_struct *work)
+{
+ for (;;) {
+ struct cpu_workqueue_struct *cwq;
+
+ if (!work_pending(work))
+ return 0;
+ if (list_empty(&work->entry))
+ return 0;
+ /* NOTE! This depends intimately on __queue_work! */
+ cwq = get_wq_data(work);
+ if (!cwq)
+ return 0;
+ if (__run_work(cwq, work))
+ return 1;
+ }
}
+EXPORT_SYMBOL(run_scheduled_work);
/* Preempt must be disabled. */
static void __queue_work(struct cpu_workqueue_struct *cwq,
{
int ret = 0, cpu = get_cpu();
- if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {
+ if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
if (unlikely(is_single_threaded(wq)))
cpu = singlethread_cpu;
BUG_ON(!list_empty(&work->entry));
/**
* queue_delayed_work - queue work on a workqueue after delay
* @wq: workqueue to use
- * @work: delayable work to queue
+ * @dwork: delayable work to queue
* @delay: number of jiffies to wait before queueing
*
* Returns 0 if @work was already on a queue, non-zero otherwise.
if (delay == 0)
return queue_work(wq, work);
- if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {
+ if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
BUG_ON(timer_pending(timer));
BUG_ON(!list_empty(&work->entry));
* 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
+ * @dwork: work to queue
* @delay: number of jiffies to wait before queueing
*
* Returns 0 if @work was already on a queue, non-zero otherwise.
struct timer_list *timer = &dwork->timer;
struct work_struct *work = &dwork->work;
- if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {
+ if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
BUG_ON(timer_pending(timer));
BUG_ON(!list_empty(&work->entry));
spin_unlock_irqrestore(&cwq->lock, flags);
BUG_ON(get_wq_data(work) != cwq);
- if (!test_bit(WORK_STRUCT_NOAUTOREL, &work->management))
+ if (!test_bit(WORK_STRUCT_NOAUTOREL, work_data_bits(work)))
work_release(work);
f(work);
+ if (unlikely(in_atomic() || lockdep_depth(current) > 0)) {
+ printk(KERN_ERR "BUG: workqueue leaked lock or atomic: "
+ "%s/0x%08x/%d\n",
+ current->comm, preempt_count(),
+ current->pid);
+ printk(KERN_ERR " last function: ");
+ print_symbol("%s\n", (unsigned long)f);
+ debug_show_held_locks(current);
+ dump_stack();
+ }
+
spin_lock_irqsave(&cwq->lock, flags);
cwq->remove_sequence++;
wake_up(&cwq->work_done);
struct k_sigaction sa;
sigset_t blocked;
- current->flags |= PF_NOFREEZE;
+ if (!cwq->freezeable)
+ current->flags |= PF_NOFREEZE;
set_user_nice(current, -5);
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop()) {
+ if (cwq->freezeable)
+ try_to_freeze();
+
add_wait_queue(&cwq->more_work, &wait);
if (list_empty(&cwq->worklist))
schedule();
EXPORT_SYMBOL_GPL(flush_workqueue);
static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq,
- int cpu)
+ int cpu, int freezeable)
{
struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu);
struct task_struct *p;
cwq->thread = NULL;
cwq->insert_sequence = 0;
cwq->remove_sequence = 0;
+ cwq->freezeable = freezeable;
INIT_LIST_HEAD(&cwq->worklist);
init_waitqueue_head(&cwq->more_work);
init_waitqueue_head(&cwq->work_done);
}
struct workqueue_struct *__create_workqueue(const char *name,
- int singlethread)
+ int singlethread, int freezeable)
{
int cpu, destroy = 0;
struct workqueue_struct *wq;
mutex_lock(&workqueue_mutex);
if (singlethread) {
INIT_LIST_HEAD(&wq->list);
- p = create_workqueue_thread(wq, singlethread_cpu);
+ p = create_workqueue_thread(wq, singlethread_cpu, freezeable);
if (!p)
destroy = 1;
else
} else {
list_add(&wq->list, &workqueues);
for_each_online_cpu(cpu) {
- p = create_workqueue_thread(wq, cpu);
+ p = create_workqueue_thread(wq, cpu, freezeable);
if (p) {
kthread_bind(p, cpu);
wake_up_process(p);
mutex_lock(&workqueue_mutex);
for_each_online_cpu(cpu) {
- INIT_WORK(per_cpu_ptr(works, cpu), func);
- __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu),
- per_cpu_ptr(works, cpu));
+ 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);
}
mutex_unlock(&workqueue_mutex);
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.
+ * cancel_rearming_delayed_workqueue - reliably kill off a delayed work whose handler rearms the delayed work.
* @wq: the controlling workqueue structure
* @dwork: the delayed work struct
*/
EXPORT_SYMBOL(cancel_rearming_delayed_workqueue);
/**
- * cancel_rearming_delayed_work - reliably kill off a delayed keventd
- * work whose handler rearms the delayed work.
+ * cancel_rearming_delayed_work - reliably kill off a delayed keventd work whose handler rearms the delayed work.
* @dwork: the delayed work struct
*/
void cancel_rearming_delayed_work(struct delayed_work *dwork)
}
-#ifdef CONFIG_HOTPLUG_CPU
/* Take the work from this (downed) CPU. */
static void take_over_work(struct workqueue_struct *wq, unsigned int cpu)
{
mutex_lock(&workqueue_mutex);
/* Create a new workqueue thread for it. */
list_for_each_entry(wq, &workqueues, list) {
- if (!create_workqueue_thread(wq, hotcpu)) {
+ if (!create_workqueue_thread(wq, hotcpu, 0)) {
printk("workqueue for %i failed\n", hotcpu);
return NOTIFY_BAD;
}
return NOTIFY_OK;
}
-#endif
void init_workqueues(void)
{