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authorOleg Nesterov <oleg@tv-sign.ru>2007-05-09 02:34:16 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-09 12:30:52 -0700
commited7c0feede39d70092d048ec30f59bb1df69eec6 (patch)
tree67ff89df1a5db2037da34ddf17002b4c7ff218df /kernel
parent06ba38a9a0f6ceffe70343f684c5a690e3710ef4 (diff)
downloadop-kernel-dev-ed7c0feede39d70092d048ec30f59bb1df69eec6.zip
op-kernel-dev-ed7c0feede39d70092d048ec30f59bb1df69eec6.tar.gz
make queue_delayed_work() friendly to flush_fork()
Currently typeof(delayed_work->work.data) is "struct workqueue_struct" when the timer is pending "struct cpu_workqueue_struct" whe the work is queued This makes impossible to use flush_fork(delayed_work->work) in addition to cancel_delayed_work/cancel_rearming_delayed_work, not good. Change queue_delayed_work/delayed_work_timer_fn to use cwq, not wq. This complicates (and uglifies) these functions a little bit, but alows us to use flush_fork(dwork) and imho makes the whole code more consistent. Also, document the fact that cancel_rearming_delayed_work() doesn't garantee the completion of work->func() upon return. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/workqueue.c28
1 files changed, 18 insertions, 10 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 7d1ebfc..d107e1c 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -90,18 +90,20 @@ static const cpumask_t *wq_cpu_map(struct workqueue_struct *wq)
* 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)
+static inline void set_wq_data(struct work_struct *work,
+ struct cpu_workqueue_struct *cwq)
{
unsigned long new;
BUG_ON(!work_pending(work));
- new = (unsigned long) wq | (1UL << WORK_STRUCT_PENDING);
+ new = (unsigned long) cwq | (1UL << WORK_STRUCT_PENDING);
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)
+static inline
+struct cpu_workqueue_struct *get_wq_data(struct work_struct *work)
{
return (void *) (atomic_long_read(&work->data) & WORK_STRUCT_WQ_DATA_MASK);
}
@@ -157,7 +159,8 @@ EXPORT_SYMBOL_GPL(queue_work);
void delayed_work_timer_fn(unsigned long __data)
{
struct delayed_work *dwork = (struct delayed_work *)__data;
- struct workqueue_struct *wq = get_wq_data(&dwork->work);
+ struct cpu_workqueue_struct *cwq = get_wq_data(&dwork->work);
+ struct workqueue_struct *wq = cwq->wq;
int cpu = smp_processor_id();
if (unlikely(is_single_threaded(wq)))
@@ -189,8 +192,9 @@ int fastcall queue_delayed_work(struct workqueue_struct *wq,
BUG_ON(timer_pending(timer));
BUG_ON(!list_empty(&work->entry));
- /* This stores wq for the moment, for the timer_fn */
- set_wq_data(work, wq);
+ /* This stores cwq for the moment, for the timer_fn */
+ set_wq_data(work,
+ per_cpu_ptr(wq->cpu_wq, raw_smp_processor_id()));
timer->expires = jiffies + delay;
timer->data = (unsigned long)dwork;
timer->function = delayed_work_timer_fn;
@@ -221,8 +225,9 @@ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
BUG_ON(timer_pending(timer));
BUG_ON(!list_empty(&work->entry));
- /* This stores wq for the moment, for the timer_fn */
- set_wq_data(work, wq);
+ /* This stores cwq for the moment, for the timer_fn */
+ set_wq_data(work,
+ per_cpu_ptr(wq->cpu_wq, raw_smp_processor_id()));
timer->expires = jiffies + delay;
timer->data = (unsigned long)dwork;
timer->function = delayed_work_timer_fn;
@@ -562,9 +567,12 @@ void flush_work_keventd(struct work_struct *work)
EXPORT_SYMBOL(flush_work_keventd);
/**
- * cancel_rearming_delayed_workqueue - reliably kill off a delayed work whose handler rearms the delayed work.
+ * cancel_rearming_delayed_workqueue - kill off a delayed work whose handler rearms the delayed work.
* @wq: the controlling workqueue structure
* @dwork: the delayed work struct
+ *
+ * Note that the work callback function may still be running on return from
+ * cancel_delayed_work(). Run flush_workqueue() or flush_work() to wait on it.
*/
void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
struct delayed_work *dwork)
@@ -579,7 +587,7 @@ void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
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 - 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)
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