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author | Oleg Nesterov <oleg@tv-sign.ru> | 2007-05-09 02:34:16 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-09 12:30:52 -0700 |
commit | ed7c0feede39d70092d048ec30f59bb1df69eec6 (patch) | |
tree | 67ff89df1a5db2037da34ddf17002b4c7ff218df /kernel | |
parent | 06ba38a9a0f6ceffe70343f684c5a690e3710ef4 (diff) | |
download | op-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.c | 28 |
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) |