workqueue: implement mod_delayed_work[_on]()

index af15545..5970342 100644
@@ -365,23 +365,24 @@ __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
 
 extern void destroy_workqueue(struct workqueue_struct *wq);
 
-extern int queue_work(struct workqueue_struct *wq, struct work_struct *work);
 extern int queue_work_on(int cpu, struct workqueue_struct *wq,
 			struct work_struct *work);
-extern int queue_delayed_work(struct workqueue_struct *wq,
-			struct delayed_work *work, unsigned long delay);
+extern int queue_work(struct workqueue_struct *wq, struct work_struct *work);
 extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 			struct delayed_work *work, unsigned long delay);
+extern int queue_delayed_work(struct workqueue_struct *wq,
+			struct delayed_work *work, unsigned long delay);
 
 extern void flush_workqueue(struct workqueue_struct *wq);
 extern void drain_workqueue(struct workqueue_struct *wq);
 extern void flush_scheduled_work(void);
 
-extern int schedule_work(struct work_struct *work);
 extern int schedule_work_on(int cpu, struct work_struct *work);
-extern int schedule_delayed_work(struct delayed_work *work, unsigned long delay);
+extern int schedule_work(struct work_struct *work);
 extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
-					unsigned long delay);
+				    unsigned long delay);
+extern int schedule_delayed_work(struct delayed_work *work,
+				 unsigned long delay);
 extern int schedule_on_each_cpu(work_func_t func);
 extern int keventd_up(void);
 

172 lines not on this page · raw message

index 5970342..278dc5d 100644
@@ -365,24 +365,24 @@ __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
 
 extern void destroy_workqueue(struct workqueue_struct *wq);
 
-extern int queue_work_on(int cpu, struct workqueue_struct *wq,
+extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
 			struct work_struct *work);
-extern int queue_work(struct workqueue_struct *wq, struct work_struct *work);
-extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
+extern bool queue_work(struct workqueue_struct *wq, struct work_struct *work);
+extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 			struct delayed_work *work, unsigned long delay);
-extern int queue_delayed_work(struct workqueue_struct *wq,
+extern bool queue_delayed_work(struct workqueue_struct *wq,
 			struct delayed_work *work, unsigned long delay);
 
 extern void flush_workqueue(struct workqueue_struct *wq);
 extern void drain_workqueue(struct workqueue_struct *wq);
 extern void flush_scheduled_work(void);
 
-extern int schedule_work_on(int cpu, struct work_struct *work);
-extern int schedule_work(struct work_struct *work);
-extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
-				    unsigned long delay);
-extern int schedule_delayed_work(struct delayed_work *work,
-				 unsigned long delay);
+extern bool schedule_work_on(int cpu, struct work_struct *work);
+extern bool schedule_work(struct work_struct *work);
+extern bool schedule_delayed_work_on(int cpu, struct delayed_work *work,
+				     unsigned long delay);
+extern bool schedule_delayed_work(struct delayed_work *work,
+				  unsigned long delay);
 extern int schedule_on_each_cpu(work_func_t func);
 extern int keventd_up(void);
 

130 lines not on this page · raw message

index 70f95ab..5c26d36 100644
@@ -1997,7 +1997,9 @@ __acquires(&gcwq->lock)
 
 	spin_unlock_irq(&gcwq->lock);
 
+	smp_wmb();	/* paired with test_and_set_bit(PENDING) */
 	work_clear_pending(work);
+
 	lock_map_acquire_read(&cwq->wq->lockdep_map);
 	lock_map_acquire(&lockdep_map);
 	trace_workqueue_execute_start(work);

index 5c26d36..147869a 100644
@@ -537,9 +537,10 @@ static int work_next_color(int color)
  * work is on queue.  Once execution starts, WORK_STRUCT_CWQ is
  * cleared and the work data contains the cpu number it was last on.
  *
- * set_work_{cwq|cpu}() and clear_work_data() can be used to set the
- * cwq, cpu or clear work->data.  These functions should only be
- * called while the work is owned - ie. while the PENDING bit is set.
+ * set_work_cwq(), set_work_cpu_and_clear_pending() and clear_work_data()
+ * can be used to set the cwq, cpu or clear work->data.  These functions
+ * should only be called while the work is owned - ie. while the PENDING
+ * bit is set.
  *
  * get_work_[g]cwq() can be used to obtain the gcwq or cwq
  * corresponding to a work.  gcwq is available once the work has been

@@ -561,9 +562,10 @@ static void set_work_cwq(struct work_struct *work,
 		      WORK_STRUCT_PENDING | WORK_STRUCT_CWQ | extra_flags);
 }
 
-static void set_work_cpu(struct work_struct *work, unsigned int cpu)
+static void set_work_cpu_and_clear_pending(struct work_struct *work,
+					   unsigned int cpu)
 {
-	set_work_data(work, cpu << WORK_STRUCT_FLAG_BITS, WORK_STRUCT_PENDING);
+	set_work_data(work, cpu << WORK_STRUCT_FLAG_BITS, 0);
 }
 
 static void clear_work_data(struct work_struct *work)

@@ -983,6 +985,15 @@ static void __queue_work(unsigned int cpu, struct workqueue_struct *wq,
 	unsigned int work_flags;
 	unsigned long flags;
 
+	/*
+	 * While a work item is PENDING && off queue, a task trying to
+	 * steal the PENDING will busy-loop waiting for it to either get
+	 * queued or lose PENDING, so a task shouldn't be preempted between
+	 * grabbing PENDING and queueing @work.  Make sure the caller has
+	 * preemption disabled.
+	 */
+	WARN_ON_ONCE(!preempt_count());
+
 	debug_work_activate(work);
 
 	/* if dying, only works from the same workqueue are allowed */

@@ -1068,10 +1079,14 @@ bool queue_work_on(int cpu, struct workqueue_struct *wq,
 {
 	bool ret = false;
 
+	preempt_disable();
+
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
 		__queue_work(cpu, wq, work);
 		ret = true;
 	}
+
+	preempt_enable();
 	return ret;
 }
 EXPORT_SYMBOL_GPL(queue_work_on);

@@ -1121,6 +1136,12 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 	struct work_struct *work = &dwork->work;
 	bool ret = false;
 
+	/*
+	 * We shouldn't get preempted between claiming PENDING and adding
+	 * timer.  Read the comment in __queue_work() for details.
+	 */
+	preempt_disable();
+
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
 		unsigned int lcpu;
 

@@ -1156,6 +1177,8 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 			add_timer(timer);
 		ret = true;
 	}
+
+	preempt_enable();
 	return ret;
 }
 EXPORT_SYMBOL_GPL(queue_delayed_work_on);

@@ -1970,15 +1993,13 @@ __acquires(&gcwq->lock)
 		return;
 	}
 
-	/* claim and process */
+	/* claim and dequeue */
 	debug_work_deactivate(work);
 	hlist_add_head(&worker->hentry, bwh);
 	worker->current_work = work;
 	worker->current_cwq = cwq;
 	work_color = get_work_color(work);
 
-	/* record the current cpu number in the work data and dequeue */
-	set_work_cpu(work, gcwq->cpu);
 	list_del_init(&work->entry);
 
 	/*

@@ -1995,10 +2016,18 @@ __acquires(&gcwq->lock)
 	if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool))
 		wake_up_worker(pool);
 
-	spin_unlock_irq(&gcwq->lock);
+	/*
+	 * Record the last CPU and clear PENDING.  The following wmb is
+	 * paired with the implied mb in test_and_set_bit(PENDING) and
+	 * ensures all updates to @work made here are visible to and
+	 * precede any updates by the next PENDING owner.  Also, clearing
+	 * PENDING is inside @gcwq->lock so that we don't get preempted
+	 * with PENDING set and @work off queue.
+	 */
+	smp_wmb();
+	set_work_cpu_and_clear_pending(work, gcwq->cpu);
 
-	smp_wmb();	/* paired with test_and_set_bit(PENDING) */
-	work_clear_pending(work);
+	spin_unlock_irq(&gcwq->lock);
 
 	lock_map_acquire_read(&cwq->wq->lockdep_map);
 	lock_map_acquire(&lockdep_map);

@@ -2836,9 +2865,11 @@ EXPORT_SYMBOL_GPL(cancel_work_sync);
  */
 bool flush_delayed_work(struct delayed_work *dwork)
 {
+	preempt_disable();
 	if (del_timer_sync(&dwork->timer))
 		__queue_work(raw_smp_processor_id(),
 			     get_work_cwq(&dwork->work)->wq, &dwork->work);
+	preempt_enable();
 	return flush_work(&dwork->work);
 }
 EXPORT_SYMBOL(flush_delayed_work);

@@ -2857,9 +2888,11 @@ EXPORT_SYMBOL(flush_delayed_work);
  */
 bool flush_delayed_work_sync(struct delayed_work *dwork)
 {
+	preempt_disable();
 	if (del_timer_sync(&dwork->timer))
 		__queue_work(raw_smp_processor_id(),
 			     get_work_cwq(&dwork->work)->wq, &dwork->work);
+	preempt_enable();
 	return flush_work_sync(&dwork->work);
 }
 EXPORT_SYMBOL(flush_delayed_work_sync);

index 5c26d36..f6eaf34 100644
@@ -537,9 +537,10 @@ static int work_next_color(int color)
  * work is on queue.  Once execution starts, WORK_STRUCT_CWQ is
  * cleared and the work data contains the cpu number it was last on.
  *
- * set_work_{cwq|cpu}() and clear_work_data() can be used to set the
- * cwq, cpu or clear work->data.  These functions should only be
- * called while the work is owned - ie. while the PENDING bit is set.
+ * set_work_cwq(), set_work_cpu_and_clear_pending() and clear_work_data()
+ * can be used to set the cwq, cpu or clear work->data.  These functions
+ * should only be called while the work is owned - ie. while the PENDING
+ * bit is set.
  *
  * get_work_[g]cwq() can be used to obtain the gcwq or cwq
  * corresponding to a work.  gcwq is available once the work has been

@@ -561,9 +562,10 @@ static void set_work_cwq(struct work_struct *work,
 		      WORK_STRUCT_PENDING | WORK_STRUCT_CWQ | extra_flags);
 }
 
-static void set_work_cpu(struct work_struct *work, unsigned int cpu)
+static void set_work_cpu_and_clear_pending(struct work_struct *work,
+					   unsigned int cpu)
 {
-	set_work_data(work, cpu << WORK_STRUCT_FLAG_BITS, WORK_STRUCT_PENDING);
+	set_work_data(work, cpu << WORK_STRUCT_FLAG_BITS, 0);
 }
 
 static void clear_work_data(struct work_struct *work)

@@ -983,6 +985,15 @@ static void __queue_work(unsigned int cpu, struct workqueue_struct *wq,
 	unsigned int work_flags;
 	unsigned long flags;
 
+	/*
+	 * While a work item is PENDING && off queue, a task trying to
+	 * steal the PENDING will busy-loop waiting for it to either get
+	 * queued or lose PENDING, so a task shouldn't be preempted between
+	 * grabbing PENDING and queueing @work.  Make sure the caller has
+	 * preemption disabled.
+	 */
+	WARN_ON_ONCE(preemptible());
+
 	debug_work_activate(work);
 
 	/* if dying, only works from the same workqueue are allowed */

@@ -1068,10 +1079,14 @@ bool queue_work_on(int cpu, struct workqueue_struct *wq,
 {
 	bool ret = false;
 
+	preempt_disable();
+
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
 		__queue_work(cpu, wq, work);
 		ret = true;
 	}
+
+	preempt_enable();
 	return ret;
 }
 EXPORT_SYMBOL_GPL(queue_work_on);

@@ -1121,6 +1136,12 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 	struct work_struct *work = &dwork->work;
 	bool ret = false;
 
+	/*
+	 * We shouldn't get preempted between claiming PENDING and adding
+	 * timer.  Read the comment in __queue_work() for details.
+	 */
+	preempt_disable();
+
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
 		unsigned int lcpu;
 

@@ -1156,6 +1177,8 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 			add_timer(timer);
 		ret = true;
 	}
+
+	preempt_enable();
 	return ret;
 }
 EXPORT_SYMBOL_GPL(queue_delayed_work_on);

@@ -1970,15 +1993,13 @@ __acquires(&gcwq->lock)
 		return;
 	}
 
-	/* claim and process */
+	/* claim and dequeue */
 	debug_work_deactivate(work);
 	hlist_add_head(&worker->hentry, bwh);
 	worker->current_work = work;
 	worker->current_cwq = cwq;
 	work_color = get_work_color(work);
 
-	/* record the current cpu number in the work data and dequeue */
-	set_work_cpu(work, gcwq->cpu);
 	list_del_init(&work->entry);
 
 	/*

@@ -1995,10 +2016,18 @@ __acquires(&gcwq->lock)
 	if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool))
 		wake_up_worker(pool);
 
-	spin_unlock_irq(&gcwq->lock);
+	/*
+	 * Record the last CPU and clear PENDING.  The following wmb is
+	 * paired with the implied mb in test_and_set_bit(PENDING) and
+	 * ensures all updates to @work made here are visible to and
+	 * precede any updates by the next PENDING owner.  Also, clearing
+	 * PENDING is inside @gcwq->lock so that we don't get preempted
+	 * with PENDING set and @work off queue.
+	 */
+	smp_wmb();
+	set_work_cpu_and_clear_pending(work, gcwq->cpu);
 
-	smp_wmb();	/* paired with test_and_set_bit(PENDING) */
-	work_clear_pending(work);
+	spin_unlock_irq(&gcwq->lock);
 
 	lock_map_acquire_read(&cwq->wq->lockdep_map);
 	lock_map_acquire(&lockdep_map);

@@ -2836,9 +2865,11 @@ EXPORT_SYMBOL_GPL(cancel_work_sync);
  */
 bool flush_delayed_work(struct delayed_work *dwork)
 {
+	preempt_disable();
 	if (del_timer_sync(&dwork->timer))
 		__queue_work(raw_smp_processor_id(),
 			     get_work_cwq(&dwork->work)->wq, &dwork->work);
+	preempt_enable();
 	return flush_work(&dwork->work);
 }
 EXPORT_SYMBOL(flush_delayed_work);

@@ -2857,9 +2888,11 @@ EXPORT_SYMBOL(flush_delayed_work);
  */
 bool flush_delayed_work_sync(struct delayed_work *dwork)
 {
+	preempt_disable();
 	if (del_timer_sync(&dwork->timer))
 		__queue_work(raw_smp_processor_id(),
 			     get_work_cwq(&dwork->work)->wq, &dwork->work);
+	preempt_enable();
 	return flush_work_sync(&dwork->work);
 }
 EXPORT_SYMBOL(flush_delayed_work_sync);

index 278dc5d..ab95fef 100644
@@ -16,6 +16,7 @@ struct workqueue_struct;
 
 struct work_struct;
 typedef void (*work_func_t)(struct work_struct *work);
+void delayed_work_timer_fn(unsigned long __data);
 
 /*
  * The first word is the work queue pointer and the flags rolled into

@@ -124,12 +125,14 @@ struct execute_work {
 
 #define __DELAYED_WORK_INITIALIZER(n, f) {			\
 	.work = __WORK_INITIALIZER((n).work, (f)),		\
-	.timer = TIMER_INITIALIZER(NULL, 0, 0),			\
+	.timer = TIMER_INITIALIZER(delayed_work_timer_fn,	\
+				0, (unsigned long)&(n)),	\
 	}
 
 #define __DEFERRED_WORK_INITIALIZER(n, f) {			\
 	.work = __WORK_INITIALIZER((n).work, (f)),		\
-	.timer = TIMER_DEFERRED_INITIALIZER(NULL, 0, 0),	\
+	.timer = TIMER_DEFERRED_INITIALIZER(delayed_work_timer_fn, \
+				0, (unsigned long)&(n)),	\
 	}
 
 #define DECLARE_WORK(n, f)					\

@@ -207,18 +210,24 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; }
 	do {							\
 		INIT_WORK(&(_work)->work, (_func));		\
 		init_timer(&(_work)->timer);			\
+		(_work)->timer.function = delayed_work_timer_fn;\
+		(_work)->timer.data = (unsigned long)(_work);	\
 	} while (0)
 
 #define INIT_DELAYED_WORK_ONSTACK(_work, _func)			\
 	do {							\
 		INIT_WORK_ONSTACK(&(_work)->work, (_func));	\
 		init_timer_on_stack(&(_work)->timer);		\
+		(_work)->timer.function = delayed_work_timer_fn;\
+		(_work)->timer.data = (unsigned long)(_work);	\
 	} while (0)
 
 #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func)		\
 	do {							\
 		INIT_WORK(&(_work)->work, (_func));		\
 		init_timer_deferrable(&(_work)->timer);		\
+		(_work)->timer.function = delayed_work_timer_fn;\
+		(_work)->timer.data = (unsigned long)(_work);	\
 	} while (0)
 
 /**

index 147869a..db8098b 100644
@@ -1112,13 +1112,14 @@ bool queue_work(struct workqueue_struct *wq, struct work_struct *work)
 }
 EXPORT_SYMBOL_GPL(queue_work);
 
-static void delayed_work_timer_fn(unsigned long __data)
+void delayed_work_timer_fn(unsigned long __data)
 {
 	struct delayed_work *dwork = (struct delayed_work *)__data;
 	struct cpu_workqueue_struct *cwq = get_work_cwq(&dwork->work);
 
 	__queue_work(smp_processor_id(), cwq->wq, &dwork->work);
 }
+EXPORT_SYMBOL_GPL(delayed_work_timer_fn);
 
 /**
  * queue_delayed_work_on - queue work on specific CPU after delay

@@ -1145,6 +1146,8 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
 		unsigned int lcpu;
 
+		WARN_ON_ONCE(timer->function != delayed_work_timer_fn ||
+			     timer->data != (unsigned long)dwork);
 		BUG_ON(timer_pending(timer));
 		BUG_ON(!list_empty(&work->entry));
 

@@ -1168,8 +1171,6 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 		set_work_cwq(work, get_cwq(lcpu, wq), 0);
 
 		timer->expires = jiffies + delay;
-		timer->data = (unsigned long)dwork;
-		timer->function = delayed_work_timer_fn;
 
 		if (unlikely(cpu >= 0))
 			add_timer_on(timer, cpu);

index db8098b..4beb9bf 100644
@@ -1005,7 +1005,7 @@ static void __queue_work(unsigned int cpu, struct workqueue_struct *wq,
 	if (!(wq->flags & WQ_UNBOUND)) {
 		struct global_cwq *last_gcwq;
 
-		if (unlikely(cpu == WORK_CPU_UNBOUND))
+		if (cpu == WORK_CPU_UNBOUND)
 			cpu = raw_smp_processor_id();
 
 		/*

@@ -1103,12 +1103,7 @@ EXPORT_SYMBOL_GPL(queue_work_on);
  */
 bool queue_work(struct workqueue_struct *wq, struct work_struct *work)
 {
-	bool ret;
-
-	ret = queue_work_on(get_cpu(), wq, work);
-	put_cpu();
-
-	return ret;
+	return queue_work_on(WORK_CPU_UNBOUND, wq, work);
 }
 EXPORT_SYMBOL_GPL(queue_work);
 

@@ -1117,7 +1112,7 @@ void delayed_work_timer_fn(unsigned long __data)
 	struct delayed_work *dwork = (struct delayed_work *)__data;
 	struct cpu_workqueue_struct *cwq = get_work_cwq(&dwork->work);
 
-	__queue_work(smp_processor_id(), cwq->wq, &dwork->work);
+	__queue_work(WORK_CPU_UNBOUND, cwq->wq, &dwork->work);
 }
 EXPORT_SYMBOL_GPL(delayed_work_timer_fn);
 

@@ -1172,7 +1167,7 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 
 		timer->expires = jiffies + delay;
 
-		if (unlikely(cpu >= 0))
+		if (unlikely(cpu != WORK_CPU_UNBOUND))
 			add_timer_on(timer, cpu);
 		else
 			add_timer(timer);

@@ -1198,7 +1193,7 @@ bool queue_delayed_work(struct workqueue_struct *wq,
 	if (delay == 0)
 		return queue_work(wq, &dwork->work);
 
-	return queue_delayed_work_on(-1, wq, dwork, delay);
+	return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
 }
 EXPORT_SYMBOL_GPL(queue_delayed_work);
 

@@ -2868,7 +2863,7 @@ bool flush_delayed_work(struct delayed_work *dwork)
 {
 	preempt_disable();
 	if (del_timer_sync(&dwork->timer))
-		__queue_work(raw_smp_processor_id(),
+		__queue_work(WORK_CPU_UNBOUND,
 			     get_work_cwq(&dwork->work)->wq, &dwork->work);
 	preempt_enable();
 	return flush_work(&dwork->work);

@@ -2891,7 +2886,7 @@ bool flush_delayed_work_sync(struct delayed_work *dwork)
 {
 	preempt_disable();
 	if (del_timer_sync(&dwork->timer))
-		__queue_work(raw_smp_processor_id(),
+		__queue_work(WORK_CPU_UNBOUND,
 			     get_work_cwq(&dwork->work)->wq, &dwork->work);
 	preempt_enable();
 	return flush_work_sync(&dwork->work);

index 4beb9bf..e3383e8 100644
@@ -1123,7 +1123,9 @@ EXPORT_SYMBOL_GPL(delayed_work_timer_fn);
  * @dwork: work to queue
  * @delay: number of jiffies to wait before queueing
  *
- * Returns %false if @work was already on a queue, %true otherwise.
+ * Returns %false if @work was already on a queue, %true otherwise.  If
+ * @delay is zero and @dwork is idle, it will be scheduled for immediate
+ * execution.
  */
 bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 			   struct delayed_work *dwork, unsigned long delay)

@@ -1132,6 +1134,9 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 	struct work_struct *work = &dwork->work;
 	bool ret = false;
 
+	if (!delay)
+		return queue_work_on(cpu, wq, &dwork->work);
+
 	/*
 	 * We shouldn't get preempted between claiming PENDING and adding
 	 * timer.  Read the comment in __queue_work() for details.

@@ -1185,14 +1190,11 @@ EXPORT_SYMBOL_GPL(queue_delayed_work_on);
  * @dwork: delayable work to queue
  * @delay: number of jiffies to wait before queueing
  *
- * Returns %false if @work was already on a queue, %true otherwise.
+ * Equivalent to queue_delayed_work_on() but tries to use the local CPU.
  */
 bool queue_delayed_work(struct workqueue_struct *wq,
 			struct delayed_work *dwork, unsigned long delay)
 {
-	if (delay == 0)
-		return queue_work(wq, &dwork->work);
-
 	return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
 }
 EXPORT_SYMBOL_GPL(queue_delayed_work);

index e3383e8..97d2f71 100644
@@ -904,6 +904,149 @@ static struct worker *find_worker_executing_work(struct global_cwq *gcwq,
 }
 
 /**
+ * move_linked_works - move linked works to a list
+ * @work: start of series of works to be scheduled
+ * @head: target list to append @work to
+ * @nextp: out paramter for nested worklist walking
+ *
+ * Schedule linked works starting from @work to @head.  Work series to
+ * be scheduled starts at @work and includes any consecutive work with
+ * WORK_STRUCT_LINKED set in its predecessor.
+ *
+ * If @nextp is not NULL, it's updated to point to the next work of
+ * the last scheduled work.  This allows move_linked_works() to be
+ * nested inside outer list_for_each_entry_safe().
+ *
+ * CONTEXT:
+ * spin_lock_irq(gcwq->lock).
+ */
+static void move_linked_works(struct work_struct *work, struct list_head *head,
+			      struct work_struct **nextp)
+{
+	struct work_struct *n;
+
+	/*
+	 * Linked worklist will always end before the end of the list,
+	 * use NULL for list head.
+	 */
+	list_for_each_entry_safe_from(work, n, NULL, entry) {
+		list_move_tail(&work->entry, head);
+		if (!(*work_data_bits(work) & WORK_STRUCT_LINKED))
+			break;
+	}
+
+	/*
+	 * If we're already inside safe list traversal and have moved
+	 * multiple works to the scheduled queue, the next position
+	 * needs to be updated.
+	 */
+	if (nextp)
+		*nextp = n;
+}
+
+static void cwq_activate_first_delayed(struct cpu_workqueue_struct *cwq)
+{
+	struct work_struct *work = list_first_entry(&cwq->delayed_works,
+						    struct work_struct, entry);
+
+	trace_workqueue_activate_work(work);
+	move_linked_works(work, &cwq->pool->worklist, NULL);
+	__clear_bit(WORK_STRUCT_DELAYED_BIT, work_data_bits(work));
+	cwq->nr_active++;
+}
+
+/**
+ * cwq_dec_nr_in_flight - decrement cwq's nr_in_flight
+ * @cwq: cwq of interest
+ * @color: color of work which left the queue
+ * @delayed: for a delayed work
+ *
+ * A work either has completed or is removed from pending queue,
+ * decrement nr_in_flight of its cwq and handle workqueue flushing.
+ *
+ * CONTEXT:
+ * spin_lock_irq(gcwq->lock).
+ */
+static void cwq_dec_nr_in_flight(struct cpu_workqueue_struct *cwq, int color,
+				 bool delayed)
+{
+	/* ignore uncolored works */
+	if (color == WORK_NO_COLOR)
+		return;
+
+	cwq->nr_in_flight[color]--;
+
+	if (!delayed) {
+		cwq->nr_active--;
+		if (!list_empty(&cwq->delayed_works)) {
+			/* one down, submit a delayed one */
+			if (cwq->nr_active < cwq->max_active)
+				cwq_activate_first_delayed(cwq);
+		}
+	}
+
+	/* is flush in progress and are we at the flushing tip? */
+	if (likely(cwq->flush_color != color))
+		return;
+
+	/* are there still in-flight works? */
+	if (cwq->nr_in_flight[color])
+		return;
+
+	/* this cwq is done, clear flush_color */
+	cwq->flush_color = -1;
+
+	/*
+	 * If this was the last cwq, wake up the first flusher.  It
+	 * will handle the rest.
+	 */
+	if (atomic_dec_and_test(&cwq->wq->nr_cwqs_to_flush))
+		complete(&cwq->wq->first_flusher->done);
+}
+
+/*
+ * Upon a successful return (>= 0), the caller "owns" WORK_STRUCT_PENDING bit,
+ * so this work can't be re-armed in any way.
+ */
+static int try_to_grab_pending(struct work_struct *work)
+{
+	struct global_cwq *gcwq;
+	int ret = -1;
+
+	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work)))
+		return 0;
+
+	/*
+	 * The queueing is in progress, or it is already queued. Try to
+	 * steal it from ->worklist without clearing WORK_STRUCT_PENDING.
+	 */
+	gcwq = get_work_gcwq(work);
+	if (!gcwq)
+		return ret;
+
+	spin_lock_irq(&gcwq->lock);
+	if (!list_empty(&work->entry)) {
+		/*
+		 * This work is queued, but perhaps we locked the wrong gcwq.
+		 * In that case we must see the new value after rmb(), see
+		 * insert_work()->wmb().
+		 */
+		smp_rmb();
+		if (gcwq == get_work_gcwq(work)) {
+			debug_work_deactivate(work);
+			list_del_init(&work->entry);
+			cwq_dec_nr_in_flight(get_work_cwq(work),
+				get_work_color(work),
+				*work_data_bits(work) & WORK_STRUCT_DELAYED);
+			ret = 1;
+		}
+	}
+	spin_unlock_irq(&gcwq->lock);
+
+	return ret;
+}
+
+/**
  * insert_work - insert a work into gcwq
  * @cwq: cwq @work belongs to
  * @work: work to insert

@@ -1832,107 +1975,6 @@ static bool manage_workers(struct worker *worker)
 }
 
 /**
- * move_linked_works - move linked works to a list
- * @work: start of series of works to be scheduled
- * @head: target list to append @work to
- * @nextp: out paramter for nested worklist walking
- *
- * Schedule linked works starting from @work to @head.  Work series to
- * be scheduled starts at @work and includes any consecutive work with
- * WORK_STRUCT_LINKED set in its predecessor.
- *
- * If @nextp is not NULL, it's updated to point to the next work of
- * the last scheduled work.  This allows move_linked_works() to be
- * nested inside outer list_for_each_entry_safe().
- *
- * CONTEXT:
- * spin_lock_irq(gcwq->lock).
- */
-static void move_linked_works(struct work_struct *work, struct list_head *head,
-			      struct work_struct **nextp)
-{
-	struct work_struct *n;
-
-	/*
-	 * Linked worklist will always end before the end of the list,
-	 * use NULL for list head.
-	 */
-	list_for_each_entry_safe_from(work, n, NULL, entry) {
-		list_move_tail(&work->entry, head);
-		if (!(*work_data_bits(work) & WORK_STRUCT_LINKED))
-			break;
-	}
-
-	/*
-	 * If we're already inside safe list traversal and have moved
-	 * multiple works to the scheduled queue, the next position
-	 * needs to be updated.
-	 */
-	if (nextp)
-		*nextp = n;
-}
-
-static void cwq_activate_first_delayed(struct cpu_workqueue_struct *cwq)
-{
-	struct work_struct *work = list_first_entry(&cwq->delayed_works,
-						    struct work_struct, entry);
-
-	trace_workqueue_activate_work(work);
-	move_linked_works(work, &cwq->pool->worklist, NULL);
-	__clear_bit(WORK_STRUCT_DELAYED_BIT, work_data_bits(work));
-	cwq->nr_active++;
-}
-
-/**
- * cwq_dec_nr_in_flight - decrement cwq's nr_in_flight
- * @cwq: cwq of interest
- * @color: color of work which left the queue
- * @delayed: for a delayed work
- *
- * A work either has completed or is removed from pending queue,
- * decrement nr_in_flight of its cwq and handle workqueue flushing.
- *
- * CONTEXT:
- * spin_lock_irq(gcwq->lock).
- */
-static void cwq_dec_nr_in_flight(struct cpu_workqueue_struct *cwq, int color,
-				 bool delayed)
-{
-	/* ignore uncolored works */
-	if (color == WORK_NO_COLOR)
-		return;
-
-	cwq->nr_in_flight[color]--;
-
-	if (!delayed) {
-		cwq->nr_active--;
-		if (!list_empty(&cwq->delayed_works)) {
-			/* one down, submit a delayed one */
-			if (cwq->nr_active < cwq->max_active)
-				cwq_activate_first_delayed(cwq);
-		}
-	}
-
-	/* is flush in progress and are we at the flushing tip? */
-	if (likely(cwq->flush_color != color))
-		return;
-
-	/* are there still in-flight works? */
-	if (cwq->nr_in_flight[color])
-		return;
-
-	/* this cwq is done, clear flush_color */
-	cwq->flush_color = -1;
-
-	/*
-	 * If this was the last cwq, wake up the first flusher.  It
-	 * will handle the rest.
-	 */
-	if (atomic_dec_and_test(&cwq->wq->nr_cwqs_to_flush))
-		complete(&cwq->wq->first_flusher->done);
-}
-
-/**
  * process_one_work - process single work
  * @worker: self
  * @work: work to process

@@ -2767,48 +2809,6 @@ bool flush_work_sync(struct work_struct *work)
 }
 EXPORT_SYMBOL_GPL(flush_work_sync);
 
-/*
- * Upon a successful return (>= 0), the caller "owns" WORK_STRUCT_PENDING bit,
- * so this work can't be re-armed in any way.
- */
-static int try_to_grab_pending(struct work_struct *work)
-{
-	struct global_cwq *gcwq;
-	int ret = -1;
-
-	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work)))
-		return 0;
-
-	/*
-	 * The queueing is in progress, or it is already queued. Try to
-	 * steal it from ->worklist without clearing WORK_STRUCT_PENDING.
-	 */
-	gcwq = get_work_gcwq(work);
-	if (!gcwq)
-		return ret;
-
-	spin_lock_irq(&gcwq->lock);
-	if (!list_empty(&work->entry)) {
-		/*
-		 * This work is queued, but perhaps we locked the wrong gcwq.
-		 * In that case we must see the new value after rmb(), see
-		 * insert_work()->wmb().
-		 */
-		smp_rmb();
-		if (gcwq == get_work_gcwq(work)) {
-			debug_work_deactivate(work);
-			list_del_init(&work->entry);
-			cwq_dec_nr_in_flight(get_work_cwq(work),
-				get_work_color(work),
-				*work_data_bits(work) & WORK_STRUCT_DELAYED);
-			ret = 1;
-		}
-	}
-	spin_unlock_irq(&gcwq->lock);
-
-	return ret;
-}
-
 static bool __cancel_work_timer(struct work_struct *work,
 				struct timer_list* timer)
 {

index ab95fef..f562674 100644
@@ -68,9 +68,15 @@ enum {
 	WORK_STRUCT_FLAG_BITS	= WORK_STRUCT_COLOR_SHIFT +
 				  WORK_STRUCT_COLOR_BITS,
 
+	/* data contains off-queue information when !WORK_STRUCT_CWQ */
+	WORK_OFFQ_FLAG_BASE	= WORK_STRUCT_FLAG_BITS,
+	WORK_OFFQ_FLAG_BITS	= 0,
+	WORK_OFFQ_CPU_SHIFT	= WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
+
+	/* convenience constants */
 	WORK_STRUCT_FLAG_MASK	= (1UL << WORK_STRUCT_FLAG_BITS) - 1,
 	WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
-	WORK_STRUCT_NO_CPU	= WORK_CPU_NONE << WORK_STRUCT_FLAG_BITS,
+	WORK_STRUCT_NO_CPU	= (unsigned long)WORK_CPU_NONE << WORK_OFFQ_CPU_SHIFT,
 
 	/* bit mask for work_busy() return values */
 	WORK_BUSY_PENDING	= 1 << 0,

index 97d2f71..58b42b2 100644
@@ -533,9 +533,9 @@ static int work_next_color(int color)
 }
 
 /*
- * A work's data points to the cwq with WORK_STRUCT_CWQ set while the
- * work is on queue.  Once execution starts, WORK_STRUCT_CWQ is
- * cleared and the work data contains the cpu number it was last on.
+ * While queued, %WORK_STRUCT_CWQ is set and non flag bits of a work's data
+ * contain the pointer to the queued cwq.  Once execution starts, the flag
+ * is cleared and the high bits contain OFFQ flags and CPU number.
  *
  * set_work_cwq(), set_work_cpu_and_clear_pending() and clear_work_data()
  * can be used to set the cwq, cpu or clear work->data.  These functions

@@ -565,7 +565,7 @@ static void set_work_cwq(struct work_struct *work,
 static void set_work_cpu_and_clear_pending(struct work_struct *work,
 					   unsigned int cpu)
 {
-	set_work_data(work, cpu << WORK_STRUCT_FLAG_BITS, 0);
+	set_work_data(work, (unsigned long)cpu << WORK_OFFQ_CPU_SHIFT, 0);
 }
 
 static void clear_work_data(struct work_struct *work)

@@ -592,7 +592,7 @@ static struct global_cwq *get_work_gcwq(struct work_struct *work)
 		return ((struct cpu_workqueue_struct *)
 			(data & WORK_STRUCT_WQ_DATA_MASK))->pool->gcwq;
 
-	cpu = data >> WORK_STRUCT_FLAG_BITS;
+	cpu = data >> WORK_OFFQ_CPU_SHIFT;
 	if (cpu == WORK_CPU_NONE)
 		return NULL;
 

@@ -3724,6 +3724,10 @@ static int __init init_workqueues(void)
 	unsigned int cpu;
 	int i;
 
+	/* make sure we have enough bits for OFFQ CPU number */
+	BUILD_BUG_ON((1LU << (BITS_PER_LONG - WORK_OFFQ_CPU_SHIFT)) <
+		     WORK_CPU_LAST);
+
 	cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP);
 	cpu_notifier(workqueue_cpu_down_callback, CPU_PRI_WORKQUEUE_DOWN);
 

index 58b42b2..358779c 100644
@@ -1259,6 +1259,46 @@ void delayed_work_timer_fn(unsigned long __data)
 }
 EXPORT_SYMBOL_GPL(delayed_work_timer_fn);
 
+static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
+				struct delayed_work *dwork, unsigned long delay)
+{
+	struct timer_list *timer = &dwork->timer;
+	struct work_struct *work = &dwork->work;
+	unsigned int lcpu;
+
+	WARN_ON_ONCE(timer->function != delayed_work_timer_fn ||
+		     timer->data != (unsigned long)dwork);
+	BUG_ON(timer_pending(timer));
+	BUG_ON(!list_empty(&work->entry));
+
+	timer_stats_timer_set_start_info(&dwork->timer);
+
+	/*
+	 * This stores cwq for the moment, for the timer_fn.  Note that the
+	 * work's gcwq is preserved to allow reentrance detection for
+	 * delayed works.
+	 */
+	if (!(wq->flags & WQ_UNBOUND)) {
+		struct global_cwq *gcwq = get_work_gcwq(work);
+
+		if (gcwq && gcwq->cpu != WORK_CPU_UNBOUND)
+			lcpu = gcwq->cpu;
+		else
+			lcpu = raw_smp_processor_id();
+	} else {
+		lcpu = WORK_CPU_UNBOUND;
+	}
+
+	set_work_cwq(work, get_cwq(lcpu, wq), 0);
+
+	timer->expires = jiffies + delay;
+
+	if (unlikely(cpu != WORK_CPU_UNBOUND))
+		add_timer_on(timer, cpu);
+	else
+		add_timer(timer);
+}
+
 /**
  * queue_delayed_work_on - queue work on specific CPU after delay
  * @cpu: CPU number to execute work on

@@ -1273,7 +1313,6 @@ EXPORT_SYMBOL_GPL(delayed_work_timer_fn);
 bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 			   struct delayed_work *dwork, unsigned long delay)
 {
-	struct timer_list *timer = &dwork->timer;
 	struct work_struct *work = &dwork->work;
 	bool ret = false;
 

@@ -1287,38 +1326,7 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 	preempt_disable();
 
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
-		unsigned int lcpu;
-
-		WARN_ON_ONCE(timer->function != delayed_work_timer_fn ||
-			     timer->data != (unsigned long)dwork);
-		BUG_ON(timer_pending(timer));
-		BUG_ON(!list_empty(&work->entry));
-
-		timer_stats_timer_set_start_info(&dwork->timer);
-
-		/*
-		 * This stores cwq for the moment, for the timer_fn.
-		 * Note that the work's gcwq is preserved to allow
-		 * reentrance detection for delayed works.
-		 */
-		if (!(wq->flags & WQ_UNBOUND)) {
-			struct global_cwq *gcwq = get_work_gcwq(work);
-
-			if (gcwq && gcwq->cpu != WORK_CPU_UNBOUND)
-				lcpu = gcwq->cpu;
-			else
-				lcpu = raw_smp_processor_id();
-		} else
-			lcpu = WORK_CPU_UNBOUND;
-
-		set_work_cwq(work, get_cwq(lcpu, wq), 0);
-
-		timer->expires = jiffies + delay;
-
-		if (unlikely(cpu != WORK_CPU_UNBOUND))
-			add_timer_on(timer, cpu);
-		else
-			add_timer(timer);
+		__queue_delayed_work(cpu, wq, dwork, delay);
 		ret = true;
 	}
 

index 358779c..a0eb033 100644
@@ -1004,15 +1004,29 @@ static void cwq_dec_nr_in_flight(struct cpu_workqueue_struct *cwq, int color,
 		complete(&cwq->wq->first_flusher->done);
 }
 
-/*
- * Upon a successful return (>= 0), the caller "owns" WORK_STRUCT_PENDING bit,
- * so this work can't be re-armed in any way.
+/**
+ * try_to_grab_pending - steal work item from worklist
+ * @work: work item to steal
+ *
+ * Try to grab PENDING bit of @work.  This function can handle @work in any
+ * stable state - idle, on timer or on worklist.  Return values are
+ *
+ *  1		if @work was pending and we successfully stole PENDING
+ *  0		if @work was idle and we claimed PENDING
+ *  -EAGAIN	if PENDING couldn't be grabbed at the moment, safe to busy-retry
+ *
+ * On >= 0 return, the caller owns @work's PENDING bit.
  */
-static int try_to_grab_pending(struct work_struct *work)
+static int try_to_grab_pending(struct work_struct *work,
+			       struct timer_list *timer)
 {
 	struct global_cwq *gcwq;
-	int ret = -1;
 
+	/* try to steal the timer if it exists */
+	if (timer && likely(del_timer(timer)))
+		return 1;
+
+	/* try to claim PENDING the normal way */
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work)))
 		return 0;
 

@@ -1022,7 +1036,7 @@ static int try_to_grab_pending(struct work_struct *work)
 	 */
 	gcwq = get_work_gcwq(work);
 	if (!gcwq)
-		return ret;
+		return -EAGAIN;
 
 	spin_lock_irq(&gcwq->lock);
 	if (!list_empty(&work->entry)) {

@@ -1038,12 +1052,14 @@ static int try_to_grab_pending(struct work_struct *work)
 			cwq_dec_nr_in_flight(get_work_cwq(work),
 				get_work_color(work),
 				*work_data_bits(work) & WORK_STRUCT_DELAYED);
-			ret = 1;
+
+			spin_unlock_irq(&gcwq->lock);
+			return 1;
 		}
 	}
 	spin_unlock_irq(&gcwq->lock);
 
-	return ret;
+	return -EAGAIN;
 }
 
 /**

@@ -2823,9 +2839,7 @@ static bool __cancel_work_timer(struct work_struct *work,
 	int ret;
 
 	do {
-		ret = (timer && likely(del_timer(timer)));
-		if (!ret)
-			ret = try_to_grab_pending(work);
+		ret = try_to_grab_pending(work, timer);
 		wait_on_work(work);
 	} while (unlikely(ret < 0));
 

index f562674..5f4aeaa 100644
@@ -70,7 +70,10 @@ enum {
 
 	/* data contains off-queue information when !WORK_STRUCT_CWQ */
 	WORK_OFFQ_FLAG_BASE	= WORK_STRUCT_FLAG_BITS,
-	WORK_OFFQ_FLAG_BITS	= 0,
+
+	WORK_OFFQ_CANCELING	= (1 << WORK_OFFQ_FLAG_BASE),
+
+	WORK_OFFQ_FLAG_BITS	= 1,
 	WORK_OFFQ_CPU_SHIFT	= WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
 
 	/* convenience constants */

109 lines not on this page · raw message

index f562674..5f4aeaa 100644
@@ -70,7 +70,10 @@ enum {
 
 	/* data contains off-queue information when !WORK_STRUCT_CWQ */
 	WORK_OFFQ_FLAG_BASE	= WORK_STRUCT_FLAG_BITS,
-	WORK_OFFQ_FLAG_BITS	= 0,
+
+	WORK_OFFQ_CANCELING	= (1 << WORK_OFFQ_FLAG_BASE),
+
+	WORK_OFFQ_FLAG_BITS	= 1,
 	WORK_OFFQ_CPU_SHIFT	= WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
 
 	/* convenience constants */

109 lines not on this page · raw message

index 5f4aeaa..2000030 100644
@@ -390,6 +390,10 @@ extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 			struct delayed_work *work, unsigned long delay);
 extern bool queue_delayed_work(struct workqueue_struct *wq,
 			struct delayed_work *work, unsigned long delay);
+extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
+			struct delayed_work *dwork, unsigned long delay);
+extern bool mod_delayed_work(struct workqueue_struct *wq,
+			struct delayed_work *dwork, unsigned long delay);
 
 extern void flush_workqueue(struct workqueue_struct *wq);
 extern void drain_workqueue(struct workqueue_struct *wq);

57 lines not on this page · raw message

index 93eb3e4..43f6c17 100644
@@ -319,10 +319,8 @@ EXPORT_SYMBOL(__blk_run_queue);
  */
 void blk_run_queue_async(struct request_queue *q)
 {
-	if (likely(!blk_queue_stopped(q))) {
-		__cancel_delayed_work(&q->delay_work);
-		queue_delayed_work(kblockd_workqueue, &q->delay_work, 0);
-	}
+	if (likely(!blk_queue_stopped(q)))
+		mod_delayed_work(kblockd_workqueue, &q->delay_work, 0);
 }
 EXPORT_SYMBOL(blk_run_queue_async);
 

index 5b06595..69516e6 100644
@@ -930,12 +930,7 @@ throtl_schedule_delayed_work(struct throtl_data *td, unsigned long delay)
 
 	/* schedule work if limits changed even if no bio is queued */
 	if (total_nr_queued(td) || td->limits_changed) {
-		/*
-		 * We might have a work scheduled to be executed in future.
-		 * Cancel that and schedule a new one.
-		 */
-		__cancel_delayed_work(dwork);
-		queue_delayed_work(kthrotld_workqueue, dwork, delay);
+		mod_delayed_work(kthrotld_workqueue, dwork, delay);
 		throtl_log(td, "schedule work. delay=%lu jiffies=%lu",
 				delay, jiffies);
 	}

index 9cf5583..ba16f2f 100644
@@ -1524,10 +1524,8 @@ void disk_flush_events(struct gendisk *disk, unsigned int mask)
 
 	spin_lock_irq(&ev->lock);
 	ev->clearing |= mask;
-	if (!ev->block) {
-		cancel_delayed_work(&ev->dwork);
-		queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0);
-	}
+	if (!ev->block)
+		mod_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0);
 	spin_unlock_irq(&ev->lock);
 }
 

index 553f43a..aebd1e8 100644
@@ -671,7 +671,6 @@ static void __reschedule_timeout(int drive, const char *message)
 
 	if (drive == current_reqD)
 		drive = current_drive;
-	__cancel_delayed_work(&fd_timeout);
 
 	if (drive < 0 || drive >= N_DRIVE) {
 		delay = 20UL * HZ;

@@ -679,7 +678,7 @@ static void __reschedule_timeout(int drive, const char *message)
 	} else
 		delay = UDP->timeout;
 
-	queue_delayed_work(floppy_wq, &fd_timeout, delay);
+	mod_delayed_work(floppy_wq, &fd_timeout, delay);
 	if (UDP->flags & FD_DEBUG)
 		DPRINT("reschedule timeout %s\n", message);
 	timeout_message = message;

index de5ba86e..9dbde5f 100644
@@ -492,7 +492,7 @@ static void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec)
 		return;
 
 	INIT_DELAYED_WORK(&mci->work, edac_mc_workq_function);
-	queue_delayed_work(edac_workqueue, &mci->work, msecs_to_jiffies(msec));
+	mod_delayed_work(edac_workqueue, &mci->work, msecs_to_jiffies(msec));
 }
 
 /*

@@ -533,21 +533,6 @@ void edac_mc_reset_delay_period(int value)
 
 	mutex_lock(&mem_ctls_mutex);
 
-	/* scan the list and turn off all workq timers, doing so under lock
-	 */
-	list_for_each(item, &mc_devices) {
-		mci = list_entry(item, struct mem_ctl_info, link);
-
-		if (mci->op_state == OP_RUNNING_POLL)
-			cancel_delayed_work(&mci->work);
-	}
-
-	mutex_unlock(&mem_ctls_mutex);
-
-
-	/* re-walk the list, and reset the poll delay */
-	mutex_lock(&mem_ctls_mutex);
-
 	list_for_each(item, &mc_devices) {
 		mci = list_entry(item, struct mem_ctl_info, link);
 

index 28058ae..eaec8d7 100644
@@ -152,13 +152,11 @@ static void set_timeout(unsigned long time)
 {
 	unsigned long delay;
 
-	cancel_delayed_work(&work);
-
 	delay = time - jiffies;
 	if ((long)delay <= 0)
 		delay = 1;
 
-	queue_delayed_work(addr_wq, &work, delay);
+	mod_delayed_work(addr_wq, &work, delay);
 }
 
 static void queue_req(struct addr_req *req)

index b0d0bc8..b593814 100644
@@ -2013,13 +2013,11 @@ static void adjust_timeout(struct ib_mad_agent_private *mad_agent_priv)
 		if (time_after(mad_agent_priv->timeout,
 			       mad_send_wr->timeout)) {
 			mad_agent_priv->timeout = mad_send_wr->timeout;
-			__cancel_delayed_work(&mad_agent_priv->timed_work);
 			delay = mad_send_wr->timeout - jiffies;
 			if ((long)delay <= 0)
 				delay = 1;
-			queue_delayed_work(mad_agent_priv->qp_info->
-					   port_priv->wq,
-					   &mad_agent_priv->timed_work, delay);
+			mod_delayed_work(mad_agent_priv->qp_info->port_priv->wq,
+					 &mad_agent_priv->timed_work, delay);
 		}
 	}
 }

@@ -2052,11 +2050,9 @@ static void wait_for_response(struct ib_mad_send_wr_private *mad_send_wr)
 	list_add(&mad_send_wr->agent_list, list_item);
 
 	/* Reschedule a work item if we have a shorter timeout */
-	if (mad_agent_priv->wait_list.next == &mad_send_wr->agent_list) {
-		__cancel_delayed_work(&mad_agent_priv->timed_work);
-		queue_delayed_work(mad_agent_priv->qp_info->port_priv->wq,
-				   &mad_agent_priv->timed_work, delay);
-	}
+	if (mad_agent_priv->wait_list.next == &mad_send_wr->agent_list)
+		mod_delayed_work(mad_agent_priv->qp_info->port_priv->wq,
+				 &mad_agent_priv->timed_work, delay);
 }
 
 void ib_reset_mad_timeout(struct ib_mad_send_wr_private *mad_send_wr,

index d42c9f4..9e0895b 100644
@@ -2679,11 +2679,9 @@ static void nes_process_mac_intr(struct nes_device *nesdev, u32 mac_number)
 			}
 		}
 		if (nesadapter->phy_type[mac_index] == NES_PHY_TYPE_SFP_D) {
-			if (nesdev->link_recheck)
-				cancel_delayed_work(&nesdev->work);
 			nesdev->link_recheck = 1;
-			schedule_delayed_work(&nesdev->work,
-					      NES_LINK_RECHECK_DELAY);
+			mod_delayed_work(system_wq, &nesdev->work,
+					 NES_LINK_RECHECK_DELAY);
 		}
 	}
 

index f3a3ecf..e43f6e4 100644
@@ -243,10 +243,9 @@ static int nes_netdev_open(struct net_device *netdev)
 
 	spin_lock_irqsave(&nesdev->nesadapter->phy_lock, flags);
 	if (nesdev->nesadapter->phy_type[nesdev->mac_index] == NES_PHY_TYPE_SFP_D) {
-		if (nesdev->link_recheck)
-			cancel_delayed_work(&nesdev->work);
 		nesdev->link_recheck = 1;
-		schedule_delayed_work(&nesdev->work, NES_LINK_RECHECK_DELAY);
+		mod_delayed_work(system_wq, &nesdev->work,
+				 NES_LINK_RECHECK_DELAY);
 	}
 	spin_unlock_irqrestore(&nesdev->nesadapter->phy_lock, flags);
 

index e7a5e36..76b7d43 100644
@@ -156,8 +156,7 @@ static irqreturn_t qt2160_irq(int irq, void *_qt2160)
 
 	spin_lock_irqsave(&qt2160->lock, flags);
 
-	__cancel_delayed_work(&qt2160->dwork);
-	schedule_delayed_work(&qt2160->dwork, 0);
+	mod_delayed_work(system_wq, &qt2160->dwork, 0);
 
 	spin_unlock_irqrestore(&qt2160->lock, flags);
 

index f1467570..063a174 100644
@@ -376,12 +376,7 @@ static void synaptics_i2c_reschedule_work(struct synaptics_i2c *touch,
 
 	spin_lock_irqsave(&touch->lock, flags);
 
-	/*
-	 * If work is already scheduled then subsequent schedules will not
-	 * change the scheduled time that's why we have to cancel it first.
-	 */
-	__cancel_delayed_work(&touch->dwork);
-	schedule_delayed_work(&touch->dwork, delay);
+	mod_delayed_work(system_wq, &touch->dwork, delay);
 
 	spin_unlock_irqrestore(&touch->lock, flags);
 }

index 95aa8e1..8a34202 100644
@@ -2180,8 +2180,7 @@ static void isr_indicate_rf_kill(struct ipw2100_priv *priv, u32 status)
 
 	/* Make sure the RF Kill check timer is running */
 	priv->stop_rf_kill = 0;
-	cancel_delayed_work(&priv->rf_kill);
-	schedule_delayed_work(&priv->rf_kill, round_jiffies_relative(HZ));
+	mod_delayed_work(system_wq, &priv->rf_kill, round_jiffies_relative(HZ));
 }
 
 static void send_scan_event(void *data)

@@ -4321,9 +4320,8 @@ static int ipw_radio_kill_sw(struct ipw2100_priv *priv, int disable_radio)
 					  "disabled by HW switch\n");
 			/* Make sure the RF_KILL check timer is running */
 			priv->stop_rf_kill = 0;
-			cancel_delayed_work(&priv->rf_kill);
-			schedule_delayed_work(&priv->rf_kill,
-					      round_jiffies_relative(HZ));
+			mod_delayed_work(system_wq, &priv->rf_kill,
+					 round_jiffies_relative(HZ));
 		} else
 			schedule_reset(priv);
 	}

index af83c43..ef2b171 100644
@@ -1164,8 +1164,7 @@ void zd_usb_reset_rx_idle_timer(struct zd_usb *usb)
 {
 	struct zd_usb_rx *rx = &usb->rx;
 
-	cancel_delayed_work(&rx->idle_work);
-	queue_delayed_work(zd_workqueue, &rx->idle_work, ZD_RX_IDLE_INTERVAL);
+	mod_delayed_work(zd_workqueue, &rx->idle_work, ZD_RX_IDLE_INTERVAL);
 }
 
 static inline void init_usb_interrupt(struct zd_usb *usb)

index d5fd4a1..00d32a7 100644
@@ -7683,25 +7683,15 @@ static int fan_set_speed(int speed)
 
 static void fan_watchdog_reset(void)
 {
-	static int fan_watchdog_active;
-
 	if (fan_control_access_mode == TPACPI_FAN_WR_NONE)
 		return;
 
-	if (fan_watchdog_active)
-		cancel_delayed_work(&fan_watchdog_task);
-
 	if (fan_watchdog_maxinterval > 0 &&
-	    tpacpi_lifecycle != TPACPI_LIFE_EXITING) {
-		fan_watchdog_active = 1;
-		if (!queue_delayed_work(tpacpi_wq, &fan_watchdog_task,
-				msecs_to_jiffies(fan_watchdog_maxinterval
-						 * 1000))) {
-			pr_err("failed to queue the fan watchdog, "
-			       "watchdog will not trigger\n");
-		}
-	} else
-		fan_watchdog_active = 0;
+	    tpacpi_lifecycle != TPACPI_LIFE_EXITING)
+		mod_delayed_work(tpacpi_wq, &fan_watchdog_task,
+			msecs_to_jiffies(fan_watchdog_maxinterval * 1000));
+	else
+		cancel_delayed_work(&fan_watchdog_task);
 }
 
 static void fan_watchdog_fire(struct work_struct *ignored)

index 86935ec..0db0444 100644
@@ -512,9 +512,8 @@ static void _setup_polling(struct work_struct *work)
 	if (!delayed_work_pending(&cm_monitor_work) ||
 	    (delayed_work_pending(&cm_monitor_work) &&
 	     time_after(next_polling, _next_polling))) {
-		cancel_delayed_work_sync(&cm_monitor_work);
 		next_polling = jiffies + polling_jiffy;
-		queue_delayed_work(cm_wq, &cm_monitor_work, polling_jiffy);
+		mod_delayed_work(cm_wq, &cm_monitor_work, polling_jiffy);
 	}
 
 out:

@@ -549,10 +548,8 @@ static void fullbatt_handler(struct charger_manager *cm)
 	if (cm_suspended)
 		device_set_wakeup_capable(cm->dev, true);
 
-	if (delayed_work_pending(&cm->fullbatt_vchk_work))
-		cancel_delayed_work(&cm->fullbatt_vchk_work);
-	queue_delayed_work(cm_wq, &cm->fullbatt_vchk_work,
-			   msecs_to_jiffies(desc->fullbatt_vchkdrop_ms));
+	mod_delayed_work(cm_wq, &cm->fullbatt_vchk_work,
+			 msecs_to_jiffies(desc->fullbatt_vchkdrop_ms));
 	cm->fullbatt_vchk_jiffies_at = jiffies + msecs_to_jiffies(
 				       desc->fullbatt_vchkdrop_ms);
 

index 076e211..704e652 100644
@@ -355,8 +355,7 @@ static void ds2760_battery_external_power_changed(struct power_supply *psy)
 
 	dev_dbg(di->dev, "%s\n", __func__);
 
-	cancel_delayed_work(&di->monitor_work);
-	queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
+	mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
 }
 
 

@@ -401,8 +400,7 @@ static void ds2760_battery_set_charged(struct power_supply *psy)
 
 	/* postpone the actual work by 20 secs. This is for debouncing GPIO
 	 * signals and to let the current value settle. See AN4188. */
-	cancel_delayed_work(&di->set_charged_work);
-	queue_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
+	mod_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
 }
 
 static int ds2760_battery_get_property(struct power_supply *psy,

@@ -616,8 +614,7 @@ static int ds2760_battery_resume(struct platform_device *pdev)
 	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
 	power_supply_changed(&di->bat);
 
-	cancel_delayed_work(&di->monitor_work);
-	queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
+	mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
 
 	return 0;
 }

index 8dbc7bf..ffbed5e 100644
@@ -173,16 +173,14 @@ static void jz_battery_external_power_changed(struct power_supply *psy)
 {
 	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
 
-	cancel_delayed_work(&jz_battery->work);
-	schedule_delayed_work(&jz_battery->work, 0);
+	mod_delayed_work(system_wq, &jz_battery->work, 0);
 }
 
 static irqreturn_t jz_battery_charge_irq(int irq, void *data)
 {
 	struct jz_battery *jz_battery = data;
 
-	cancel_delayed_work(&jz_battery->work);
-	schedule_delayed_work(&jz_battery->work, 0);
+	mod_delayed_work(system_wq, &jz_battery->work, 0);
 
 	return IRQ_HANDLED;
 }

index 2d7a9fe..a937838 100644
@@ -694,17 +694,14 @@ thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz)
 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
 					    int delay)
 {
-	cancel_delayed_work(&(tz->poll_queue));
-
-	if (!delay)
-		return;
-
 	if (delay > 1000)
-		queue_delayed_work(system_freezable_wq, &(tz->poll_queue),
-				      round_jiffies(msecs_to_jiffies(delay)));
+		mod_delayed_work(system_freezable_wq, &tz->poll_queue,
+				 round_jiffies(msecs_to_jiffies(delay)));
+	else if (delay)
+		mod_delayed_work(system_freezable_wq, &tz->poll_queue,
+				 msecs_to_jiffies(delay));
 	else
-		queue_delayed_work(system_freezable_wq, &(tz->poll_queue),
-				      msecs_to_jiffies(delay));
+		cancel_delayed_work(&tz->poll_queue);
 }
 
 static void thermal_zone_device_passive(struct thermal_zone_device *tz,

index 587ef51..7ef637d 100644
@@ -351,9 +351,7 @@ void afs_dispatch_give_up_callbacks(struct work_struct *work)
  */
 void afs_flush_callback_breaks(struct afs_server *server)
 {
-	cancel_delayed_work(&server->cb_break_work);
-	queue_delayed_work(afs_callback_update_worker,
-			   &server->cb_break_work, 0);
+	mod_delayed_work(afs_callback_update_worker, &server->cb_break_work, 0);
 }
 
 #if 0

index d59b751..f342acf 100644
@@ -285,12 +285,7 @@ static void afs_reap_server(struct work_struct *work)
 		expiry = server->time_of_death + afs_server_timeout;
 		if (expiry > now) {
 			delay = (expiry - now) * HZ;
-			if (!queue_delayed_work(afs_wq, &afs_server_reaper,
-						delay)) {
-				cancel_delayed_work(&afs_server_reaper);
-				queue_delayed_work(afs_wq, &afs_server_reaper,
-						   delay);
-			}
+			mod_delayed_work(afs_wq, &afs_server_reaper, delay);
 			break;
 		}
 

@@ -323,6 +318,5 @@ static void afs_reap_server(struct work_struct *work)
 void __exit afs_purge_servers(void)
 {
 	afs_server_timeout = 0;
-	cancel_delayed_work(&afs_server_reaper);
-	queue_delayed_work(afs_wq, &afs_server_reaper, 0);
+	mod_delayed_work(afs_wq, &afs_server_reaper, 0);
 }

index 431984d..57bcb15 100644
@@ -561,12 +561,7 @@ static void afs_vlocation_reaper(struct work_struct *work)
 		if (expiry > now) {
 			delay = (expiry - now) * HZ;
 			_debug("delay %lu", delay);
-			if (!queue_delayed_work(afs_wq, &afs_vlocation_reap,
-						delay)) {
-				cancel_delayed_work(&afs_vlocation_reap);
-				queue_delayed_work(afs_wq, &afs_vlocation_reap,
-						   delay);
-			}
+			mod_delayed_work(afs_wq, &afs_vlocation_reap, delay);
 			break;
 		}
 

@@ -614,13 +609,10 @@ void afs_vlocation_purge(void)
 	spin_lock(&afs_vlocation_updates_lock);
 	list_del_init(&afs_vlocation_updates);
 	spin_unlock(&afs_vlocation_updates_lock);
-	cancel_delayed_work(&afs_vlocation_update);
-	queue_delayed_work(afs_vlocation_update_worker,
-			   &afs_vlocation_update, 0);
+	mod_delayed_work(afs_vlocation_update_worker, &afs_vlocation_update, 0);
 	destroy_workqueue(afs_vlocation_update_worker);
 
-	cancel_delayed_work(&afs_vlocation_reap);
-	queue_delayed_work(afs_wq, &afs_vlocation_reap, 0);
+	mod_delayed_work(afs_wq, &afs_vlocation_reap, 0);
 }
 
 /*

index 6930bec..1720d32 100644
@@ -117,8 +117,7 @@ nfs4_schedule_state_renewal(struct nfs_client *clp)
 		timeout = 5 * HZ;
 	dprintk("%s: requeueing work. Lease period = %ld\n",
 			__func__, (timeout + HZ - 1) / HZ);
-	cancel_delayed_work(&clp->cl_renewd);
-	schedule_delayed_work(&clp->cl_renewd, timeout);
+	mod_delayed_work(system_wq, &clp->cl_renewd, timeout);
 	set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
 	spin_unlock(&clp->cl_lock);
 }

index 069d51d..ed5a0b4 100644
@@ -214,8 +214,8 @@ void __dst_free(struct dst_entry *dst)
 	if (dst_garbage.timer_inc > DST_GC_INC) {
 		dst_garbage.timer_inc = DST_GC_INC;
 		dst_garbage.timer_expires = DST_GC_MIN;
-		cancel_delayed_work(&dst_gc_work);
-		schedule_delayed_work(&dst_gc_work, dst_garbage.timer_expires);
+		mod_delayed_work(system_wq, &dst_gc_work,
+				 dst_garbage.timer_expires);
 	}
 	spin_unlock_bh(&dst_garbage.lock);
 }

index c3519c6..8e397a6 100644
@@ -120,22 +120,13 @@ static void linkwatch_schedule_work(int urgent)
 		delay = 0;
 
 	/*
-	 * This is true if we've scheduled it immeditately or if we don't
-	 * need an immediate execution and it's already pending.
+	 * If urgent, schedule immediate execution; otherwise, don't
+	 * override the existing timer.
 	 */
-	if (schedule_delayed_work(&linkwatch_work, delay) == !delay)
-		return;
-
-	/* Don't bother if there is nothing urgent. */
-	if (!test_bit(LW_URGENT, &linkwatch_flags))
-		return;
-
-	/* It's already running which is good enough. */
-	if (!__cancel_delayed_work(&linkwatch_work))
-		return;
-
-	/* Otherwise we reschedule it again for immediate execution. */
-	schedule_delayed_work(&linkwatch_work, 0);
+	if (test_bit(LW_URGENT, &linkwatch_flags))
+		mod_delayed_work(system_wq, &linkwatch_work, 0);
+	else
+		schedule_delayed_work(&linkwatch_work, delay);
 }
 
 

index 24c55c5..c9d931e 100644
@@ -164,8 +164,7 @@ static void rfkill_schedule_global_op(enum rfkill_sched_op op)
 	rfkill_op_pending = true;
 	if (op == RFKILL_GLOBAL_OP_EPO && !rfkill_is_epo_lock_active()) {
 		/* bypass the limiter for EPO */
-		cancel_delayed_work(&rfkill_op_work);
-		schedule_delayed_work(&rfkill_op_work, 0);
+		mod_delayed_work(system_wq, &rfkill_op_work, 0);
 		rfkill_last_scheduled = jiffies;
 	} else
 		rfkill_schedule_ratelimited();

index 9cf5583..ba16f2f 100644
@@ -1524,10 +1524,8 @@ void disk_flush_events(struct gendisk *disk, unsigned int mask)
 
 	spin_lock_irq(&ev->lock);
 	ev->clearing |= mask;
-	if (!ev->block) {
-		cancel_delayed_work(&ev->dwork);
-		queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0);
-	}
+	if (!ev->block)
+		mod_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0);
 	spin_unlock_irq(&ev->lock);
 }
 

index de5ba86e..9dbde5f 100644
@@ -492,7 +492,7 @@ static void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec)
 		return;
 
 	INIT_DELAYED_WORK(&mci->work, edac_mc_workq_function);
-	queue_delayed_work(edac_workqueue, &mci->work, msecs_to_jiffies(msec));
+	mod_delayed_work(edac_workqueue, &mci->work, msecs_to_jiffies(msec));
 }
 
 /*

@@ -533,21 +533,6 @@ void edac_mc_reset_delay_period(int value)
 
 	mutex_lock(&mem_ctls_mutex);
 
-	/* scan the list and turn off all workq timers, doing so under lock
-	 */
-	list_for_each(item, &mc_devices) {
-		mci = list_entry(item, struct mem_ctl_info, link);
-
-		if (mci->op_state == OP_RUNNING_POLL)
-			cancel_delayed_work(&mci->work);
-	}
-
-	mutex_unlock(&mem_ctls_mutex);
-
-
-	/* re-walk the list, and reset the poll delay */
-	mutex_lock(&mem_ctls_mutex);
-
 	list_for_each(item, &mc_devices) {
 		mci = list_entry(item, struct mem_ctl_info, link);
 

index 28058ae..eaec8d7 100644
@@ -152,13 +152,11 @@ static void set_timeout(unsigned long time)
 {
 	unsigned long delay;
 
-	cancel_delayed_work(&work);
-
 	delay = time - jiffies;
 	if ((long)delay <= 0)
 		delay = 1;
 
-	queue_delayed_work(addr_wq, &work, delay);
+	mod_delayed_work(addr_wq, &work, delay);
 }
 
 static void queue_req(struct addr_req *req)

index d42c9f4..9e0895b 100644
@@ -2679,11 +2679,9 @@ static void nes_process_mac_intr(struct nes_device *nesdev, u32 mac_number)
 			}
 		}
 		if (nesadapter->phy_type[mac_index] == NES_PHY_TYPE_SFP_D) {
-			if (nesdev->link_recheck)
-				cancel_delayed_work(&nesdev->work);
 			nesdev->link_recheck = 1;
-			schedule_delayed_work(&nesdev->work,
-					      NES_LINK_RECHECK_DELAY);
+			mod_delayed_work(system_wq, &nesdev->work,
+					 NES_LINK_RECHECK_DELAY);
 		}
 	}
 

index f3a3ecf..e43f6e4 100644
@@ -243,10 +243,9 @@ static int nes_netdev_open(struct net_device *netdev)
 
 	spin_lock_irqsave(&nesdev->nesadapter->phy_lock, flags);
 	if (nesdev->nesadapter->phy_type[nesdev->mac_index] == NES_PHY_TYPE_SFP_D) {
-		if (nesdev->link_recheck)
-			cancel_delayed_work(&nesdev->work);
 		nesdev->link_recheck = 1;
-		schedule_delayed_work(&nesdev->work, NES_LINK_RECHECK_DELAY);
+		mod_delayed_work(system_wq, &nesdev->work,
+				 NES_LINK_RECHECK_DELAY);
 	}
 	spin_unlock_irqrestore(&nesdev->nesadapter->phy_lock, flags);
 

index 95aa8e1..8a34202 100644
@@ -2180,8 +2180,7 @@ static void isr_indicate_rf_kill(struct ipw2100_priv *priv, u32 status)
 
 	/* Make sure the RF Kill check timer is running */
 	priv->stop_rf_kill = 0;
-	cancel_delayed_work(&priv->rf_kill);
-	schedule_delayed_work(&priv->rf_kill, round_jiffies_relative(HZ));
+	mod_delayed_work(system_wq, &priv->rf_kill, round_jiffies_relative(HZ));
 }
 
 static void send_scan_event(void *data)

@@ -4321,9 +4320,8 @@ static int ipw_radio_kill_sw(struct ipw2100_priv *priv, int disable_radio)
 					  "disabled by HW switch\n");
 			/* Make sure the RF_KILL check timer is running */
 			priv->stop_rf_kill = 0;
-			cancel_delayed_work(&priv->rf_kill);
-			schedule_delayed_work(&priv->rf_kill,
-					      round_jiffies_relative(HZ));
+			mod_delayed_work(system_wq, &priv->rf_kill,
+					 round_jiffies_relative(HZ));
 		} else
 			schedule_reset(priv);
 	}

index af83c43..ef2b171 100644
@@ -1164,8 +1164,7 @@ void zd_usb_reset_rx_idle_timer(struct zd_usb *usb)
 {
 	struct zd_usb_rx *rx = &usb->rx;
 
-	cancel_delayed_work(&rx->idle_work);
-	queue_delayed_work(zd_workqueue, &rx->idle_work, ZD_RX_IDLE_INTERVAL);
+	mod_delayed_work(zd_workqueue, &rx->idle_work, ZD_RX_IDLE_INTERVAL);
 }
 
 static inline void init_usb_interrupt(struct zd_usb *usb)

index d5fd4a1..00d32a7 100644
@@ -7683,25 +7683,15 @@ static int fan_set_speed(int speed)
 
 static void fan_watchdog_reset(void)
 {
-	static int fan_watchdog_active;
-
 	if (fan_control_access_mode == TPACPI_FAN_WR_NONE)
 		return;
 
-	if (fan_watchdog_active)
-		cancel_delayed_work(&fan_watchdog_task);
-
 	if (fan_watchdog_maxinterval > 0 &&
-	    tpacpi_lifecycle != TPACPI_LIFE_EXITING) {
-		fan_watchdog_active = 1;
-		if (!queue_delayed_work(tpacpi_wq, &fan_watchdog_task,
-				msecs_to_jiffies(fan_watchdog_maxinterval
-						 * 1000))) {
-			pr_err("failed to queue the fan watchdog, "
-			       "watchdog will not trigger\n");
-		}
-	} else
-		fan_watchdog_active = 0;
+	    tpacpi_lifecycle != TPACPI_LIFE_EXITING)
+		mod_delayed_work(tpacpi_wq, &fan_watchdog_task,
+			msecs_to_jiffies(fan_watchdog_maxinterval * 1000));
+	else
+		cancel_delayed_work(&fan_watchdog_task);
 }
 
 static void fan_watchdog_fire(struct work_struct *ignored)

index 86935ec..0db0444 100644
@@ -512,9 +512,8 @@ static void _setup_polling(struct work_struct *work)
 	if (!delayed_work_pending(&cm_monitor_work) ||
 	    (delayed_work_pending(&cm_monitor_work) &&
 	     time_after(next_polling, _next_polling))) {
-		cancel_delayed_work_sync(&cm_monitor_work);
 		next_polling = jiffies + polling_jiffy;
-		queue_delayed_work(cm_wq, &cm_monitor_work, polling_jiffy);
+		mod_delayed_work(cm_wq, &cm_monitor_work, polling_jiffy);
 	}
 
 out:

@@ -549,10 +548,8 @@ static void fullbatt_handler(struct charger_manager *cm)
 	if (cm_suspended)
 		device_set_wakeup_capable(cm->dev, true);
 
-	if (delayed_work_pending(&cm->fullbatt_vchk_work))
-		cancel_delayed_work(&cm->fullbatt_vchk_work);
-	queue_delayed_work(cm_wq, &cm->fullbatt_vchk_work,
-			   msecs_to_jiffies(desc->fullbatt_vchkdrop_ms));
+	mod_delayed_work(cm_wq, &cm->fullbatt_vchk_work,
+			 msecs_to_jiffies(desc->fullbatt_vchkdrop_ms));
 	cm->fullbatt_vchk_jiffies_at = jiffies + msecs_to_jiffies(
 				       desc->fullbatt_vchkdrop_ms);
 

index 076e211..704e652 100644
@@ -355,8 +355,7 @@ static void ds2760_battery_external_power_changed(struct power_supply *psy)
 
 	dev_dbg(di->dev, "%s\n", __func__);
 
-	cancel_delayed_work(&di->monitor_work);
-	queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
+	mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
 }
 
 

@@ -401,8 +400,7 @@ static void ds2760_battery_set_charged(struct power_supply *psy)
 
 	/* postpone the actual work by 20 secs. This is for debouncing GPIO
 	 * signals and to let the current value settle. See AN4188. */
-	cancel_delayed_work(&di->set_charged_work);
-	queue_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
+	mod_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
 }
 
 static int ds2760_battery_get_property(struct power_supply *psy,

@@ -616,8 +614,7 @@ static int ds2760_battery_resume(struct platform_device *pdev)
 	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
 	power_supply_changed(&di->bat);
 
-	cancel_delayed_work(&di->monitor_work);
-	queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
+	mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
 
 	return 0;
 }

index 8dbc7bf..ffbed5e 100644
@@ -173,16 +173,14 @@ static void jz_battery_external_power_changed(struct power_supply *psy)
 {
 	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
 
-	cancel_delayed_work(&jz_battery->work);
-	schedule_delayed_work(&jz_battery->work, 0);
+	mod_delayed_work(system_wq, &jz_battery->work, 0);
 }
 
 static irqreturn_t jz_battery_charge_irq(int irq, void *data)
 {
 	struct jz_battery *jz_battery = data;
 
-	cancel_delayed_work(&jz_battery->work);
-	schedule_delayed_work(&jz_battery->work, 0);
+	mod_delayed_work(system_wq, &jz_battery->work, 0);
 
 	return IRQ_HANDLED;
 }

index 2d7a9fe..a937838 100644
@@ -694,17 +694,14 @@ thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz)
 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
 					    int delay)
 {
-	cancel_delayed_work(&(tz->poll_queue));
-
-	if (!delay)
-		return;
-
 	if (delay > 1000)
-		queue_delayed_work(system_freezable_wq, &(tz->poll_queue),
-				      round_jiffies(msecs_to_jiffies(delay)));
+		mod_delayed_work(system_freezable_wq, &tz->poll_queue,
+				 round_jiffies(msecs_to_jiffies(delay)));
+	else if (delay)
+		mod_delayed_work(system_freezable_wq, &tz->poll_queue,
+				 msecs_to_jiffies(delay));
 	else
-		queue_delayed_work(system_freezable_wq, &(tz->poll_queue),
-				      msecs_to_jiffies(delay));
+		cancel_delayed_work(&tz->poll_queue);
 }
 
 static void thermal_zone_device_passive(struct thermal_zone_device *tz,

index 587ef51..7ef637d 100644
@@ -351,9 +351,7 @@ void afs_dispatch_give_up_callbacks(struct work_struct *work)
  */
 void afs_flush_callback_breaks(struct afs_server *server)
 {
-	cancel_delayed_work(&server->cb_break_work);
-	queue_delayed_work(afs_callback_update_worker,
-			   &server->cb_break_work, 0);
+	mod_delayed_work(afs_callback_update_worker, &server->cb_break_work, 0);
 }
 
 #if 0

index d59b751..f342acf 100644
@@ -285,12 +285,7 @@ static void afs_reap_server(struct work_struct *work)
 		expiry = server->time_of_death + afs_server_timeout;
 		if (expiry > now) {
 			delay = (expiry - now) * HZ;
-			if (!queue_delayed_work(afs_wq, &afs_server_reaper,
-						delay)) {
-				cancel_delayed_work(&afs_server_reaper);
-				queue_delayed_work(afs_wq, &afs_server_reaper,
-						   delay);
-			}
+			mod_delayed_work(afs_wq, &afs_server_reaper, delay);
 			break;
 		}
 

@@ -323,6 +318,5 @@ static void afs_reap_server(struct work_struct *work)
 void __exit afs_purge_servers(void)
 {
 	afs_server_timeout = 0;
-	cancel_delayed_work(&afs_server_reaper);
-	queue_delayed_work(afs_wq, &afs_server_reaper, 0);
+	mod_delayed_work(afs_wq, &afs_server_reaper, 0);
 }

index 431984d..57bcb15 100644
@@ -561,12 +561,7 @@ static void afs_vlocation_reaper(struct work_struct *work)
 		if (expiry > now) {
 			delay = (expiry - now) * HZ;
 			_debug("delay %lu", delay);
-			if (!queue_delayed_work(afs_wq, &afs_vlocation_reap,
-						delay)) {
-				cancel_delayed_work(&afs_vlocation_reap);
-				queue_delayed_work(afs_wq, &afs_vlocation_reap,
-						   delay);
-			}
+			mod_delayed_work(afs_wq, &afs_vlocation_reap, delay);
 			break;
 		}
 

@@ -614,13 +609,10 @@ void afs_vlocation_purge(void)
 	spin_lock(&afs_vlocation_updates_lock);
 	list_del_init(&afs_vlocation_updates);
 	spin_unlock(&afs_vlocation_updates_lock);
-	cancel_delayed_work(&afs_vlocation_update);
-	queue_delayed_work(afs_vlocation_update_worker,
-			   &afs_vlocation_update, 0);
+	mod_delayed_work(afs_vlocation_update_worker, &afs_vlocation_update, 0);
 	destroy_workqueue(afs_vlocation_update_worker);
 
-	cancel_delayed_work(&afs_vlocation_reap);
-	queue_delayed_work(afs_wq, &afs_vlocation_reap, 0);
+	mod_delayed_work(afs_wq, &afs_vlocation_reap, 0);
 }
 
 /*

index 6930bec..1720d32 100644
@@ -117,8 +117,7 @@ nfs4_schedule_state_renewal(struct nfs_client *clp)
 		timeout = 5 * HZ;
 	dprintk("%s: requeueing work. Lease period = %ld\n",
 			__func__, (timeout + HZ - 1) / HZ);
-	cancel_delayed_work(&clp->cl_renewd);
-	schedule_delayed_work(&clp->cl_renewd, timeout);
+	mod_delayed_work(system_wq, &clp->cl_renewd, timeout);
 	set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
 	spin_unlock(&clp->cl_lock);
 }

index 069d51d..ed5a0b4 100644
@@ -214,8 +214,8 @@ void __dst_free(struct dst_entry *dst)
 	if (dst_garbage.timer_inc > DST_GC_INC) {
 		dst_garbage.timer_inc = DST_GC_INC;
 		dst_garbage.timer_expires = DST_GC_MIN;
-		cancel_delayed_work(&dst_gc_work);
-		schedule_delayed_work(&dst_gc_work, dst_garbage.timer_expires);
+		mod_delayed_work(system_wq, &dst_gc_work,
+				 dst_garbage.timer_expires);
 	}
 	spin_unlock_bh(&dst_garbage.lock);
 }

index 24c55c5..c9d931e 100644
@@ -164,8 +164,7 @@ static void rfkill_schedule_global_op(enum rfkill_sched_op op)
 	rfkill_op_pending = true;
 	if (op == RFKILL_GLOBAL_OP_EPO && !rfkill_is_epo_lock_active()) {
 		/* bypass the limiter for EPO */
-		cancel_delayed_work(&rfkill_op_work);
-		schedule_delayed_work(&rfkill_op_work, 0);
+		mod_delayed_work(system_wq, &rfkill_op_work, 0);
 		rfkill_last_scheduled = jiffies;
 	} else
 		rfkill_schedule_ratelimited();

index 43f6c17..7befb9c 100644
@@ -262,7 +262,7 @@ EXPORT_SYMBOL(blk_start_queue);
  **/
 void blk_stop_queue(struct request_queue *q)
 {
-	__cancel_delayed_work(&q->delay_work);
+	cancel_delayed_work(&q->delay_work);
 	queue_flag_set(QUEUE_FLAG_STOPPED, q);
 }
 EXPORT_SYMBOL(blk_stop_queue);

index aebd1e8..0e1e364 100644
@@ -889,7 +889,7 @@ static void unlock_fdc(void)
 
 	raw_cmd = NULL;
 	command_status = FD_COMMAND_NONE;
-	__cancel_delayed_work(&fd_timeout);
+	cancel_delayed_work(&fd_timeout);
 	do_floppy = NULL;
 	cont = NULL;
 	clear_bit(0, &fdc_busy);

index b593814..dc3fd1e 100644
@@ -2004,7 +2004,7 @@ static void adjust_timeout(struct ib_mad_agent_private *mad_agent_priv)
 	unsigned long delay;
 
 	if (list_empty(&mad_agent_priv->wait_list)) {
-		__cancel_delayed_work(&mad_agent_priv->timed_work);
+		cancel_delayed_work(&mad_agent_priv->timed_work);
 	} else {
 		mad_send_wr = list_entry(mad_agent_priv->wait_list.next,
 					 struct ib_mad_send_wr_private,

index 14ce8cc..7869767 100644
@@ -4307,7 +4307,7 @@ static void dsi_framedone_irq_callback(void *data, u32 mask)
 	 * and is sending the data.
 	 */
 
-	__cancel_delayed_work(&dsi->framedone_timeout_work);
+	cancel_delayed_work(&dsi->framedone_timeout_work);
 
 	dsi_handle_framedone(dsidev, 0);
 }

index 2000030..feed2bb 100644
@@ -445,7 +445,7 @@ static inline bool cancel_delayed_work(struct delayed_work *work)
  * if it returns 0 the timer function may be running and the queueing is in
  * progress.
  */
-static inline bool __cancel_delayed_work(struct delayed_work *work)
+static inline bool __deprecated __cancel_delayed_work(struct delayed_work *work)
 {
 	bool ret;