aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--include/linux/completion.h46
-rw-r--r--kernel/sched.c46
2 files changed, 48 insertions, 44 deletions
diff --git a/include/linux/completion.h b/include/linux/completion.h
index 57faa60de9bd..02ef8835999c 100644
--- a/include/linux/completion.h
+++ b/include/linux/completion.h
@@ -49,6 +49,8 @@ extern unsigned long wait_for_completion_timeout(struct completion *x,
49 unsigned long timeout); 49 unsigned long timeout);
50extern unsigned long wait_for_completion_interruptible_timeout( 50extern unsigned long wait_for_completion_interruptible_timeout(
51 struct completion *x, unsigned long timeout); 51 struct completion *x, unsigned long timeout);
52extern bool try_wait_for_completion(struct completion *x);
53extern bool completion_done(struct completion *x);
52 54
53extern void complete(struct completion *); 55extern void complete(struct completion *);
54extern void complete_all(struct completion *); 56extern void complete_all(struct completion *);
@@ -56,48 +58,4 @@ extern void complete_all(struct completion *);
56#define INIT_COMPLETION(x) ((x).done = 0) 58#define INIT_COMPLETION(x) ((x).done = 0)
57 59
58 60
59/**
60 * try_wait_for_completion - try to decrement a completion without blocking
61 * @x: completion structure
62 *
63 * Returns: 0 if a decrement cannot be done without blocking
64 * 1 if a decrement succeeded.
65 *
66 * If a completion is being used as a counting completion,
67 * attempt to decrement the counter without blocking. This
68 * enables us to avoid waiting if the resource the completion
69 * is protecting is not available.
70 */
71static inline bool try_wait_for_completion(struct completion *x)
72{
73 int ret = 1;
74
75 spin_lock_irq(&x->wait.lock);
76 if (!x->done)
77 ret = 0;
78 else
79 x->done--;
80 spin_unlock_irq(&x->wait.lock);
81 return ret;
82}
83
84/**
85 * completion_done - Test to see if a completion has any waiters
86 * @x: completion structure
87 *
88 * Returns: 0 if there are waiters (wait_for_completion() in progress)
89 * 1 if there are no waiters.
90 *
91 */
92static inline bool completion_done(struct completion *x)
93{
94 int ret = 1;
95
96 spin_lock_irq(&x->wait.lock);
97 if (!x->done)
98 ret = 0;
99 spin_unlock_irq(&x->wait.lock);
100 return ret;
101}
102
103#endif 61#endif
diff --git a/kernel/sched.c b/kernel/sched.c
index d601fb0406ca..95e6ad3c231d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4669,6 +4669,52 @@ int __sched wait_for_completion_killable(struct completion *x)
4669} 4669}
4670EXPORT_SYMBOL(wait_for_completion_killable); 4670EXPORT_SYMBOL(wait_for_completion_killable);
4671 4671
4672/**
4673 * try_wait_for_completion - try to decrement a completion without blocking
4674 * @x: completion structure
4675 *
4676 * Returns: 0 if a decrement cannot be done without blocking
4677 * 1 if a decrement succeeded.
4678 *
4679 * If a completion is being used as a counting completion,
4680 * attempt to decrement the counter without blocking. This
4681 * enables us to avoid waiting if the resource the completion
4682 * is protecting is not available.
4683 */
4684bool try_wait_for_completion(struct completion *x)
4685{
4686 int ret = 1;
4687
4688 spin_lock_irq(&x->wait.lock);
4689 if (!x->done)
4690 ret = 0;
4691 else
4692 x->done--;
4693 spin_unlock_irq(&x->wait.lock);
4694 return ret;
4695}
4696EXPORT_SYMBOL(try_wait_for_completion);
4697
4698/**
4699 * completion_done - Test to see if a completion has any waiters
4700 * @x: completion structure
4701 *
4702 * Returns: 0 if there are waiters (wait_for_completion() in progress)
4703 * 1 if there are no waiters.
4704 *
4705 */
4706bool completion_done(struct completion *x)
4707{
4708 int ret = 1;
4709
4710 spin_lock_irq(&x->wait.lock);
4711 if (!x->done)
4712 ret = 0;
4713 spin_unlock_irq(&x->wait.lock);
4714 return ret;
4715}
4716EXPORT_SYMBOL(completion_done);
4717
4672static long __sched 4718static long __sched
4673sleep_on_common(wait_queue_head_t *q, int state, long timeout) 4719sleep_on_common(wait_queue_head_t *q, int state, long timeout)
4674{ 4720{