[PATCH] wait: document timeout corner case

From: Scot Doyle
Date: Sun Aug 24 2014 - 13:15:27 EST


The timeout may elapse without 0 being returned, such as when waiting
on an unused queue. Document this possibility.

Signed-off-by: Scot Doyle <lkml14@xxxxxxxxxxxxx>
---
include/linux/wait.h | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/include/linux/wait.h b/include/linux/wait.h
index 6fb1ba5..034f6fc 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -280,9 +280,11 @@ do { \
* wake_up() has to be called after changing any variable that could
* change the result of the wait condition.
*
- * The function returns 0 if the @timeout elapsed, or the remaining
- * jiffies (at least 1) if the @condition evaluated to %true before
- * the @timeout elapsed.
+ * Returns:
+ * 0 if the @condition evaluated to %false after the @timeout elapsed,
+ * 1 if the @condition evaluated to %true after the @timeout elapsed,
+ * or the remaining jiffies (at least 1) if the @condition evaluated
+ * to %true before the @timeout elapsed.
*/
#define wait_event_timeout(wq, condition, timeout) \
({ \
@@ -363,9 +365,11 @@ do { \
* change the result of the wait condition.
*
* Returns:
- * 0 if the @timeout elapsed, -%ERESTARTSYS if it was interrupted by
- * a signal, or the remaining jiffies (at least 1) if the @condition
- * evaluated to %true before the @timeout elapsed.
+ * 0 if the @condition evaluated to %false after the @timeout elapsed,
+ * 1 if the @condition evaluated to %true after the @timeout elapsed,
+ * the remaining jiffies (at least 1) if the @condition evaluated
+ * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
+ * interrupted by a signal.
*/
#define wait_event_interruptible_timeout(wq, condition, timeout) \
({ \
--
2.0.4

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