I'd like to use a version of wait_event_killable() with a timeout, but it seems
to be missing? I found a mention of it in a recent LKML message though:
https://lkml.org/lkml/2015/10/14/337
Does this patch look reasonable?
diff --git a/include/linux/wait.h b/include/linux/wait.h
index 1e1bf9f..8419986 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -738,6 +738,41 @@ do {
\
__ret; \
})
+#define __wait_event_killable_timeout(wq, condition, timeout) \
+ ___wait_event(wq, ___wait_cond_timeout(condition), \
+ TASK_KILLABLE, 0, timeout, \
+ __ret = schedule_timeout(__ret))
+
+/**
+ * wait_event_killable_timeout - sleep until a condition gets true or a
timeout elapses
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ * @timeout: timeout, in jiffies
+ *
+ * The process is put to sleep (TASK_KILLABLE) until the @condition
+ * evaluates to true or a signal is received.
+ * The @condition is checked each time the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ *
+ * Returns:
+ * 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_killable_timeout(wq, condition, timeout) \
+({ \
+ long __ret = timeout; \
+ might_sleep(); \
+ if (!___wait_cond_timeout(condition)) \
+ __ret = __wait_event_killable_timeout(wq, \
+ condition, timeout); \
+ __ret; \
+})
+
#define __wait_event_lock_irq(wq, condition, lock, cmd)
\
(void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
--
Jens Kilian
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