Re: [PATCH 13/32] wait: Add wait_event_hrtimeout()

From: Andrew Morton
Date: Thu Jan 03 2013 - 18:08:17 EST


On Wed, 26 Dec 2012 17:59:51 -0800
Kent Overstreet <koverstreet@xxxxxxxxxx> wrote:

> Analagous to wait_event_timeout() and friends, this adds
> wait_event_hrtimeout() and wait_event_interruptible_hrtimeout().
>
> Note that unlike the versions that use regular timers, these don't
> return the amount of time remaining when they return - instead, they
> return 0 or -ETIME if they timed out.

Why is this?

> +/**
> + * wait_event_hrtimeout - 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_UNINTERRUPTIBLE) 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.
> + *
> + * The function returns 0 if @condition became true, or -ETIME if the timeout
> + * elapsed.
> + */

this, methinks:

--- a/include/linux/wait.h~wait-add-wait_event_hrtimeout-fix
+++ a/include/linux/wait.h
@@ -370,7 +370,7 @@ do { \
* wait_event_hrtimeout - 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
+ * @timeout: timeout, as a ktime_t
*
* The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
* @condition evaluates to true or a signal is received.
@@ -395,7 +395,7 @@ do { \
* wait_event_interruptible_hrtimeout - 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
+ * @timeout: timeout, as a ktime_t
*
* The process is put to sleep (TASK_INTERRUPTIBLE) until the
* @condition evaluates to true or a signal is received.
_

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