Could someone ... anyone take a look at these kernel doc additions?
Thanks!
kevin
On Mon, Aug 18, 2008 at 06:53:51PM -0700, Kevin Diggs wrote:
> Could someone ... anyone take a look at these kernel doc additions?
.....
>
> +/**
> + * complete: - signals a single thread waiting on this completion
> + * @x: holds the state of this particular completion
> + *
> + * This will wake up a single thread waiting on this completion. If
> multiple
Your mailer appears to be wrapping lines.
> + * threads are waiting ???
> + */
> void complete(struct completion *x)
> {
> unsigned long flags;
complete() will only wake one waiting thread. If there are multiple
waiters, then further calls to complete() are required to wake them,
or a single call to complete_all() could be used.
> EXPORT_SYMBOL(wait_for_completion);
>
> +/**
> + * wait_for_completion_timeout: - waits for completion of a task
> (w/timeout)
> + * @x: holds the state of this particular completion
> + * @timeout: timeout value in jiffies
> + *
> + * This waits to be signaled for completion of a specific task. It is NOT
> + * interruptible. But there is a timeout in jiffies.
Doesn't read very well.
"This waits for either a completion of a specific task to be signalled
or for a defined length of time. It is not interruptible."
> +/**
> + * wait_for_completion_interruptible_timeout: - waits for completion
> (w/(to,int
> r))
> + * @x: holds the state of this particular completion
> + * @timeout: timeout value in jiffies
> + *
> + * This waits to be signaled for completion of a specific task. It is
> + * interruptible. And there is a timeout in jiffies.
> + */
Same as for wait_for_completion_timeout().
> +/**
> + * wait_for_completion_killable: - waits for completion of a task
> (killable)
> + * @x: holds the state of this particular completion
> + *
> + * This waits to be signaled for completion of a specific task. It is
> + * killable (???).
> + */
Killable means that a kill signal will interrupt the wait, but not
all signals will. Typically used in places where you want a user
ctrl-c or a kill command to succeed but don't want any other signal
to interrupt the completion.
Cheers,
Dave.
--
Dave Chinner
[email protected]
--- kernel/sched.c.orig 2008-08-13 02:22:42.000000000 -0700
+++ kernel/sched.c 2008-08-19 00:42:41.000000000 -0700
@@ -4363,6 +4363,16 @@
}
EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
+/**
+ * complete: - signals a single thread waiting on this completion
+ * @x: holds the state of this particular completion
+ *
+ * This will wake up a single thread waiting on this completion. If multiple
+ * threads are waiting ??? (looking for comments on which thread/context will
+ * be awakened?)
+ *
+ * See also complete_all().
+ */
void complete(struct completion *x)
{
unsigned long flags;
@@ -4374,6 +4384,12 @@
}
EXPORT_SYMBOL(complete);
+/**
+ * complete_all: - signals all threads waiting on this completion
+ * @x: holds the state of this particular completion
+ *
+ * This will wake up all threads waiting on this particular completion event.
+ */
void complete_all(struct completion *x)
{
unsigned long flags;
@@ -4425,12 +4441,28 @@
return timeout;
}
+/**
+ * wait_for_completion: - waits for completion of a task
+ * @x: holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It is NOT
+ * interruptible and there is no timeout.
+ */
void __sched wait_for_completion(struct completion *x)
{
wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion);
+/**
+ * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
+ * @x: holds the state of this particular completion
+ * @timeout: timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. The timeout is in jiffies. It is not
+ * interruptible.
+ */
unsigned long __sched
wait_for_completion_timeout(struct completion *x, unsigned long timeout)
{
@@ -4438,6 +4470,13 @@
}
EXPORT_SYMBOL(wait_for_completion_timeout);
+/**
+ * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
+ * @x: holds the state of this particular completion
+ *
+ * This waits for completion of a specific task to be signaled. It is
+ * interruptible.
+ */
int __sched wait_for_completion_interruptible(struct completion *x)
{
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
@@ -4447,6 +4486,14 @@
}
EXPORT_SYMBOL(wait_for_completion_interruptible);
+/**
+ * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
+ * @x: holds the state of this particular completion
+ * @timeout: timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. It is interruptible. The timeout is in jiffies.
+ */
unsigned long __sched
wait_for_completion_interruptible_timeout(struct completion *x,
unsigned long timeout)
@@ -4455,6 +4502,13 @@
}
EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
+/**
+ * wait_for_completion_killable: - waits for completion of a task (killable)
+ * @x: holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It can be
+ * interrupted by a kill signal.
+ */
int __sched wait_for_completion_killable(struct completion *x)
{
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
Kevin Diggs wrote:
> Files attached this time ...
Alas several MUAs don't quote attachments in replies. Hence the optimum
would be if you use a MUA which allows to insert text files without
whitespace change.
Also, when you respond on LKML, always use "reply to all" to keep
previous responders in a thread Cc'd. This is necessary due to the high
volume of LKML, and in order to not force people to subscribe to LKML.
> --- include/linux/completion.h.orig 2008-08-13 00:56:52.000000000 -0700
> +++ include/linux/completion.h 2008-08-18 13:00:23.000000000 -0700
> @@ -10,6 +10,16 @@
>
> #include <linux/wait.h>
>
> +/**
> + * struct completion - structure used to maintain state for a "completion"
> + * @done: counting variable used to signal completion
> + * @wait: internal wait queue head; used for locking and synchronization
> + *
> + * This is the structure used to maintain the state for a "completion". See
> + * also: complete(), wait_for_completion() (and friends _timeout,
> + * _interruptible, _interruptible_timeout, and _killable), init_completion(),
> + * and macros DECLARE_COMPLETION() and INIT_COMPLETION().
> + */
> struct completion {
> unsigned int done;
> wait_queue_head_t wait;
.done and .wait are not public AFAIU and should therefore not be
documented as an API.
> @@ -36,6 +46,13 @@
> # define DECLARE_COMPLETION_ONSTACK(work) DECLARE_COMPLETION(work)
> #endif
>
> +/**
> + * init_completion: - Initialize a dynamically allocated completion
> + * @x: completion structure that is to be initialized
> + *
> + * This inline function will initialize a dynamically created completion
> + * structure.
> + */
> static inline void init_completion(struct completion *x)
> {
> x->done = 0;
The last sentence is redundant and should be omitted.
--
Stefan Richter
-=====-==--- =--- =--==
http://arcgraph.de/sr/
On Tue, Aug 19, 2008 at 01:07:35AM -0700, Kevin Diggs wrote:
> Dave Chinner wrote:
>> On Mon, Aug 18, 2008 at 06:53:51PM -0700, Kevin Diggs wrote:
>>> Could someone ... anyone take a look at these kernel doc additions?
>> .....
>>> +/**
>>> + * complete: - signals a single thread waiting on this completion
>>> + * @x: holds the state of this particular completion
>>> + *
>>> + * This will wake up a single thread waiting on this completion. If
>>> multiple
>> Your mailer appears to be wrapping lines.
>>> + * threads are waiting ???
>>> + */
>>> void complete(struct completion *x)
>>> {
>>> unsigned long flags;
>> complete() will only wake one waiting thread. If there are multiple
>> waiters, then further calls to complete() are required to wake them,
>> or a single call to complete_all() could be used.
>>> EXPORT_SYMBOL(wait_for_completion);
>>>
>>> +/**
>
> Take 2 ...
You might want to read Documentation/SubmittingPatches.
(Especially points 2, 7, 11 and 12)
Marcin