Re: [patch] Real-Time Preemption, -RT-2.6.9-rc4-mm1-U6

[Ingo Molnar]

* Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:

> On Tue, 2004-10-19 at 16:46, Ingo Molnar wrote:
> > * Ingo Molnar <mingo@xxxxxxx> wrote:
> > i've re-released the patch because shortly after releasing it i found a
> > false-positive in the deadlock-detector that was triggering in oowriter. 
> 
> Hit and converted another one. There are more, but they need more
> modifications as they don't have a condition to wait for and therefor
> must be converted to use the completion API, which must be extended to
> provide completion_timemout() first.

thanks, i've applied your patch to my tree. Find below an untested
implementation of wait_for_completion_timeout().

	Ingo

--- linux/kernel/sched.c.orig
+++ linux/kernel/sched.c
@@ -3070,6 +3148,31 @@ void fastcall __sched wait_for_completio
 }
 EXPORT_SYMBOL(wait_for_completion);
 
+unsigned long fastcall __sched
+wait_for_completion_timeout(struct completion *x, unsigned long timeout)
+{
+	might_sleep();
+	spin_lock_irq(&x->wait.lock);
+	if (!x->done) {
+		DECLARE_WAITQUEUE(wait, current);
+
+		wait.flags |= WQ_FLAG_EXCLUSIVE;
+		__add_wait_queue_tail(&x->wait, &wait);
+		do {
+			__set_current_state(TASK_UNINTERRUPTIBLE);
+			spin_unlock_irq(&x->wait.lock);
+			timeout = schedule_timeout(timeout);
+			spin_lock_irq(&x->wait.lock);
+		} while (!x->done);
+		__remove_wait_queue(&x->wait, &wait);
+	}
+	x->done--;
+	spin_unlock_irq(&x->wait.lock);
+
+	return timeout;
+}
+EXPORT_SYMBOL(wait_for_completion_timeout);
+
 #define	SLEEP_ON_VAR					\
 	unsigned long flags;				\
 	wait_queue_t wait;				\
--- linux/include/linux/completion.h.orig
+++ linux/include/linux/completion.h
@@ -28,6 +28,8 @@ static inline void init_completion(struc
 }
 
 extern void FASTCALL(wait_for_completion(struct completion *));
+extern unsigned long FASTCALL(wait_for_completion_timeout(struct completion *,
+							  unsigned long));
 extern void FASTCALL(complete(struct completion *));
 extern void FASTCALL(complete_all(struct completion *));
 
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