5.3-RELEASE: WARNING - WRITE_DMA interrupt timout - what does it mean?

[Andrea Campi]

Nitpicking mode on...

On Wed, Nov 10, 2004 at 09:17:39AM +0000, Robert Watson wrote:
> I'm still a bit skeptical that the task queue is at fault -- I run my
> notebook with continuous measurement of the latency to schedule tasks,
> generating a warning for any latency > .5 seconds, and the only time I
[...]

> @@ -187,8 +198,16 @@
>  		pending = task->ta_pending;
>  		task->ta_pending = 0;
>  		task->ta_flags |= TAF_PENDING;
> +		tq_out++;
>  		mtx_unlock(&queue->tq_mutex);
>  
> +		getnanotime(&tv);
> +		timespecsub(&tv, &task->ta_queuetime);
> +		if (tv.tv_nsec >= 0500000000) {

Unless this is a typo while generating the patch for the list, and you
are actually running with correct code, you're measuring latencies
greater than 500M OCTAL, that is about 0.084 sec... Although that
makes you argument even stronger I guess.

Bye,
	Andrea

-- 
      ...and that is how we know the Earth to be banana-shaped.