Re: calling kthread_create() from interrupt thread

[Jeff Garzik <jgarzik@pobox.com>]

Jesse Barnes wrote:
> On Tuesday, June 15, 2004 2:05 pm, Dean Nelson wrote:
> 
>>As mentioned above, it is possible for this "simple" function to
>>sleep/block for an indefinite period of time. I was under the impression
>>that one couldn't block a work queue thread for an indefinite period of
>>time. Am I mistaken?
> 
> 
> For tasklets and softirqs you're not allowed to sleep, but I think it's ok for 
> work queues.


Dean is correct and incorrect ;-)

If you are using schedule_work() or schedule_task(), blocking for 
extended periods of time would be very undesirable.  We see this on 
occasion in 2.6 uniprocessor, where a long-running keventd task may 
block a console or tty update.

In 2.6, the solution is easy... create your own private workqueue.  No 
such solution in 2.4 (though I would argue that workqueues would help 
drivers, if accepted into 2.4 at this late stage).

	Jeff