Re: [PATCH UPDATED 1/3] vhost: replace vhost_workqueue with per-vhost kthread

Tejun Heo
2010-07-28T07:48:31Z

On 07/27/2010 09:19 PM, Michael S. Tsirkin wrote:
>> Thinking a bit more about it, it kind of sucks that queueing to
>> another worker from worker->func() breaks flush. Maybe the right
>> thing to do there is using atomic_t for done_seq?
>
> I don't believe it will help: we might have:
>
> worker1 runs work
> work requeues itself queued index = 1
> worker1 reads queued index = 1
> worker2 runs work
> work requeues itself queued index = 2
> worker2 runs work
> worker2 reads queued index = 2
> worker2 writes done index = 2
> worker1 writes done index = 1
>
> As you see, done index got moved back.

Yeah, I think the flushing logic should be moved to the worker. Are
you interested in doing it w/ your change?

Thanks.

--
tejun