Re: [RFC][PATCH] irq_work

Huang Ying
2010-06-24T07:27:36Z

On Thu, 2010-06-24 at 15:19 +0800, Peter Zijlstra wrote:
> On Thu, 2010-06-24 at 15:04 +0800, Huang Ying wrote:
>
> > Yes. NMI is there from 8259 age.
>
> But do we really care about such systems?
>
> > That is possible. But in NO_HZ system, we have no tick to rely on.
>
> Of course you have, you can delay the NO_HZ state when there's pending
> callbacks, that's all of 1 line.
>
> > soft_irq is better here, because it will be triggered for any interrupt.
>
> Well, you can do the callbacks from irq_exit() as well, that's no
> problem.

I think it is not a good idea to add overhead in such a hot path if the
overhead can be avoided.

Best Regards,
Huang Ying