RE: [patch 3/9] LTTng instrumentation tasklets

Peter Zijlstra
2009-03-25T14:22:31Z

On Wed, 2009-03-25 at 06:52 -0700, Chetan.Loke@Emulex.Com wrote:
> Quick question. I understand this is unrelated to this patch. So I
> apologize in advance.
> Ingo - you mentioned "tasklets are a legacy mechanism". Is there a
> plan to phase them out ? Let me draw a small picture as to what's
> bothering me.
>
> With the SR-IOV support if there are 'N' virtual functions then there
> will be 'N' driver instances(actually N+1, 1 for the PF). If that
> driver drains the responses in the interrupt context then all such
> VF-instances could virtually block everyone else(because SR-IOV guys
> might also have MSI-X enabled).
> So now all such drivers should alter their Rx path.Driver's can queue
> tasklets and can also get the performance they want.
>
> Any suggestions?

Threaded interrupts?