Re: [PATCH 00/10] PV-IO v3

Avi Kivity
2007-08-21T17:12:38Z

Gregory Haskins wrote:
> On Tue, 2007-08-21 at 10:06 -0400, Gregory Haskins wrote:
>
>> On Tue, 2007-08-21 at 23:47 +1000, Rusty Russell wrote:
>>
>>> In the guest -> host direction, an interface like virtio is designed
>>> for batching, with the explicit distinction between add_buf & sync.
>>>
>> Right. IOQ has "iter_push()" and "signal()" as synonymous operations.
>>
>
> Hi Rusty,
> This reminded me of an area that I thought might have been missing in
> virtio compared to IOQ. That is, flexibility in the io-completion via
> the distinction between "signal" and "sync". sync() implies that its a
> blocking call based on the full drain of the queue, correct?

No, sync() means "make the other side aware that there's work to be done".

--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.