Re: [PATCH 5/5] ioeventfd: Introduce KVM_IOEVENTFD_FLAG_SOCKET

[Pekka Enberg <penberg@kernel.org>]

On 07/13/2011 04:00 PM, Pekka Enberg wrote:
>> On Wed, Jul 13, 2011 at 3:57 PM, Avi Kivity<avi@redhat.com>  wrote:
>> >>  We'd like to keep 8250 emulation because it's the most robust method
>> >>  for getting data out of the kernel when there's problems. It's also
>> >>  compatible with earlyprintk and such.
>> >
>> >  What do you hope to gain from the optimization? 100ms less boot time?
>>
>> Hmm? I use serial console for logging into the guest and actually
>> using it all the time.

On 7/13/11 4:32 PM, Avi Kivity wrote:
> Just how fast do you type?
>
> It's not enough to make something faster, it has to be slow to being 
> with.  The interface is good, but use it where it helps.

I don't know why you bring up serial console input here. Sasha's
original KVM_IOEVENTFD_FLAG_PIPE patch clearly stated:

   A simple example for practical use is the serial port. we are not
   interested in an exit every time a char is written to the port, but
   we do need to know what was written so we could handle it on the
   guest.

So it's talking about the serial console output, not input.

                             Pekka