[Spice-devel] keypress-delay issue

[Jared Kwek]

On Tue, Jun 23, 2015 at 4:14 PM, Marc-André Lureau <mlureau at redhat.com> wrote:
>
>
> It's interesting that I can barely notice the lag, and possibly most
> people, judging by the amount of people complaining.

While true that the lag is barely noticeable, the fact is that it is
there and more noticeable to some people than others.

>
>
> This was introduced to solve a real problem though, to avoid spurious
> software key repeat on guest side. This is particularly annoying with
> remote guest with a lag of several 100's of ms, but could also happen
> locally if the VM get stuck due to scheduling.
>

I also understand the problem you were trying to solve, as it is a
common issue in remote desktop situations.  But instead of a
one-size-fits-all solution, I'm advocating for a configurable value
since different values make sense in different situations.  If my
desktop is on a VM on my local machine, it would be a better user
experience for me to turn down compression, keypress delays, etc.
rather than use the same settings as if my desktop were streaming
across a slow network connection.

>
> I am not sure more tweaking should be advertised, as this is fairly
> obscure and could reopen the issue I was trying to solve. Instead I
> wish we would have a better/more clever solution to this issue.
> Unfortunately, I don't have good one, adjusting the latency
> based on local vs remote "measurements" would still let spurious
> key repeats on slow scheduling, is this a better tradeoff?


I don't think adjusting the latency based on measurements would be a
good alternative unless it could be done with confidence in those
measurements.  I think an easier method would be to set the
keypress-delay to a sane value by default and allow it as a
configuration item in case a person wants to tweak it.  Similar to how
compression works now with the SPICE protocol...most people don't
change the defaults but those that want to have the option to do so.

With the risk of generalizing too much, I value the fact that most
open source software packages are more configurable than their
commercial counterparts.  Having more options to tweak if I desire
allows me to tailor the software to my specific use case.

Thanks for considering my suggestions.

Regards,
Jared Kwek