[Spice-devel] XSpice status report / todo list

[Jeremy White]

>> </heresy>
> Well, spice has some bad corner cases. Actually it lack a continuous
> bandwidth analysis and there are some implementation of the protocol
> that make latency affect badly on some conditions.
> Just an example of extreme case think about if interface was designed
> pixel by pixel it could happen that each pixel is transformed into a 1x1
> image drawing (there is no "PutPixel" call on the protocol).
> spice should try better to balance CPU usage and bandwidth also
> considering that a lot of small drawing tend to cost quite lot of CPU too.
> Well... this adaptive protocol would solve lot of problems possibly
> making a full DFPS useless.

Yes, the case that triggered DFPS was in fact a pixel by pixel draw 
operation.


>> Another todo is profiling; XSpice cpu usage, particularly for the spice
>> server, is substantially higher than that of vnc.  I'm hoping that as we
>> refactor some of the red_*, it may be possible to carve out simpler code
>> paths for XSpice (or at least to profile and understand the pain).
> Do you have some profiling data?

I don't have anything formal I've captured lately.  Here is the thread I 
originally reported:
   http://lists.freedesktop.org/archives/spice-devel/2012-August/010276.html

I've tweaked the tools I list there slightly, but the bones of them 
remain unchanged.  I spent a lot of time trying to create a tool to 
measure 'user experience' but did not finish it.  (My approach was to 
take a screen cap of the X frame buffer - so 'perfect' fidelity and 
compare it to a screen cap of the Spice window - e.g. 'experienced' 
fidelity - and then use image analysis to decide how far off we were. 
It proves to be Hard(TM)).

I can't find the thread where I reported the CPU usage, but Spice is 
visibly worse than VNC on that front.

> Never worked with Wayland. But probably 3D would be even more fun. But
> looks like a much bigger project. For now let's focus on making Xspice
> driver into a better shape!

Woohoo!

Cheers,

Jeremy