[Spice-devel] hardcoded NUM_DRAWABLES too small

[Marc-André Lureau]

----- Original Message -----
> > > I just detected that my simple spiceterm generates more than
> > >
> > > 1000 drawables, so alloc_drawable() always fail.
> > >
> > >
> > >
> > > The effect is that I always draw twice (on server and at client)!
> > 
> > This is an area I am newbie ;)
> > 
> > Isn't the server always drawing anyway at some point?
> 
> No. There is no need to draw anything at the server side (for spiceterm).

Ok, that would be interesting. I wonder if you are not better off implementing a new display channel for your use case, if you just need to send off your own rendering commands without any change.

> > Isnt't the 1000 drawables limit just slowing down the caller (guest/vm
> > side), to
> > leave time for clients to process all drawables in the pipes.
> 
> no, it leads to additional draw commands on the server side. So this is a
> waste
> of computing power.
> 
> > What alternative do you propose?
> 
> NUM_DRAWABLES=3000

Explain 3000? What if tomorrow you need a bigger terminal? We will need to change it again.

> but I guess that can have a negative performance impact elsewhere?

Mostly on memory consumption, but also probably on some other area, like latency or cpu usage.

> > > I guess one would see the same effect when running a xterm inside a
> > > VM, because
> > >
> > > a terminal has a size of 80x25 characters, which gives 2000 different
> > > regions.
> > >
> > >
> > >
> > > What is the suggested way to avoid such things?
> > 
> > I'll let someone else reply suggestion, as I don't know myself.
> > 
> > > Also, I don’t think I need the rendered content on the server side for
> > > spiceterm (why?).
> > 
> > > So is it possible to disable server side rendering at all?
> > 
> > If you don't have client connected or for reconnection, you still want
> > complete
> > rendering ready, no?
> 
> No, I do not really need that. spiceterm only allows a single connection.

Ok, but even for the first connection, you want to be shown with the current content, don't you?