[Spice-devel] Delay in Gimp when using qxl driver

[Alon Levy]

On Wed, Jan 18, 2012 at 10:26:44AM -0500, John A. Sullivan III wrote:
> On Wed, 2012-01-18 at 10:44 +0200, Alon Levy wrote:
> > On Wed, Jan 18, 2012 at 08:06:40AM +0100, Dominique Rodrigues wrote:
> > > Hi,
> > > 
> > > Since I use qxl driver in virtual desktop powered by qemu-kvm, I
> > > found a strange problem with Gimp.
> > > 
> > > After launching Gimp, open a new windows, and then try to draw
> > > something. It appears that the drawing is very slow and does not
> > > follow the mouse at all.
> > > 
> > > It is the same if I use spicy, spicec or vnc to connect to my
> > > virtual desktop.
> > > 
> > > This problem does not appear with cirrus or vmware graphic drivers.
> > > 
> > > I found that on any Linux distribution (CentOS, RHEL, Scientific
> > > Linux, Debian, Ubuntu).
> > > 
> > > I currently use :
> > > - qemu-kvm 1.0 compiled with spice support
> > > - spice-protocol 0.10.1
> > > - spice 0.10
> > > - spice-gtk 0.7
> > > - xorg-qxl driver 0.16
> > > 
> > > Is there any explanation for that ?
> > 
> > I would assume it is qxl driver cpu bound on something, probably busy
> > waiting on the command ring. Can you run perf top on the guest?
> <snip>
> I believe I had reported a similar issue many months go where just about
> any X activity drove our Fedora based CPU through the roof though
> Windows was fine.  At the time, I thought you mentioned it was a driver
> issue - John

I've been recently working on the X driver, that's why I responded
quickly. When we spoke then I wasn't.

>