Weston framerate (Re: bare bones opengl weston client sample)

jegde jedge bubbah.t at gmail.com
Fri Sep 7 17:48:17 PDT 2012

Sorry for the delay, my mail tool didn't link up this thread fro me.

I am running w/ DRM not X11; running weston in an X client was not
adequate for my test app.
I start by obtaining a virtual terminal ;init 3 ; then weston-launch
This way I eliminate any X11 variables.
You can see egl loading the dri driver when it starts up.
If there is a better way please let me know.

I run the the application with glut and weston using the same MESA
stack that I compiled for weston.
So, the only real difference is between glut/simple-egl and gnome(X11)/weston

My CPU usage is:
weston - ~20+ fps - 3%
glut(X11) - 60 fps - 17% - (60 is a hard limit for glut)
tells me there is more to be had.
This application renders  ~100 256x256 rgb textures on a moving map display.

I don't understand the wayland frame listener callback and how the
wl_iterate works to drive redraw in simple-egl.
So, I am hoping I am just using it wrong.

I was hoping to do something similar to glutPostRedisplay() in a mouse
drag event.
This way I can start panning my textured tiles for a good test.

On Fri, Sep 7, 2012 at 2:16 AM, Pekka Paalanen <ppaalanen at gmail.com> wrote:
> On Thu, 6 Sep 2012 11:25:20 -0400
> jegde jedge <bubbah.t at gmail.com> wrote:
>> Thank you so much, that did the trick!
>> Next Question :)
>> On the same code, on the same hardware...
>> I am getting the glut 60 fps limit when running my app using the glut
>> front end via
>> gnome and X.
>> I am getting ~24 fps using the simple-egl front end on top of wayland.
>> I also noticed the display using wayland likes to hover around 20 fps.
>> Is there some kind of throttle built into the frame rate for the
>> redraw callback?
> Hi,
> could you remind us, are you running Weston with the X11 or DRM backend?
> If you use the X11 backend, sloppy framerates are expected. X has no
> method of telling the X application (weston) that the image it posted
> has now hit the screen. Therefore the X11 backend fakes it by using a
> timer to blindly to trigger this "image hit the screen" callback.
> Obviously that is very flakey and inaccurate, but cannot really do any
> better.
> However, if you are on DRM backend, it is worth investigating.
> Thanks,
> pq

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