Weston on framebuffer?

Pekka Paalanen ppaalanen at gmail.com
Thu Jul 21 20:48:44 UTC 2016

On Thu, 21 Jul 2016 08:30:54 +0900
Carsten Haitzler (The Rasterman) <raster at rasterman.com> wrote:

> On Wed, 20 Jul 2016 21:49:57 +0200 Christer Weinigel <christer at weinigel.se>
> said:

> > On the framebuffer I don't perceive any lag at all between a keypress 
> > and the character appearing on the screen.
> > 
> > With weston-terminal running I can drag the window around and even 
> > though it's not very fast and there's a bit of tearing it isn't too bad. 
> > The response when dragging feels ok.  Keypresses feel laggy even though 
> > mouse motion doesn't, but I'm not sure if that's because I don't notice 
> > the lag when moving the mouse or if it is a real difference.  
> well they are done by different things. the move will be done directly by
> weston itself. it will be asked to begin a window move by the client and then
> just do it itself. render the changes. key events have a different path. they
> go to client, client handles it, draws new frame, then weston has to update
> screen with that new frame.
> it seems to be either weston-terminal is just slow at drawing there and thus is
> ending up taking a while to draw, add another 200ms or so for weston itself and
> thats probably what's going on.

The first. I recall people saying that weston-terminal is
particularly bad at rendering performance. You might want to try a
more "serious" terminal, though I'm not sure what to suggest.

Just keeping a key pressed and looking the output of 'top' at the
same time (via a remote login or serial) should tell you what eats
the CPU if any. I would guess CPU is running at 100% and most of it
is in weston-terminal. That would confirm that weston-terminal is
just inefficient in its drawing.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 811 bytes
Desc: OpenPGP digital signature
URL: <https://lists.freedesktop.org/archives/wayland-devel/attachments/20160721/068562de/attachment.sig>

More information about the wayland-devel mailing list