[Qemu-devel] Re: text updates slow after commit 7d957bd8cbcbf56f7916d375e65042d767f544b5

[Anthony Liguori]

Chris Frey wrote:
> On Tue, Apr 28, 2009 at 04:40:58PM -0500, Anthony Liguori wrote:
>   
> > What's your configuration (host type, etc.)?  Are you remoting over X?
> >     
>
> Oops, forgot to say that I am using X through an SSH forward.
>
>         ssh -Y -a -2 ...
>   

That's what I figured.  You should use -vnc instead.

In the 0.10.x series, we changed the way we interact with libsdl.  We're 
now relying on libsdl to do pixel conversion.  It appears that SDL is 
sending a lot more data to the X server when you do this than it was 
previously.  The result is a marked slowdown when remoting QEMU over X.

Fortunately, we have an integrated remoting mechanism (-vnc) that 
doesn't suffer from these problems.

If you think this really should be addressed, I'd suggest reporting it 
to the SDL community as they're the ones who are best positioned to 
detect that it's a remote X server and then do local conversion 
appropriately.  Alternatively, I suspect using an X protocol optimizer 
(like NX) would make this problem go away.

Regards,

Anthony Liguori

> - Chris
>
>