Re: Slow draw times under dom0

[Jean-Yves Migeon <jeanyves.migeon%free.fr@localhost>]

On Wed, 31 Aug 2011 10:16:12 -0500, Grant Friday wrote:
> Hello,
>
> I have been running NetBSD current dom0 on an amd64 server for over a
> year now.  I have noticed that the X server draw times are very slow.
> I am letting Xorg auto-configure itself and the X server seems quick
> and responsive on a generic kernel.  The only errors I see in the log
> are:
>
> [  3253.759] (EE) RADEON(0): Acceleration initialization failed
> [  3253.346] (EE) RADEON(0): [dri] RADEONDRIGetVersion failed to open 
> the DRM
> [dri] Disabling DRI.
>
> Is this normal performance because of Xen limitations or do I need to
> manually configure an xorg.conf?  I apologize in advance if this is
> the wrong list for this question. The full Xorg log follows.

Maybe; when using DRM with a GENERIC kernel, you should see somewhere 
in the dmesg a line telling that "radeondrm attached to vga". Under Xen, 
the attachment may fail for different reasons like hypervisor refusing 
to setup memory mappings. In that case, you cannot use all the whizzbang 
acceleration you get with DRI and that makes everything look more 
sluggish.

Now, why it can/cannot attach is difficult to guess; "xm dmesg" output 
helps, as it usually warns when hypervisor refused to perform some 
action submitted by a domain.

--
Jean-Yves Migeon
jeanyves.migeon%free.fr@localhost