Regression introduced in drm/i915 kernel modules for 965GM system

[Jesse Barnes]

On Saturday, January 26, 2008 12:35 pm Richard Goedeken wrote:
> I recently noticed a massive memory leak somewhere in the OpenGL
> software stack, so I decided to update everything and rebuild from
> the tip again.  I did that and discovered a new bug.  After running
> an OpenGL program a few times, the system becomes extremely slow
> (even after the OpenGL program is terminated).  I can watch X/Gnome
> redraw the windows when I switch between desktops.  I ran an OProfile
> session and it seems the CPU time is being eaten inside the kernel.
> Unfortunately Fedora 8 doesn't provide a vmlinux image, and building
> a Fedora kernel is a 30-step process or so (thanks, RPM), so I don't
> have any more detail than this.
>
> I found that I could bring the system back to its normal
> responsiveness by doing 'telinit 3' and then 'rmmod i915' and 'rmmod
> drm'.  When I removed i915.ko it took a very long time and spit out a
> message "kernel: Disabling IRQ #16".  Then I brought back X with
> 'telinit 5' and it was fast as usual.  So the problem seems to be in
> the drm or i915 kernel module.

Yeah, Keith noticed something similar.  The vblank rework has exposed 
some latent interrupt handling bugs.  He posted a patch to dri-devel 
that might work for you; it worked on his 965GM at least.  We should be 
pushing the fixes upstream soon...

Thanks,
Jesse