Re: [ilk] using GNOME 3 makes computer sluggish after a few minutes

[Jonathan Nieder <jrnieder@gmail.com>]

found 697029 linux/3.7.3-1~experimental.1
tags 697029 - wontfix
affects 697029 + release-notes
quit

Hi,

Chris Wilson wrote:

> The performance issue on 3.7 is not due to the missed irq, but a
> combination of using UXA and VT-d. In order to workaround an erratum
> on Ironlake, every time we touch the GPU's page tables, we have to
> idle the GPU before doing so. This causes extremely noticeable display
> lag.

Pierre AUSSAGUEL wrote:

> Appending intel_iommu=off seems to fix the problem (I tested a few
> days befor posting).

Daniel Vetter wrote:

> Since we can't fix the hw, closing this as wontfix. Thanks for
> reporting this issue anyway.

That makes this a distro issue, I suppose.

Ben and X team, any ideas?  Would it makes sense to disable
intel_iommu by default on this hardware and require intel_iommu=on to
reenable it?  Should GNOME somehow detect that it should use classic
mode by default when the iommu is enabled?

If we can't come up with a workaround, this should be mentioned in the
release notes to prevent a regression on upgrade.  Please feel free to
remind me in that case so I can come up with some wording (though I
also wouldn't mind if someone else does).

Thanks,
Jonathan