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<b><a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO --- - [ilk] missed irq"
href="https://bugs.freedesktop.org/show_bug.cgi?id=59792#c9">Comment # 9</a>
on <a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO --- - [ilk] missed irq"
href="https://bugs.freedesktop.org/show_bug.cgi?id=59792">bug 59792</a>
from <span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span></b>
<pre>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.
Try appending intel_iommu=off to you kernel commandline.</pre>
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