Created attachment 123115 [details] Xorg log and gpu dump Using Mathematica to make a lot of plots concurrently. Apparently each subkernel creates a new window for each plot (I can see the window tab flicker). kernel 4.4.5 x86_64 Xorg 1.18.3 mesa 11.1.0 libdrm 2.4.66 xorg-x11-drv-intel 2.99.917
Well that is curious. The GPU completed all the work we told it do, but we are waiting upon a batch that doesn't seem to have been submitted to the ring.
It's not a direct match, but I could believe that commit aa9b78104fe3210758fa9e6c644e9a108d371e8b Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Wed Apr 13 17:35:15 2016 +0100 drm/i915: Late request cancellations are harmful is relevant here. Could you run a kernel from https://cgit.freedesktop.org/drm-intel/ #drm-intel-nightly or equivalent package?
it just happened once in a series of run of the same thing and I've never compiled the kernel myself, but I'll see what i can do.
mind that while the scree nwas frozen I hit sysrq-f (oom) a few times. Other times when I did so, sometimes the message "gpu: cannot release memory because of lock contention". in case it's relevant here.
I'm failing to reproduce this bug with the very same setup, so i wouldn't be able to conclude anything trying the testing kernel. I'll try when and if it happens again.
Reopen the bug if this is still occuring, even after applying Chris' patch
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