BUG: kworker hangs the GPU on drm and i915 since 3.8.x under X11

[Georgios Amanakis]

Thanks for all your efforts. It is really fun to see such an immediate response.

Daniel Vetter <daniel.vetter at ffwll.ch> wrote:

>On Sat, Apr 6, 2013 at 6:24 PM, George Amanakis <g_amanakis at yahoo.com> wrote:
>> Indeed, I set explicitly drm_kms_helper.poll=0 since 2.35.x. See here:
>> http://souriguha.wordpress.com/2011/03/08/how-to-solve-problem-with-thinkpadkslowd-kworker-on-linux-kernel-2-35-2-36/
>>
>> Mouse and keyboard freezes intermittently some time after boot up. Actually
>> the problem has to do with the GPU lagging and displaying the changes later.
>> This results in an almost unusable desktop environment. Top will report the
>> high CPU usage by 3-4 processes named kworker. With the
>> drm_kms_helper.poll=0 it was until the 3.8.x kernel resolved.
>>
>> Since the 3.8.x kernels the exact same problem appeared again. The problem
>> persists with the latest 3.9-rc5 too.
>
>Ah, so it seems to be a plain hpd irq storm (since you have massive
>cpu loads), not edid readings taking forever (which would still cause
>the mouse to lag horribly on 3.8 and earlier, but without cpu load).
>The edid reading issues should be fixed in 3.9. For hpd irq storms
>Egbert Eich from Suse is working on some patches to mitigate this.
>Infrastructure prep work is already merged for 3.10, hopefully we can
>merge the actual mitigation logic, too.
>
>I'll try no to forget to ping you once it's merged, so that you can
>test it a bit.
>
>Cheers, Daniel
>--
>Daniel Vetter
>Software Engineer, Intel Corporation
>+41 (0) 79 365 57 48 - http://blog.ffwll.ch