Michel Dänzer wrote:
That does sound like the GPU locks up. Do you get any messages in dmesg about lockups and attempts to reset the GPU at any time?
No.
Hmm, I guess the constant SIGALRMs might prevent the lockup detection from kicking in... Maybe you can try starting the X server with -dumbSched to see if that gets things along any further, but in the end there's probably no way around figuring out what causes the lockup and fixing that anyway.
I have an old AGP box that locks with 600g + agpgart - It used to give GPU lockup to dmesg/log, but (I only test it occasionally) it doesn't anymore. I can still sysrq OK.
I wonder if something changed in recent months in the drm/whatever code that has changed/blocked the logging.