Comment 581 for bug 1690085

(In reply to Maxim Bakulin from comment #492)
> Created attachment 280669 [details]
> dmesg of freeze with 4.20.3 kernel and nomwait, rcu_nocbs, max_cstate applied
>
> some older info here:
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1690085/comments/566
>
> I have three machines with new 2700x CPUs, and all three of them experience
> freezes in xubuntu 18.04 after some time of work. I use compiling QEMU with
> make -j16 in a loop to test for stability.
>
> I'm not sure it is the same bug, because I observe different behaviour: one
> machine, that was compiling QEMU, froze during the night, and the one left
> idle worked for 1 day. Another thing that SEEM to help is disabling SMT:
> machine with disabled SMT is currently at 7 hours of uptime, which is much
> more, than usual 1-3 hours before freeze. Windows 10 seem to work fine: I
> used WSL with ubuntu 18.04 for the same test compilations for 3 days, and no
> freezes with the same bios settings.
>
> Things I've tried that didn't help:
> idle=nomwait
> rcu_nocbs=0-15 with new kernel (4.20.3)
> disabled cool n quiet and c6 states
> Typical Current Idle in uefi
> Set SoC voltage to 1.1v
> Set DRAM voltage to 1.3v
> Update to latest BIOS
> High-end PSU

With my Threadripper 2950X I can confirm that none of these were sufficient. I have an excellent PSU which I have confirmed is operating well better than spec, the voltage is definitely sufficient, the power states people are saying cause this are disabled, mwait is disabled, AGESA is current, etc.