Comment 272 for bug 1690085

(In reply to Chris Hall from comment #185)
> I have Ryzen 7 1800X, ASUS Prime X370-PRO, with CPU replaced by AMD.
>
> The damn thing has not worked properly since I bought it.
>
> I have: kernel 4.14.18-300.fc27
> CONFIG_RCU_NOCB_CPU=y
> rcu-nocbs=0-15
>
> I have seen streams of "watchdog: BUG: soft lockup", but mostly the system
> just stops and I can find no logging that tells me why.
>
> Currently I find the machine has stopped over night (when it is idle), every
> two or three days.
>
> I have just installed kernel 4.15.3-300.fc27. But I can find nothing to
> suggest that this fault is understood, let alone fixed.
>
> I have just added processor.max_cstate=5 -- though I have failed to find any
> way to check what difference that has made.
>
> So: is the "work-around" still the only available solution ?
>
> [FWIW, while the AMD CPU went through the RMA process, I bought an Intel
> Coffee Lake i7-8700K machine. Will I buy another AMD ? I doubt it.]

Run the python script mentioned earlier.

For me new kernel/params with RCU setting enabled & python script to turn off C states has had my machine running for 60 days now.