I think this bug is mostly about the official AMD Errata 1109 "MWAIT
Instruction May Hang a Thread".

This is described here ( https://developer.amd.com/wp-
content/resources/55449_1.12.pdf ) as:

"Under a highly specific and detailed set of internal timing conditions, the 
MWAIT instruction may cause a
thread to hang in SMT (Simultaneous Multithreading) Mode."

Since this is a nofix for AMD, this must be fixed by the OS. The AMD
document states:

"Suggested Workaround
System software may contain the workaround for this erratum."

So, unfortunately AMD will never solve that hardware error. I suggest
they change the first two letters of their company name ;)

This in fact leaves every linux system with a Ryzen CPU instable, so
this should be considered serious.

I didn't read a comment from any kernel developer in the history of this
bug report. Did I overlook something?

Question: Will the Linux kernel ever implement a workaround (as
suggested by AMD??

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https://bugs.launchpad.net/bugs/1690085

Title:
  Ryzen 1800X freeze - rcu_sched detected stalls on CPUs/tasks

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