[PATCH v2 1/4] nmi_backtrace: add more trigger_*_cpu_backtrace() methods

On Thu, Mar 17, 2016 at 03:55:57PM -0700, Paul E. McKenney wrote:

That said, RCU used to use NMI-based stack traces, but switched to the
current scheme due to the NMIs having the unfortunate habit of locking
things up, which IIRC often meant no stack traces at all.  If I recall
correctly, one of the problems was self-deadlock in printk().

Have these problems been fixed?

Improved is I think the word.

Although I've butchered my printk() into absolute submission :-)