[PATCH] kprobes for s390 architecture

[Frank Ch. Eigler]

I wrote:

> grundym wrote:
> > I'll have to do some timing tests to measure how much overhead it
> > puts on the system. It's a trade off of safety vs speed. [...] 
> 
> No question, safety has to be paramount.

To elaborate: safety here would mean system stability.  If a method of
probe insertion/removal can be found that does not risk stability,
merely may cause unpredictable early/late probe hits, or gradual
deferred cleanup that would be fine.  For example, it may likely be
fine if different processors on an SMP start or stop to see the kprobe
breakpoints at different times.  A "softer" method analogous to RCU
may work for us here.

- FChE