Would it be plausible to somehow, get the (ruby) stack of the running =
ruby process (or a particular thread), periodically?  For example, every =
10 seconds.

One approach might be to have a separate thread with a timer that popped =
and it would get the current stack for a particular thread (not itself).

The overall objective is to have a very light weight (low impact) =
technique for profiling a Rails app as it is running in production.  =
Over the course of a week, for example, gather enough statistics to =
understand where the app is spending the most time.

Of course, the other question is: has this already been done?  (I =
couldn't find anything.)

Thank you for your time,
pedz