Profile requirements tapset checked in

["Spirakis, Charles" <charles dot spirakis at intel dot com>]

All --

There is a profile tapset checked into
.../src/tapsets/profile/profile_tapset.txt that covers common usage
models and defines many of the requirements that should be considered
when we try to implement things. Some areas to highlight:

1) Data ordering: there is a need for "trace history" and having the
data
   ordered is important

2) Timestamps: there is a need for reasonably accurate, smp independent
   method of computing delta/interval times

3) Fast "lookup" routines: translate ptregs->ip to image name,
   translate ptregs->sp to stack trace

4) There can be a large volume of data that is collected during a
profiling run.
   4a) How (and when) should that data be merged/aggregated?
   4b) Do we want to allow for a general purpose merge (ie, not only
merge
       data from relayfs/per-cpu buffers but also information provided
       elsewhere (such as image information from dynamically generated
       code generators)?

-- charles