perfmon2 minimal v3: introduction

The following patches implement a minimal perfmon2 subsystem which provides access to the hardware performance counters of modern processors. Performance counters are very useful resource to extract micro-architectural-level information such the number of caches misses, or the number of instructions executed. The list of events which can be monitored in highly specific to each processor implmentation.

This series supports ONLY per-thread counting of PMU events (no sampling) for AMD64 and Intel processors with support for architectural perfmon (Core Duo/Solo, Core 2) in both 32 and 64 bit modes.

This is version 3 of the series. It is against Stephen Rothwell linux-next GIT tree. Compared to the previous version, there were a few more cleanups in the Makefile structure suggested by Stephen. The series also merges more code between 32 and 64 bit x86.

Please review.

More information about the perfmon2 project can be found at:

http://perfmon2.sourceforge.net

To test this series, it is possible to use libpfm and pfmon, both available from the web site above.