perfmon3: introduction

Hello,

This series of patches implements the perfmon interface which provides access to the hardware performance counters of modern processors. In particular, this version supports per-thread counting for all AMD64 processors, and recent Intel processors with architectural PMU (Core Duo, Core 2, Atom).

It does not supersede Oprofile in this first implementation. Oprofile and perfmon can be compiled in the same kernel, but only one can have an active session at a time.

This implementation takes into account the various comments received from previous reviews on LKML. This is a much simplified version compared to the fully featured version maintained as a separate GIT tree on kernel.org.

This new version, named perfmon3, uses only 5 system calls (instead of 12). Each call was carefully designed to allow for future extensions.

Full documentation is available in Documentation/perfmon.txt and is provided by one of the patches.

Once this basic set of perfmon functionalities is upstream, we will build on it and add other features such as support for sampling, event set multiplexing and multi-architecture.

I will be releasing updated versions of libpfm and pfmon which can work with this new API while continuing to work with the v2.x versions.

The patch series is against 2.6.27.

Please consider adding this patch series for 2.6.28.

Thanks to all the people who have contributed to this new release.

S.Eranian