perf: offcore and load latency monitoring patches

Hi, all

This series includes Andi's offcore patches and my load latency monitoring patch. And also some incremental patches on top of Andi's patches per Peter's comments.

The entry of the first version,
[RFC PATCH] perf: Add load latency monitoring on Intel
http://marc.info/?l=linux-kernel&m=129300537003611&w=2

[PATCH 1/7] perf: Document enhanced event encoding for OFFCORE_MSR [PATCH 2/7] perf-events: Add support for supplementary event registers v4 [PATCH 3/7] perf-events: Fix LLC-* events on Intel Nehalem/Westmere v2 [PATCH 4/7] perf: Check if HT is supported and enabled
[PATCH 5/7] perf: Optimize topology iteration
[PATCH 6/7] perf: Use MSR names in the extra reg lists
[PATCH 7/7] perf: Add load latency monitoring on Intel Nehalem/Westmere v2

Thanks for review and feedback.
Lin Ming