Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC: r246166

Update hwpmc to support the Xeon class of Ivybridge processors.
case 0x3E: /* Per Intel document 325462-045US 01/2013. */

Add manpage to document all the goodness that is available in this
processor model.

No support for uncore events at this time.

Approved by: sbruno (mentor)

MFC r241974

Cleanup and rename some variables in libpmc and hwpmc.

Testing MFC of merge to root of stable/9 with peter@ lurking.

MFC r241745,241738,241741

Update hwpmc to support the Xeon class of Sandybridge processors.
(Model 0x2D /* Per Intel document 253669-044US 08/2012. */)

Update man page crossreferences to sandybridge xeon class

Remove trailing whitespace.

MFC r240164, r240203:
Add Intel Ivy Bridge support to hwpmc(9).
Update offcore RSP token for Sandy Bridge.
Note: No uncore support.

MFC r233628, r234598, r235229, r235831, r226986.

Add software PMC support.

New kernel events can be added at various location for sampling or counting.
This will for example allow easy system profiling whatever the processor is
with known tools like pmcstat(8).

Simultaneous usage of software PMC and hardware PMC is possible, for example
looking at the lock acquire failure, page fault while sampling on
instructions.

Sponsored by: NETASQ

MFC: r232366

- Add support for the Intel Sandy Bridge microarchitecture (both core and
uncore counting events)
- New manpages with event lists.
- Add MSRs for the Intel Sandy Bridge microarchitecture

Approved by: gnn (mentor)

- Add support for the Intel Sandy Bridge microarchitecture (both core and uncore counting events)
- New manpages with event lists.
- Add MSRs for the Intel Sandy Bridge microarchitecture

Reviewed by: attilio, brueffer, fabient
Approved by: gnn (mentor)
MFC after: 3 weeks