- Normally driven through MSRs
- RDPMC instruction: http://www.x86.org/secrets/opcodes/rdpmc.htm
- FreeBSD includes libpmc as part of the base system
- On Linux, we have libpfm from perfmon2
- This is the preferred way we get at TSC (TSC has fallen out of favor, though)
- Collectors include oprofile and perf.
|MACHINE_CLEARS.ASSIST_FUSION||Core i7||Number of macro-fusions performed|
|LSD.UOPS||Core i7||Number of μops delivered by the Loop Stream Decoder|