Import latest ARC change from OpenSolaris:
- large ghost eviction causes high write latency
- arc_adjust might adjust MRU unnecessarily
- arc_adapt can lead to wild arc_p adjustment
OpenSolaris onnv-revision: 12636:13b5d698941e
Submitted by: avg
Approved by: pjd, delphij (mentor)
Obtained from: OpenSolaris (Bug ID 6950219, 6953403, 6951024)
MFC after: 1 month