hipe: change mfa_info_table lock to rwmutex

The hipe_mfa_info_table lock is currently a mutex, causing
unnecessary contention and serialization of lookups for
apply-like constructs.

- change the lock from a mutex to an rwmutex
- split hipe_get_na_nofail_locked into a "try" path which
  only needs a read lock, and a "slow" path which requires
  a write lock
- reimplement hipe_get_na_nofail (used by apply ops etc) to
  first call the "try" path with a read lock, and if that
  fails the "slow" path with a write lock
- reimplement hipe_get_na_nofail_locked (used by maintenance
  code) to call the "try" path and then optionally the "slow"
  path, but without taking locks since its caller already has
  the write lock
- adjust remaining lock ops to take/release full write lock
- use _rwlocked as suffix on functions requiring a write lock
- change hipe_mfa_get_trampoline to call get_locked not put_locked,
  allowing it to take a read lock instead of a write lock
- change hipe_find_mfa_from_ra() to only take a read lock

0 files changed, 0 insertions, 0 deletions