The flag is not used by anything for years and supporting it requires an
explicit read from the lock when entering slow path.
Flag value is left unused on purpose.
Sponsored by: The FreeBSD Foundation
- Emulate Linux mutex API using sx(9) locks with only exclusive operations
instead of mutex(9), in Linux mutexes are sleepable.
- Emulate Linux rwlock_t using rwlock(9) instead of sx(9). rwlock_t
in Linux are spin locks
years for head. However, it is continuously misused as the mpsafe argument
for callout_init(9). Deprecate the flag and clean up callout_init() calls
to make them more consistent.
Differential Revision: https://reviews.freebsd.org/D2613
Reviewed by: jhb
MFC after: 2 weeks
