Submitted by: green
- Speed up synchronization process by using configurable number of I/O
requests in parallel.
+ Add kern.geom.raid3.sync_requests tunable which defines how many parallel
I/O requests should be used.
+ Retire kern.geom.raid3.reqs_per_sync and kern.geom.raid3.syncs_per_sec
sysctls.
- Fix race between regular and synchronization requests.
- Reimplement raid3's data synchronization - do not use the topology lock
for this purpose, as it may case deadlocks.
- Stop synchronization from pre-sync hook.
- Fix some other minor issues.
Tested by: Mike Tancsa <mike@sentex.net>
MFC after: 3 days
3650be51e2