- remove mbuf iovec - useful, but adds too much complexity when isolated to
the driver
- remove driver private caching - insufficient benefit over UMA to justify
the added complexity and maintenance overhead
- remove separate logic for managing multiple transmit queues, with the
new drbr routines the control flow can be made to much more closely resemble
legacy drivers
- remove dedicated service threads, with per-cpu callouts one can get the same
benefit much more simply by registering a callout 1 tick in the future if there
are still buffered packets
- remove embedded mbuf usage - Jeffr's changes will (I hope) soon be integrated
greatly reducing the overhead of using kernel APIs for reference counting
clusters
- add hysteresis to descriptor coalescing logic
- add coalesce threshold sysctls to allow users to decide at run-time
between optimizing for forwarding / UDP or optimizing for TCP
- add once per second watchdog to effectively close the very rare races
occurring from coalescing
- incorporate Navdeep's changes to the initialization path required to
convert port and adapter locks back to ordinary mutexes (silencing BPF
LOR complaints)
- enable prefetches in get_packet and tx cleaning
Reviewed by: navdeep@
MFC after: 2 weeks
3f345a5d09