or overflow the netisr queue and fall back to the interface
queue so that we can garuantee that the ifnet pointer stays
valid. Formerly we ended up with reference counts <= 0 in
case the netisr had returned ENOBUFS. The idea is to track
any packet in the netisr queue and only change the refount
on edge operations for the fallback interface queue. This
also avoids problems in case the if_snd.ifq_len lies to us.
Also rework refount assertions to make sure they trigger if
we go below 1. Formerly a negative refence count did not
trigger the assert as the refcount variable is u_int.
Sponsored by: ISPsystem
MFC after: 5 days
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks. Minor cleanups are done in the process,
and comments updated to reflect these changes.
Reviewed by: bz
Approved by: re (vimage blanket)
things a bit:
- use dpcpu data to track the ifps with packets queued up,
- per-cpu locking and driver flags
- along with .nh_drainedcpu and NETISR_POLICY_CPU.
- Put the mbufs in flight reference count, preventing interfaces
from going away, under INVARIANTS as this is a general problem
of the stack and should be solved in if.c/netisr but still good
to verify the internal queuing logic.
- Permit changing the MTU to virtually everythinkg like we do for loopback.
Hook epair(4) up to the build.
Approved by: re (kib)
Import if_epair(4), a virtual cross-over Ethernet-like interface pair.
Note these files are 1:1 from p4 and not yet connected to the build
not knowing about the new netisr interface.
Sponsored by: The FreeBSD Foundation
