$NetBSD: TODO.smpnet,v 1.2 2017/02/10 03:59:02 ozaki-r Exp $

MP-safe components
==================

 - bridge(4)
 - bpf(4)
 - gif(4)
 - npf(7)
 - pfil(9)
 - pppoe(4)
   - if_spppsubr.c
 - tun(4)
 - vioif(4)
 - vmx(4)
 - wm(4)

 - Layer 2 (only Ethernet)
   - if_ethersubr.c
 - Most Layer 3

Non MP-safe components and kernel options
=========================================

 - agr(4)
 - altq(4)
 - carp(4)
 - etherip(4)
 - faith(4)
 - gre(4)
 - ieee80211(4)
 - ipf(4)
 - ipsec(4)
 - kttcp(4)
 - mpls(4)
 - opencrypto(9)
 - pf(4)
 - ppp(4)
 - sl(4)
 - stf(4)
 - strip(4)
 - if_srt
 - tap(4)
 - vlan(4)

 - netsmb
 - netnatm
 - netisbn
 - netatalk
 - netbt
 - netkey

 - if_arcsubr.c
 - if_atmsubr.c
 - if_ecosubr.c
 - if_fddisubr.c
 - if_hippisubr.c
 - if_ieee1394subr.c
 - if_tokensubr.c

 - DCCP
 - IGMP
 - IPSELSRC
 - MROUTING
 - NFS
 - PIM
 - SCTP
 - TCP
 - UDP

 - Layer 4
 - IP multicast
 - Most network device drivers

Know issues
===========

bpf
---

MP-ification of bpf requires all of bpf_mtap* are called in normal LWP context
or softint context, i.e., not in hardware interrupt context.  For Tx, all
bpf_mtap satisfy the requrement.  For Rx, most of bpf_mtap are called in softint.
Unfortunately some bpf_mtap on Rx are still called in hardware interrupt context.

This is the list of the functions that have such bpf_mtap:

 - sca_frame_process() @ sys/dev/ic/hd64570.c
 - en_intr() @ sys/dev/ic/midway.c
 - rxintr_cleanup() and txintr_cleanup() @ sys/dev/pci/if_lmc.c
 - ipr_rx_data_rdy() @ sys/netisdn/i4b_ipr.c

Ideally we should make the functions run in softint somehow, but we don't have
actual devices, no time (or interest/love) to work on the task, so instead we
provide a deferred bpf_mtap mechanism that forcibly runs bpf_mtap in softint
context.  It's a workaround and once the functions run in softint, we should use
the original bpf_mtap again.