MPSAFE - Warning

[Robert Watson]

On Mon, 15 Nov 2004, Kris Kennaway wrote:

> > I got some messages for my customized kernel, using IPsec and IPv6:
> > 
> > WARNING: MPSAFE network stack disabled, expect reduced performance.
> > 
> > My kernel have the following option:
> > 
> > options         NET_WITH_GIANT
> > 
> > How is possible to correct this warning 
> 
> Wait for a later release, or disable IPv6 :-) 
> 
> IPv6 is not yet MP-safe. 

FWIW, the IPv6 code is probably about 80%+ safe -- certainly most of the
common code paths, so in practice you can run without Giant and use IPv6
without too much problem (the routing, UDP and TCP code is all safe, and
that's most of where IPv6 munges data structures).  The real problem is
KAME IPSEC, right now.  I know that George Neville-Neil has been working
on this, but I'm not sure he has specific plans for when it will be done.
My hope is that in 5.4, the KAME IPSEC code will be locked down.  Now that
the KAME developers have switched to 5.3 as their baseline, they will also
be getting that message every boot, which might improve motivation to fix
it :-).

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert at fledge.watson.org      Principal Research Scientist, McAfee Research