HEADS UP: netatm disabling taking place shortly

This is a warning to CVS HEAD users -- per countless previous e-mail threads, 
I will shortly be committing a patch to disable the build of netatm.  As you 
may well know from earlier e-mails, netatm is one of three ATM stacks in the 
FreeBSD CVS repository, and currently the only one that is not MPSAFE.  We 
will be disabling the build of netatm in 7.0, but continuing to ship source 
code so that efforts to make it MPSAFE are made easier.  If we don't have 
MPSAFEty work done in the next few months, we can remove the source code from 
7.x/8.x.  I will send out a reversion patch that may be applied with "patch 
-R" to re-enable the netatm build once the final patch is committed.

As this patch touches quite a few bits of build infrastructure, there may well 
be a window in which the build is broken during merging of the parts, but 
hopefully not long.  Once this has settled I will be removing NET_NEEDS_GIANT, 
the compile-time compatibility functionality that allowed non-MPSAFE network 
protocols to operate in the stack.  This will substantially simplify the 
socket code, which currently jumps through quite a few hoops to optionally 
acquire Giant when non-MPSAFE components are compiled into the stack.

As has been observed, this may lead to problems with credential-based firewall 
rules, which currently rely on debug.mpsafenet to prevent deadlock scenarios 
due to bugs in the locking of the firewalls.  Hopefully this will motivate 
fixing those problems in short order.  Once the NET_NEEDS_GIANT removal is 
dealt with, I'm happy to help investigate those bugs.

Robert N M Watson
Computer Laboratory
University of Cambridge