MFC: r238172 (partial)

Don't use Maxmem when the amount of memory is meant. Use realmem instead.
Maxmem is not only a MD variable, it represents the highest physical memory
address in use. On systems where memory is sparsely layed-out the highest
memory address and the amount of memory are not interchangeable. Scaling the
AGP aperture based on the actual amount of memory (= realmem) rather than
the available memory (= physmem) makes sure there's consistent behaviour
across architectures.
MFC r251485:

Revert r238399.

The "failok" option doesn't have any effect at all unless specified in
fstab(5) and combined with the -a flag. The "failok" option is already
documented in fstab(5).

PR:		177630
MFC	r251658, 251823:

Turn DIAGNOSTICs to INVARIANTS in ext2fs. following other filesystems.
MFC r250251:

Use FF02:0:0:0:0:2:FF00::/104 prefix for IPv6 Node Information Group
Address.  Although KAME implementation used FF02:0:0:0:0:2::/96 based on
older versions of draft-ietf-ipngwg-icmp-name-lookup, it has been changed
in RFC 4620.

The kernel always joins the /104-prefixed address, and additionally does
/96-prefixed one only when net.inet6.icmp6.nodeinfo_oldmcprefix=1.
The default value of the sysctl is 1.

ping6(8) -N flag now uses /104-prefixed one.  When this flag is specified
twice, it uses /96-prefixed one instead.

Reviewed by:		ume
Based on work by:	Thomas Scheffler
PR:			conf/174957
MFC r250523:

Add IFF_MONITOR support to gre(4).

Tested by:	Chip Marshall
Fix a copy/paste error introduced by r248313 (s/ftp/http/ in menu text).

MFC after:	3 days
MFC r248573:
Don't register repair writes in the trim map.
MFC: r249406

- Do not bail out if stat(2) fails with ENOENT in the spool directory. This
  happens if another atrm process removes a job while we're scanning through
  the directory.
- While at it, optimize a bit the directory scanning, so that we quit
  looping as soon as all jobs specified in argv have been dealt with.

Approved by:	cognet
Fix two swapped definitions.  Note it is directly committed to this branch
because it fixes r250496, i.e., MFC of r247369 to stable/9.
MFC 251617:
Store a reference to the vnode associated with a file descriptor in the
linux_file structure and use it instead of directly accessing td_fpop
when destroying the linux_file structure.  The td_fpop pointer is not
valid when a cdevpriv destructor is run, and the type-specific close
method has already been called, so f_vnode may not be valid (and the
vnode might have been recycled without our own reference).
MFC r251439: Remove unneeded reference to link.h (sys/link_elf.h).
MFC r251440: use calloc().
share/mk: merge: r241298,243393,249057,251506 from head for bmake support.

Makefile: buildworld etc will be done with make from src tree,
make sure that bmake's -J 15,16 are not passed to it.

Reviewed by: obrien
MFC r251959:
Remove stray empty line.
MFC 250333: Don't pad disk partition sizes with leading zeros.
MFC r252010, r252011:

Mark geom_mirror as capable of unmapped i/o

Obtained from:	Netflix
MFC 251637:
Borrow the algorithm from kvm_getprocs() to fix procstat_getprocs() to
handle the case where the process tables grows in between the calls to
fetch the size and fetch the table.
MFC: r251444, r251476
Add a "-v" (verbose) option to the gssd daemon, to help
with diagnosis of kerberized NFS mount problems. When set,
messages are sent to syslog() (or fprintf(stderr,...) if
"-d" is also specified) to indicate activity/results of
kgssapi upcalls.
MFC: r251445
Document the new "-v" option for the gssd daemon.
This is a content change.
MFC: 249514
Point args[0] not at the thread that is ending but at the one that
is starting.  This is in line with practice in OpenSolaris.

Note that this change is only in ULE and not in the 4BSD scheduler.
Once this change settles in (MFC timeout has expired) we'll try it out
on 4BSD as well.

PR:		177706
Submitted by:	Tiwei Bie