mdoc sweep
Set st_nlink in the stat structure within the inode to 1 as well.
The cd9660 file system uses that field for the link count and it
was 0. This impacts pwd_mkdb(8) as it checks for st_nlink not being
0 as part of closing a race.
Begin tidying up the reassociation and node sleep/wakeup paths.

* Move the node sleep/wake state under the TX lock rather than the
  node lock.  Let's leave the node lock protecting rate control only
  for now.

* When reassociating, various state needs to be cleared.  For example,
  the aggregate session needs to be torn down, including any pending
  aggregation negotiation and BAR TX waiting.

* .. and we need to do a "cleanup" pass since frames in the hardware
  TX queue need to be transmitted.

Modify ath_tx_tid_cleanup() to be called with the TX lock held and push
frames into a completion list.  This allows for the cleanup to be
done atomically for all TIDs in a node rather than grabbing and
releasing the TX lock each time.
This lock only protects the rate control state for now, mention this.
Oops, commit the other half of r250606.
Since the node state is 100% back under the TX lock, just kill the use
of atomics.

I'll re-think this nonsense later.
Improve the debugging output - use the MAC address rather than various
pointer values everywhere.
As python3 does not have raw_input(), convert it to input() when we
are using python3.

PR:	177214
Reviewed by:	gnn
Approved by:	sbruno (mentor)
Fix typo in net.inet.tcp.minmss sysctl description.

MFC after:	3 days
Deal correctly with 40G ports that don't have any transceiver plugged
in.  Do not claim that they have unknown tranceivers.

MFC after:	3 days
Remove a bogus re-assignment.

MFC after:	3 days
Use an ugly hack to get around bootstrapping problems when building
clang on head between r239347 and r245428.

The former revision introduced CLOCK_PROCESS_CPUTIME_ID as a clock id
for the clock_gettime() function and friends, but it was only added in
<sys/time.h>, not in <time.h>.  Any program including <time.h> would
therefore not be able to use CLOCK_PROCESS_CPUTIME_ID, even though the
value of _POSIX_CPUTIME indicates its existence.  The latter revision
synchronized the defines again.

Work around this problem by defining the id on the command line for the
particular .cpp file that needs it.  If the id ever changes value, this
hack will need to be updated.
etc/rc.d/syslogd
	Add netif as a requirement of syslogd to get lo0 up.  Currently, this
	doesn't affect the rc order, because mountcritremote already depends on
	netif.

Reviewed by:	eadler
Approved by:	kenm (mentor)
MFC after:	2 weeks
Support sending ATH_ALQ messages with no payload.
Add ALQ beacon debugging.
Rework the way C11 keywords are defined.

Instead of only checking the __STDC_VERSION__, we can also use Clang's
__has_extension() to check for features specifically. This allows us to,
say, use Clang's native _Static_assert() instead of the typedef hack,
making the compiler error messages a lot more readable.

Reviewed by:	theraven
Improve readability of static assertions for OFFSET_* macros.

Instead of doing all sorts of weird casting of constants to
pointer-pointers, simply use the standard C offsetof() macro to obtain
the offset of the respective fields in the structures.
Add less to rescue build.  On amd64, this increases rescue size by about
130KB or 2.4%.

MFC after:	1 month
Centralize standard getopts arguments, both for convenience and to correct
a bug in which certain combinations of arguments produced unexpected results
such as `-dX' (now properly produces debugging and X11), `-XS' (now properly
produces X11 in secure mode), `-df-' (enables debugging when reading a
script from standard-input, etc. Multi-word variations such as `-d -X',
`-X -S', `-d -f-', `-d -f -', etc. also work as expected. Also tested were
variations in argument order, which are now working as expected.
Port the new PV entry allocator from amd64/i386/mips to armv6/v7.

PV entries are now roughly half the size.
Instead of using a shared UMA zone for 28 byte pv entries
(two 8-byte tailq nodes, a 4 byte pointer, a 4 byte address and 4 byte
flags), we allocate a page at a time per process.
This provides 252 pv entries per process (actually, per pmap address space)
and eliminates one of the 8-byte tailq entries since we now can track
per-process pv entries implicitly.
The pointer to the pmap can be eliminated by doing address arithmetic to
find the metadata on the page headers to find a single pointer shared by
all 252 entries. There is an 8-int bitmap for the freelist of those 252
entries.
When in serious low memory condition, allocation of another pv_chunk is
possible by freeing some pages in pmap_pv_reclaim().

Added pv_entry/pv_chunk related statistics to pmap.
pv_entry/pv_chunk statistics can be accessed via sysctl vm.pmap.

Ported PTE freelist of KVA allocation and maintenance from i386.
Using an idea from Stephan Uphoff, use the empty pte's that correspond
to the unused kva in the pv memory block to thread a freelist through.
This allows us to free pages that used to be used for pv entry chunks
since we can now track holes in the kva memory block.

As both ARM pmap.c and pmap-v6.c use the same header and pv_entry, pmap and
md_page structures are different, it was needed to separate code designed
for ARMv6/7 from the one for other ARMs.

Submitted by:	Zbigniew Bodek <zbb@semihalf.com>
Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation, Semihalf