sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

Remove duplicated empty lines from kern/*.c

No functional changes.

Mark mtxpool_sleep as read mostly, not frequently.

The latter is not justified.

Mark some more hot global variables with __read_mostly.

MFC after: 1 week

Increase MTX_POOL_SLEEP_SIZE from 128 to 1024.

This value remained unchanged for 15 years, and now this bump reduces
lock spinning in GEOM and BIO layers while doing ~1.6M IOPS to 4 NVMe
on 72-core system from ~25% to ~5% by the cost of additional 28KB RAM.

While there, align struct mtx_pool fields to cache lines.

MFC after: 1 month

sys/kern: adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

sys/kern: spelling fixes in comments.

No functional change.

Garbage collect mtxpool_lockbuilder, the mutex pool historically used
for lockmgr and sx interlocks, but unused since optimised versions of
those sleep locks were introduced. This will save a (quite) small
amount of memory in all kernel configurations. The sleep mutex pool is
retained as it is used for 'struct bio' and several other consumers.

Discussed with: jhb
MFC after: 3 days

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Fix a number of style issues in the MALLOC / FREE commit. I've tried to
be careful not to fix anything that was already broken; the NFSv4 code is
particularly bad in this respect.

Retire the MALLOC and FREE macros. They are an abomination unto style(9).

MFC after: 3 months

- Import the HEAD csup code which is the basis for the cvsmode work.

Universally adopt most conventional spelling of acquire.

Make a bunch of malloc types static.

Found by: src/tools/tools/kernxref

Expand COPYRIGHT inline, per Matthew Dillon's earlier approval.

Rearrange the SYSINIT order to call lockmgr_init() earlier so that
the runtime lockmgr initialization code in lockinit() can be eliminated.

Reviewed by: jhb

Extend the mutex pool implementation to permit the creation and use of
multiple mutex pools with different options and sizes. Mutex pools can
be created with either the default sleep mutexes or with spin mutexes.
A dynamically created mutex pool can now be destroyed if it is no longer
needed.

Create two pools by default, one that matches the existing pool that
uses the MTX_NOWITNESS option that should be used for building higher
level locks, and a new pool with witness checking enabled.

Modify the users of the existing mutex pool to use the appropriate pool
in the new implementation.

Reviewed by: jhb

Style(9).

Use __FBSDID().

Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on: i386, alpha, sparc64

Rename SI_SUB_MUTEX to SI_SUB_MTX_POOL to make the name at all accurate.
While doing this, move it earlier in the sysinit boot process so that the
VM system can use it.

After that, the system is now able to use sx locks instead of lockmgr
locks in the VM system. To accomplish this, some of the more
questionable uses of the locks (such as testing whether they are
owned or not, as well as allowing shared+exclusive recursion) are
removed, and simpler logic throughout is used so locks should also be
easier to understand.

This has been tested on my laptop for months, and has not shown any
problems on SMP systems, either, so appears quite safe. One more
user of lockmgr down, many more to go :)

cast hashing index to (int)(intptr_t) for calculation.

mtx_init() with MTX_QUIET and MTX_NOWITNESS to avoid bogus warnings

Fix some warnings on 64 bit platforms.

Create a mutex pool API for short term leaf mutexes.
Replace the manual mutex pool in kern_lock.c (lockmgr locks) with the new API.
Replace the mutexes embedded in sxlocks with the new API.