on a pagequeue.

Reported by:	pho

This #ifdef is misleading as there are actually no user-serviceable parts
inside and, as far as I can tell, there is no pollution leading from
userland to this header. Furthermore, it becomes a slight nuisance when
attempting to move things around in this header.

that if fault fails to progress and needs to restart the loop it must free
the page it is working on and allocate again on restart.  Resolve the few
places that need to be modified to support this condition and simply
deactivate the page.  Presently, we only permit this when fault restarts
for busy contention.  This has an added benefit of removing some object
trylocking in this case.

While here consolidate some page cleanup logic into fault_page_free() and
fault_page_release() to reduce redundant code and automate some teardown.

Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D22653

an exclusive object lock.

Previously swap space was freed on a best effort basis when a page that
had valid swap was dirtied, thus invalidating the swap copy.  This may be
done inconsistently and requires the object lock which is not always
convenient.

Instead, track when swap space is present.  The first dirty is responsible
for deleting space or setting PGA_SWAP_FREE which will trigger background
scans to free the swap space.

Simplify the locking in vm_fault_dirty() now that we can reliably identify
the first dirty.

Discussed with:	alc, kib, markj
Differential Revision:	https://reviews.freebsd.org/D22654

require the object lock to synchronize collapse.  Other swap objects such
as tmpfs do not.

Reported by:	mjg
Reviewed by:	kib, markj
Differential Revision:	https://reviews.freebsd.org/D22747

exec_map_first_page().  This will also enable pagein clustering for other
interested consumers (tmpfs, md, etc).

Discussed with:	alc
Approved by:	kib
Differential Revision:	https://reviews.freebsd.org/D22731

The message argument in the "deprecated" attribute was introduced in GCC 4.5 *.
Use the accurate version number for consistency, as done already with other
attributes.

* https://gcc.gnu.org/onlinedocs/gcc-4.5.0/gcc/Function-Attributes.html

This bit is already inside of a larger __BSD_VISIBLE block.

Reported by:	vangyzen

Probably all of these linuxkpi stubs should be '#ifndef' guarded, but maybe
that would prevent people from noticing when they are defined.

Introduced in r355759.  For some reason I only ran a buildworld and not a
kernel.  Mea culpa.

Reported by:	Mark Millard
X-MFC-with:	r355759

The legacy version of GCC4 currently in base does not support the
parameterized form of this function attribute, as recent introduced in
stdlib.h (r355747).

As we have done for other function attributes with similar compatibility
problems, add a version-compatibile definition in sys/cdefs.h.  Note that
Clang defines itself to be GCC 4, so one must check for __clang__ in
addition to __GNUC__ version.  On legacy GCC 4, the macro expands to just
the __deprecated__ attribute; on modern GCC or Clang, the macro expands to
the parameterized variant with the message.

Ignoring legacy or unsupported compilers, the macro is also beneficial in
that it is a bit more ergonomic than the full
__attribute__((__deprecated__())) boilerplate.

Reported by:	CI (but not tinderbox); imp and others
Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D22817

r355677 added NFSv4.2 support to the NFS client. This patch updates the
mount_nfs.8 man page to reflect that.
It also clarifies that the "nolockd" option does not apply to NFSv4 mounts.

This is a content change.

bits, by storing and modifying the complement of the original leaf
mask, and by avoiding some unnecessary intermediate variables in
computing the shift amounts. The logic is similar to what has recently
been committed to sys/sys/bitstring.h.

Compute better hint updates for the case when the cursor starts in
mid-leaf, and eliminates some otherwise viable solutions. Assume the
worst case, that all the eliminated offsets could have been solutions,
and you can still compute a better hint than we use now.

Eliminate some unnecessary conditional control flow.

Approved by: alc
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D22666

Unfortunately, there are some limitations:
- memory aperture of his controller is only 16MiB, so it is nearly
  unusable for graphic cards
- every attempt to generate type 1 config cycle always causes trap.
  These config cycles are disabled now and we don't support cards
  with PCIe switch.
- in some cases, attempt to do config cycle to (probably) not-yet ready
  card also causes trap. This cannot be detected at runtime, but it seems
  like very rare issue.

MFC after:	3 weeks
Differential Revision:  https://reviews.freebsd.org/D22724

over the usual fsync(2).

This silences some warnings when running "apt-get upgrade".

Reviewed by:	brooks, emaste
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D22371

MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D22371

Reviewed by:	brooks, emaste
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D22371

in a user-friendly way.

Reviewed by:	allanjude, bcr (manpages)
MFC after:	2 weeks
Relnotes:	yes
Sponsored by:	Klara Inc.
Differential Revision:	https://reviews.freebsd.org/D22567

statistics obtained with stats(3) in JSON format to standard error.

Reviewed by:	allanjude, thj, cem (earlier version)
Tested by:	thj
MFC after:	2 weeks
Relnotes:	yes
Sponsored by:	Klara Inc.
Differential Revision:	https://reviews.freebsd.org/D21324

It serves no useful purpose and wasn't as popular as its equally meritless
cousin, srandomdev(3).

Setting aside the problems with rand(3) in general, the problem with this
interface is that the seed isn't shared with the caller (other than by
attacking the output of the generator, which is trivial, but not a hallmark of
pleasant API design).  The (arguable) utility of rand(3) or random(3) is as a
semi-fast simulation generator which produces consistent results from a given
seed.  These are mutually at odd.  Furthermore, sometimes people got the
mistaken impression that a high quality random seed meant a weak generator like
rand(3) or random(3) could be used for things like cryptographic key
generation.  This is absolutely not so.

The API was never part of a standard and was not widely used in tree.  Existing
in-tree uses have all been removed.

Possible replacement in out of tree codebases:

	char buf[3];
	time_t t;

	time(t);
	strftime(buf, sizeof(buf), "%S", gmtime(&t));
	srand(atoi(buf));

Relnotes:	yes

Recently (r355315) the size of the struct uma_slab bitset field us_free
became dynamic instead of conservative.  Now, make the debug bitset
size dynamic too.  The debug bitset is INVARIANTS-only, so in fact we
don't care too much about the space savings that results from this, but
enabling minimally-sized slabs on INVARIANTS builds is still important
in order to be able to test new slab layouts effectively.

Reviewed by:	jeff (previous version), markj (previous version)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D22759

There's no reason for this to be a tunable. It's perfectly safe to
change this at runtime.

Reviewed by:	Lutz Donnerhacke
Differential Revision:	https://reviews.freebsd.org/D22737

Warn users when they try to add/delete/modify more items than the kernel will
allow.

Reviewed by:	allanjude (previous version), Lutz Donnerhacke
Differential Revision:	https://reviews.freebsd.org/D22733

Parse out the VSEC.  If the user invokes a second -c command line option,
do a hex dump of the vendor data.

Reviewed by:	imp
MFC after:	3 days
Sponsored by:	Intel
Differential Revision:	http://reviews.freebsd.org/D22808

Reviewed by:	np
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D22483

Merge ACPICA 20191213.

Document the common practices around copyrights with "all rights reserved" in
them as new copyright notices get added.

It's an open question qhether to point people at the fact that since the Berne
convention was ratified, All rights reserved is largely obsolete.
https://en.wikipedia.org/wiki/All_rights_reserved#Obsolescence has the
details. The committer's guide will be revised shortly, and it's likely that's a
better place for this discussion. If not, I'll add a blurb here.

Reviewed by: jhb@, brooks@
Differential Review: https://reviews.freebsd.org/D22800

Instead of passing NULL to fzap_name_equal and crashing, just return
ENOENT.  This happened when higher bits of a hash of the searched key
(its hash prefix) matched a hash prefix of some key in the ZAP, but the
full hash value of the searched key did not match any key in the ZAP.

I observerved this problem when loader tried to look up
"features_for_read" in a particular old pool that predates pool
features.

MFC after:	2 weeks
Sponsored by:	Panzura

Most places checked, but a couple last minute changes didn't. Make them all use
the return value.

Noticed by: rpokala@

Contractions cause problems for translators, so s/aren't/are not/ in the one
place this slipped through.

While here, noticed I commited with the date I did the work, not today's
date. Fix that too.

Noticed by: bjk@

None of these case were actually using the variable(s) uninitialized, but
I figured that silencing the warnings via initializing them made sense.

Some of these predated r355677.

All in-tree consumers have been converted to callout(9).

Reviewed by:	kib, markj
Differential Revision:	https://reviews.freebsd.org/D22602

CPL_TX_PKT_XT disables the internal parser on the chip and instead
relies on the driver to provide the exact length of the L2 and L3
headers.  This allows hw checksumming and TSO to be used with L2 and
L3 encapsulations that the chip doesn't understand directly.

Note that netmap tx still uses the old CPL as it never uses the hw
to generate the checksum on tx.

Reviewed by:	jhb@
MFC after:	1 month
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D22788

The settings in arith.h were not fully defined on powerpc64 after the gdtoa
switchover. Generate them using arithchk.c, similar to what AMD64 did for
r114814.

Technically, none of this is necessary in FreeBSD gdtoa, but since the other
platforms have full definitions, we might as well have full definitions
too.

Approved by:	jhibbits (in irc)
Differential Revision:	https://reviews.freebsd.org/D22775

Reviewed by:	imp
Tested by:	Scott Benesh
Differential Revision:	https://reviews.freebsd.org/D22598

Delay the attachment of children, when requested, until after interrutps are
running. This is often needed to allow children to run transactions on i2c or
spi busses. It's a common enough idiom that it will be useful to have its own
wrapper.

Reviewed by: ian
Differential Revision: https://reviews.freebsd.org/D21465

Reviewed by:	avg
Differential Revision:	https://reviews.freebsd.org/D22597

Allocate the callout structure on-demand from
fail_point_use_timeout_path() since most fail points do not use
timeouts.

Reviewed by:	markj (earlier version), cem
Differential Revision:	https://reviews.freebsd.org/D22599

- Allow the userland hypervisor to intercept breakpoint exceptions
  (BP#) in the guest.  A new capability (VM_CAP_BPT_EXIT) is used to
  enable this feature.  These exceptions are reported to userland via
  a new VM_EXITCODE_BPT that includes the length of the original
  breakpoint instruction.  If userland wishes to pass the exception
  through to the guest, it must be explicitly re-injected via
  vm_inject_exception().

- Export VMCS_ENTRY_INST_LENGTH as a VM_REG_GUEST_ENTRY_INST_LENGTH
  pseudo-register.  Injecting a BP# on Intel requires setting this to
  the length of the breakpoint instruction.  AMD SVM currently ignores
  writes to this register (but reports success) and fails to read it.

- Rework the per-vCPU state tracked by the debug server.  Rather than
  a single 'stepping_vcpu' global, add a structure for each vCPU that
  tracks state about that vCPU ('stepping', 'stepped', and
  'hit_swbreak').  A global 'stopped_vcpu' tracks which vCPU is
  currently reporting an event.  Event handlers for MTRAP and
  breakpoint exits loop until the associated event is reported to the
  debugger.

  Breakpoint events are discarded if the breakpoint is not present
  when a vCPU resumes in the breakpoint handler to retry submitting
  the breakpoint event.

- Maintain a linked-list of active breakpoints in response to the GDB
  'Z0' and 'z0' packets.

Reviewed by:	markj (earlier version)
MFC after:	2 months
Differential Revision:	https://reviews.freebsd.org/D20309