MFC r304910, r304912, r304915, r304952, r325019, r328164, r331094, r332664,
r335341-r335345, r335347, r335379-r335380, r335382

r304910:
Introduce cnv man page.

r304912:
Add missed header file for cnv.h .

r304915:
Bump date in the man page.

r304952:
Remove duplicated declaration.

r325019:
Introduce cnvlist_name() and cnvlist_type() functions.

Those function can be used when we are iterating over nvlist to reduce
amount of extra variables we need to declare.

r328164:
libnv: Use mallocarray(9) for the nv_calloc.

r331094:
Fix formatting errors that resulted in apropos(1) output looking weird.

r332664:
Add missing argument in the cnv man page.

r335341:
libnv: change name of cookie from cookiep to cookie.

The name was inconsistent with rest of the library.
No functional change intended.

r335342:
libnv: add const to cookies arguments

r335343:
libnv: Remove nvlist argument from cnvlist_{take,free}_* functions.

All information which are need for those operations is already stored in
the cookie.

We decided not to bump libnv version because this API is not used yet in the
base system.

r335344:
libnv: clean parent in nvlist_array when removing it.

When we are removing element form the nvlist we should also clean parent,
because the array is not a part of the nvlist anymore.

r335345:
libnv: add regression test for r335344.

r335347:
libnv: Add nvlist_append_*_array() family of functions.

The nvlist_append_{bool,number,string,nvlist,descriptor}_array() functions
allows to dynamically extend array stored in the nvlist.

r335379:
Set prev to NULL so its garaunteed to have a value of some kind and
gcc doesn't explode. Feel free to fix this correctly or whatever for
gcc builds.

This *should* quiesce tinderbox after r335347 for the gcc builds.

r335380:
style(9) fix, I was also going to silence gcc.

r335382:
Really fix the style.

Merge r317444, r317445:

UMA_ZONE_REFCNT was removed.

PR: 209715
PR: 218887

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix a bunch of "sentence not on new line" warnings in section 9.

MFC after: 1 month

Spelling fixes supplied by pfg@, detected with codespell, plus
additional misspellings detected by igor.

MFC after: 1 week

Read-only is hyphenated when it modifies a noun.

Add a safety net to reclaim mbufs when one of the mbuf zones become
exhausted.

It is possible for a bug in the code (or, theoretically, even unusual
network conditions) to exhaust all possible mbufs or mbuf clusters.
When this occurs, things can grind to a halt fairly quickly. However,
we currently do not call mb_reclaim() unless the entire system is
experiencing a low-memory condition.

While it is best to try to prevent exhaustion of one of the mbuf zones,
it would also be useful to have a mechanism to attempt to recover from
these situations by freeing "expendable" mbufs.

This patch makes two changes:

a) The patch adds a generic API to the UMA zone allocator to set a
function that should be called when an allocation fails because the
zone limit has been reached. Because of the way this function can be
called, it really should do minimal work.

b) The patch uses this API to try to free mbufs when an allocation
fails from one of the mbuf zones because the zone limit has been
reached. The function schedules a callout to run mb_reclaim().

Differential Revision: https://reviews.freebsd.org/D3864
Reviewed by: gnn
Comments by: rrs, glebius
MFC after: 2 weeks
Sponsored by: Juniper Networks

Fix various mdoc issues and some EOL whitespace.

Found with: mandoc -Tlint

use .Mt to mark up email addresses consistently (part6)

PR: 191174
Submitted by: Franco Fichtner <franco at lastsummer.de>

Provide macros that allow easily export uma(9) zone limits and
current usage via sysctl(9):

SYSCTL_UMA_MAX()
SYSCTL_ADD_UMA_MAX()
SYSCTL_UMA_CUR()
SYSCTL_ADD_UMA_CUR()

Sponsored by: Nginx, Inc.

Remove contractions.

Merge from projects/counters: UMA_ZONE_PCPU zones.

These zones have slab size == sizeof(struct pcpu), but request from VM
enough pages to fit (uk_slabsize * mp_ncpus). An item allocated from such
zone would have a separate twin for each CPU in the system, and these twins
are at a distance of sizeof(struct pcpu) from each other. This magic value
of distance would allow us to make some optimizations later.

To address private item from a CPU simple arithmetics should be used:

item = (type *)((char *)base + sizeof(struct pcpu) * curcpu)

These arithmetics are available as zpcpu_get() macro in pcpu.h.

To introduce non-page size slabs a new field had been added to uma_keg
uk_slabsize. This shifted some frequently used fields of uma_keg to the
fourth cache line on amd64. To mitigate this pessimization, uma_keg fields
were a bit rearranged and least frequently used uk_name and uk_link moved
down to the fourth cache line. All other fields, that are dereferenced
frequently fit into first three cache lines.

Sponsored by: Nginx, Inc.

Document some flags to the uma_zcreate(). Not all flags are documented,
only those that at least are used in the kernel, or that definitely
work.

Document uma_find_refcnt().

Implemented uma_zone_set_warning(9) function that sets a warning, which
will be printed once the given zone becomes full and cannot allocate an
item. The warning will not be printed more often than every five minutes.

All UMA warnings can be globally turned off by setting sysctl/tunable
vm.zone_warnings to 0.

Discussed on: arch
Obtained from: WHEEL Systems
MFC after: 2 weeks

Make it clear that NULL can only be returned when M_NOWAIT was used.

Fix various typos in manual pages.

Submitted by: amdmi3
PR: 165431
MFC after: 1 week

Globally replace u_int*_t from (non-contributed) man pages.

The reasoning behind this, is that if we are consistent in our
documentation about the uint*_t stuff, people will be less tempted to
write new code that uses the non-standard types.

I am not going to bump the man page dates, as these changes can be
considered style nits. The meaning of the man pages is unaffected.

MFC after: 1 month

Re-encode files from ISO-8859-1 to UTF-8

uma_zfree(zone, NULL) should do nothing, to match free(9).

Noticed by: Ron Steinke <rsteinke at isilon dot com>
MFC after: 3 days

Change uma_zone_set_max to return the effective value of "nitems" after
rounding. The same value can also be obtained with uma_zone_get_max, but this
change avoids a caller having to make two back-to-back calls.

Sponsored by: FreeBSD Foundation
Reviewed by: gnn, jhb

- Simplify implementation of uma_zone_get_max.
- Add uma_zone_get_cur which returns the current approximate occupancy of
a zone. This is useful for providing stats via sysctl amongst other things.

Sponsored by: FreeBSD Foundation
Reviewed by: gnn, jhb
MFC after: 2 weeks

Document the _arg versions of the uma_zalloc and uma_zfree functions.

PR: docs/120357
Submitted by: gahr
MFC after: 3 days

Bump document date for the previous change.

Remove long untrue note about storing state information inside free items.

OKed by: rwatson, tegge
Approved by: pjd (mentor)
MFC after: 1 week

I don't normally use my middle name, so remove it from attributions in
man pages (though not from copyright notices). While I'm here, add email
addresses where appropriate.

Document uma_zone_set_max and its non-obvious behaviour.

Reviewed by: bmilekic

Various mdoc(7) fixes:

Add devfs(5) reference - make_dev.9
Change .Xr from VFS_VGET(9) to vget(9) - vnode.9
Spelling fix, 'useage' to 'usage' - zone.9

Approved by: des (mentor)

mdoc(7) police: scheduled sweep.

Approved by: re

Flesh out the description of the uma_zcreate callback function arguements
a bit. As there may be changes soon we're still a bit vague unfortunatly.

mdoc(7) police: Fix SYNOPSIS, bump document date.

Add description for uma_zcreate().

Submitted by: arr

Chase the sources and document the change of wait to flags, which are
the normal malloc(9) flags.

Submitted by: arr

Remove references to zinit() which does not exist anymore.

Document the zone allocator is now a slab allocator.
Show Jeff's work and your's truly manual page updates.

Document uma_zalloc() behaviour.

Update function arguments to what is current used.

Prefix the remaining functions with uma_ as is now the case in UMA.

zinit() does not exist anymore.

Remove references to zbootinit() and zinitna().

Do not use a contraction, aren't -> are not.

Remove wrong include, one is supposed to include vm/uma.h instead of
vm_zone.h.

mdoc(7) police: get rid of WEOL and HSB introduced in rev 1.6.

Update function definitions and required include files to reflect
the current state of the system.

Approved by: alfred

Make the man page reflec t the code a bit better.
Specifically, note the condition of the memory on initial
and subsequent allocations is different.

mdoc(7) police: Use the new .In macro for #include statements.

mdoc(7) police: add zdestroy() to NAME.

Document zdestroy().

Reviewed by: des

Fixed missing and/or wrong and/or extra includes in synopsis.

Style police.

Submitted by: ru

Add a man page for the zone allocator.