Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC 253656: Enhance the description of NOTE_TRACK:
- NOTE_TRACK has never triggered a NOTE_TRACK event from the parent pid.
If NOTE_FORK is set, the listener will get a NOTE_FORK event from
the parent pid, but not a separate NOTE_TRACK event.
- Explicitly note that the event added to monitor the child process
preserves the fflags from the original event.
- Move the description of NOTE_TRACKERR under NOTE_TRACK as it is not a
bit for the user to set (which is what this list pupports to be).
Also, explicitly note that if an error occurs, the NOTE_CHILD event
will not be generated.

MFC r233648:
Remove trailing whitespace per mdoc lint warning

Approved by: cperciva (implicit)

MFC 230857:

If multiple threads call kevent() to get AIO events on same kqueue fd,
it is possible that a single AIO event will be reported to multiple
threads, it is not threading friendly, and the existing API can not
control this behavior.
Allocate a kevent flags field sigev_notify_kevent_flags for AIO event
notification in sigevent, and allow user to pass EV_CLEAR, EV_DISPATCH
or EV_ONESHOT to AIO kernel code, user can control whether the event
should be cleared once it is retrieved by a thread. This change should
be comptaible with existing application, because the field should have
already been zero-filled, and no additional action will be taken by
kernel.

PR: kern/156567

MFC 231006:

Add 32-bit compat code for AIO kevent flags introduced in revision 230857.

MFC 231724:

Add notes about sigev_notify_kevent_flags introduced in revision 230857
which enables thread-friendly polling on same fd for AIO events.

Reviewed by: delphij

MFC 231777:

Bump .Dd date for previous revision.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

mdoc: drop redundant .Pp and .LP calls

They have no effect when coming in pairs, or before .Bl/.Bd

Fix typos and spelling mistakes.

The devices that supported EVFILT_NETDEV kqueue filters were removed in
r195175. Remove all definitions, documentation, and usage.

fifo_misc.c:
Remove all kqueue tests as fifo_io.c performs all those that
would have remained.

Reviewed by: rwatson
MFC after: 3 weeks
X-MFC note: don't change vlan_link_state() function signature

Add EV_RECEIPT to kevents.

EV_RECEIPT is useful to disambiguating error conditions when multiple
events structures are passed to kevent(2). The error code is returned
in the data field and EV_ERROR is set.

Approved by: rwatson (co-mentor)

Add the EV_DISPATCH flag to kevents.

When the EV_DISPATCH flag is used the event source will be disabled
immediately after the delivery of an event. This is similar to the
EV_ONESHOT flag but it doesn't delete the event.

Approved by: rwatson (co-mentor)

Add EVFILT_USER to kevents.

Add user events support to kernel events which are not associated with any
kernel mechanism but are triggered by user level code. This is useful for
adding user level events to an event handler that may also be monitoring
kernel events.

Approved by: rwatson (co-mentor)

We've been able to support EVFILT_VNODE filtering on non-UFS
file systems since 2005.

Submitted by: Igor Sysoev
Approved by: re (bmah)
MFC after: 3 days

Document that the data field for NOTE_EXIT holds the process exit status.

Submitted by: Jared Yanovich -phirerunner at comcast.net-
MFC after: 2 weeks

Markup fixes.

Note that the system only allows a maximum of kern.kq_calloutmax timers.

PR: docs/102353
Submitted by: phk
MFC after: 1 week

Update .Dd value.

Eliminate the original method of requesting notification of aio_read(2) and
aio_write(2) completion through kevent(2). This method does not work on
64-bit architectures. It was deprecated in FreeBSD 4.4. See revisions
1.87 and 1.70.2.7.

Change aio_physwakeup() to call psignal(9) directly rather than indirectly
through a timeout(9). Discussed with: bde

Correct a bug introduced in revision 1.65 that could result in premature
delivery of a signal if an lio_listio(2) consisted of a mixture of
direct/raw and queued I/O operations. Observed by: tegge

Eliminate a field from struct kaioinfo that is now unused.

Reviewed by: tegge

Mechanically kill hard sentence breaks.

Markup, grammar, and spelling fixes.

Spelling fixes.

Add mention of the fact that timeouts are silently limited to 24 hours.

Observed by: jmg

Add information about the EVFILT_NETDEV filter

PR: docs/56872 (based on)
Submitted by: Suleiman Souhlal <refugee@vt.edu>
Reviewed by: hmp, jmg

document the fact that kqueue will immediately return and not timeout when
nevents is 0.

PR: kern/45291

mdoc(7): Use the new feature of the .In macro.

add support for using kqueue to watch bpf sockets.

Submitted by: Brian Buchanan of nCircle, Inc.
Tested on: i386 and sparc64

mdoc(7) police: "The .Fa argument.".

mdoc(7) police: Tidy up the syscall language.

Stop calling system calls "function calls".

Use "The .Fn system call" a-la "The .Nm utility".

When referring to a non-BSD implementation in
the HISTORY section, call syscall a function,
to be safe.

Track the number of non-data chararacters stored in socket buffers so that
the data value returned by kevent()'s EVFILT_READ filter on non-TCP
sockets accurately reflects the amount of data that can be read from the
sockets by applications.

PR: 30634
Reviewed by: -net, -arch
Sponsored by: NTT Multimedia Communications Labs
MFC after: 2 weeks

While an interface can be depreciated, we prefer deprecated.

Submitted by: Wayne Morrison <tewok@tislabs.com>

Fix typo (SIGEV_EVENT -> SIGEV_KEVENT).

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

Typo: s/conatains/contains/

MFC after: 1 week

mdoc(7) police: remove whitespace at EOL.

Document EVFILT_TIMER.

MFC after: 1 week

Remove whitespace at EOL.

event.h -> sys/event.h

Submitted by: David Hill <david@phobia.ms>

Remove duplicate words.

Fix small bogon.

Submitted by: Anton Berezin <tobez@tobez.org>

Document various changes to kq:
- new EV_SET macro,
- NOTE_LOWAT option for low water marks on read/write filters,
- NOTE_REVOKE for filesystem unmounting (and revoke() calls)
- improved API for EVFILT_AIO

Add include <sys/time.h> because kevent uses struct timespec

Prepare for mdoc(7)NG.

mdoc(7) police: Er macro usage cleanup.

Fix a logic reversal: the RFFDG flag must be unset in order to share
a file descriptor table. (Thanks to Alan Cox)

Clarify the fact that the changelist and eventlist can be shared.

Clarify the time parameter of the kevent() system call.

Inspired by PR: 21708
Submitted by: Ronald F. Guilmette <rfg@monkeys.com>
Reviewed by: jlemon

Document return value of ENOENT for nonexistent/invalid filter entries.

Clean up some nits, with the permission of the author:
* Grammar fixes.
* Mark up rfork and vnode as cross-references.
* Clarify the use of the RFFDG flag to rfork(2).

Simplify kqueue API slightly.

Discussed on: -arch

remove sys/time.h by instruction from bde.

change first release date to 4.1-R as 5.0-R won't be out for at least a
year (from jkh)..

Caught by: Fx macro warning on 3.4-R

Replace .Va, .Ar and .Nm with .Fa or .Va where necessary, examples:
``.Ar errno'' -> ``.Va errno''
``.Nm ops'' -> ``.Fa ops''
``.Va fd'' -> ``.Fa fd''

add a BUGS section on how we can only watch VNODE's on a UFS file system
right now...

I talked w/ phk last night and "fixing" this in a generic way is going
to require a lot of complex thought on stacking let alone the NFS problems..

add missing sys/time.h for struct timespec def...

fix up the kqueue documentation... comment some things that were left
out that really needed to be here...

Reviewed-by: jlemon

Back out NOTE_EXIT status reporting pending discussion.

Put the wait(2) exit status in "data" for NOTE_EXIT kevents.

Fixed missing include in synopsis.

Use a long line instead splitting a line with backslash-newline in synopsis.
My synopsis checker doesn't understand backslash-newline.

Some mdoc cleanups for the manual page.

Submitted by: phantom

Add a kqueue(2) manual page.