- Copy stable/10@285827 to releng/10.2 in preparation for 10.2-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.2.
- Update default pkg(8) configuration to use the quarterly branch.[1]

Discussed with: re, portmgr [1]
Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r273966:
Fix two issues with lockmgr(9) LK_CAN_SHARE() test, related
to the exclusive locker starvation.

MFC r273986:
Fix the build with ADAPTIVE_LOCKMGRS kernel option.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Document LK_TRYUPGRADE.

Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Approved by: re (marius)

lock.9: fix incorrect descriptions of LK_SHARED and LK_DOWNGRADE behavior

Reviewed by: attilio
MFC after: 5 days
X-MFC after: r243900

Typo and mdoc(7) style fixes.

PR: 168117
Submitted by: Nobuyuki Koganemaru (kogane&jp!freebsd!org)
MFC after: 3 days

Remove trailing whitespace per mdoc lint warning

Disussed with: gavin
No objection from: doc
Approved by: joel
MFC after: 3 days

Remove superfluous paragraph macro.

Constify arguments for locking KPIs where possible.

This enables locking consumers to pass their own structures around as const and
be able to assert locks embedded into those structures.

Reviewed by: ed, kib, jhb

Introduce support for adaptive spinning in lockmgr.
Actually, as it did receive few tuning, the support is disabled by
default, but it can opt-in with the option ADAPTIVE_LOCKMGRS.
Due to the nature of lockmgrs, adaptive spinning needs to be
selectively enabled for any interested lockmgr.
The support is bi-directional, or, in other ways, it will work in both
cases if the lock is held in read or write way. In particular, the
read path is passible of further tunning using the sysctls
debug.lockmgr.retries and debug.lockmgr.loops . Ideally, such sysctls
should be axed or compiled out before release.

Addictionally note that adaptive spinning doesn't cope well with
LK_SLEEPFAIL. The reason is that many (and probabilly all) consumers
of LK_SLEEPFAIL are mainly interested in knowing if the interlock was
dropped or not in order to reacquire it and re-test initial conditions.
This directly interacts with adaptive spinning because lockmgr needs
to drop the interlock while spinning in order to avoid a deadlock
(further details in the comments inside the patch).

Final note: finding someone willing to help on tuning this with
relevant workloads would be either very important and appreciated.

Tested by: jeff, pho
Requested by: many

Remove the assertive KA_HELD and KA_UNHELD as long as they are dangerous,
and not really helpful.

LK_NOWITNESS can be used now in lockmgr*() functions in order to skip
witness(4) checks on a per-instance basis.

Commit manpages for lockmgr_args_rw(9) and lockmgr_rw(9).

Document lockmgr_waiters(9).

Reviewed by: attilio

New sentence -> new line.

Fix lockstatus sorting on the top list.

- Add the informations for lockmgr_args(9)
- Sort rightly lockstatus(9) in the manpage

Update lockmgr manpage with last lockmgr modifies:
- Remove LK_SLEEPFAIL and LK_NOWAIT for lockinit() and add LK_QUIET and
LK_NOPROFILE
- Include sys/lock.h as mandatory for the lockmgr support

Modify VOP_ISLOCKED() and lockstatus() prototypes in order to reflect
'thread' argument axing.

Some language and mdoc style improvements.

Update manpage with lockmgr_assert() description.

Update manpage in order to reflect LK_NODUP and LK_NOWITNESS options
introduction.

Reflect lockcount() axing and lockmgr() prototype changing.

Add the newly added function lockmgr_recursed() to the manpages.

Fix typos.

Add lockmgr_disown() and relative explanation.

Trimm out now unused option LK_EXCLUPGRADE from the lockmgr namespace.
This option just adds complexity and the new implementation no longer
will support it, so axing it now that it is unused is probabilly the
better idea.

FreeBSD version is bumped in order to reflect the KPI breakage introduced
by this patch.

In the ports tree, kris found that only old OSKit code uses it, but as
it is thought to work only on 2.x kernels serie, version bumping will
solve any problem.

Remove duplicate xref and add missing commas.

PR: 113891
Submitted by: pluknet <pluknet@gmail.com>
Approved by: re (blanket)

Add some cross references to locking.9 from related pages.

Allow threads to atomically release rw and sx locks while waiting for an
event. Locking primitives that support this (mtx, rw, and sx) now each
include their own foo_sleep() routine.
- Rename msleep() to _sleep() and change it's 'struct mtx' object to a
'struct lock_object' pointer. _sleep() uses the recently added
lc_unlock() and lc_lock() function pointers for the lock class of the
specified lock to release the lock while the thread is suspended.
- Add wrappers around _sleep() for mutexes (mtx_sleep()), rw locks
(rw_sleep()), and sx locks (sx_sleep()). msleep() still exists and
is now identical to mtx_sleep(), but it is deprecated.
- Rename SLEEPQ_MSLEEP to SLEEPQ_SLEEP.
- Rewrite much of sleep.9 to not be msleep(9) centric.
- Flesh out the 'RETURN VALUES' section in sleep.9 and add an 'ERRORS'
section.
- Add __nonnull(1) to _sleep() and msleep_spin() so that the compiler will
warn if you try to pass a NULL wait channel. The functions already have
a KASSERT to that effect.

Note that LK_UPGRADE may drop the shared lock before taking the
exclusive one.

Reviewed and edited by: tegge
MFC after: 3 days
Approved by: pjd (mentor)

o Remove LK_REENABLE and LK_NOPAUSE lockinit(9) flags, add LK_NOSHARE.

MFC after: 1 week

Use 'manual page' instead of 'man page' for consistency.

Approved by: re (hrs)

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

Update the prototype for lockinit to reflect that wmesg is a const char *.

Fixed bad wording/spelling in few paragraphs.

Merged all of the lockmgr functions into a single file (lock.9); as well,
some content and layout changes were made.

lock.9 had existed before but was never added to Makefile, so it was
never installed. That is why the duplicate files were created in the
first place.

Reviewed by: ru, alfred

mdoc(7) police: tidy up the markup.

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

Approved by: alfred

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

mdoc(7) police: removed HISTORY info from the .Os call.

mdoc(7) police: remove extraneous .Pp before and/or after .Sh.

mdoc(7) police: add the missing and required .Dd macro call.

Add some very crude man pages to try to induce folk to work on them.

Agreed to work on them: jasone