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

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

ksched: correct return code for invalid priority

By convention, EINVAL is returned when validating arguments, not EPERM.
This matches the documented behaviour of sched_setscheduler(3), and that
of SCHED_OTHER.

PR: 227735
MFC after: 1 week
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D37021

spdx: initial adoption of licensing ID tags.

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.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Initially, only tag files that use BSD 4-Clause "Original" license.

RelNotes: yes
Differential Revision: https://reviews.freebsd.org/D13133

Use P1B_PRIO_MAX to designate max posix priority for the RR/FIFO
scheduler types. It was intended to be used there, compare with the
min value, and with the test for correctness in ksched_setscheduler().

Note that P1B_PRIO_MAX and RTP_PRIO_MAX do have the same numerical
values, the change is cosmetical.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Remove single-use macros obfuscating malloc(9) and free(9) calls.
Style.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

sched_rr_interval() seems always returned period in hz ticks, but same
always it was used as rate. Fix use side units to period in hz ticks.

Use p4prio_to_tsprio to calculate TS priority instead of using
p4prio_to_rtpprio which is for RT priority.

PR: kern/157657
Submitted by: krivenok.dmitry at gmail dot com
MFC after: 3 days

Add some FEATURE macros for various features (AUDIT/CAM/IPC/KTR/MAC/NFS/NTP/
PMC/SYSV/...).

No FreeBSD version bump, the userland application to query the features will
be committed last and can serve as an indication of the availablility if
needed.

Sponsored by: Google Summer of Code 2010
Submitted by: kibab
Reviewed by: arch@ (parts by rwatson, trasz, jhb)
X-MFC after: to be determined in last commit with code from this project

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

MFC of 204670:
-------------------------
sched_getparam was just plain broke for time-share
processes. It did not return an error but instead
just let garbage be passed back. This I fix so
it actually properly translates the priority the
process is at to a posix's high means more priority.
I also fix it so that if the ULE scheduler has bumped
it up to a realtime process you get back a sane value
i.e. the highest priority (63 for time-share).

sched_setscheduler() had the setting of the
timeshare class priority disabled. With some notes
about rejecting the posix high numbers is greater
priority and use nice instead. This fix also
adjusts that to work, with the cavet that a t-s
process may well get bumped up or down i.e. the
setscheduler() will NOT change the nice value only
the current priority. I think this is reasonable
considering if the user wants to play with nice then
he can. At least all the posix'ish interfaces now
respond sanely.
-----------------------

sched_getparam was just plain broke for time-share
processes. It did not return an error but instead
just let garbage be passed back. This I fix so
it actually properly translates the priority the
process is at to a posix's high means more priority.
I also fix it so that if the ULE scheduler has bumped
it up to a realtime process you get back a sane value
i.e. the highest priority (63 for time-share).

sched_setscheduler() had the setting of the
timeshare class priority disabled. With some notes
about rejecting the posix high numbers is greater
priority and use nice instead. This fix also
adjusts that to work, with the cavet that a t-s
process may well get bumped up or down i.e. the
setscheduler() will NOT change the nice value only
the current priority. I think this is reasonable
considering if the user wants to play with nice then
he can. At least all the posix'ish interfaces now
respond sanely.

MFC after: 3 weeks

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

Commit 14/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.

Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)

Threading cleanup.. part 2 of several.

Make part of John Birrell's KSE patch permanent..
Specifically, remove:
Any reference of the ksegrp structure. This feature was
never fully utilised and made things overly complicated.
All code in the scheduler that tried to make threaded programs
fair to unthreaded programs. Libpthread processes will already
do this to some extent and libthr processes already disable it.

Also:
Since this makes such a big change to the scheduler(s), take the opportunity
to rename some structures and elements that had to be moved anyhow.
This makes the code a lot more readable.

The ULE scheduler compiles again but I have no idea if it works.

The 4bsd scheduler still reqires a little cleaning and some functions that now do
ALMOST nothing will go away, but I thought I'd do that as a separate commit.

Tested by David Xu, and Dan Eischen using libthr and libpthread.

Update #includes list.

Make KSE a kernel option, turned on by default in all GENERIC
kernel configs except sun4v (which doesn't process signals properly
with KSE).

Reviewed by: davidxu@

Return priority range 0..PRI_MAX_TIMESHARE-PRI_MIN_TIMESHARE for
SCHED_OTHER, the same range as rtprio() is using. In old code,
it returns nice range -20 .. 20, nice should be treated as process
weight, it is really managed by getpriority() and setpriority()
syscalls, they are different.

Extended the POSIX scheduler APIs to accept lwpid as well, we've already
done this in ptrace syscall, when a pid is large than PID_MAX, the syscall
will search a thread in current process. It permits 1:1 thread library to
get and set a thread's scheduler attributes.

Add scheduler API sched_relinquish(), the API is used to implement
yield() and sched_yield() syscalls. Every scheduler has its own way
to relinquish cpu, the ULE and CORE schedulers have two internal run-
queues, a timesharing thread which calls yield() syscall should be
moved to inactive queue.

Style fixes.

Submitted by: Diane Bruce < db at db dot net >

Use proc lock to prevent a thread from exiting, Giant was no longer used to
protect thread list.

/* -> /*- for license, minor formatting changes

sched_setscheduler: Return EINVAL when a invalid policy is specified,
thus complying with POLA and the man page. (Previously, no error was
returned for this case.)

Use __FBSDID().

Move a bunch of flags from the KSE to the thread.
I was in two minds as to where to put them in the first case..
I should have listenned to the other mind.

Submitted by: parts by davidxu@
Reviewed by: jeff@ mini@

headers should not really include "opt_foo.h" (in this case opt_posix.h).
remove it from the header and add it to the files that require it.

Tidy up the scheduler's code for changing the priority of a thread.
Logically pretty much a NOP.

- Create a new scheduler api that is defined in sys/sched.h
- Begin moving scheduler specific functionality into sched_4bsd.c
- Replace direct manipulation of scheduler data with hooks provided by the
new api.
- Remove KSE specific state modifications and single runq assumptions from
kern_switch.c

Reviewed by: -arch

Completely redo thread states.

Reviewed by: davidxu@freebsd.org

Part 1 of KSE-III

The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)

Reviewed by: Almost everyone who counts
(at various times, peter, jhb, matt, alfred, mini, bernd,
and a cast of thousands)

NOTE: this is still Beta code, and contains lots of debugging stuff.
expect slight instability in signals..

In a threaded world, differnt priorirites become properties of
different entities. Make it so.

Reviewed by: jhb@freebsd.org (john baldwin)

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after: ha ha ha ha

Protect pri_to_rtp() with sched_lock when needed.

- Close races with signals and other AST's being triggered while we are in
the process of exiting the kernel. The ast() function now loops as long
as the PS_ASTPENDING or PS_NEEDRESCHED flags are set. It returns with
preemption disabled so that any further AST's that arrive via an
interrupt will be delayed until the low-level MD code returns to user
mode.
- Use u_int's to store the tick counts for profiling purposes so that we
do not need sched_lock just to read p_sticks. This also closes a
problem where the call to addupc_task() could screw up the arithmetic
due to non-atomic reads of p_sticks.
- Axe need_proftick(), aston(), astoff(), astpending(), need_resched(),
clear_resched(), and resched_wanted() in favor of direct bit operations
on p_sflag.
- Fix up locking with sched_lock some. In addupc_intr(), use sched_lock
to ensure pr_addr and pr_ticks are updated atomically with setting
PS_OWEUPC. In ast() we clear pr_ticks atomically with clearing
PS_OWEUPC. We also do not grab the lock just to test a flag.
- Simplify the handling of Giant in ast() slightly.

Reviewed by: bde (mostly)

Undo part of the tangle of having sys/lock.h and sys/mutex.h included in
other "system" header files.

Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.

Sort sys/*.h includes where possible in affected files.

OK'ed by: bde (with reservations)

Overhaul of the SMP code. Several portions of the SMP kernel support have
been made machine independent and various other adjustments have been made
to support Alpha SMP.

- It splits the per-process portions of hardclock() and statclock() off
into hardclock_process() and statclock_process() respectively. hardclock()
and statclock() call the *_process() functions for the current process so
that UP systems will run as before. For SMP systems, it is simply necessary
to ensure that all other processors execute the *_process() functions when the
main clock functions are triggered on one CPU by an interrupt. For the alpha
4100, clock interrupts are delievered in a staggered broadcast fashion, so
we simply call hardclock/statclock on the boot CPU and call the *_process()
functions on the secondaries. For x86, we call statclock and hardclock as
usual and then call forward_hardclock/statclock in the MD code to send an IPI
to cause the AP's to execute forwared_hardclock/statclock which then call the
*_process() functions.
- forward_signal() and forward_roundrobin() have been reworked to be MI and to
involve less hackery. Now the cpu doing the forward sets any flags, etc. and
sends a very simple IPI_AST to the other cpu(s). AST IPIs now just basically
return so that they can execute ast() and don't bother with setting the
astpending or needresched flags themselves. This also removes the loop in
forward_signal() as sched_lock closes the race condition that the loop worked
around.
- need_resched(), resched_wanted() and clear_resched() have been changed to take
a process to act on rather than assuming curproc so that they can be used to
implement forward_roundrobin() as described above.
- Various other SMP variables have been moved to a MI subr_smp.c and a new
header sys/smp.h declares MI SMP variables and API's. The IPI API's from
machine/ipl.h have moved to machine/smp.h which is included by sys/smp.h.
- The globaldata_register() and globaldata_find() functions as well as the
SLIST of globaldata structures has become MI and moved into subr_smp.c.
Also, the globaldata list is only available if SMP support is compiled in.

Reviewed by: jake, peter
Looked over by: eivind

Lock need_resched with sched_lock.

Reported by: des

Implement a unified run queue and adjust priority levels accordingly.

- All processes go into the same array of queues, with different
scheduling classes using different portions of the array. This
allows user processes to have their priorities propogated up into
interrupt thread range if need be.
- I chose 64 run queues as an arbitrary number that is greater than
32. We used to have 4 separate arrays of 32 queues each, so this
may not be optimal. The new run queue code was written with this
in mind; changing the number of run queues only requires changing
constants in runq.h and adjusting the priority levels.
- The new run queue code takes the run queue as a parameter. This
is intended to be used to create per-cpu run queues. Implement
wrappers for compatibility with the old interface which pass in
the global run queue structure.
- Group the priority level, user priority, native priority (before
propogation) and the scheduling class into a struct priority.
- Change any hard coded priority levels that I found to use
symbolic constants (TTIPRI and TTOPRI).
- Remove the curpriority global variable and use that of curproc.
This was used to detect when a process' priority had lowered and
it should yield. We now effectively yield on every interrupt.
- Activate propogate_priority(). It should now have the desired
effect without needing to also propogate the scheduling class.
- Temporarily comment out the call to vm_page_zero_idle() in the
idle loop. It interfered with propogate_priority() because
the idle process needed to do a non-blocking acquire of Giant
and then other processes would try to propogate their priority
onto it. The idle process should not do anything except idle.
vm_page_zero_idle() will return in the form of an idle priority
kernel thread which is woken up at apprioriate times by the vm
system.
- Update struct kinfo_proc to the new priority interface. Deliberately
change its size by adjusting the spare fields. It remained the same
size, but the layout has changed, so userland processes that use it
would parse the data incorrectly. The size constraint should really
be changed to an arbitrary version number. Also add a debug.sizeof
sysctl node for struct kinfo_proc.

Remove unneeded #include <sys/kernel.h>

Commit major SMP cleanups and move the BGL (big giant lock) in the
syscall path inward. A system call may select whether it needs the MP
lock or not (the default being that it does need it).

A great deal of conditional SMP code for various deadended experiments
has been removed. 'cil' and 'cml' have been removed entirely, and the
locking around the cpl has been removed. The conditional
separately-locked fast-interrupt code has been removed, meaning that
interrupts must hold the CPL now (but they pretty much had to anyway).
Another reason for doing this is that the original separate-lock for
interrupts just doesn't apply to the interrupt thread mechanism being
contemplated.

Modifications to the cpl may now ONLY occur while holding the MP
lock. For example, if an otherwise MP safe syscall needs to mess with
the cpl, it must hold the MP lock for the duration and must (as usual)
save/restore the cpl in a nested fashion.

This is precursor work for the real meat coming later: avoiding having
to hold the MP lock for common syscalls and I/O's and interrupt threads.
It is expected that the spl mechanisms and new interrupt threading
mechanisms will be able to run in tandem, allowing a slow piecemeal
transition to occur.

This patch should result in a moderate performance improvement due to
the considerable amount of code that has been removed from the critical
path, especially the simplification of the spl*() calls. The real
performance gains will come later.

Approved by: jkh
Reviewed by: current, bde (exception.s)
Some work taken from: luoqi's patch

Fixed some type mismatches. p_retval[0] in struct proc has type
register_t, so pointers to it must be passed around as `register_t *',
not as `int *'. The type mismatches were non-benign on alphas, but
the broken code is normally only configured by LINT.

1. Add new defs for mins and maxs for the POSIX flavor priorities. They
end up being the same, but it doesn't look like you're comparing
apples and oranges.

2. Use need_resched instead of reset_priority. This isn't right
either, since for example you'll round-robin against equal priority FIFO
processes when lowering the priority of another process,
but this works better and a real fix needs to be in kern_synch and
not out here.

3. This is not a device driver: copyin/copyout the structure.

1. Don't use "nosys" and generate coredumps for unconfigured
system calls - return ENOSYS per the spec.

2. Fix interface stub to set priority properly.

Support compiling with `gcc -ansi'.

Include sys/resource.h to get PRIO_MAX.

Finish _POSIX_PRIORITY_SCHEDULING. Needs P1003_1B and
_KPOSIX_PRIORITY_SCHEDULING options to work. Changes:

Change all "posix4" to "p1003_1b". Misnamed files are left
as "posix4" until I'm told if I can simply delete them and add
new ones;

Add _POSIX_PRIORITY_SCHEDULING system calls for FreeBSD and Linux;

Add man pages for _POSIX_PRIORITY_SCHEDULING system calls;

Add options to LINT;

Minor fixes to P1003_1B code during testing.

Reviewed by: msmith, bde long ago
POSIX.4 headers and sysctl variables. Nothing should change
unless POSIX4 is defined or _POSIX_VERSION is set to 199309.