make MAXLWP a real option that triggers rebuilds properly.

Set a better default for MAXFILES on larger RAM machines if not
otherwise specified the kernel config file. Arbitary numbers are
20,000 files for 16GB RAM or more and 10,000 files for 1GB RAM or
more.

TODO: Adjust this and other values totally dynamically.

branches: 1.68.4; 1.68.12;
defparam all of the config variables associated with SYSV IPC stuff.
The variables were removed from sys/conf/param.c and moved into the
SYSV IPC code, but config options were never propagated via any opt_*
file.

This should fix an issue reported on netbsd-users list from Dima Veselov.

Note that this does not address other parameters included in that report,
including CHILD_MAX and NOFILE; this commit only affects items related to
the SYSV IPC code. Also note that this does not affect non-built-in
sysv_ipc modules, for which you need to update the Makefile to use any
non-standard config values - just like any other non-built-in modules
which have config params.

XXX Pull-up to -8 and -8-0

XXX Note that there are a couple of panic() calls in msginit() which
XXX really should be changed to simple printf() and then result in
XXX msginit failure. Unfortunately msginit() currently doesn't return
XXX a value so we cannot indicate failure to the caller. I will fix
XXX this is a future commit.

branches: 1.67.10; 1.67.18;
Whether or not the semaphore code is loaded as a module or built-in, its
sysctl data belongs with the module code. Move it from kern/init_sysctl.c
to kern/uipc_sem.c

While here, add a new sysctl variable kern.posix.semcnt (current count of
semaphores) to complement the existing kern.posix.semmax (maximum number
of semaphores).

to garnish, dust with _KERNEL_OPT

Create a new sysv_ipc module to contain the SYSVSHM, SYSVSEM, and
SYSVMSG options. Move associated variables out of param.c and into
the module's source file.

branches: 1.64.2; 1.64.16;
Add a new resource to limit the number of lwps per user, RLIMIT_NTHR. There
is a global sysctl kern.maxlwp to control this, which is by default 2048.
The first lwp of each process or kernel threads are not counted against the
limit. To show the current resource usage per user, I added a new sysctl
that dumps the uidinfo structure fields.

branches: 1.63.10;
Remove separate mb_map. The nmbclusters is computed at boot time based
on the amount of physical memory and limited by NMBCLUSTERS if present.
Architectures without direct mapping also limit it based on the kmem_map
size, which is used as backing store. On i386 and ARM, the maximum KVA
used for mbuf clusters is limited to 64MB by default.

The old default limits and limits based on GATEWAY have been removed.
key_registered_sb_max is hard-wired to a value derived from 2048
clusters.

branches: 1.62.2;
Move dovfsusermount to secmodel_bsd44, where it really belongs.

The secmodel code now creates the same knob in two places: both under the
secmodel itself, as well as the widely known location.

Mailing list references:

http://mail-index.netbsd.org/source-changes/2009/05/02/msg220641.html
http://mail-index.netbsd.org/tech-kern/2009/05/03/msg005015.html

Move dovfsusermount from vfs_syscalls.c to param.c: secmodel bsd44
depends on it and we can't isolate it in vfs.
(no, it doesn't really belong in param.c, but I couldn't figure out
a better place for it)

Remove SHMMAXPGS from all kernel configs. Dynamically compute the
initial limit as 1/4 of the physical memory. Ensure the limit is at
least 1024 pages, the old default on most platforms.

branches: 1.59.4;
Allow the POSIX semaphore code to be loaded as a module.

branches: 1.58.2;
Disable INCLUDE_CONFIG_FILE if compiling with PCC, since PCC cannot
handle 80KB string literals. Documented as hack.

branches: 1.57.2;
Replce exec_map with a pool. Proposed on tech-kern@, reviewed by chs@.

branches: 1.56.4; 1.56.6; 1.56.8;
ALIGNBYTES + 1, not ALIGNBYTES in previous.

Introduce COHERENCY_UNIT/coherency_unit as proposed on tech-kern.

Add a 'maxcpus' global.

branches: 1.53.2; 1.53.6;
Merge more changes from vmlocking2, mainly:

- Locking improvements.
- Use pool_cache for more items.

branches: 1.52.8; 1.52.14; 1.52.16; 1.52.20;
merge yamt-idlelwp branch. asked by core@. some ports still needs work.

from doc/BRANCHES:

idle lwp, and some changes depending on it.

1. separate context switching and thread scheduling.
(cf. gmcgarry_ctxsw)
2. implement idle lwp.
3. clean up related MD/MI interfaces.
4. make scheduler(s) modular.

branches: 1.51.2; 1.51.6; 1.51.8;
Remove long unused 'ncallout'.

branches: 1.50.20;
defparam NMBCLUSTERS.

merge ktrace-lwp.

branches: 1.48.12;
Disable autonicetime. As discusses in tech-kern.

avoid divide-by-zero in adjtime1() in the case of HZ > 6000.

defparam HZ.

s/NBPG/PAGE_SIZE/ in a comment.
From Jeff Ito in PR kern/23935.

Replace the traditional buffer memory management -- based on fixed per buffer
virtual memory reservation and a private pool of memory pages -- by a scheme
based on memory pools.

This allows better utilization of memory because buffers can now be allocated
with a granularity finer than the system's native page size (useful for
filesystems with e.g. 1k or 2k fragment sizes). It also avoids fragmentation
of virtual to physical memory mappings (due to the former fixed virtual
address reservation) resulting in better utilization of MMU resources on some
platforms. Finally, the scheme is more flexible by allowing run-time decisions
on the amount of memory to be used for buffers.

On the other hand, the effectiveness of the LRU queue for buffer recycling
may be somewhat reduced compared to the traditional method since, due to the
nature of the pool based memory allocation, the actual least recently used
buffer may release its memory to a pool different from the one needed by a
newly allocated buffer. However, this effect will kick in only if the
system is under memory pressure.

there is no SHMMMNI

Cache the "adjusted" value of sb_max when sb_max is changed, in order
to avoid doing quad math in sbreserve().

Change suggested by Simon Burge, and code inspired by a similar change
in FreeBSD.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.40.16;
Provide hooks to include the config file(s) in the kernel binary.

add RCSID

branches: 1.38.4;
allow SHMMAX, SHMMIN, SHMMNI and SHMSEG to be specified in the kernel config file.

branches: 1.37.2; 1.37.4;
Make SHMSEG much larger to accomodate GNOME and imlib.
It's limited by SHMMAXPGS anyway.

defopt SHMMAXPGS, SEMMNI, SEMMNS, SEMUME and SEMMNU

branches: 1.35.4;
Remove shmsegs declaration from conf/param.c - it doesn't belong here.
Instead, put it in kern/sysv_shm.c.

Declare the SysV IPC *info structures and shmsegs pointer as extern.
Add declaration for shmsegs to param.c after shminfo structure.

New callout mechanism with two major improvements over the old
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.

The old timeout()/untimeout() API has been removed from the kernel.

CL* discarding.

branches: 1.31.2; 1.31.8;
remove nbuf, nswbuf. cleanup def of AUTONICE(TIME|VAL)

g.c. now-unneeded variable declarations (cfree, swbuf, utsname

Add `mblowat' and `mcllowat' low water mark variables for mbufs and mbuf
clusters.

Const msize & mclbytes.

g/c REAL_CLISTS.

Move inclusion of "opt_sb_max.h" from sys/socketvar.h to
conf/param.c, and move the initialisation of the sb_max
variable from kern/uipc_socket2.c to conf/param.c. Now
everthing that includes sys/socketvar.h doesn't get
recompiled when SB_MAX's value changes.

branches: 1.25.8;
Compute compile-time value of old-VM parameter MAX_KMAPENT from NPROC
(2x NPROC plus slop) unless expclitly set. Use current constant value
(100) as a lower bound, as suggested by Chuck Cranor.

Move NPROC and other parameter definitions from param.c to param.h so
they are visible to vm/vm_map.h.

Systems with hand-tuned NPROC should now support that many processes.

Defopt SYSVMSG, SYSVSEM and SYSVSHM.

initial import of the new virtual memory system, UVM, into -current.

UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code. i provided some help
getting swap and paging working, and other bug fixes/ideas. chuck
silvers <chuq@chuq.com> also provided some other fixes.

this is the rest of the MI portion changes.

this will be KNF'd shortly. :-)

branches: 1.22.2;
Convert RTC_OFFSET, DEVPAGER, SWAPPAGER and VNODEPAGER to be declared
by defopt.

branches: 1.21.4;
Add compiled-in MCLBYTES and MSIZE to conf/param.c, as 'mclbytes" and "msize".

Add code to netstat to use libkvm to for kernel variables "mclbytes"
and "msize', and if found, use those for netstat -m rather than
compiled-in defaults.

branches: 1.20.4;
fix a large number of braindead unconditional #defines

Eliminate obsolete TIMEZONE and DST options.
Eliminate obsolete global kernel variable "struct timezone tz"
Add RTC_OFFSET option
Add global kernel variable rtc_offset, which is initialized by
RTC_OFFSET at kernel compile time.
on i386, x68k, mac68k, pc532 and arm32, RTC_OFFSET indicates how many
minutes west (east) of GMT the hardware RTC runs. Defaults to 0.
Places where tz variable was used to indicate this in the past have
been replaced with rtc_offset.
Add sysctl interface to rtc_offset.
Kill obsolete DST_* macros in sys/time.h
gettimeofday now always returns zeroed timezone if zone is requested.
settimeofday now ignores and logs attempts to set non-existant kernel
timezone.

branches: 1.18.2;
Fix p_nice vs. NZERO code.
Change NZERO to 20 to always make p_nice positive.
On Christos' suggestion make p_nice explicitly u_char.

Add compile-time and run-time control over automatic niceing

default DST and TIMEZONE to 0, if not already defined

don't do things that should only be necessary for 'real' clists.

Minor style cleanup.

Convert process, file, and namei lists and hash tables to use queue.h.

initialize shmmax to `# of pages' at compile time; multiply by NBPG at
boot time (in shminit). This supports architecture families with varying
values for NBPG, and does not break ipcs.

New RCS ID's, take two. they're more aesthecially pleasant, and use 'NetBSD'

new standard, minimally intrusive ID format

Update for 4.4 fs code.

maxfdescs checks out

copyright foo

Canonicalize all #includes.

Add the System V message queue and semaphore facilities. Implemented
by Daniel Boulet <danny@BouletFermat.ab.ca>

branches: 1.4.4;
fixed rcsids and cleaned up headers

diffs for uname (posix!) system call, provided by John Brezak <brezak@osf.org>

added maxfdescs definition

branches: 1.1.1;
Initial revision

Set a better default for MAXFILES on larger RAM machines if not
otherwise specified the kernel config file. Arbitary numbers are
20,000 files for 16GB RAM or more and 10,000 files for 1GB RAM or
more.

TODO: Adjust this and other values totally dynamically.

defparam all of the config variables associated with SYSV IPC stuff.
The variables were removed from sys/conf/param.c and moved into the
SYSV IPC code, but config options were never propagated via any opt_*
file.

This should fix an issue reported on netbsd-users list from Dima Veselov.

Note that this does not address other parameters included in that report,
including CHILD_MAX and NOFILE; this commit only affects items related to
the SYSV IPC code. Also note that this does not affect non-built-in
sysv_ipc modules, for which you need to update the Makefile to use any
non-standard config values - just like any other non-built-in modules
which have config params.

XXX Pull-up to -8 and -8-0

XXX Note that there are a couple of panic() calls in msginit() which
XXX really should be changed to simple printf() and then result in
XXX msginit failure. Unfortunately msginit() currently doesn't return
XXX a value so we cannot indicate failure to the caller. I will fix
XXX this is a future commit.

branches: 1.67.10; 1.67.18;
Whether or not the semaphore code is loaded as a module or built-in, its
sysctl data belongs with the module code. Move it from kern/init_sysctl.c
to kern/uipc_sem.c

While here, add a new sysctl variable kern.posix.semcnt (current count of
semaphores) to complement the existing kern.posix.semmax (maximum number
of semaphores).

to garnish, dust with _KERNEL_OPT

Create a new sysv_ipc module to contain the SYSVSHM, SYSVSEM, and
SYSVMSG options. Move associated variables out of param.c and into
the module's source file.

branches: 1.64.2; 1.64.16;
Add a new resource to limit the number of lwps per user, RLIMIT_NTHR. There
is a global sysctl kern.maxlwp to control this, which is by default 2048.
The first lwp of each process or kernel threads are not counted against the
limit. To show the current resource usage per user, I added a new sysctl
that dumps the uidinfo structure fields.

branches: 1.63.10;
Remove separate mb_map. The nmbclusters is computed at boot time based
on the amount of physical memory and limited by NMBCLUSTERS if present.
Architectures without direct mapping also limit it based on the kmem_map
size, which is used as backing store. On i386 and ARM, the maximum KVA
used for mbuf clusters is limited to 64MB by default.

The old default limits and limits based on GATEWAY have been removed.
key_registered_sb_max is hard-wired to a value derived from 2048
clusters.

branches: 1.62.2;
Move dovfsusermount to secmodel_bsd44, where it really belongs.

The secmodel code now creates the same knob in two places: both under the
secmodel itself, as well as the widely known location.

Mailing list references:

http://mail-index.netbsd.org/source-changes/2009/05/02/msg220641.html
http://mail-index.netbsd.org/tech-kern/2009/05/03/msg005015.html

Move dovfsusermount from vfs_syscalls.c to param.c: secmodel bsd44
depends on it and we can't isolate it in vfs.
(no, it doesn't really belong in param.c, but I couldn't figure out
a better place for it)

Remove SHMMAXPGS from all kernel configs. Dynamically compute the
initial limit as 1/4 of the physical memory. Ensure the limit is at
least 1024 pages, the old default on most platforms.

branches: 1.59.4;
Allow the POSIX semaphore code to be loaded as a module.

branches: 1.58.2;
Disable INCLUDE_CONFIG_FILE if compiling with PCC, since PCC cannot
handle 80KB string literals. Documented as hack.

branches: 1.57.2;
Replce exec_map with a pool. Proposed on tech-kern@, reviewed by chs@.

branches: 1.56.4; 1.56.6; 1.56.8;
ALIGNBYTES + 1, not ALIGNBYTES in previous.

Introduce COHERENCY_UNIT/coherency_unit as proposed on tech-kern.

Add a 'maxcpus' global.

branches: 1.53.2; 1.53.6;
Merge more changes from vmlocking2, mainly:

- Locking improvements.
- Use pool_cache for more items.

branches: 1.52.8; 1.52.14; 1.52.16; 1.52.20;
merge yamt-idlelwp branch. asked by core@. some ports still needs work.

from doc/BRANCHES:

idle lwp, and some changes depending on it.

1. separate context switching and thread scheduling.
(cf. gmcgarry_ctxsw)
2. implement idle lwp.
3. clean up related MD/MI interfaces.
4. make scheduler(s) modular.

branches: 1.51.2; 1.51.6; 1.51.8;
Remove long unused 'ncallout'.

branches: 1.50.20;
defparam NMBCLUSTERS.

merge ktrace-lwp.

branches: 1.48.12;
Disable autonicetime. As discusses in tech-kern.

avoid divide-by-zero in adjtime1() in the case of HZ > 6000.

defparam HZ.

s/NBPG/PAGE_SIZE/ in a comment.
From Jeff Ito in PR kern/23935.

Replace the traditional buffer memory management -- based on fixed per buffer
virtual memory reservation and a private pool of memory pages -- by a scheme
based on memory pools.

This allows better utilization of memory because buffers can now be allocated
with a granularity finer than the system's native page size (useful for
filesystems with e.g. 1k or 2k fragment sizes). It also avoids fragmentation
of virtual to physical memory mappings (due to the former fixed virtual
address reservation) resulting in better utilization of MMU resources on some
platforms. Finally, the scheme is more flexible by allowing run-time decisions
on the amount of memory to be used for buffers.

On the other hand, the effectiveness of the LRU queue for buffer recycling
may be somewhat reduced compared to the traditional method since, due to the
nature of the pool based memory allocation, the actual least recently used
buffer may release its memory to a pool different from the one needed by a
newly allocated buffer. However, this effect will kick in only if the
system is under memory pressure.

there is no SHMMMNI

Cache the "adjusted" value of sb_max when sb_max is changed, in order
to avoid doing quad math in sbreserve().

Change suggested by Simon Burge, and code inspired by a similar change
in FreeBSD.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.40.16;
Provide hooks to include the config file(s) in the kernel binary.

add RCSID

branches: 1.38.4;
allow SHMMAX, SHMMIN, SHMMNI and SHMSEG to be specified in the kernel config file.

branches: 1.37.2; 1.37.4;
Make SHMSEG much larger to accomodate GNOME and imlib.
It's limited by SHMMAXPGS anyway.

defopt SHMMAXPGS, SEMMNI, SEMMNS, SEMUME and SEMMNU

branches: 1.35.4;
Remove shmsegs declaration from conf/param.c - it doesn't belong here.
Instead, put it in kern/sysv_shm.c.

Declare the SysV IPC *info structures and shmsegs pointer as extern.
Add declaration for shmsegs to param.c after shminfo structure.

New callout mechanism with two major improvements over the old
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.

The old timeout()/untimeout() API has been removed from the kernel.

CL* discarding.

branches: 1.31.2; 1.31.8;
remove nbuf, nswbuf. cleanup def of AUTONICE(TIME|VAL)

g.c. now-unneeded variable declarations (cfree, swbuf, utsname

Add `mblowat' and `mcllowat' low water mark variables for mbufs and mbuf
clusters.

Const msize & mclbytes.

g/c REAL_CLISTS.

Move inclusion of "opt_sb_max.h" from sys/socketvar.h to
conf/param.c, and move the initialisation of the sb_max
variable from kern/uipc_socket2.c to conf/param.c. Now
everthing that includes sys/socketvar.h doesn't get
recompiled when SB_MAX's value changes.

branches: 1.25.8;
Compute compile-time value of old-VM parameter MAX_KMAPENT from NPROC
(2x NPROC plus slop) unless expclitly set. Use current constant value
(100) as a lower bound, as suggested by Chuck Cranor.

Move NPROC and other parameter definitions from param.c to param.h so
they are visible to vm/vm_map.h.

Systems with hand-tuned NPROC should now support that many processes.

Defopt SYSVMSG, SYSVSEM and SYSVSHM.

initial import of the new virtual memory system, UVM, into -current.

UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code. i provided some help
getting swap and paging working, and other bug fixes/ideas. chuck
silvers <chuq@chuq.com> also provided some other fixes.

this is the rest of the MI portion changes.

this will be KNF'd shortly. :-)

branches: 1.22.2;
Convert RTC_OFFSET, DEVPAGER, SWAPPAGER and VNODEPAGER to be declared
by defopt.

branches: 1.21.4;
Add compiled-in MCLBYTES and MSIZE to conf/param.c, as 'mclbytes" and "msize".

Add code to netstat to use libkvm to for kernel variables "mclbytes"
and "msize', and if found, use those for netstat -m rather than
compiled-in defaults.

branches: 1.20.4;
fix a large number of braindead unconditional #defines

Eliminate obsolete TIMEZONE and DST options.
Eliminate obsolete global kernel variable "struct timezone tz"
Add RTC_OFFSET option
Add global kernel variable rtc_offset, which is initialized by
RTC_OFFSET at kernel compile time.
on i386, x68k, mac68k, pc532 and arm32, RTC_OFFSET indicates how many
minutes west (east) of GMT the hardware RTC runs. Defaults to 0.
Places where tz variable was used to indicate this in the past have
been replaced with rtc_offset.
Add sysctl interface to rtc_offset.
Kill obsolete DST_* macros in sys/time.h
gettimeofday now always returns zeroed timezone if zone is requested.
settimeofday now ignores and logs attempts to set non-existant kernel
timezone.

branches: 1.18.2;
Fix p_nice vs. NZERO code.
Change NZERO to 20 to always make p_nice positive.
On Christos' suggestion make p_nice explicitly u_char.

Add compile-time and run-time control over automatic niceing

default DST and TIMEZONE to 0, if not already defined

don't do things that should only be necessary for 'real' clists.

Minor style cleanup.

Convert process, file, and namei lists and hash tables to use queue.h.

initialize shmmax to `# of pages' at compile time; multiply by NBPG at
boot time (in shminit). This supports architecture families with varying
values for NBPG, and does not break ipcs.

New RCS ID's, take two. they're more aesthecially pleasant, and use 'NetBSD'

new standard, minimally intrusive ID format

Update for 4.4 fs code.

maxfdescs checks out

copyright foo

Canonicalize all #includes.

Add the System V message queue and semaphore facilities. Implemented
by Daniel Boulet <danny@BouletFermat.ab.ca>

branches: 1.4.4;
fixed rcsids and cleaned up headers

diffs for uname (posix!) system call, provided by John Brezak <brezak@osf.org>

added maxfdescs definition

branches: 1.1.1;
Initial revision

defparam all of the config variables associated with SYSV IPC stuff.
The variables were removed from sys/conf/param.c and moved into the
SYSV IPC code, but config options were never propagated via any opt_*
file.

This should fix an issue reported on netbsd-users list from Dima Veselov.

Note that this does not address other parameters included in that report,
including CHILD_MAX and NOFILE; this commit only affects items related to
the SYSV IPC code. Also note that this does not affect non-built-in
sysv_ipc modules, for which you need to update the Makefile to use any
non-standard config values - just like any other non-built-in modules
which have config params.

XXX Pull-up to -8 and -8-0

XXX Note that there are a couple of panic() calls in msginit() which
XXX really should be changed to simple printf() and then result in
XXX msginit failure. Unfortunately msginit() currently doesn't return
XXX a value so we cannot indicate failure to the caller. I will fix
XXX this is a future commit.

branches: 1.67.10;
Whether or not the semaphore code is loaded as a module or built-in, its
sysctl data belongs with the module code. Move it from kern/init_sysctl.c
to kern/uipc_sem.c

While here, add a new sysctl variable kern.posix.semcnt (current count of
semaphores) to complement the existing kern.posix.semmax (maximum number
of semaphores).

to garnish, dust with _KERNEL_OPT

Create a new sysv_ipc module to contain the SYSVSHM, SYSVSEM, and
SYSVMSG options. Move associated variables out of param.c and into
the module's source file.

branches: 1.64.2; 1.64.16;
Add a new resource to limit the number of lwps per user, RLIMIT_NTHR. There
is a global sysctl kern.maxlwp to control this, which is by default 2048.
The first lwp of each process or kernel threads are not counted against the
limit. To show the current resource usage per user, I added a new sysctl
that dumps the uidinfo structure fields.

branches: 1.63.10;
Remove separate mb_map. The nmbclusters is computed at boot time based
on the amount of physical memory and limited by NMBCLUSTERS if present.
Architectures without direct mapping also limit it based on the kmem_map
size, which is used as backing store. On i386 and ARM, the maximum KVA
used for mbuf clusters is limited to 64MB by default.

The old default limits and limits based on GATEWAY have been removed.
key_registered_sb_max is hard-wired to a value derived from 2048
clusters.

branches: 1.62.2;
Move dovfsusermount to secmodel_bsd44, where it really belongs.

The secmodel code now creates the same knob in two places: both under the
secmodel itself, as well as the widely known location.

Mailing list references:

http://mail-index.netbsd.org/source-changes/2009/05/02/msg220641.html
http://mail-index.netbsd.org/tech-kern/2009/05/03/msg005015.html

Move dovfsusermount from vfs_syscalls.c to param.c: secmodel bsd44
depends on it and we can't isolate it in vfs.
(no, it doesn't really belong in param.c, but I couldn't figure out
a better place for it)

Remove SHMMAXPGS from all kernel configs. Dynamically compute the
initial limit as 1/4 of the physical memory. Ensure the limit is at
least 1024 pages, the old default on most platforms.

branches: 1.59.4;
Allow the POSIX semaphore code to be loaded as a module.

branches: 1.58.2;
Disable INCLUDE_CONFIG_FILE if compiling with PCC, since PCC cannot
handle 80KB string literals. Documented as hack.

branches: 1.57.2;
Replce exec_map with a pool. Proposed on tech-kern@, reviewed by chs@.

branches: 1.56.4; 1.56.6; 1.56.8;
ALIGNBYTES + 1, not ALIGNBYTES in previous.

Introduce COHERENCY_UNIT/coherency_unit as proposed on tech-kern.

Add a 'maxcpus' global.

branches: 1.53.2; 1.53.6;
Merge more changes from vmlocking2, mainly:

- Locking improvements.
- Use pool_cache for more items.

branches: 1.52.8; 1.52.14; 1.52.16; 1.52.20;
merge yamt-idlelwp branch. asked by core@. some ports still needs work.

from doc/BRANCHES:

idle lwp, and some changes depending on it.

1. separate context switching and thread scheduling.
(cf. gmcgarry_ctxsw)
2. implement idle lwp.
3. clean up related MD/MI interfaces.
4. make scheduler(s) modular.

branches: 1.51.2; 1.51.6; 1.51.8;
Remove long unused 'ncallout'.

branches: 1.50.20;
defparam NMBCLUSTERS.

merge ktrace-lwp.

branches: 1.48.12;
Disable autonicetime. As discusses in tech-kern.

avoid divide-by-zero in adjtime1() in the case of HZ > 6000.

defparam HZ.

s/NBPG/PAGE_SIZE/ in a comment.
From Jeff Ito in PR kern/23935.

Replace the traditional buffer memory management -- based on fixed per buffer
virtual memory reservation and a private pool of memory pages -- by a scheme
based on memory pools.

This allows better utilization of memory because buffers can now be allocated
with a granularity finer than the system's native page size (useful for
filesystems with e.g. 1k or 2k fragment sizes). It also avoids fragmentation
of virtual to physical memory mappings (due to the former fixed virtual
address reservation) resulting in better utilization of MMU resources on some
platforms. Finally, the scheme is more flexible by allowing run-time decisions
on the amount of memory to be used for buffers.

On the other hand, the effectiveness of the LRU queue for buffer recycling
may be somewhat reduced compared to the traditional method since, due to the
nature of the pool based memory allocation, the actual least recently used
buffer may release its memory to a pool different from the one needed by a
newly allocated buffer. However, this effect will kick in only if the
system is under memory pressure.

there is no SHMMMNI

Cache the "adjusted" value of sb_max when sb_max is changed, in order
to avoid doing quad math in sbreserve().

Change suggested by Simon Burge, and code inspired by a similar change
in FreeBSD.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.40.16;
Provide hooks to include the config file(s) in the kernel binary.

add RCSID

branches: 1.38.4;
allow SHMMAX, SHMMIN, SHMMNI and SHMSEG to be specified in the kernel config file.

branches: 1.37.2; 1.37.4;
Make SHMSEG much larger to accomodate GNOME and imlib.
It's limited by SHMMAXPGS anyway.

defopt SHMMAXPGS, SEMMNI, SEMMNS, SEMUME and SEMMNU

branches: 1.35.4;
Remove shmsegs declaration from conf/param.c - it doesn't belong here.
Instead, put it in kern/sysv_shm.c.

Declare the SysV IPC *info structures and shmsegs pointer as extern.
Add declaration for shmsegs to param.c after shminfo structure.

New callout mechanism with two major improvements over the old
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.

The old timeout()/untimeout() API has been removed from the kernel.

CL* discarding.

branches: 1.31.2; 1.31.8;
remove nbuf, nswbuf. cleanup def of AUTONICE(TIME|VAL)

g.c. now-unneeded variable declarations (cfree, swbuf, utsname

Add `mblowat' and `mcllowat' low water mark variables for mbufs and mbuf
clusters.

Const msize & mclbytes.

g/c REAL_CLISTS.

Move inclusion of "opt_sb_max.h" from sys/socketvar.h to
conf/param.c, and move the initialisation of the sb_max
variable from kern/uipc_socket2.c to conf/param.c. Now
everthing that includes sys/socketvar.h doesn't get
recompiled when SB_MAX's value changes.

branches: 1.25.8;
Compute compile-time value of old-VM parameter MAX_KMAPENT from NPROC
(2x NPROC plus slop) unless expclitly set. Use current constant value
(100) as a lower bound, as suggested by Chuck Cranor.

Move NPROC and other parameter definitions from param.c to param.h so
they are visible to vm/vm_map.h.

Systems with hand-tuned NPROC should now support that many processes.

Defopt SYSVMSG, SYSVSEM and SYSVSHM.

initial import of the new virtual memory system, UVM, into -current.

UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code. i provided some help
getting swap and paging working, and other bug fixes/ideas. chuck
silvers <chuq@chuq.com> also provided some other fixes.

this is the rest of the MI portion changes.

this will be KNF'd shortly. :-)

branches: 1.22.2;
Convert RTC_OFFSET, DEVPAGER, SWAPPAGER and VNODEPAGER to be declared
by defopt.

branches: 1.21.4;
Add compiled-in MCLBYTES and MSIZE to conf/param.c, as 'mclbytes" and "msize".

Add code to netstat to use libkvm to for kernel variables "mclbytes"
and "msize', and if found, use those for netstat -m rather than
compiled-in defaults.

branches: 1.20.4;
fix a large number of braindead unconditional #defines

Eliminate obsolete TIMEZONE and DST options.
Eliminate obsolete global kernel variable "struct timezone tz"
Add RTC_OFFSET option
Add global kernel variable rtc_offset, which is initialized by
RTC_OFFSET at kernel compile time.
on i386, x68k, mac68k, pc532 and arm32, RTC_OFFSET indicates how many
minutes west (east) of GMT the hardware RTC runs. Defaults to 0.
Places where tz variable was used to indicate this in the past have
been replaced with rtc_offset.
Add sysctl interface to rtc_offset.
Kill obsolete DST_* macros in sys/time.h
gettimeofday now always returns zeroed timezone if zone is requested.
settimeofday now ignores and logs attempts to set non-existant kernel
timezone.

branches: 1.18.2;
Fix p_nice vs. NZERO code.
Change NZERO to 20 to always make p_nice positive.
On Christos' suggestion make p_nice explicitly u_char.

Add compile-time and run-time control over automatic niceing

default DST and TIMEZONE to 0, if not already defined

don't do things that should only be necessary for 'real' clists.

Minor style cleanup.

Convert process, file, and namei lists and hash tables to use queue.h.

initialize shmmax to `# of pages' at compile time; multiply by NBPG at
boot time (in shminit). This supports architecture families with varying
values for NBPG, and does not break ipcs.

New RCS ID's, take two. they're more aesthecially pleasant, and use 'NetBSD'

new standard, minimally intrusive ID format

Update for 4.4 fs code.

maxfdescs checks out

copyright foo

Canonicalize all #includes.

Add the System V message queue and semaphore facilities. Implemented
by Daniel Boulet <danny@BouletFermat.ab.ca>

branches: 1.4.4;
fixed rcsids and cleaned up headers

diffs for uname (posix!) system call, provided by John Brezak <brezak@osf.org>

added maxfdescs definition

branches: 1.1.1;
Initial revision

Whether or not the semaphore code is loaded as a module or built-in, its
sysctl data belongs with the module code. Move it from kern/init_sysctl.c
to kern/uipc_sem.c

While here, add a new sysctl variable kern.posix.semcnt (current count of
semaphores) to complement the existing kern.posix.semmax (maximum number
of semaphores).

to garnish, dust with _KERNEL_OPT

Create a new sysv_ipc module to contain the SYSVSHM, SYSVSEM, and
SYSVMSG options. Move associated variables out of param.c and into
the module's source file.

branches: 1.64.16;
Add a new resource to limit the number of lwps per user, RLIMIT_NTHR. There
is a global sysctl kern.maxlwp to control this, which is by default 2048.
The first lwp of each process or kernel threads are not counted against the
limit. To show the current resource usage per user, I added a new sysctl
that dumps the uidinfo structure fields.

branches: 1.63.10;
Remove separate mb_map. The nmbclusters is computed at boot time based
on the amount of physical memory and limited by NMBCLUSTERS if present.
Architectures without direct mapping also limit it based on the kmem_map
size, which is used as backing store. On i386 and ARM, the maximum KVA
used for mbuf clusters is limited to 64MB by default.

The old default limits and limits based on GATEWAY have been removed.
key_registered_sb_max is hard-wired to a value derived from 2048
clusters.

branches: 1.62.2;
Move dovfsusermount to secmodel_bsd44, where it really belongs.

The secmodel code now creates the same knob in two places: both under the
secmodel itself, as well as the widely known location.

Mailing list references:

http://mail-index.netbsd.org/source-changes/2009/05/02/msg220641.html
http://mail-index.netbsd.org/tech-kern/2009/05/03/msg005015.html

Move dovfsusermount from vfs_syscalls.c to param.c: secmodel bsd44
depends on it and we can't isolate it in vfs.
(no, it doesn't really belong in param.c, but I couldn't figure out
a better place for it)

Remove SHMMAXPGS from all kernel configs. Dynamically compute the
initial limit as 1/4 of the physical memory. Ensure the limit is at
least 1024 pages, the old default on most platforms.

branches: 1.59.4;
Allow the POSIX semaphore code to be loaded as a module.

branches: 1.58.2;
Disable INCLUDE_CONFIG_FILE if compiling with PCC, since PCC cannot
handle 80KB string literals. Documented as hack.

branches: 1.57.2;
Replce exec_map with a pool. Proposed on tech-kern@, reviewed by chs@.

branches: 1.56.4; 1.56.6; 1.56.8;
ALIGNBYTES + 1, not ALIGNBYTES in previous.

Introduce COHERENCY_UNIT/coherency_unit as proposed on tech-kern.

Add a 'maxcpus' global.

branches: 1.53.2; 1.53.6;
Merge more changes from vmlocking2, mainly:

- Locking improvements.
- Use pool_cache for more items.

branches: 1.52.8; 1.52.14; 1.52.16; 1.52.20;
merge yamt-idlelwp branch. asked by core@. some ports still needs work.

from doc/BRANCHES:

idle lwp, and some changes depending on it.

1. separate context switching and thread scheduling.
(cf. gmcgarry_ctxsw)
2. implement idle lwp.
3. clean up related MD/MI interfaces.
4. make scheduler(s) modular.

branches: 1.51.2; 1.51.6; 1.51.8;
Remove long unused 'ncallout'.

branches: 1.50.20;
defparam NMBCLUSTERS.

merge ktrace-lwp.

branches: 1.48.12;
Disable autonicetime. As discusses in tech-kern.

avoid divide-by-zero in adjtime1() in the case of HZ > 6000.

defparam HZ.

s/NBPG/PAGE_SIZE/ in a comment.
From Jeff Ito in PR kern/23935.

Replace the traditional buffer memory management -- based on fixed per buffer
virtual memory reservation and a private pool of memory pages -- by a scheme
based on memory pools.

This allows better utilization of memory because buffers can now be allocated
with a granularity finer than the system's native page size (useful for
filesystems with e.g. 1k or 2k fragment sizes). It also avoids fragmentation
of virtual to physical memory mappings (due to the former fixed virtual
address reservation) resulting in better utilization of MMU resources on some
platforms. Finally, the scheme is more flexible by allowing run-time decisions
on the amount of memory to be used for buffers.

On the other hand, the effectiveness of the LRU queue for buffer recycling
may be somewhat reduced compared to the traditional method since, due to the
nature of the pool based memory allocation, the actual least recently used
buffer may release its memory to a pool different from the one needed by a
newly allocated buffer. However, this effect will kick in only if the
system is under memory pressure.

there is no SHMMMNI

Cache the "adjusted" value of sb_max when sb_max is changed, in order
to avoid doing quad math in sbreserve().

Change suggested by Simon Burge, and code inspired by a similar change
in FreeBSD.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.40.16;
Provide hooks to include the config file(s) in the kernel binary.

add RCSID

branches: 1.38.4;
allow SHMMAX, SHMMIN, SHMMNI and SHMSEG to be specified in the kernel config file.

branches: 1.37.2; 1.37.4;
Make SHMSEG much larger to accomodate GNOME and imlib.
It's limited by SHMMAXPGS anyway.

defopt SHMMAXPGS, SEMMNI, SEMMNS, SEMUME and SEMMNU

branches: 1.35.4;
Remove shmsegs declaration from conf/param.c - it doesn't belong here.
Instead, put it in kern/sysv_shm.c.

Declare the SysV IPC *info structures and shmsegs pointer as extern.
Add declaration for shmsegs to param.c after shminfo structure.

New callout mechanism with two major improvements over the old
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.

The old timeout()/untimeout() API has been removed from the kernel.

CL* discarding.

branches: 1.31.2; 1.31.8;
remove nbuf, nswbuf. cleanup def of AUTONICE(TIME|VAL)

g.c. now-unneeded variable declarations (cfree, swbuf, utsname

Add `mblowat' and `mcllowat' low water mark variables for mbufs and mbuf
clusters.

Const msize & mclbytes.

g/c REAL_CLISTS.

Move inclusion of "opt_sb_max.h" from sys/socketvar.h to
conf/param.c, and move the initialisation of the sb_max
variable from kern/uipc_socket2.c to conf/param.c. Now
everthing that includes sys/socketvar.h doesn't get
recompiled when SB_MAX's value changes.

branches: 1.25.8;
Compute compile-time value of old-VM parameter MAX_KMAPENT from NPROC
(2x NPROC plus slop) unless expclitly set. Use current constant value
(100) as a lower bound, as suggested by Chuck Cranor.

Move NPROC and other parameter definitions from param.c to param.h so
they are visible to vm/vm_map.h.

Systems with hand-tuned NPROC should now support that many processes.

Defopt SYSVMSG, SYSVSEM and SYSVSHM.

initial import of the new virtual memory system, UVM, into -current.

UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code. i provided some help
getting swap and paging working, and other bug fixes/ideas. chuck
silvers <chuq@chuq.com> also provided some other fixes.

this is the rest of the MI portion changes.

this will be KNF'd shortly. :-)

branches: 1.22.2;
Convert RTC_OFFSET, DEVPAGER, SWAPPAGER and VNODEPAGER to be declared
by defopt.

branches: 1.21.4;
Add compiled-in MCLBYTES and MSIZE to conf/param.c, as 'mclbytes" and "msize".

Add code to netstat to use libkvm to for kernel variables "mclbytes"
and "msize', and if found, use those for netstat -m rather than
compiled-in defaults.

branches: 1.20.4;
fix a large number of braindead unconditional #defines

Eliminate obsolete TIMEZONE and DST options.
Eliminate obsolete global kernel variable "struct timezone tz"
Add RTC_OFFSET option
Add global kernel variable rtc_offset, which is initialized by
RTC_OFFSET at kernel compile time.
on i386, x68k, mac68k, pc532 and arm32, RTC_OFFSET indicates how many
minutes west (east) of GMT the hardware RTC runs. Defaults to 0.
Places where tz variable was used to indicate this in the past have
been replaced with rtc_offset.
Add sysctl interface to rtc_offset.
Kill obsolete DST_* macros in sys/time.h
gettimeofday now always returns zeroed timezone if zone is requested.
settimeofday now ignores and logs attempts to set non-existant kernel
timezone.

branches: 1.18.2;
Fix p_nice vs. NZERO code.
Change NZERO to 20 to always make p_nice positive.
On Christos' suggestion make p_nice explicitly u_char.

Add compile-time and run-time control over automatic niceing

default DST and TIMEZONE to 0, if not already defined

don't do things that should only be necessary for 'real' clists.

Minor style cleanup.

Convert process, file, and namei lists and hash tables to use queue.h.

initialize shmmax to `# of pages' at compile time; multiply by NBPG at
boot time (in shminit). This supports architecture families with varying
values for NBPG, and does not break ipcs.

New RCS ID's, take two. they're more aesthecially pleasant, and use 'NetBSD'

new standard, minimally intrusive ID format

Update for 4.4 fs code.

maxfdescs checks out

copyright foo

Canonicalize all #includes.

Add the System V message queue and semaphore facilities. Implemented
by Daniel Boulet <danny@BouletFermat.ab.ca>

branches: 1.4.4;
fixed rcsids and cleaned up headers

diffs for uname (posix!) system call, provided by John Brezak <brezak@osf.org>

added maxfdescs definition

branches: 1.1.1;
Initial revision