xref: /freebsd/sys/kern/subr_param.c (revision b0aaf8beb12609f8a94575ee21f849474bf7e03a)
19454b2d8SWarner Losh /*-
251369649SPedro F. Giffuni  * SPDX-License-Identifier: BSD-3-Clause
351369649SPedro F. Giffuni  *
4df8bae1dSRodney W. Grimes  * Copyright (c) 1980, 1986, 1989, 1993
5df8bae1dSRodney W. Grimes  *	The Regents of the University of California.  All rights reserved.
6df8bae1dSRodney W. Grimes  * (c) UNIX System Laboratories, Inc.
7df8bae1dSRodney W. Grimes  * All or some portions of this file are derived from material licensed
8df8bae1dSRodney W. Grimes  * to the University of California by American Telephone and Telegraph
9df8bae1dSRodney W. Grimes  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10df8bae1dSRodney W. Grimes  * the permission of UNIX System Laboratories, Inc.
11df8bae1dSRodney W. Grimes  *
12df8bae1dSRodney W. Grimes  * Redistribution and use in source and binary forms, with or without
13df8bae1dSRodney W. Grimes  * modification, are permitted provided that the following conditions
14df8bae1dSRodney W. Grimes  * are met:
15df8bae1dSRodney W. Grimes  * 1. Redistributions of source code must retain the above copyright
16df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer.
17df8bae1dSRodney W. Grimes  * 2. Redistributions in binary form must reproduce the above copyright
18df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer in the
19df8bae1dSRodney W. Grimes  *    documentation and/or other materials provided with the distribution.
2069a28758SEd Maste  * 3. Neither the name of the University nor the names of its contributors
21df8bae1dSRodney W. Grimes  *    may be used to endorse or promote products derived from this software
22df8bae1dSRodney W. Grimes  *    without specific prior written permission.
23df8bae1dSRodney W. Grimes  *
24df8bae1dSRodney W. Grimes  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25df8bae1dSRodney W. Grimes  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26df8bae1dSRodney W. Grimes  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27df8bae1dSRodney W. Grimes  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28df8bae1dSRodney W. Grimes  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29df8bae1dSRodney W. Grimes  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30df8bae1dSRodney W. Grimes  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31df8bae1dSRodney W. Grimes  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32df8bae1dSRodney W. Grimes  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33df8bae1dSRodney W. Grimes  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34df8bae1dSRodney W. Grimes  * SUCH DAMAGE.
35df8bae1dSRodney W. Grimes  */
36df8bae1dSRodney W. Grimes 
37677b542eSDavid E. O'Brien #include <sys/cdefs.h>
384bd49128SPeter Wemm #include "opt_param.h"
394053b05bSSergey Kandaurov #include "opt_msgbuf.h"
40cd853791SKonstantin Belousov #include "opt_maxphys.h"
41ee342e1bSPeter Wemm #include "opt_maxusers.h"
4250c73f36SGarrett Wollman 
43df8bae1dSRodney W. Grimes #include <sys/param.h>
44ee342e1bSPeter Wemm #include <sys/systm.h>
45756a5412SGleb Smirnoff #include <sys/buf.h>
46ee342e1bSPeter Wemm #include <sys/kernel.h>
4702c6fc21SKonstantin Belousov #include <sys/limits.h>
484053b05bSSergey Kandaurov #include <sys/msgbuf.h>
4902c6fc21SKonstantin Belousov #include <sys/sysctl.h>
5002c6fc21SKonstantin Belousov #include <sys/proc.h>
513b1f974bSKonstantin Belousov #include <sys/vnode.h>
52df8bae1dSRodney W. Grimes 
53e9a3f785SAlan Cox #include <vm/vm.h>
547419d1e2SDag-Erling Smørgrav #include <vm/vm_param.h>
55e9a3f785SAlan Cox #include <vm/pmap.h>
56cbc89bfbSPaul Saab 
57df8bae1dSRodney W. Grimes /*
58df8bae1dSRodney W. Grimes  * System parameter formulae.
59df8bae1dSRodney W. Grimes  */
60df8bae1dSRodney W. Grimes 
61df8bae1dSRodney W. Grimes #ifndef HZ
62bcebf6a1SNathan Whitehorn #  define	HZ 1000
637f03c419SMaxim Sobolev #  ifndef HZ_VM
64347e22a6SMike Silbersack #    define	HZ_VM 100
657f03c419SMaxim Sobolev #  endif
667f03c419SMaxim Sobolev #else
677f03c419SMaxim Sobolev #  ifndef HZ_VM
687f03c419SMaxim Sobolev #    define	HZ_VM HZ
697f03c419SMaxim Sobolev #  endif
708f650450SPeter Wemm #endif
71ee342e1bSPeter Wemm #define	NPROC (20 + 16 * maxusers)
72ee342e1bSPeter Wemm #ifndef NBUF
73ee342e1bSPeter Wemm #define NBUF 0
74ee342e1bSPeter Wemm #endif
755a00f364SDag-Erling Smørgrav #ifndef MAXFILES
761f57d8c6SKonstantin Belousov #define	MAXFILES (40 + 32 * maxusers)
775a00f364SDag-Erling Smørgrav #endif
78dd0b2081SDavid Greenman 
793610a226SIvan Voras static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS);
803610a226SIvan Voras 
815b999a6bSDavide Italiano int	hz;				/* system clock's frequency */
825b999a6bSDavide Italiano int	tick;				/* usec per tick (1000000 / hz) */
8335a33d14SHans Petter Selasky time_t	tick_seconds_max;		/* max hz * seconds an integer can hold */
845b999a6bSDavide Italiano struct bintime tick_bt;			/* bintime per tick (1s / hz) */
855b999a6bSDavide Italiano sbintime_t tick_sbt;
86ee342e1bSPeter Wemm int	maxusers;			/* base tunable */
87ee342e1bSPeter Wemm int	maxproc;			/* maximum # of processes */
88ee342e1bSPeter Wemm int	maxprocperuid;			/* max # of procs per user */
89ee342e1bSPeter Wemm int	maxfiles;			/* sys. wide open files limit */
90ee342e1bSPeter Wemm int	maxfilesperproc;		/* per-proc open files limit */
914053b05bSSergey Kandaurov int	msgbufsize;			/* size of kernel message buffer */
92cd853791SKonstantin Belousov int	nbuf;				/* number of bcache bufs */
93ee75e7deSKonstantin Belousov int	bio_transient_maxcnt;
94412f9500SBrooks Davis int	ngroups_max;			/* max # groups per process */
95ee342e1bSPeter Wemm int	nswbuf;
9602c6fc21SKonstantin Belousov pid_t	pid_max = PID_MAX;
97cd853791SKonstantin Belousov u_long	maxswzone;			/* max swmeta KVA storage */
98cd853791SKonstantin Belousov u_long	maxbcache;			/* max buffer cache KVA storage */
99cd853791SKonstantin Belousov u_long	maxpipekva;			/* Limit on pipe KVA */
100cd853791SKonstantin Belousov u_long	maxphys;			/* max raw I/O transfer size */
10101e1933dSJohn Baldwin int	vm_guest = VM_GUEST_NO;		/* Running as virtual machine guest? */
1027419d1e2SDag-Erling Smørgrav u_long	maxtsiz;			/* max text size */
1037419d1e2SDag-Erling Smørgrav u_long	dfldsiz;			/* initial data size limit */
1047419d1e2SDag-Erling Smørgrav u_long	maxdsiz;			/* max data size */
1057419d1e2SDag-Erling Smørgrav u_long	dflssiz;			/* initial stack size limit */
1067419d1e2SDag-Erling Smørgrav u_long	maxssiz;			/* max stack size */
1077419d1e2SDag-Erling Smørgrav u_long	sgrowsiz;			/* amount to grow stack */
108df8bae1dSRodney W. Grimes 
109af3b2549SHans Petter Selasky SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &hz, 0,
1109b84ba1cSJohn Baldwin     "Number of clock ticks per second");
111ee29897fSHans Petter Selasky SYSCTL_INT(_kern, OID_AUTO, hz_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MAXIMUM,
112ee29897fSHans Petter Selasky     "Maximum hz value supported");
113ee29897fSHans Petter Selasky SYSCTL_INT(_kern, OID_AUTO, hz_min, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MINIMUM,
114ee29897fSHans Petter Selasky     "Minimum hz value supported");
115af3b2549SHans Petter Selasky SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0,
1169b84ba1cSJohn Baldwin     "Number of buffers in the buffer cache");
117af3b2549SHans Petter Selasky SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0,
118b9f2a7daSJohn Baldwin     "Number of swap buffers");
119af3b2549SHans Petter Selasky SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0,
1204053b05bSSergey Kandaurov     "Size of the kernel message buffer");
121af3b2549SHans Petter Selasky SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0,
1229b84ba1cSJohn Baldwin     "Maximum memory for swap metadata");
123af3b2549SHans Petter Selasky SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0,
1249b84ba1cSJohn Baldwin     "Maximum value of vfs.maxbufspace");
125af3b2549SHans Petter Selasky SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
126ee75e7deSKonstantin Belousov     &bio_transient_maxcnt, 0,
127ee75e7deSKonstantin Belousov     "Maximum number of transient BIOs mappings");
128af3b2549SHans Petter Selasky SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0,
1299b84ba1cSJohn Baldwin     "Maximum text size");
130af3b2549SHans Petter Selasky SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0,
1319b84ba1cSJohn Baldwin     "Initial data size limit");
132af3b2549SHans Petter Selasky SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0,
1339b84ba1cSJohn Baldwin     "Maximum data size");
134af3b2549SHans Petter Selasky SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0,
1359b84ba1cSJohn Baldwin     "Initial stack size limit");
136af3b2549SHans Petter Selasky SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0,
1379b84ba1cSJohn Baldwin     "Maximum stack size");
138af3b2549SHans Petter Selasky SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0,
139ceb0f715SAndrey Zonov     "Amount to grow stack on a stack fault");
1407029da5cSPawel Biernacki SYSCTL_PROC(_kern, OID_AUTO, vm_guest,
1417029da5cSPawel Biernacki     CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE, NULL, 0,
1427029da5cSPawel Biernacki     sysctl_kern_vm_guest, "A",
14301e1933dSJohn Baldwin     "Virtual machine guest detected?");
1447c45a9c4SAlfred Perlstein 
145df8bae1dSRodney W. Grimes /*
1460b993ee5SAlan Cox  * The elements of this array are ordered based upon the values of the
1470b993ee5SAlan Cox  * corresponding enum VM_GUEST members.
1480b993ee5SAlan Cox  */
14934820bbfSBjoern A. Zeeb static const char *const vm_guest_sysctl_names[] = {
1501177d38cSStephen J. Kiernan 	[VM_GUEST_NO] = "none",
1511177d38cSStephen J. Kiernan 	[VM_GUEST_VM] = "generic",
1521177d38cSStephen J. Kiernan 	[VM_GUEST_XEN] = "xen",
1531177d38cSStephen J. Kiernan 	[VM_GUEST_HV] = "hv",
1541177d38cSStephen J. Kiernan 	[VM_GUEST_VMWARE] = "vmware",
1551177d38cSStephen J. Kiernan 	[VM_GUEST_KVM] = "kvm",
1561177d38cSStephen J. Kiernan 	[VM_GUEST_BHYVE] = "bhyve",
1571177d38cSStephen J. Kiernan 	[VM_GUEST_VBOX] = "vbox",
1581177d38cSStephen J. Kiernan 	[VM_GUEST_PARALLELS] = "parallels",
15934820bbfSBjoern A. Zeeb };
160*b0aaf8beSMateusz Guzik _Static_assert(nitems(vm_guest_sysctl_names) == VM_GUEST_LAST,
161733a6684SMateusz Guzik     "new vm guest type not added to vm_guest_sysctl_names");
16234820bbfSBjoern A. Zeeb 
1639722d88fSJason Evans /*
16466a11b9fSMatthew Dillon  * Boot time overrides that are not scaled against main memory
165ee342e1bSPeter Wemm  */
166ee342e1bSPeter Wemm void
16766a11b9fSMatthew Dillon init_param1(void)
168ee342e1bSPeter Wemm {
16901e1933dSJohn Baldwin 
1709d6ae1e3SColin Percival 	TSENTER();
17139cddbd7SKonstantin Belousov 
17239cddbd7SKonstantin Belousov 	/*
17339cddbd7SKonstantin Belousov 	 * arm64 and riscv currently hard-code the thread0 kstack size
17439cddbd7SKonstantin Belousov 	 * to KSTACK_PAGES, ignoring the tunable.
17539cddbd7SKonstantin Belousov 	 */
176edc82223SKonstantin Belousov 	TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages);
17739cddbd7SKonstantin Belousov 
1787f03c419SMaxim Sobolev 	hz = -1;
179ee342e1bSPeter Wemm 	TUNABLE_INT_FETCH("kern.hz", &hz);
1809bd2cbe4SJung-uk Kim 	if (hz == -1)
1813dc30911SIvan Voras 		hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ;
182ee29897fSHans Petter Selasky 
183ee29897fSHans Petter Selasky 	/* range check the "hz" value */
184ee29897fSHans Petter Selasky 	if (__predict_false(hz < HZ_MINIMUM))
185ee29897fSHans Petter Selasky 		hz = HZ_MINIMUM;
186ee29897fSHans Petter Selasky 	else if (__predict_false(hz > HZ_MAXIMUM))
187ee29897fSHans Petter Selasky 		hz = HZ_MAXIMUM;
188ee29897fSHans Petter Selasky 
189ee342e1bSPeter Wemm 	tick = 1000000 / hz;
1905b999a6bSDavide Italiano 	tick_sbt = SBT_1S / hz;
1915b999a6bSDavide Italiano 	tick_bt = sbttobt(tick_sbt);
19235a33d14SHans Petter Selasky 	tick_seconds_max = INT_MAX / hz;
193ee342e1bSPeter Wemm 
1945d8cce17SJohn Baldwin 	/*
1955d8cce17SJohn Baldwin 	 * Arrange for ticks to wrap 10 minutes after boot to help catch
1965d8cce17SJohn Baldwin 	 * sign problems sooner.
1975d8cce17SJohn Baldwin 	 */
1985d8cce17SJohn Baldwin 	ticks = INT_MAX - (hz * 10 * 60);
1995d8cce17SJohn Baldwin 
2003b1f974bSKonstantin Belousov 	vn_lock_pair_pause_max = hz / 100;
2013b1f974bSKonstantin Belousov 	if (vn_lock_pair_pause_max == 0)
2023b1f974bSKonstantin Belousov 		vn_lock_pair_pause_max = 1;
2033b1f974bSKonstantin Belousov 
204e1616f3aSMatthew Dillon #ifdef VM_SWZONE_SIZE_MAX
2052f9e4e80SMatthew Dillon 	maxswzone = VM_SWZONE_SIZE_MAX;
206e1616f3aSMatthew Dillon #endif
2075bd65606SJohn Baldwin 	TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
208e1616f3aSMatthew Dillon #ifdef VM_BCACHE_SIZE_MAX
2092f9e4e80SMatthew Dillon 	maxbcache = VM_BCACHE_SIZE_MAX;
210e1616f3aSMatthew Dillon #endif
2115bd65606SJohn Baldwin 	TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
2124053b05bSSergey Kandaurov 	msgbufsize = MSGBUF_SIZE;
2134053b05bSSergey Kandaurov 	TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize);
214cbc89bfbSPaul Saab 
215cbc89bfbSPaul Saab 	maxtsiz = MAXTSIZ;
2167419d1e2SDag-Erling Smørgrav 	TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
217cbc89bfbSPaul Saab 	dfldsiz = DFLDSIZ;
2187419d1e2SDag-Erling Smørgrav 	TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz);
219cbc89bfbSPaul Saab 	maxdsiz = MAXDSIZ;
2207419d1e2SDag-Erling Smørgrav 	TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz);
221cbc89bfbSPaul Saab 	dflssiz = DFLSSIZ;
2227419d1e2SDag-Erling Smørgrav 	TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz);
223cbc89bfbSPaul Saab 	maxssiz = MAXSSIZ;
2247419d1e2SDag-Erling Smørgrav 	TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz);
225cbc89bfbSPaul Saab 	sgrowsiz = SGROWSIZ;
2267419d1e2SDag-Erling Smørgrav 	TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz);
227412f9500SBrooks Davis 
228412f9500SBrooks Davis 	/*
229412f9500SBrooks Davis 	 * Let the administrator set {NGROUPS_MAX}, but disallow values
230412f9500SBrooks Davis 	 * less than NGROUPS_MAX which would violate POSIX.1-2008 or
231412f9500SBrooks Davis 	 * greater than INT_MAX-1 which would result in overflow.
232412f9500SBrooks Davis 	 */
233412f9500SBrooks Davis 	ngroups_max = NGROUPS_MAX;
234412f9500SBrooks Davis 	TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max);
235412f9500SBrooks Davis 	if (ngroups_max < NGROUPS_MAX)
236412f9500SBrooks Davis 		ngroups_max = NGROUPS_MAX;
23702c6fc21SKonstantin Belousov 
23802c6fc21SKonstantin Belousov 	/*
23902c6fc21SKonstantin Belousov 	 * Only allow to lower the maximal pid.
2403fa615bcSKonstantin Belousov 	 * Prevent setting up a non-bootable system if pid_max is too low.
24102c6fc21SKonstantin Belousov 	 */
24202c6fc21SKonstantin Belousov 	TUNABLE_INT_FETCH("kern.pid_max", &pid_max);
24302c6fc21SKonstantin Belousov 	if (pid_max > PID_MAX)
24402c6fc21SKonstantin Belousov 		pid_max = PID_MAX;
2453fa615bcSKonstantin Belousov 	else if (pid_max < 300)
2463fa615bcSKonstantin Belousov 		pid_max = 300;
247ee75e7deSKonstantin Belousov 
248ee75e7deSKonstantin Belousov 	TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed);
2499d6ae1e3SColin Percival 	TSEXIT();
250ee342e1bSPeter Wemm }
25166a11b9fSMatthew Dillon 
25266a11b9fSMatthew Dillon /*
25366a11b9fSMatthew Dillon  * Boot time overrides that are scaled against main memory
25466a11b9fSMatthew Dillon  */
25566a11b9fSMatthew Dillon void
256447b3772SPeter Wemm init_param2(long physpages)
25766a11b9fSMatthew Dillon {
25866a11b9fSMatthew Dillon 
2599d6ae1e3SColin Percival 	TSENTER();
26066a11b9fSMatthew Dillon 	/* Base parameters */
2610b94a0e9SMatthew Dillon 	maxusers = MAXUSERS;
2620b94a0e9SMatthew Dillon 	TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
2630b94a0e9SMatthew Dillon 	if (maxusers == 0) {
2644fbd563eSMatthew Dillon 		maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
26566a11b9fSMatthew Dillon 		if (maxusers < 32)
26666a11b9fSMatthew Dillon 			maxusers = 32;
26779f62ed6SAlfred Perlstein #ifdef VM_MAX_AUTOTUNE_MAXUSERS
26879f62ed6SAlfred Perlstein                 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS)
26979f62ed6SAlfred Perlstein                         maxusers = VM_MAX_AUTOTUNE_MAXUSERS;
27079f62ed6SAlfred Perlstein #endif
2717b6d92c0SAlfred Perlstein                 /*
27279f62ed6SAlfred Perlstein                  * Scales down the function in which maxusers grows once
27379f62ed6SAlfred Perlstein                  * we hit 384.
2747b6d92c0SAlfred Perlstein                  */
27579f62ed6SAlfred Perlstein                 if (maxusers > 384)
27679f62ed6SAlfred Perlstein                         maxusers = 384 + ((maxusers - 384) / 8);
27766a11b9fSMatthew Dillon         }
27866a11b9fSMatthew Dillon 
27966a11b9fSMatthew Dillon 	/*
28066a11b9fSMatthew Dillon 	 * The following can be overridden after boot via sysctl.  Note:
2812b7d656fSGordon Bergling 	 * unless overridden, these macros are ultimately based on maxusers.
28277a7d074SMike Silbersack 	 * Limit maxproc so that kmap entries cannot be exhausted by
28377a7d074SMike Silbersack 	 * processes.
28477a7d074SMike Silbersack 	 */
285ead46972SAndre Oppermann 	maxproc = NPROC;
286ead46972SAndre Oppermann 	TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
28777a7d074SMike Silbersack 	if (maxproc > (physpages / 12))
28877a7d074SMike Silbersack 		maxproc = physpages / 12;
2891f57d8c6SKonstantin Belousov 	if (maxproc > pid_max)
2901f57d8c6SKonstantin Belousov 		maxproc = pid_max;
291ebacce5eSMike Silbersack 	maxprocperuid = (maxproc * 9) / 10;
292ead46972SAndre Oppermann 
293ead46972SAndre Oppermann 	/*
294ead46972SAndre Oppermann 	 * The default limit for maxfiles is 1/12 of the number of
295ead46972SAndre Oppermann 	 * physical page but not less than 16 times maxusers.
296ead46972SAndre Oppermann 	 * At most it can be 1/6 the number of physical pages.
297ead46972SAndre Oppermann 	 */
298ead46972SAndre Oppermann 	maxfiles = imax(MAXFILES, physpages / 8);
299ead46972SAndre Oppermann 	TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
300ead46972SAndre Oppermann 	if (maxfiles > (physpages / 4))
301ead46972SAndre Oppermann 		maxfiles = physpages / 4;
302ead46972SAndre Oppermann 	maxfilesperproc = (maxfiles / 10) * 9;
30332766cd2SAdrian Chadd 	TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc);
30466a11b9fSMatthew Dillon 
30566a11b9fSMatthew Dillon 	/*
306347194c1SMike Silbersack 	 * Cannot be changed after boot.
307347194c1SMike Silbersack 	 */
308347194c1SMike Silbersack 	nbuf = NBUF;
309347194c1SMike Silbersack 	TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
310ee75e7deSKonstantin Belousov 	TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt);
311cd853791SKonstantin Belousov 	maxphys = MAXPHYS;
312cd853791SKonstantin Belousov 	TUNABLE_ULONG_FETCH("kern.maxphys", &maxphys);
313cd853791SKonstantin Belousov 	if (maxphys == 0) {
314cd853791SKonstantin Belousov 		maxphys = MAXPHYS;
315cd853791SKonstantin Belousov 	} else if (__bitcountl(maxphys) != 1) {	/* power of two */
316cd853791SKonstantin Belousov 		if (flsl(maxphys) == NBBY * sizeof(maxphys))
317cd853791SKonstantin Belousov 			maxphys = MAXPHYS;
318cd853791SKonstantin Belousov 		else
319cd853791SKonstantin Belousov 			maxphys = 1UL << flsl(maxphys);
320cd853791SKonstantin Belousov 	}
321cd853791SKonstantin Belousov 	if (maxphys < PAGE_SIZE)
322cd853791SKonstantin Belousov 		maxphys = MAXPHYS;
323347194c1SMike Silbersack 
324ead46972SAndre Oppermann 	/*
325756a5412SGleb Smirnoff 	 * Physical buffers are pre-allocated buffers (struct buf) that
326756a5412SGleb Smirnoff 	 * are used as temporary holders for I/O, such as paging I/O.
327756a5412SGleb Smirnoff 	 */
328756a5412SGleb Smirnoff 	TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf);
329756a5412SGleb Smirnoff 
330756a5412SGleb Smirnoff 	/*
331e9a3f785SAlan Cox 	 * The default for maxpipekva is min(1/64 of the kernel address space,
332e9a3f785SAlan Cox 	 * max(1/64 of main memory, 512KB)).  See sys_pipe.c for more details.
333347194c1SMike Silbersack 	 */
334cd853791SKonstantin Belousov 	maxpipekva = ptoa(physpages / 64);
335ead46972SAndre Oppermann 	TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva);
336289016f2SMike Silbersack 	if (maxpipekva < 512 * 1024)
337289016f2SMike Silbersack 		maxpipekva = 512 * 1024;
338e9a3f785SAlan Cox 	if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64)
339e9a3f785SAlan Cox 		maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) /
340e9a3f785SAlan Cox 		    64;
3419d6ae1e3SColin Percival 	TSEXIT();
34266a11b9fSMatthew Dillon }
3433610a226SIvan Voras 
3443610a226SIvan Voras /*
34546038d7fSKonstantin Belousov  * Sysctl stringifying handler for kern.vm_guest.
3463610a226SIvan Voras  */
3473610a226SIvan Voras static int
3483610a226SIvan Voras sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS)
3493610a226SIvan Voras {
350acfc962fSIan Lepore 	return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest]));
3513610a226SIvan Voras }
352