xref: /freebsd/sys/kern/subr_param.c (revision 3157ba21)
1 /*-
2  * Copyright (c) 1980, 1986, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)param.c	8.3 (Berkeley) 8/20/94
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "opt_param.h"
41 #include "opt_maxusers.h"
42 
43 #include <sys/limits.h>
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/sysctl.h>
48 
49 #include <vm/vm_param.h>
50 
51 /*
52  * System parameter formulae.
53  */
54 
55 #ifndef HZ
56 #  if defined(__amd64__) || defined(__i386__) || defined(__ia64__) || defined(__sparc64__)
57 #    define	HZ 1000
58 #  else
59 #    define	HZ 100
60 #  endif
61 #  ifndef HZ_VM
62 #    define	HZ_VM 100
63 #  endif
64 #else
65 #  ifndef HZ_VM
66 #    define	HZ_VM HZ
67 #  endif
68 #endif
69 #define	NPROC (20 + 16 * maxusers)
70 #ifndef NBUF
71 #define NBUF 0
72 #endif
73 #ifndef MAXFILES
74 #define	MAXFILES (maxproc * 2)
75 #endif
76 
77 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS);
78 
79 int	hz;
80 int	tick;
81 int	maxusers;			/* base tunable */
82 int	maxproc;			/* maximum # of processes */
83 int	maxprocperuid;			/* max # of procs per user */
84 int	maxfiles;			/* sys. wide open files limit */
85 int	maxfilesperproc;		/* per-proc open files limit */
86 int	ncallout;			/* maximum # of timer events */
87 int	nbuf;
88 int	ngroups_max;			/* max # groups per process */
89 int	nswbuf;
90 long	maxswzone;			/* max swmeta KVA storage */
91 long	maxbcache;			/* max buffer cache KVA storage */
92 long	maxpipekva;			/* Limit on pipe KVA */
93 int 	vm_guest;			/* Running as virtual machine guest? */
94 u_long	maxtsiz;			/* max text size */
95 u_long	dfldsiz;			/* initial data size limit */
96 u_long	maxdsiz;			/* max data size */
97 u_long	dflssiz;			/* initial stack size limit */
98 u_long	maxssiz;			/* max stack size */
99 u_long	sgrowsiz;			/* amount to grow stack */
100 
101 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN, &hz, 0,
102     "Number of clock ticks per second");
103 SYSCTL_INT(_kern, OID_AUTO, ncallout, CTLFLAG_RDTUN, &ncallout, 0,
104     "Number of pre-allocated timer events");
105 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN, &nbuf, 0,
106     "Number of buffers in the buffer cache");
107 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN, &nswbuf, 0,
108     "Number of swap buffers");
109 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN, &maxswzone, 0,
110     "Maximum memory for swap metadata");
111 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN, &maxbcache, 0,
112     "Maximum value of vfs.maxbufspace");
113 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RDTUN, &maxtsiz, 0,
114     "Maximum text size");
115 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RDTUN, &dfldsiz, 0,
116     "Initial data size limit");
117 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RDTUN, &maxdsiz, 0,
118     "Maximum data size");
119 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RDTUN, &dflssiz, 0,
120     "Initial stack size limit");
121 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RDTUN, &maxssiz, 0,
122     "Maximum stack size");
123 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RDTUN, &sgrowsiz, 0,
124     "Amount to grow stack on a stack fault");
125 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, CTLFLAG_RD | CTLTYPE_STRING,
126     NULL, 0, sysctl_kern_vm_guest, "A",
127     "Virtual machine guest detected? (none|generic|xen)");
128 
129 /*
130  * These have to be allocated somewhere; allocating
131  * them here forces loader errors if this file is omitted
132  * (if they've been externed everywhere else; hah!).
133  */
134 struct	buf *swbuf;
135 
136 /*
137  * The elements of this array are ordered based upon the values of the
138  * corresponding enum VM_GUEST members.
139  */
140 static const char *const vm_guest_sysctl_names[] = {
141 	"none",
142 	"generic",
143 	"xen",
144 	NULL
145 };
146 
147 #ifndef XEN
148 static const char *const vm_bnames[] = {
149 	"QEMU",				/* QEMU */
150 	"Plex86",			/* Plex86 */
151 	"Bochs",			/* Bochs */
152 	NULL
153 };
154 
155 static const char *const vm_pnames[] = {
156 	"VMware Virtual Platform",	/* VMWare VM */
157 	"Virtual Machine",		/* Microsoft VirtualPC */
158 	"VirtualBox",			/* Sun xVM VirtualBox */
159 	"Parallels Virtual Platform",	/* Parallels VM */
160 	NULL
161 };
162 
163 
164 /*
165  * Detect known Virtual Machine hosts by inspecting the emulated BIOS.
166  */
167 static enum VM_GUEST
168 detect_virtual(void)
169 {
170 	char *sysenv;
171 	int i;
172 
173 	sysenv = getenv("smbios.bios.vendor");
174 	if (sysenv != NULL) {
175 		for (i = 0; vm_bnames[i] != NULL; i++)
176 			if (strcmp(sysenv, vm_bnames[i]) == 0) {
177 				freeenv(sysenv);
178 				return (VM_GUEST_VM);
179 			}
180 		freeenv(sysenv);
181 	}
182 	sysenv = getenv("smbios.system.product");
183 	if (sysenv != NULL) {
184 		for (i = 0; vm_pnames[i] != NULL; i++)
185 			if (strcmp(sysenv, vm_pnames[i]) == 0) {
186 				freeenv(sysenv);
187 				return (VM_GUEST_VM);
188 			}
189 		freeenv(sysenv);
190 	}
191 	return (VM_GUEST_NO);
192 }
193 #endif
194 
195 /*
196  * Boot time overrides that are not scaled against main memory
197  */
198 void
199 init_param1(void)
200 {
201 #ifndef XEN
202 	vm_guest = detect_virtual();
203 #else
204 	vm_guest = VM_GUEST_XEN;
205 #endif
206 	hz = -1;
207 	TUNABLE_INT_FETCH("kern.hz", &hz);
208 	if (hz == -1)
209 		hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ;
210 	tick = 1000000 / hz;
211 
212 #ifdef VM_SWZONE_SIZE_MAX
213 	maxswzone = VM_SWZONE_SIZE_MAX;
214 #endif
215 	TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
216 #ifdef VM_BCACHE_SIZE_MAX
217 	maxbcache = VM_BCACHE_SIZE_MAX;
218 #endif
219 	TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
220 
221 	maxtsiz = MAXTSIZ;
222 	TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
223 	dfldsiz = DFLDSIZ;
224 	TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz);
225 	maxdsiz = MAXDSIZ;
226 	TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz);
227 	dflssiz = DFLSSIZ;
228 	TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz);
229 	maxssiz = MAXSSIZ;
230 	TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz);
231 	sgrowsiz = SGROWSIZ;
232 	TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz);
233 
234 	/*
235 	 * Let the administrator set {NGROUPS_MAX}, but disallow values
236 	 * less than NGROUPS_MAX which would violate POSIX.1-2008 or
237 	 * greater than INT_MAX-1 which would result in overflow.
238 	 */
239 	ngroups_max = NGROUPS_MAX;
240 	TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max);
241 	if (ngroups_max < NGROUPS_MAX)
242 		ngroups_max = NGROUPS_MAX;
243 }
244 
245 /*
246  * Boot time overrides that are scaled against main memory
247  */
248 void
249 init_param2(long physpages)
250 {
251 
252 	/* Base parameters */
253 	maxusers = MAXUSERS;
254 	TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
255 	if (maxusers == 0) {
256 		maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
257 		if (maxusers < 32)
258 			maxusers = 32;
259 		if (maxusers > 384)
260 			maxusers = 384;
261 	}
262 
263 	/*
264 	 * The following can be overridden after boot via sysctl.  Note:
265 	 * unless overriden, these macros are ultimately based on maxusers.
266 	 */
267 	maxproc = NPROC;
268 	TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
269 	/*
270 	 * Limit maxproc so that kmap entries cannot be exhausted by
271 	 * processes.
272 	 */
273 	if (maxproc > (physpages / 12))
274 		maxproc = physpages / 12;
275 	maxfiles = MAXFILES;
276 	TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
277 	maxprocperuid = (maxproc * 9) / 10;
278 	maxfilesperproc = (maxfiles * 9) / 10;
279 
280 	/*
281 	 * Cannot be changed after boot.
282 	 */
283 	nbuf = NBUF;
284 	TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
285 
286 	ncallout = 16 + maxproc + maxfiles;
287 	TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
288 }
289 
290 /*
291  * Boot time overrides that are scaled against the kmem map
292  */
293 void
294 init_param3(long kmempages)
295 {
296 
297 	/*
298 	 * The default for maxpipekva is max(5% of the kmem map, 512KB).
299 	 * See sys_pipe.c for more details.
300 	 */
301 	maxpipekva = (kmempages / 20) * PAGE_SIZE;
302 	if (maxpipekva < 512 * 1024)
303 		maxpipekva = 512 * 1024;
304 	TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva);
305 }
306 
307 /*
308  * Sysctl stringiying handler for kern.vm_guest.
309  */
310 static int
311 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS)
312 {
313 	return (SYSCTL_OUT(req, vm_guest_sysctl_names[vm_guest],
314 	    strlen(vm_guest_sysctl_names[vm_guest])));
315 }
316