subr_param.c revision 189744 
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: head/sys/kern/subr_param.c 189744 2009-03-12 17:21:58Z jhb $");
39
40#include "opt_param.h"
41#include "opt_maxusers.h"
42
43#include <sys/param.h>
44#include <sys/systm.h>
45#include <sys/kernel.h>
46#include <sys/sysctl.h>
47
48#include <vm/vm_param.h>
49
50/*
51 * System parameter formulae.
52 */
53
54#ifndef HZ
55#  if defined(__amd64__) || defined(__i386__) || defined(__ia64__) || defined(__sparc64__)
56#    define	HZ 1000
57#  else
58#    define	HZ 100
59#  endif
60#  ifndef HZ_VM
61#    define	HZ_VM 10
62#  endif
63#else
64#  ifndef HZ_VM
65#    define	HZ_VM HZ
66#  endif
67#endif
68#define	NPROC (20 + 16 * maxusers)
69#ifndef NBUF
70#define NBUF 0
71#endif
72#ifndef MAXFILES
73#define	MAXFILES (maxproc * 2)
74#endif
75
76/* Values of enum VM_GUEST members are used as indices in
77 * vm_guest_sysctl_names */
78enum VM_GUEST { VM_GUEST_NO = 0, VM_GUEST_VM, VM_GUEST_XEN };
79
80static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS);
81
82int	hz;
83int	tick;
84int	maxusers;			/* base tunable */
85int	maxproc;			/* maximum # of processes */
86int	maxprocperuid;			/* max # of procs per user */
87int	maxfiles;			/* sys. wide open files limit */
88int	maxfilesperproc;		/* per-proc open files limit */
89int	ncallout;			/* maximum # of timer events */
90int	nbuf;
91int	nswbuf;
92long	maxswzone;			/* max swmeta KVA storage */
93long	maxbcache;			/* max buffer cache KVA storage */
94long	maxpipekva;			/* Limit on pipe KVA */
95int 	vm_guest;			/* Running as virtual machine guest? */
96u_long	maxtsiz;			/* max text size */
97u_long	dfldsiz;			/* initial data size limit */
98u_long	maxdsiz;			/* max data size */
99u_long	dflssiz;			/* initial stack size limit */
100u_long	maxssiz;			/* max stack size */
101u_long	sgrowsiz;			/* amount to grow stack */
102
103SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN, &hz, 0, "ticks/second");
104SYSCTL_INT(_kern, OID_AUTO, ncallout, CTLFLAG_RDTUN, &ncallout, 0,
105    "Number of pre-allocated timer events");
106SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN, &nbuf, 0,
107    "Number of buffer-cache I/O buffers");
108SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN, &nswbuf, 0,
109    "Number of swap buffers");
110SYSCTL_INT(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN, &maxswzone, 0,
111    "max swmeta KVA storage");
112SYSCTL_INT(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN, &maxbcache, 0,
113    "max buffer cache KVA storage");
114SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RDTUN, &maxtsiz, 0,
115    "max text size");
116SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RDTUN, &dfldsiz, 0,
117    "initial data size limit");
118SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RDTUN, &maxdsiz, 0,
119    "max data size");
120SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RDTUN, &dflssiz, 0,
121    "initial stack size limit");
122SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RDTUN, &maxssiz, 0,
123    "max stack size");
124SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RDTUN, &sgrowsiz, 0,
125    "amount to grow stack");
126SYSCTL_PROC(_kern, OID_AUTO, vm_guest, CTLFLAG_RD | CTLTYPE_STRING,
127    NULL, 0, sysctl_kern_vm_guest, "A",
128    "Virtual machine detected? (none|generic|xen)");
129
130/*
131 * These have to be allocated somewhere; allocating
132 * them here forces loader errors if this file is omitted
133 * (if they've been externed everywhere else; hah!).
134 */
135struct	buf *swbuf;
136
137static const char *const vm_guest_sysctl_names[] = {
138	"none",
139	"generic",
140	"xen",
141	NULL
142};
143
144#ifndef XEN
145static const char *const vm_bnames[] = {
146	"QEMU",				/* QEMU */
147	"Plex86",			/* Plex86 */
148	"Bochs",			/* Bochs */
149	NULL
150};
151
152static const char *const vm_pnames[] = {
153	"VMware Virtual Platform",	/* VMWare VM */
154	"Virtual Machine",		/* Microsoft VirtualPC */
155	"VirtualBox",			/* Sun xVM VirtualBox */
156	"Parallels Virtual Platform",	/* Parallels VM */
157	NULL
158};
159
160
161/*
162 * Detect known Virtual Machine hosts by inspecting the emulated BIOS.
163 */
164static enum VM_GUEST
165detect_virtual(void)
166{
167	char *sysenv;
168	int i;
169
170	sysenv = getenv("smbios.bios.vendor");
171	if (sysenv != NULL) {
172		for (i = 0; vm_bnames[i] != NULL; i++)
173			if (strcmp(sysenv, vm_bnames[i]) == 0) {
174				freeenv(sysenv);
175				return (VM_GUEST_VM);
176			}
177		freeenv(sysenv);
178	}
179	sysenv = getenv("smbios.system.product");
180	if (sysenv != NULL) {
181		for (i = 0; vm_pnames[i] != NULL; i++)
182			if (strcmp(sysenv, vm_pnames[i]) == 0) {
183				freeenv(sysenv);
184				return (VM_GUEST_VM);
185			}
186		freeenv(sysenv);
187	}
188	return (VM_GUEST_NO);
189}
190#endif
191
192/*
193 * Boot time overrides that are not scaled against main memory
194 */
195void
196init_param1(void)
197{
198#ifndef XEN
199	vm_guest = detect_virtual();
200#else
201	vm_guest = VM_GUEST_XEN;
202#endif
203	hz = -1;
204	TUNABLE_INT_FETCH("kern.hz", &hz);
205	if (hz == -1)
206		hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ;
207	tick = 1000000 / hz;
208
209#ifdef VM_SWZONE_SIZE_MAX
210	maxswzone = VM_SWZONE_SIZE_MAX;
211#endif
212	TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
213#ifdef VM_BCACHE_SIZE_MAX
214	maxbcache = VM_BCACHE_SIZE_MAX;
215#endif
216	TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
217
218	maxtsiz = MAXTSIZ;
219	TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
220	dfldsiz = DFLDSIZ;
221	TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz);
222	maxdsiz = MAXDSIZ;
223	TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz);
224	dflssiz = DFLSSIZ;
225	TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz);
226	maxssiz = MAXSSIZ;
227	TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz);
228	sgrowsiz = SGROWSIZ;
229	TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz);
230}
231
232/*
233 * Boot time overrides that are scaled against main memory
234 */
235void
236init_param2(long physpages)
237{
238
239	/* Base parameters */
240	maxusers = MAXUSERS;
241	TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
242	if (maxusers == 0) {
243		maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
244		if (maxusers < 32)
245			maxusers = 32;
246		if (maxusers > 384)
247			maxusers = 384;
248	}
249
250	/*
251	 * The following can be overridden after boot via sysctl.  Note:
252	 * unless overriden, these macros are ultimately based on maxusers.
253	 */
254	maxproc = NPROC;
255	TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
256	/*
257	 * Limit maxproc so that kmap entries cannot be exhausted by
258	 * processes.
259	 */
260	if (maxproc > (physpages / 12))
261		maxproc = physpages / 12;
262	maxfiles = MAXFILES;
263	TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
264	maxprocperuid = (maxproc * 9) / 10;
265	maxfilesperproc = (maxfiles * 9) / 10;
266
267	/*
268	 * Cannot be changed after boot.
269	 */
270	nbuf = NBUF;
271	TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
272
273	ncallout = 16 + maxproc + maxfiles;
274	TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
275}
276
277/*
278 * Boot time overrides that are scaled against the kmem map
279 */
280void
281init_param3(long kmempages)
282{
283
284	/*
285	 * The default for maxpipekva is max(5% of the kmem map, 512KB).
286	 * See sys_pipe.c for more details.
287	 */
288	maxpipekva = (kmempages / 20) * PAGE_SIZE;
289	if (maxpipekva < 512 * 1024)
290		maxpipekva = 512 * 1024;
291	TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva);
292}
293
294/*
295 * Sysctl stringiying handler for kern.vm_guest.
296 */
297static int
298sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS)
299{
300	return (SYSCTL_OUT(req, vm_guest_sysctl_names[vm_guest],
301	    strlen(vm_guest_sysctl_names[vm_guest])));
302}
303