subr_param.c revision 172696 
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 172696 2007-10-16 10:40:53Z alfred $");
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#endif
61#define	NPROC (20 + 16 * maxusers)
62#ifndef NBUF
63#define NBUF 0
64#endif
65#ifndef MAXFILES
66#define	MAXFILES (maxproc * 2)
67#endif
68
69int	hz;
70int	tick;
71int	maxusers;			/* base tunable */
72int	maxproc;			/* maximum # of processes */
73int	maxprocperuid;			/* max # of procs per user */
74int	maxfiles;			/* sys. wide open files limit */
75int	maxfilesperproc;		/* per-proc open files limit */
76int	ncallout;			/* maximum # of timer events */
77int	nbuf;
78int	nswbuf;
79int	maxswzone;			/* max swmeta KVA storage */
80int	maxbcache;			/* max buffer cache KVA storage */
81int	maxpipekva;			/* Limit on pipe KVA */
82u_long	maxtsiz;			/* max text size */
83u_long	dfldsiz;			/* initial data size limit */
84u_long	maxdsiz;			/* max data size */
85u_long	dflssiz;			/* initial stack size limit */
86u_long	maxssiz;			/* max stack size */
87u_long	sgrowsiz;			/* amount to grow stack */
88
89SYSCTL_INT(_kern, OID_AUTO, maxswzone, CTLFLAG_RD, &maxswzone, 0, "");
90SYSCTL_INT(_kern, OID_AUTO, maxbcache, CTLFLAG_RD, &maxbcache, 0, "");
91SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RD, &maxtsiz, 0, "");
92SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RD, &dfldsiz, 0, "");
93SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RD, &maxdsiz, 0, "");
94SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RD, &dflssiz, 0, "");
95SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RD, &maxssiz, 0, "");
96SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RD, &sgrowsiz, 0, "");
97
98/*
99 * These have to be allocated somewhere; allocating
100 * them here forces loader errors if this file is omitted
101 * (if they've been externed everywhere else; hah!).
102 */
103struct	buf *swbuf;
104
105/*
106 * Boot time overrides that are not scaled against main memory
107 */
108void
109init_param1(void)
110{
111
112	hz = HZ;
113	TUNABLE_INT_FETCH("kern.hz", &hz);
114	tick = 1000000 / hz;
115
116#ifdef VM_SWZONE_SIZE_MAX
117	maxswzone = VM_SWZONE_SIZE_MAX;
118#endif
119	TUNABLE_INT_FETCH("kern.maxswzone", &maxswzone);
120#ifdef VM_BCACHE_SIZE_MAX
121	maxbcache = VM_BCACHE_SIZE_MAX;
122#endif
123	TUNABLE_INT_FETCH("kern.maxbcache", &maxbcache);
124
125	maxtsiz = MAXTSIZ;
126	TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
127	dfldsiz = DFLDSIZ;
128	TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz);
129	maxdsiz = MAXDSIZ;
130	TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz);
131	dflssiz = DFLSSIZ;
132	TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz);
133	maxssiz = MAXSSIZ;
134	TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz);
135	sgrowsiz = SGROWSIZ;
136	TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz);
137}
138
139/*
140 * Boot time overrides that are scaled against main memory
141 */
142void
143init_param2(long physpages)
144{
145
146	/* Base parameters */
147	maxusers = MAXUSERS;
148	TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
149	if (maxusers == 0) {
150		maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
151		if (maxusers < 32)
152			maxusers = 32;
153		if (maxusers > 384)
154			maxusers = 384;
155	}
156
157	/*
158	 * The following can be overridden after boot via sysctl.  Note:
159	 * unless overriden, these macros are ultimately based on maxusers.
160	 */
161	maxproc = NPROC;
162	TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
163	/*
164	 * Limit maxproc so that kmap entries cannot be exhausted by
165	 * processes.
166	 */
167	if (maxproc > (physpages / 12))
168		maxproc = physpages / 12;
169	maxfiles = MAXFILES;
170	TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
171	maxprocperuid = (maxproc * 9) / 10;
172	maxfilesperproc = (maxfiles * 9) / 10;
173
174	/*
175	 * Cannot be changed after boot.
176	 */
177	nbuf = NBUF;
178	TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
179
180	ncallout = 16 + maxproc + maxfiles;
181	TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
182}
183
184/*
185 * Boot time overrides that are scaled against the kernel map
186 */
187void
188init_param3(long kmempages)
189{
190
191	/*
192	 * The default for maxpipekva is max(5% of the kernel map, 512KB).
193	 * See sys_pipe.c for more details.
194	 */
195	maxpipekva = (kmempages / 20) * PAGE_SIZE;
196	if (maxpipekva < 512 * 1024)
197		maxpipekva = 512 * 1024;
198	TUNABLE_INT_FETCH("kern.ipc.maxpipekva", &maxpipekva);
199}
200