xref: /freebsd/sys/kern/subr_param.c (revision 035e325c81b75ea3b5c878c55cc133672b6ac06d)
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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)param.c	8.3 (Berkeley) 8/20/94
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include "opt_param.h"
45 #include "opt_maxusers.h"
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/kernel.h>
50 
51 #include <machine/vmparam.h>
52 
53 /*
54  * System parameter formulae.
55  */
56 
57 #ifndef HZ
58 #define	HZ 100
59 #endif
60 #define	NPROC (20 + 16 * maxusers)
61 #ifndef NBUF
62 #define NBUF 0
63 #endif
64 #ifndef MAXFILES
65 #define	MAXFILES (maxproc * 2)
66 #endif
67 
68 int	hz;
69 int	tick;
70 int	maxusers;			/* base tunable */
71 int	maxproc;			/* maximum # of processes */
72 int	maxprocperuid;			/* max # of procs per user */
73 int	maxfiles;			/* sys. wide open files limit */
74 int	maxfilesperproc;		/* per-proc open files limit */
75 int	ncallout;			/* maximum # of timer events */
76 int	nbuf;
77 int	nswbuf;
78 int	maxswzone;			/* max swmeta KVA storage */
79 int	maxbcache;			/* max buffer cache KVA storage */
80 int	maxpipes;			/* Limit on # of pipes */
81 int	maxpipekva;			/* Limit on pipe KVA */
82 int	maxpipekvawired;		/* Limit on wired pipe KVA */
83 u_quad_t	maxtsiz;			/* max text size */
84 u_quad_t	dfldsiz;			/* initial data size limit */
85 u_quad_t	maxdsiz;			/* max data size */
86 u_quad_t	dflssiz;			/* initial stack size limit */
87 u_quad_t	maxssiz;			/* max stack size */
88 u_quad_t	sgrowsiz;			/* amount to grow stack */
89 
90 /*
91  * These have to be allocated somewhere; allocating
92  * them here forces loader errors if this file is omitted
93  * (if they've been externed everywhere else; hah!).
94  */
95 struct	buf *swbuf;
96 
97 /*
98  * Boot time overrides that are not scaled against main memory
99  */
100 void
101 init_param1(void)
102 {
103 
104 	hz = HZ;
105 	TUNABLE_INT_FETCH("kern.hz", &hz);
106 	tick = 1000000 / hz;
107 
108 #ifdef VM_SWZONE_SIZE_MAX
109 	maxswzone = VM_SWZONE_SIZE_MAX;
110 #endif
111 	TUNABLE_INT_FETCH("kern.maxswzone", &maxswzone);
112 #ifdef VM_BCACHE_SIZE_MAX
113 	maxbcache = VM_BCACHE_SIZE_MAX;
114 #endif
115 	TUNABLE_INT_FETCH("kern.maxbcache", &maxbcache);
116 
117 	maxtsiz = MAXTSIZ;
118 	TUNABLE_QUAD_FETCH("kern.maxtsiz", &maxtsiz);
119 	dfldsiz = DFLDSIZ;
120 	TUNABLE_QUAD_FETCH("kern.dfldsiz", &dfldsiz);
121 	maxdsiz = MAXDSIZ;
122 	TUNABLE_QUAD_FETCH("kern.maxdsiz", &maxdsiz);
123 	dflssiz = DFLSSIZ;
124 	TUNABLE_QUAD_FETCH("kern.dflssiz", &dflssiz);
125 	maxssiz = MAXSSIZ;
126 	TUNABLE_QUAD_FETCH("kern.maxssiz", &maxssiz);
127 	sgrowsiz = SGROWSIZ;
128 	TUNABLE_QUAD_FETCH("kern.sgrowsiz", &sgrowsiz);
129 }
130 
131 /*
132  * Boot time overrides that are scaled against main memory
133  */
134 void
135 init_param2(long physpages)
136 {
137 
138 	/* Base parameters */
139 	maxusers = MAXUSERS;
140 	TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
141 	if (maxusers == 0) {
142 		maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
143 		if (maxusers < 32)
144 			maxusers = 32;
145 		if (maxusers > 384)
146 			maxusers = 384;
147 	}
148 
149 	/*
150 	 * The following can be overridden after boot via sysctl.  Note:
151 	 * unless overriden, these macros are ultimately based on maxusers.
152 	 */
153 	maxproc = NPROC;
154 	TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
155 	/*
156 	 * Limit maxproc so that kmap entries cannot be exhausted by
157 	 * processes.
158 	 */
159 	if (maxproc > (physpages / 12))
160 		maxproc = physpages / 12;
161 	maxfiles = MAXFILES;
162 	TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
163 	maxprocperuid = (maxproc * 9) / 10;
164 	maxfilesperproc = (maxfiles * 9) / 10;
165 
166 	/*
167 	 * Cannot be changed after boot.
168 	 */
169 	nbuf = NBUF;
170 	TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
171 
172 	ncallout = 16 + maxproc + maxfiles;
173 	TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
174 }
175 
176 /*
177  * Boot time overrides that are scaled against the kernel map
178  */
179 void
180 init_param3(long kmempages)
181 {
182 	/*
183 	 * Limit number of pipes to a reasonable fraction of kmap entries,
184 	 * pageable pipe memory usage to 2.5% of the kernel map, and wired
185 	 * pipe memory usage to 1% of the same.  Ensure that all have
186 	 * reasonable floors.  (See sys_pipe.c for more info.)
187 	 */
188 	maxpipes = kmempages / 5;
189 	maxpipekva = (kmempages / 40) * PAGE_SIZE;
190 	maxpipekvawired = (kmempages / 100) * PAGE_SIZE;
191 
192 	if (maxpipes < 128)
193 		maxpipes = 128;
194 	if (maxpipekva < 512 * 1024)
195 		maxpipekva = 512 * 1024;
196 	if (maxpipekvawired < 512 * 1024)
197 		maxpipekvawired = 512 * 1024;
198 }
199