xref: /freebsd/sys/kern/subr_param.c (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
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	8.2 (Berkeley) 1/21/94
39  * $Id: param.c,v 1.7 1995/02/16 11:29:19 joerg Exp $
40  */
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/socket.h>
45 #include <sys/proc.h>
46 #include <sys/vnode.h>
47 #include <sys/file.h>
48 #include <sys/callout.h>
49 #include <sys/clist.h>
50 #include <sys/mbuf.h>
51 #include <sys/kernel.h>
52 
53 #include <ufs/ufs/quota.h>
54 
55 #ifdef SYSVSHM
56 #include <machine/vmparam.h>
57 #include <sys/shm.h>
58 #endif
59 #ifdef SYSVSEM
60 #include "sys/sem.h"
61 #endif
62 #ifdef SYSVMSG
63 #include "sys/msg.h"
64 #endif
65 
66 /*
67  * System parameter formulae.
68  *
69  * This file is copied into each directory where we compile
70  * the kernel; it should be modified there to suit local taste
71  * if necessary.
72  *
73  * Compiled with -DHZ=xx -DTIMEZONE=x -DDST=x -DMAXUSERS=xx
74  */
75 
76 #ifndef HZ
77 #define	HZ 100
78 #endif
79 int	hz = HZ;
80 int	tick = 1000000 / HZ;
81 int	tickadj = 30000 / (60 * HZ);		/* can adjust 30ms in 60s */
82 struct	timezone tz = { TIMEZONE, DST };
83 #define	NPROC (20 + 16 * MAXUSERS)
84 int	maxproc = NPROC;			/* maximum # of processes */
85 int	maxprocperuid = NPROC-1;		/* maximum # of processes per user */
86 int	maxfiles = NPROC*2;			/* system wide open files limit */
87 int	maxfilesperproc = NPROC*2;			/* system wide open files limit */
88 int	ncallout = 16 + NPROC;			/* maximum # of timer events */
89 int	nmbclusters = NMBCLUSTERS;
90 int	fscale = FSCALE;	/* kernel uses `FSCALE', user uses `fscale' */
91 
92 /*
93  * Values in support of System V compatible shared memory.	XXX
94  */
95 #ifdef SYSVSHM
96 #ifndef SHMMAX
97 #define	SHMMAX	(SHMMAXPGS*NBPG)
98 #endif
99 #ifndef SHMMIN
100 #define	SHMMIN	1
101 #endif
102 #ifndef SHMMNI
103 #define	SHMMNI	32			/* <= SHMMMNI in shm.h */
104 #endif
105 #ifndef SHMSEG
106 #define	SHMSEG	8
107 #endif
108 #ifndef SHMALL
109 #define	SHMALL	(SHMMAXPGS/CLSIZE)
110 #endif
111 
112 struct	shminfo shminfo = {
113 	SHMMAX,
114 	SHMMIN,
115 	SHMMNI,
116 	SHMSEG,
117 	SHMALL
118 };
119 #endif
120 
121 /*
122  * Values in support of System V compatible semaphores.
123  */
124 
125 #ifdef SYSVSEM
126 
127 struct seminfo seminfo = {
128                 SEMMAP,         /* # of entries in semaphore map */
129                 SEMMNI,         /* # of semaphore identifiers */
130                 SEMMNS,         /* # of semaphores in system */
131                 SEMMNU,         /* # of undo structures in system */
132                 SEMMSL,         /* max # of semaphores per id */
133                 SEMOPM,         /* max # of operations per semop call */
134                 SEMUME,         /* max # of undo entries per process */
135                 SEMUSZ,         /* size in bytes of undo structure */
136                 SEMVMX,         /* semaphore maximum value */
137                 SEMAEM          /* adjust on exit max value */
138 };
139 #endif
140 
141 /*
142  * Values in support of System V compatible messages.
143  */
144 
145 #ifdef SYSVMSG
146 
147 struct msginfo msginfo = {
148                 MSGMAX,         /* max chars in a message */
149                 MSGMNI,         /* # of message queue identifiers */
150                 MSGMNB,         /* max chars in a queue */
151                 MSGTQL,         /* max messages in system */
152                 MSGSSZ,         /* size of a message segment */
153                 		/* (must be small power of 2 greater than 4) */
154                 MSGSEG          /* number of message segments */
155 };
156 #endif
157 
158 /*
159  * These are initialized at bootstrap time
160  * to values dependent on memory size
161  */
162 int	nbuf, nswbuf;
163 
164 /*
165  * These have to be allocated somewhere; allocating
166  * them here forces loader errors if this file is omitted
167  * (if they've been externed everywhere else; hah!).
168  */
169 struct 	callout *callout;
170 struct	cblock *cfree;
171 struct	buf *buf, *swbuf;
172 char	*buffers;
173 
174 /*
175  * Proc/pgrp hashing.
176  * Here so that hash table sizes can depend on MAXUSERS/NPROC.
177  * Hash size must be a power of two.
178  * NOW omission of this file will cause loader errors!
179  */
180 
181 #if NPROC > 1024
182 #define	PIDHSZ		512
183 #else
184 #if NPROC > 512
185 #define	PIDHSZ		256
186 #else
187 #if NPROC > 256
188 #define	PIDHSZ		128
189 #else
190 #define	PIDHSZ		64
191 #endif
192 #endif
193 #endif
194 
195 struct	proc *pidhash[PIDHSZ];
196 struct	pgrp *pgrphash[PIDHSZ];
197 int	pidhashmask = PIDHSZ - 1;
198