xref: /freebsd/sys/kern/subr_param.c (revision a316b26e50bbed7cf655fbba726ab87d8ab7599d)
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 1.4 1994/09/13 14:46:24 dfr 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	maxfiles = 256;				/* open files per process limit */
86 int	ncallout = 16 + NPROC;			/* maximum # of timer events */
87 int	nmbclusters = NMBCLUSTERS;
88 int	fscale = FSCALE;	/* kernel uses `FSCALE', user uses `fscale' */
89 
90 /*
91  * Values in support of System V compatible shared memory.	XXX
92  */
93 #ifdef SYSVSHM
94 #define	SHMMAX	(SHMMAXPGS*NBPG)
95 #define	SHMMIN	1
96 #define	SHMMNI	32			/* <= SHMMMNI in shm.h */
97 #define	SHMSEG	8
98 #define	SHMALL	(SHMMAXPGS/CLSIZE)
99 
100 struct	shminfo shminfo = {
101 	SHMMAX,
102 	SHMMIN,
103 	SHMMNI,
104 	SHMSEG,
105 	SHMALL
106 };
107 #endif
108 
109 /*
110  * Values in support of System V compatible semaphores.
111  */
112 
113 #ifdef SYSVSEM
114 
115 struct seminfo seminfo = {
116                 SEMMAP,         /* # of entries in semaphore map */
117                 SEMMNI,         /* # of semaphore identifiers */
118                 SEMMNS,         /* # of semaphores in system */
119                 SEMMNU,         /* # of undo structures in system */
120                 SEMMSL,         /* max # of semaphores per id */
121                 SEMOPM,         /* max # of operations per semop call */
122                 SEMUME,         /* max # of undo entries per process */
123                 SEMUSZ,         /* size in bytes of undo structure */
124                 SEMVMX,         /* semaphore maximum value */
125                 SEMAEM          /* adjust on exit max value */
126 };
127 #endif
128 
129 /*
130  * Values in support of System V compatible messages.
131  */
132 
133 #ifdef SYSVMSG
134 
135 struct msginfo msginfo = {
136                 MSGMAX,         /* max chars in a message */
137                 MSGMNI,         /* # of message queue identifiers */
138                 MSGMNB,         /* max chars in a queue */
139                 MSGTQL,         /* max messages in system */
140                 MSGSSZ,         /* size of a message segment */
141                 		/* (must be small power of 2 greater than 4) */
142                 MSGSEG          /* number of message segments */
143 };
144 #endif
145 
146 /*
147  * These are initialized at bootstrap time
148  * to values dependent on memory size
149  */
150 int	nbuf, nswbuf;
151 
152 /*
153  * These have to be allocated somewhere; allocating
154  * them here forces loader errors if this file is omitted
155  * (if they've been externed everywhere else; hah!).
156  */
157 struct 	callout *callout;
158 struct	cblock *cfree;
159 struct	buf *buf, *swbuf;
160 char	*buffers;
161 
162 /*
163  * Proc/pgrp hashing.
164  * Here so that hash table sizes can depend on MAXUSERS/NPROC.
165  * Hash size must be a power of two.
166  * NOW omission of this file will cause loader errors!
167  */
168 
169 #if NPROC > 1024
170 #define	PIDHSZ		512
171 #else
172 #if NPROC > 512
173 #define	PIDHSZ		256
174 #else
175 #if NPROC > 256
176 #define	PIDHSZ		128
177 #else
178 #define	PIDHSZ		64
179 #endif
180 #endif
181 #endif
182 
183 struct	proc *pidhash[PIDHSZ];
184 struct	pgrp *pgrphash[PIDHSZ];
185 int	pidhashmask = PIDHSZ - 1;
186