xref: /netbsd/sys/sys/param.h (revision c4a72b64)
1 /*	$NetBSD: param.h,v 1.153 2002/11/17 22:53:46 chs Exp $	*/
2 
3 /*-
4  * Copyright (c) 1982, 1986, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * (c) UNIX System Laboratories, Inc.
7  * All or some portions of this file are derived from material licensed
8  * to the University of California by American Telephone and Telegraph
9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10  * the permission of UNIX System Laboratories, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the University of
23  *	California, Berkeley and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  *
40  *	@(#)param.h	8.3 (Berkeley) 4/4/95
41  */
42 
43 #ifndef _SYS_PARAM_H_
44 #define	_SYS_PARAM_H_
45 
46 /*
47  * Historic BSD #defines -- probably will remain untouched for all time.
48  */
49 #define	BSD	199506		/* System version (year & month). */
50 #define	BSD4_3	1
51 #define	BSD4_4	1
52 
53 /*
54  *	#define __NetBSD_Version__ MMmmrrpp00
55  *
56  *	M = major version
57  *	m = minor version
58  *	r = release ["",A-Z,Z[A-Z] but numeric]
59  *	p = patchlevel
60  *
61  *	So:
62  *	     NetBSD-1.2D  = 102040000
63  *	And:
64  *	     NetBSD-1.2.1 = 102000100
65  *
66  *
67  * Don't forget to change conf/osrelease.sh too.
68  */
69 
70 #define	__NetBSD_Version__	106110000	/* NetBSD 1.6K */
71 
72 /*
73  * Historical NetBSD #define
74  *
75  * NetBSD 1.4 was the last release for which this value was incremented.
76  * The value is now permanently fixed at 199905. It will never be
77  * changed again.
78  *
79  * New code must use __NetBSD_Version__ instead, and should not even
80  * count on NetBSD being defined.
81  *
82  */
83 
84 #define	NetBSD	199905		/* NetBSD version (year & month). */
85 
86 #include <sys/null.h>
87 
88 #ifndef _LOCORE
89 #include <sys/inttypes.h>
90 #include <sys/types.h>
91 #endif
92 
93 /*
94  * Machine-independent constants (some used in following include files).
95  * Redefined constants are from POSIX 1003.1 limits file.
96  *
97  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
98  * MAXLOGNAME should be >= UT_NAMESIZE (see <utmp.h>)
99  */
100 #include <sys/syslimits.h>
101 
102 #define	MAXCOMLEN	16		/* max command name remembered */
103 #define	MAXINTERP	64		/* max interpreter file name length */
104 /* DEPRECATED: use LOGIN_NAME_MAX instead. */
105 #define	MAXLOGNAME	(LOGIN_NAME_MAX - 1) /* max login name length */
106 #define	NCARGS		ARG_MAX		/* max bytes for an exec function */
107 #define	NGROUPS		NGROUPS_MAX	/* max number groups */
108 #define	NOFILE		OPEN_MAX	/* max open files per process */
109 #define	NOGROUP		65535		/* marker for empty group set member */
110 #define	MAXHOSTNAMELEN	256		/* max hostname size */
111 
112 #ifndef MAXUPRC				/* max simultaneous processes */
113 #define	MAXUPRC		CHILD_MAX	/* POSIX 1003.1-compliant default */
114 #else
115 #if (MAXUPRC - 0) < CHILD_MAX
116 #error MAXUPRC less than CHILD_MAX.  See options(4) for details.
117 #endif /* (MAXUPRC - 0) < CHILD_MAX */
118 #endif /* !defined(MAXUPRC) */
119 
120 /* More types and definitions used throughout the kernel. */
121 #ifdef _KERNEL
122 #include <sys/cdefs.h>
123 #include <sys/errno.h>
124 #include <sys/time.h>
125 #include <sys/resource.h>
126 #include <sys/ucred.h>
127 #include <sys/uio.h>
128 #ifndef NPROC
129 #define	NPROC	(20 + 16 * MAXUSERS)
130 #endif
131 #ifndef NTEXT
132 #define	NTEXT	(80 + NPROC / 8)		/* actually the object cache */
133 #endif
134 #ifndef NVNODE
135 #define	NVNODE	(NPROC + NTEXT + 100)
136 #define	NVNODE_IMPLICIT
137 #endif
138 #endif /* _KERNEL */
139 
140 /* Signals. */
141 #include <sys/signal.h>
142 
143 /* Machine type dependent parameters. */
144 #include <machine/param.h>
145 #include <machine/limits.h>
146 
147 /*
148  * Stack macros.  On most architectures, the stack grows down,
149  * towards lower addresses; it is the rare architecture where
150  * it grows up, towards higher addresses.
151  *
152  * STACK_GROW and STACK_SHRINK adjust a stack pointer by some
153  * size, no questions asked.  STACK_ALIGN aligns a stack pointer.
154  *
155  * STACK_ALLOC returns a pointer to allocated stack space of
156  * some size; given such a pointer and a size, STACK_MAX gives
157  * the maximum (in the "maxsaddr" sense) stack address of the
158  * allocated memory.
159  */
160 #ifdef _KERNEL
161 #ifdef __MACHINE_STACK_GROWS_UP
162 #define	STACK_GROW(sp, _size)		(((caddr_t)(sp)) + (_size))
163 #define	STACK_SHRINK(sp, _size)		(((caddr_t)(sp)) - (_size))
164 #define	STACK_ALIGN(sp, bytes)	\
165 	((caddr_t)((((unsigned long)(sp)) + (bytes)) & ~(bytes)))
166 #define	STACK_ALLOC(sp, _size)		((caddr_t)(sp))
167 #define	STACK_MAX(p, _size)		(((caddr_t)(p)) + (_size))
168 #else
169 #define	STACK_GROW(sp, _size)		(((caddr_t)(sp)) - (_size))
170 #define	STACK_SHRINK(sp, _size)		(((caddr_t)(sp)) + (_size))
171 #define	STACK_ALIGN(sp, bytes)	\
172 	((caddr_t)(((unsigned long)(sp)) & ~(bytes)))
173 #define	STACK_ALLOC(sp, _size)		(((caddr_t)(sp)) - (_size))
174 #define	STACK_MAX(p, _size)		((caddr_t)(p))
175 #endif
176 #endif /* _KERNEL */
177 
178 /*
179  * Priorities.  Note that with 32 run queues, differences less than 4 are
180  * insignificant.
181  */
182 #define	PSWP	0
183 #define	PVM	4
184 #define	PINOD	8
185 #define	PRIBIO	16
186 #define	PVFS	20
187 #define	PZERO	22		/* No longer magic, shouldn't be here.  XXX */
188 #define	PSOCK	24
189 #define	PWAIT	32
190 #define	PLOCK	36
191 #define	PPAUSE	40
192 #define	PUSER	50
193 #define	MAXPRI	127		/* Priorities range from 0 through MAXPRI. */
194 
195 #define	PRIMASK 	0x0ff
196 #define	PCATCH		0x100	/* OR'd with pri for tsleep to check signals */
197 #define	PNORELOCK	0x200	/* OR'd with pri for cond_wait() to not relock
198 				   the interlock */
199 
200 #define	NBPW	sizeof(int)	/* number of bytes per word (integer) */
201 
202 #define	CMASK	022		/* default file mask: S_IWGRP|S_IWOTH */
203 #define	NODEV	(dev_t)(-1)	/* non-existent device */
204 
205 #define	CBLOCK	64		/* Clist block size, must be a power of 2. */
206 #define	CBQSIZE	(CBLOCK/NBBY)	/* Quote bytes/cblock - can do better. */
207 				/* Data chars/clist. */
208 #define	CBSIZE	(CBLOCK - (int)sizeof(struct cblock *) - CBQSIZE)
209 #define	CROUND	(CBLOCK - 1)	/* Clist rounding. */
210 
211 /*
212  * File system parameters and macros.
213  *
214  * The file system is made out of blocks of at most MAXBSIZE units, with
215  * smaller units (fragments) only in the last direct block.  MAXBSIZE
216  * primarily determines the size of buffers in the buffer pool.  It may be
217  * made larger without any effect on existing file systems; however making
218  * it smaller may make some file systems unmountable.
219  */
220 #ifndef MAXBSIZE				/* XXX */
221 #define	MAXBSIZE	MAXPHYS
222 #endif
223 #define	MAXFRAG 	8
224 
225 /*
226  * MAXPATHLEN defines the longest permissible path length after expanding
227  * symbolic links. It is used to allocate a temporary buffer from the buffer
228  * pool in which to do the name expansion, hence should be a power of two,
229  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
230  * maximum number of symbolic links that may be expanded in a path name.
231  * It should be set high enough to allow all legitimate uses, but halt
232  * infinite loops reasonably quickly.
233  */
234 #define	MAXPATHLEN	PATH_MAX
235 #define	MAXSYMLINKS	32
236 
237 /* Bit map related macros. */
238 #define	setbit(a,i)	((a)[(i)/NBBY] |= 1<<((i)%NBBY))
239 #define	clrbit(a,i)	((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
240 #define	isset(a,i)	((a)[(i)/NBBY] & (1<<((i)%NBBY)))
241 #define	isclr(a,i)	(((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
242 
243 /* Macros for counting and rounding. */
244 #ifndef howmany
245 #define	howmany(x, y)	(((x)+((y)-1))/(y))
246 #endif
247 #define	roundup(x, y)	((((x)+((y)-1))/(y))*(y))
248 #define	powerof2(x)	((((x)-1)&(x))==0)
249 
250 /* Macros for min/max. */
251 #define	MIN(a,b)	(((a)<(b))?(a):(b))
252 #define	MAX(a,b)	(((a)>(b))?(a):(b))
253 
254 /*
255  * Constants for setting the parameters of the kernel memory allocator.
256  *
257  * 2 ** MINBUCKET is the smallest unit of memory that will be
258  * allocated. It must be at least large enough to hold a pointer.
259  *
260  * Units of memory less or equal to MAXALLOCSAVE will permanently
261  * allocate physical memory; requests for these size pieces of
262  * memory are quite fast. Allocations greater than MAXALLOCSAVE must
263  * always allocate and free physical memory; requests for these
264  * size allocations should be done infrequently as they will be slow.
265  *
266  * Constraints: NBPG <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
267  * MAXALLOCSAVE must be a power of two.
268  */
269 #define	MINBUCKET	4		/* 4 => min allocation of 16 bytes */
270 #define	MAXALLOCSAVE	(2 * NBPG)
271 
272 /*
273  * Scale factor for scaled integers used to count %cpu time and load avgs.
274  *
275  * The number of CPU `tick's that map to a unique `%age' can be expressed
276  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
277  * can be calculated (assuming 32 bits) can be closely approximated using
278  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
279  *
280  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
281  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
282  */
283 #define	FSHIFT	11		/* bits to right of fixed binary point */
284 #define	FSCALE	(1<<FSHIFT)
285 
286 /*
287  * The time for a process to be blocked before being very swappable.
288  * This is a number of seconds which the system takes as being a non-trivial
289  * amount of real time.  You probably shouldn't change this;
290  * it is used in subtle ways (fractions and multiples of it are, that is, like
291  * half of a ``long time'', almost a long time, etc.)
292  * It is related to human patience and other factors which don't really
293  * change over time.
294  */
295 #define        MAXSLP          20
296 
297 /*
298  * Defaults for Unified Buffer Cache parameters.
299  * These may be overridden in <machine/param.h>.
300  */
301 
302 #ifndef UBC_WINSHIFT
303 #define	UBC_WINSHIFT	13
304 #endif
305 #ifndef UBC_NWINS
306 #define	UBC_NWINS	1024
307 #endif
308 
309 #ifdef _KERNEL
310 /*
311  * macro to convert from milliseconds to hz without integer overflow
312  * Default version using only 32bits arithmetics.
313  * 64bit port can define 64bit version in their <machine/param.h>
314  * 0x20000 is safe for hz < 20000
315  */
316 #ifndef mstohz
317 #define mstohz(ms) \
318 	(__predict_false((ms) >= 0x20000) ? \
319 	    ((ms +0u) / 1000u) * hz : \
320 	    ((ms +0u) * hz) / 1000u)
321 #endif
322 #endif /* _KERNEL */
323 
324 #endif /* !_SYS_PARAM_H_ */
325