2 * Copyright (c) 1982, 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.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
38 * @(#)param.h 8.3 (Berkeley) 4/4/95
39 * $FreeBSD: src/sys/sys/param.h,v 1.61.2.38 2003/05/22 17:12:01 fjoe Exp $
40 * $DragonFly: src/sys/sys/param.h,v 1.12 2004/03/02 20:55:10 drhodus Exp $
46 #define BSD 200307 /* XXX kern.osrevision */
47 #define BSD4_3 1 /* XXX obsolete */
48 #define BSD4_4 1 /* XXX obsolete */
51 * __DragonFly_version number. Note that the name and comment are pattern
52 * searched from conf/newvers.sh.
54 * Version changes should be documented in:
55 * doc/en_US.ISO8859-1/books/porters-handbook/book.sgml
57 #undef __DragonFly_version
58 #define __DragonFly_version 100000 /* Master, propagated to newvers */
61 * __FreeBSD_version numbers for source compatibility. This is temporary
62 * along with the __FreeBSD__ define in gcc.
64 #undef __FreeBSD_version
65 #define __FreeBSD_version 480101
72 #include <sys/types.h>
76 * Machine-independent constants (some used in following include files).
77 * Redefined constants are from POSIX 1003.1 limits file.
79 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
80 * MAXLOGNAME should be == UT_NAMESIZE+1 (see <utmp.h>)
82 #include <sys/syslimits.h>
84 #define MAXCOMLEN 16 /* max command name remembered */
85 #define MAXINTERP 32 /* max interpreter file name length */
86 #define MAXLOGNAME 17 /* max login name length (incl. NUL) */
87 #define MAXUPRC CHILD_MAX /* max simultaneous processes */
88 #define NCARGS ARG_MAX /* max bytes for an exec function */
89 #define NGROUPS NGROUPS_MAX /* max number groups */
90 #define NOFILE OPEN_MAX /* max open files per process */
91 #define NOGROUP 65535 /* marker for empty group set member */
92 #define MAXHOSTNAMELEN 256 /* max hostname size */
94 /* More types and definitions used throughout the kernel. */
96 #include <sys/cdefs.h>
97 #include <sys/errno.h>
106 #include <sys/signal.h>
109 /* Machine type dependent parameters. */
110 #include <machine/param.h>
112 #include <machine/limits.h>
116 * Priorities. Note that with 32 run queues, differences less than 4 are
119 #define MAXPRI 127 /* Priorities range from 0 through MAXPRI. */
122 #define PRIBASE_REALTIME 0
123 #define PRIBASE_NORMAL 128
124 #define PRIBASE_IDLE 256
125 #define PRIBASE_THREAD 384 /* huh? */
127 #define PCATCH 0x0100 /* OR'd with pri for tsleep to check signals */
128 #define PUSRFLAG1 0x0200 /* Subsystem specific flag */
130 #define NZERO 0 /* default "nice" */
132 #define NBPW sizeof(int) /* number of bytes per word (integer) */
134 #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
136 #define NODEV (dev_t)(-1) /* non-existent device */
137 #define NOUDEV (udev_t)(-1) /* non-existent device */
138 #define NOMAJ 256 /* non-existent device */
140 #define NODEV (dev_t)(-1) /* non-existent device */
144 * Clustering of hardware pages on machines with ridiculously small
145 * page sizes is done here. The paging subsystem deals with units of
146 * CLSIZE pte's describing PAGE_SIZE (from machine/machparam.h) pages each.
149 #define CLBYTES (CLSIZE*PAGE_SIZE)
152 #define CBLOCK 128 /* Clist block size, must be a power of 2. */
153 #define CBQSIZE (CBLOCK/NBBY) /* Quote bytes/cblock - can do better. */
154 /* Data chars/clist. */
155 #define CBSIZE (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
156 #define CROUND (CBLOCK - 1) /* Clist rounding. */
159 * File system parameters and macros.
161 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes
162 * per block. MAXBSIZE may be made larger without effecting
163 * any existing filesystems as long as it does not exceed MAXPHYS,
164 * and may be made smaller at the risk of not being able to use
165 * filesystems which require a block size exceeding MAXBSIZE.
167 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the
168 * minimum KVM memory reservation the kernel is willing to make.
169 * Filesystems can of course request smaller chunks. Actual
170 * backing memory uses a chunk size of a page (PAGE_SIZE).
172 * If you make BKVASIZE too small you risk seriously fragmenting
173 * the buffer KVM map which may slow things down a bit. If you
174 * make it too big the kernel will not be able to optimally use
175 * the KVM memory reserved for the buffer cache and will wind
176 * up with too-few buffers.
178 * The default is 16384, roughly 2x the block size used by a
179 * normal UFS filesystem.
181 #define MAXBSIZE 65536 /* must be power of 2 */
182 #define BKVASIZE 16384 /* must be power of 2 */
183 #define BKVAMASK (BKVASIZE-1)
187 * MAXPATHLEN defines the longest permissible path length after expanding
188 * symbolic links. It is used to allocate a temporary buffer from the buffer
189 * pool in which to do the name expansion, hence should be a power of two,
190 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
191 * maximum number of symbolic links that may be expanded in a path name.
192 * It should be set high enough to allow all legitimate uses, but halt
193 * infinite loops reasonably quickly.
195 #define MAXPATHLEN PATH_MAX
196 #define MAXSYMLINKS 32
198 /* Bit map related macros. */
199 #define setbit(a,i) ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
200 #define clrbit(a,i) ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
201 #define isset(a,i) ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
202 #define isclr(a,i) (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
204 /* Macros for counting and rounding. */
206 #define howmany(x, y) (((x)+((y)-1))/(y))
208 #define rounddown(x, y) (((x)/(y))*(y))
209 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
210 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
211 #define powerof2(x) ((((x)-1)&(x))==0)
213 /* Macros for min/max. */
214 #define MIN(a,b) (((a)<(b))?(a):(b))
215 #define MAX(a,b) (((a)>(b))?(a):(b))
218 * Constants for setting the parameters of the kernel memory allocator.
220 * 2 ** MINBUCKET is the smallest unit of memory that will be
221 * allocated. It must be at least large enough to hold a pointer.
223 * Units of memory less or equal to MAXALLOCSAVE will permanently
224 * allocate physical memory; requests for these size pieces of
225 * memory are quite fast. Allocations greater than MAXALLOCSAVE must
226 * always allocate and free physical memory; requests for these
227 * size allocations should be done infrequently as they will be slow.
229 * Constraints: PAGE_SIZE <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
230 * MAXALLOCSIZE must be a power of two.
232 #if defined(__alpha__)
233 #define MINBUCKET 5 /* 5 => min allocation of 32 bytes */
235 #define MINBUCKET 4 /* 4 => min allocation of 16 bytes */
237 #define MAXALLOCSAVE (2 * PAGE_SIZE)
240 * Scale factor for scaled integers used to count %cpu time and load avgs.
242 * The number of CPU `tick's that map to a unique `%age' can be expressed
243 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
244 * can be calculated (assuming 32 bits) can be closely approximated using
245 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
247 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
248 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
250 #define FSHIFT 11 /* bits to right of fixed binary point */
251 #define FSCALE (1<<FSHIFT)
253 #define dbtoc(db) /* calculates devblks to pages */ \
254 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
256 #define ctodb(db) /* calculates pages to devblks */ \
257 ((db) << (PAGE_SHIFT - DEV_BSHIFT))
261 * Make this available for most of the kernel. There were too many
262 * things that included sys/systm.h just for panic().
265 void panic (const char *, ...) __dead2 __printflike(1, 2);
268 #endif /* _SYS_PARAM_H_ */