Change sendfile() to use the new m_ext callback scheme for cleaning up after
[dragonfly.git] / sys / sys / param.h
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1/*-
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.
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.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 $
8ec60c3f 40 * $DragonFly: src/sys/sys/param.h,v 1.15 2004/07/24 20:21:35 dillon Exp $
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41 */
42
43#ifndef _SYS_PARAM_H_
44#define _SYS_PARAM_H_
45
6bb39c45 46#define BSD 200307 /* XXX kern.osrevision */
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47#define BSD4_3 1 /* XXX obsolete */
48#define BSD4_4 1 /* XXX obsolete */
984263bc 49
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50/*
51 * __DragonFly_version number. Note that the name and comment are pattern
52 * searched from conf/newvers.sh.
53 *
54 * Version changes should be documented in:
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55 * doc/en_US.ISO8859-1/books/porters-handbook/book.sgml
56 */
e9ddd87b 57#undef __DragonFly_version
acb76797 58#define __DragonFly_version 110000 /* Master, propagated to newvers */
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59
60/*
61 * __FreeBSD_version numbers for source compatibility. This is temporary
62 * along with the __FreeBSD__ define in gcc.
63 */
64#undef __FreeBSD_version
65#define __FreeBSD_version 480101
e9ddd87b 66
984263bc 67#ifndef NULL
6bb39c45 68#define NULL 0
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69#endif
70
71#ifndef LOCORE
72#include <sys/types.h>
73#endif
74
75/*
76 * Machine-independent constants (some used in following include files).
77 * Redefined constants are from POSIX 1003.1 limits file.
78 *
79 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
80 * MAXLOGNAME should be == UT_NAMESIZE+1 (see <utmp.h>)
81 */
82#include <sys/syslimits.h>
83
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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 */
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92#define MAXHOSTNAMELEN 256 /* max hostname size */
93
94/* More types and definitions used throughout the kernel. */
95#ifdef _KERNEL
96#include <sys/cdefs.h>
97#include <sys/errno.h>
98#include <sys/time.h>
99
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100#define FALSE 0
101#define TRUE 1
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102#endif
103
104#ifndef _KERNEL
105/* Signals. */
106#include <sys/signal.h>
107#endif
108
109/* Machine type dependent parameters. */
110#include <machine/param.h>
111#ifndef _KERNEL
112#include <machine/limits.h>
113#endif
114
115/*
116 * Priorities. Note that with 32 run queues, differences less than 4 are
117 * insignificant.
118 */
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119#define MAXPRI 127 /* Priorities range from 0 through MAXPRI. */
120#define PPAUSE 40
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121#define PRIMASK 127
122#define PRIBASE_REALTIME 0
123#define PRIBASE_NORMAL 128
124#define PRIBASE_IDLE 256
125#define PRIBASE_THREAD 384 /* huh? */
8ec60c3f 126#define PRIBASE_NULL 512
984263bc 127
6bb39c45 128#define PCATCH 0x0100 /* OR'd with pri for tsleep to check signals */
377d4740 129#define PUSRFLAG1 0x0200 /* Subsystem specific flag */
0a3f9b47 130#define PNORESCHED 0x0400 /* Do not force a reschedule on wakeup */
984263bc 131
6bb39c45 132#define NZERO 0 /* default "nice" */
984263bc 133
6bb39c45 134#define NBPW sizeof(int) /* number of bytes per word (integer) */
984263bc 135
6bb39c45 136#define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
984263bc 137#ifdef _KERNEL
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138#define NODEV (dev_t)(-1) /* non-existent device */
139#define NOUDEV (udev_t)(-1) /* non-existent device */
140#define NOMAJ 256 /* non-existent device */
984263bc 141#else
6bb39c45 142#define NODEV (dev_t)(-1) /* non-existent device */
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143#endif
144
145/*
146 * Clustering of hardware pages on machines with ridiculously small
147 * page sizes is done here. The paging subsystem deals with units of
148 * CLSIZE pte's describing PAGE_SIZE (from machine/machparam.h) pages each.
149 */
150#if 0
6bb39c45 151#define CLBYTES (CLSIZE*PAGE_SIZE)
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152#endif
153
6bb39c45 154#define CBLOCK 128 /* Clist block size, must be a power of 2. */
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155#define CBQSIZE (CBLOCK/NBBY) /* Quote bytes/cblock - can do better. */
156 /* Data chars/clist. */
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157#define CBSIZE (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
158#define CROUND (CBLOCK - 1) /* Clist rounding. */
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159
160/*
161 * File system parameters and macros.
162 *
163 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes
164 * per block. MAXBSIZE may be made larger without effecting
165 * any existing filesystems as long as it does not exceed MAXPHYS,
166 * and may be made smaller at the risk of not being able to use
167 * filesystems which require a block size exceeding MAXBSIZE.
168 *
169 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the
170 * minimum KVM memory reservation the kernel is willing to make.
171 * Filesystems can of course request smaller chunks. Actual
172 * backing memory uses a chunk size of a page (PAGE_SIZE).
173 *
174 * If you make BKVASIZE too small you risk seriously fragmenting
175 * the buffer KVM map which may slow things down a bit. If you
176 * make it too big the kernel will not be able to optimally use
177 * the KVM memory reserved for the buffer cache and will wind
178 * up with too-few buffers.
179 *
180 * The default is 16384, roughly 2x the block size used by a
181 * normal UFS filesystem.
182 */
183#define MAXBSIZE 65536 /* must be power of 2 */
184#define BKVASIZE 16384 /* must be power of 2 */
185#define BKVAMASK (BKVASIZE-1)
186#define MAXFRAG 8
187
188/*
189 * MAXPATHLEN defines the longest permissible path length after expanding
190 * symbolic links. It is used to allocate a temporary buffer from the buffer
191 * pool in which to do the name expansion, hence should be a power of two,
192 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
193 * maximum number of symbolic links that may be expanded in a path name.
194 * It should be set high enough to allow all legitimate uses, but halt
195 * infinite loops reasonably quickly.
196 */
6bb39c45 197#define MAXPATHLEN PATH_MAX
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198#define MAXSYMLINKS 32
199
200/* Bit map related macros. */
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201#define setbit(a,i) ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
202#define clrbit(a,i) ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
203#define isset(a,i) ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
204#define isclr(a,i) (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
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205
206/* Macros for counting and rounding. */
207#ifndef howmany
6bb39c45 208#define howmany(x, y) (((x)+((y)-1))/(y))
984263bc 209#endif
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210#define rounddown(x, y) (((x)/(y))*(y))
211#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
212#define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
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213#define powerof2(x) ((((x)-1)&(x))==0)
214
215/* Macros for min/max. */
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216#define MIN(a,b) (((a)<(b))?(a):(b))
217#define MAX(a,b) (((a)>(b))?(a):(b))
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218
219/*
220 * Constants for setting the parameters of the kernel memory allocator.
221 *
222 * 2 ** MINBUCKET is the smallest unit of memory that will be
223 * allocated. It must be at least large enough to hold a pointer.
224 *
225 * Units of memory less or equal to MAXALLOCSAVE will permanently
226 * allocate physical memory; requests for these size pieces of
227 * memory are quite fast. Allocations greater than MAXALLOCSAVE must
228 * always allocate and free physical memory; requests for these
229 * size allocations should be done infrequently as they will be slow.
230 *
231 * Constraints: PAGE_SIZE <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
232 * MAXALLOCSIZE must be a power of two.
233 */
234#if defined(__alpha__)
235#define MINBUCKET 5 /* 5 => min allocation of 32 bytes */
236#else
237#define MINBUCKET 4 /* 4 => min allocation of 16 bytes */
238#endif
239#define MAXALLOCSAVE (2 * PAGE_SIZE)
240
241/*
242 * Scale factor for scaled integers used to count %cpu time and load avgs.
243 *
244 * The number of CPU `tick's that map to a unique `%age' can be expressed
245 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
246 * can be calculated (assuming 32 bits) can be closely approximated using
247 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
248 *
249 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
250 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
251 */
6bb39c45 252#define FSHIFT 11 /* bits to right of fixed binary point */
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253#define FSCALE (1<<FSHIFT)
254
255#define dbtoc(db) /* calculates devblks to pages */ \
256 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
257
258#define ctodb(db) /* calculates pages to devblks */ \
259 ((db) << (PAGE_SHIFT - DEV_BSHIFT))
260
261
262/*
263 * Make this available for most of the kernel. There were too many
264 * things that included sys/systm.h just for panic().
265 */
266#ifdef _KERNEL
b153f746 267void panic (const char *, ...) __dead2 __printflike(1, 2);
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268#endif
269
270#endif /* _SYS_PARAM_H_ */