Annotation of sys/sys/param.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: param.h,v 1.72 2007/07/25 20:07:28 deraadt Exp $ */
! 2: /* $NetBSD: param.h,v 1.23 1996/03/17 01:02:29 thorpej Exp $ */
! 3:
! 4: /*-
! 5: * Copyright (c) 1982, 1986, 1989, 1993
! 6: * The Regents of the University of California. All rights reserved.
! 7: * (c) UNIX System Laboratories, Inc.
! 8: * All or some portions of this file are derived from material licensed
! 9: * to the University of California by American Telephone and Telegraph
! 10: * Co. or Unix System Laboratories, Inc. and are reproduced herein with
! 11: * the permission of UNIX System Laboratories, Inc.
! 12: *
! 13: * Redistribution and use in source and binary forms, with or without
! 14: * modification, are permitted provided that the following conditions
! 15: * are met:
! 16: * 1. Redistributions of source code must retain the above copyright
! 17: * notice, this list of conditions and the following disclaimer.
! 18: * 2. Redistributions in binary form must reproduce the above copyright
! 19: * notice, this list of conditions and the following disclaimer in the
! 20: * documentation and/or other materials provided with the distribution.
! 21: * 3. Neither the name of the University nor the names of its contributors
! 22: * may be used to endorse or promote products derived from this software
! 23: * without specific prior written permission.
! 24: *
! 25: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 26: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 27: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 28: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 29: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 30: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 31: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 32: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 33: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 34: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 35: * SUCH DAMAGE.
! 36: *
! 37: * @(#)param.h 8.2 (Berkeley) 1/21/94
! 38: */
! 39:
! 40: #define BSD 199306 /* System version (year & month). */
! 41: #define BSD4_3 1
! 42: #define BSD4_4 1
! 43:
! 44: #define OpenBSD 200711 /* OpenBSD version (year & month). */
! 45: #define OpenBSD4_2 1 /* OpenBSD 4.2 */
! 46:
! 47: #ifndef NULL
! 48: #ifdef __GNUG__
! 49: #define NULL __null
! 50: #else
! 51: #define NULL 0L
! 52: #endif
! 53: #endif
! 54:
! 55: #ifndef _LOCORE
! 56: #include <sys/types.h>
! 57: #include <sys/simplelock.h>
! 58: #endif
! 59:
! 60: /*
! 61: * Machine-independent constants (some used in following include files).
! 62: * Redefined constants are from POSIX 1003.1 limits file.
! 63: *
! 64: * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
! 65: * MAXLOGNAME should be >= UT_NAMESIZE (see <utmp.h>)
! 66: */
! 67: #include <sys/syslimits.h>
! 68:
! 69: #define MAXCOMLEN 16 /* max command name remembered */
! 70: #define MAXINTERP 64 /* max interpreter file name length */
! 71: #define MAXLOGNAME LOGIN_NAME_MAX /* max login name length w/ NUL */
! 72: #define MAXUPRC CHILD_MAX /* max simultaneous processes */
! 73: #define NCARGS ARG_MAX /* max bytes for an exec function */
! 74: #define NGROUPS NGROUPS_MAX /* max number groups */
! 75: #define NOFILE OPEN_MAX /* max open files per process (soft) */
! 76: #define NOFILE_MAX 1024 /* max open files per process (hard) */
! 77: #define NOGROUP 65535 /* marker for empty group set member */
! 78: #define MAXHOSTNAMELEN 256 /* max hostname size */
! 79:
! 80: /* More types and definitions used throughout the kernel. */
! 81: #ifdef _KERNEL
! 82: #include <sys/cdefs.h>
! 83: #include <sys/errno.h>
! 84: #include <sys/time.h>
! 85: #include <sys/resource.h>
! 86: #include <sys/ucred.h>
! 87: #include <sys/uio.h>
! 88: #endif
! 89:
! 90: /* Signals. */
! 91: #include <sys/signal.h>
! 92:
! 93: /* Machine type dependent parameters. */
! 94: #include <sys/limits.h>
! 95: #include <machine/param.h>
! 96:
! 97: /*
! 98: * Priorities. Note that with 32 run queues, differences less than 4 are
! 99: * insignificant.
! 100: */
! 101: #define PSWP 0
! 102: #define PVM 4
! 103: #define PINOD 8
! 104: #define PRIBIO 16
! 105: #define PVFS 20
! 106: #define PZERO 22 /* No longer magic, shouldn't be here. XXX */
! 107: #define PSOCK 24
! 108: #define PWAIT 32
! 109: #define PLOCK 36
! 110: #define PPAUSE 40
! 111: #define PUSER 50
! 112: #define MAXPRI 127 /* Priorities range from 0 through MAXPRI. */
! 113:
! 114: #define PRIMASK 0x0ff
! 115: #define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */
! 116: #define PNORELOCK 0x200 /* OR'd with pri for ltsleep to not relock
! 117: the interlock */
! 118:
! 119: #define NBPW sizeof(int) /* number of bytes per word (integer) */
! 120:
! 121: #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
! 122: #define NODEV (dev_t)(-1) /* non-existent device */
! 123: #define NETDEV (dev_t)(-2) /* network device (for nfs swap) */
! 124:
! 125: #define CBLOCK 64 /* Clist block size, must be a power of 2. */
! 126: #define CBQSIZE (CBLOCK/NBBY) /* Quote bytes/cblock - can do better. */
! 127: /* Data chars/clist. */
! 128: #define CBSIZE (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
! 129: #define CROUND (CBLOCK - 1) /* Clist rounding. */
! 130:
! 131: /*
! 132: * Constants related to network buffer management.
! 133: * MCLBYTES must be no larger than NBPG (the software page size), and,
! 134: * on machines that exchange pages of input or output buffers with mbuf
! 135: * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
! 136: * of the hardware page size.
! 137: */
! 138: #define MSIZE 256 /* size of an mbuf */
! 139: #define MCLSHIFT 11 /* convert bytes to m_buf clusters */
! 140: /* 2K cluster can hold Ether frame */
! 141: #define MCLBYTES (1 << MCLSHIFT) /* size of a m_buf cluster */
! 142: #define MCLOFSET (MCLBYTES - 1)
! 143:
! 144:
! 145: /*
! 146: * File system parameters and macros.
! 147: *
! 148: * The file system is made out of blocks of at most MAXBSIZE units, with
! 149: * smaller units (fragments) only in the last direct block. MAXBSIZE
! 150: * primarily determines the size of buffers in the buffer pool. It may be
! 151: * made larger without any effect on existing file systems; however making
! 152: * it smaller makes some file systems unmountable.
! 153: */
! 154: #ifndef MAXBSIZE /* XXX temp until sun3 DMA chaining */
! 155: #define MAXBSIZE MAXPHYS
! 156: #endif
! 157: #define MAXFRAG 8
! 158:
! 159: /*
! 160: * MAXPATHLEN defines the longest permissible path length after expanding
! 161: * symbolic links. It is used to allocate a temporary buffer from the buffer
! 162: * pool in which to do the name expansion, hence should be a power of two,
! 163: * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
! 164: * maximum number of symbolic links that may be expanded in a path name.
! 165: * It should be set high enough to allow all legitimate uses, but halt
! 166: * infinite loops reasonably quickly.
! 167: */
! 168: #define MAXPATHLEN PATH_MAX
! 169: #define MAXSYMLINKS SYMLOOP_MAX
! 170:
! 171: /* Macros to set/clear/test flags. */
! 172: #ifdef _KERNEL
! 173: #define SET(t, f) ((t) |= (f))
! 174: #define CLR(t, f) ((t) &= ~(f))
! 175: #define ISSET(t, f) ((t) & (f))
! 176: #endif
! 177:
! 178: /* Bit map related macros. */
! 179: #define setbit(a,i) ((a)[(i)>>3] |= 1<<((i)&(NBBY-1)))
! 180: #define clrbit(a,i) ((a)[(i)>>3] &= ~(1<<((i)&(NBBY-1))))
! 181: #define isset(a,i) ((a)[(i)>>3] & (1<<((i)&(NBBY-1))))
! 182: #define isclr(a,i) (((a)[(i)>>3] & (1<<((i)&(NBBY-1)))) == 0)
! 183:
! 184: /* Macros for counting and rounding. */
! 185: #ifndef howmany
! 186: #define howmany(x, y) (((x)+((y)-1))/(y))
! 187: #endif
! 188: #define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
! 189: #define powerof2(x) ((((x)-1)&(x))==0)
! 190:
! 191: /* Macros for min/max. */
! 192: #define MIN(a,b) (((a)<(b))?(a):(b))
! 193: #define MAX(a,b) (((a)>(b))?(a):(b))
! 194:
! 195: /* Macros for calculating the offset of a field */
! 196: #if !defined(offsetof) && defined(_KERNEL)
! 197: #define offsetof(s, e) ((size_t)&((s *)0)->e)
! 198: #endif
! 199:
! 200: /*
! 201: * Constants for setting the parameters of the kernel memory allocator.
! 202: *
! 203: * 2 ** MINBUCKET is the smallest unit of memory that will be
! 204: * allocated. It must be at least large enough to hold a pointer.
! 205: *
! 206: * Units of memory less or equal to MAXALLOCSAVE will permanently
! 207: * allocate physical memory; requests for these size pieces of
! 208: * memory are quite fast. Allocations greater than MAXALLOCSAVE must
! 209: * always allocate and free physical memory; requests for these
! 210: * size allocations should be done infrequently as they will be slow.
! 211: *
! 212: * Constraints: PAGE_SIZE <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
! 213: * MAXALLOCSIZE must be a power of two.
! 214: */
! 215: #define MINBUCKET 4 /* 4 => min allocation of 16 bytes */
! 216: #define MAXALLOCSAVE (2 * PAGE_SIZE)
! 217:
! 218: /*
! 219: * Scale factor for scaled integers used to count %cpu time and load avgs.
! 220: *
! 221: * The number of CPU `tick's that map to a unique `%age' can be expressed
! 222: * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
! 223: * can be calculated (assuming 32 bits) can be closely approximated using
! 224: * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
! 225: *
! 226: * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
! 227: * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
! 228: */
! 229: #define FSHIFT 11 /* bits to right of fixed binary point */
! 230: #define FSCALE (1<<FSHIFT)
! 231:
! 232: /*
! 233: * The time for a process to be blocked before being very swappable.
! 234: * This is a number of seconds which the system takes as being a non-trivial
! 235: * amount of real time. You probably shouldn't change this;
! 236: * it is used in subtle ways (fractions and multiples of it are, that is, like
! 237: * half of a ``long time'', almost a long time, etc.)
! 238: * It is related to human patience and other factors which don't really
! 239: * change over time.
! 240: */
! 241: #define MAXSLP 20
! 242:
! 243: /*
! 244: * rfork() options.
! 245: *
! 246: * XXX currently, operations without RFPROC set are not supported.
! 247: */
! 248: #define RFNAMEG (1<<0) /* UNIMPL new plan9 `name space' */
! 249: #define RFENVG (1<<1) /* UNIMPL copy plan9 `env space' */
! 250: #define RFFDG (1<<2) /* copy fd table */
! 251: #define RFNOTEG (1<<3) /* UNIMPL create new plan9 `note group' */
! 252: #define RFPROC (1<<4) /* change child (else changes curproc) */
! 253: #define RFMEM (1<<5) /* share `address space' */
! 254: #define RFNOWAIT (1<<6) /* parent need not wait() on child */
! 255: #define RFCNAMEG (1<<10) /* UNIMPL zero plan9 `name space' */
! 256: #define RFCENVG (1<<11) /* UNIMPL zero plan9 `env space' */
! 257: #define RFCFDG (1<<12) /* zero fd table */
! 258: #define RFTHREAD (1<<13) /* create a thread, not a process */
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