sysdeps/unix/bsd/bsd4.4/kfreebsd/bits/param.h

   1 /* Copyright (C) 1995,1996,1997,2000,2001,2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #ifndef _SYS_PARAM_H
  20 # error "Never use <bits/param.h> directly; include <sys/param.h> instead."
  21 #endif
  22
  23 #include <limits.h>
  24 #include <sys/syslimits.h>
  25
  26 /*
  27  * __FreeBSD_version numbers are documented in the Porter's Handbook.
  28  * If you bump the version for any reason, you should update the documentation
  29  * there.
  30  * Currently this lives here:
  31  *
  32  *      doc/en_US.ISO8859-1/books/porters-handbook/book.sgml
  33  *
  34  * scheme is:  <major><two digit minor><0 if release branch, otherwise 1>xx
  35  */
  36 #include <osreldate.h>
  37
  38 /* Some inet code expects that this file defines the 'u_int32_t' type.  */
  39 #include <stdint.h>
  40
  41 /* FreeBSD code expects that this file implicitly defines SIG* macros.  */
  42 #include <signal.h>
  43
  44 /*
  45  * Machine-independent constants (some used in following include files).
  46  * Redefined constants are from POSIX 1003.1 limits file.
  47  *
  48  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
  49  * MAXLOGNAME should be == UT_NAMESIZE+1 (see <utmp.h>)
  50  */
  51
  52 #define MAXCOMLEN       19              /* max command name remembered */
  53 #define MAXINTERP       32              /* max interpreter file name length */
  54 #define MAXLOGNAME      33              /* max login name length (incl. NUL) */
  55 #define MAXUPRC         CHILD_MAX       /* max simultaneous processes */
  56 #define NGROUPS         (NGROUPS_MAX+1) /* max number groups */
  57 #define MAXHOSTNAMELEN  256             /* max hostname size */
  58 #define SPECNAMELEN     63              /* max length of devicename */
  59 #define TTY_NAME_MAX    SPECNAMELEN
  60
  61 /* BSD names for some <limits.h> values.  */
  62
  63 #define MAXSYMLINKS     32
  64 #define CANBSIZ         MAX_CANON
  65
  66 /* Machine type dependent parameters. */
  67 #include <machine/param.h>
  68
  69 #ifndef BLKDEV_IOSIZE
  70 #define BLKDEV_IOSIZE   PAGE_SIZE        /* default block device I/O size */
  71 #endif
  72 #ifndef DFLTPHYS
  73 #define DFLTPHYS        (64 * 1024)     /* default max raw I/O transfer size */
  74 #endif
  75 #ifndef MAXPHYS
  76 #define MAXPHYS         (128 * 1024)    /* max raw I/O transfer size */
  77 #endif
  78 #ifndef MAXDUMPPGS
  79 #define MAXDUMPPGS      (DFLTPHYS/PAGE_SIZE)
  80 #endif
  81
  82 /*
  83  * Constants related to network buffer management.
  84  * MCLBYTES must be no larger than PAGE_SIZE.
  85  */
  86 #ifndef MSIZE
  87 #define MSIZE           256             /* size of an mbuf */
  88 #endif  /* MSIZE */
  89
  90 #ifndef MCLSHIFT
  91 #define MCLSHIFT        11              /* convert bytes to mbuf clusters */
  92 #endif  /* MCLSHIFT */
  93
  94 #define MCLBYTES        (1 << MCLSHIFT) /* size of an mbuf cluster */
  95
  96 /*
  97  * Some macros for units conversion
  98  */
  99
 100 /* clicks to bytes */
 101 #ifndef ctob
 102 #define ctob(x) ((x)<<PAGE_SHIFT)
 103 #endif
 104
 105 /* bytes to clicks */
 106 #ifndef btoc
 107 #define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
 108 #endif
 109
 110 /*
 111  * btodb() is messy and perhaps slow because `bytes' may be an off_t.  We
 112  * want to shift an unsigned type to avoid sign extension and we don't
 113  * want to widen `bytes' unnecessarily.  Assume that the result fits in
 114  * a daddr_t.
 115  */
 116 #ifndef btodb
 117 #define btodb(bytes)                    /* calculates (bytes / DEV_BSIZE) */ \
 118         (sizeof (bytes) > sizeof(long) \
 119          ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
 120          : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
 121 #endif
 122
 123 #ifndef dbtob
 124 #define dbtob(db)                       /* calculates (db * DEV_BSIZE) */ \
 125         ((off_t)(db) << DEV_BSHIFT)
 126 #endif
 127
 128 #define PRIMASK 0x0ff
 129 #define PCATCH  0x100           /* OR'd with pri for tsleep to check signals */
 130 #define PDROP   0x200   /* OR'd with pri to stop re-entry of interlock mutex */
 131
 132 #define NBPW    sizeof(int)     /* number of bytes per word (integer) */
 133
 134 #define CMASK   022             /* default file mask: S_IWGRP|S_IWOTH */
 135
 136 #define NODEV   (dev_t)(-1)     /* non-existent device */
 137
 138 #define CBLOCK  128             /* Clist block size, must be a power of 2. */
 139 #define CBQSIZE (CBLOCK/NBBY)   /* Quote bytes/cblock - can do better. */
 140                                 /* Data chars/clist. */
 141 #define CBSIZE  (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
 142 #define CROUND  (CBLOCK - 1)    /* Clist rounding. */
 143
 144 /*
 145  * File system parameters and macros.
 146  *
 147  * MAXBSIZE -   Filesystems are made out of blocks of at most MAXBSIZE bytes
 148  *              per block.  MAXBSIZE may be made larger without effecting
 149  *              any existing filesystems as long as it does not exceed MAXPHYS,
 150  *              and may be made smaller at the risk of not being able to use
 151  *              filesystems which require a block size exceeding MAXBSIZE.
 152  *
 153  * BKVASIZE -   Nominal buffer space per buffer, in bytes.  BKVASIZE is the
 154  *              minimum KVM memory reservation the kernel is willing to make.
 155  *              Filesystems can of course request smaller chunks.  Actual
 156  *              backing memory uses a chunk size of a page (PAGE_SIZE).
 157  *
 158  *              If you make BKVASIZE too small you risk seriously fragmenting
 159  *              the buffer KVM map which may slow things down a bit.  If you
 160  *              make it too big the kernel will not be able to optimally use
 161  *              the KVM memory reserved for the buffer cache and will wind
 162  *              up with too-few buffers.
 163  *
 164  *              The default is 16384, roughly 2x the block size used by a
 165  *              normal UFS filesystem.
 166  */
 167 #define MAXBSIZE        65536   /* must be power of 2 */
 168 #define BKVASIZE        16384   /* must be power of 2 */
 169 #define BKVAMASK        (BKVASIZE-1)
 170
 171 /*
 172  * Scale factor for scaled integers used to count %cpu time and load avgs.
 173  *
 174  * The number of CPU `tick's that map to a unique `%age' can be expressed
 175  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
 176  * can be calculated (assuming 32 bits) can be closely approximated using
 177  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
 178  *
 179  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
 180  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
 181  */
 182 #define FSHIFT  11              /* bits to right of fixed binary point */
 183 #define FSCALE  (1<<FSHIFT)
 184
 185 #define dbtoc(db)                       /* calculates devblks to pages */ \
 186         ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
 187
 188 #define ctodb(db)                       /* calculates pages to devblks */ \
 189         ((db) << (PAGE_SHIFT - DEV_BSHIFT))