4.3BSD - /usr/src/sys/h/cmap.h

   1: /*
   2:  * Copyright (c) 1982, 1986 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  *
   6:  *	@(#)cmap.h	7.1 (Berkeley) 6/4/86
   7:  */
   8: 
   9: /*
  10:  * core map entry
  11:  *
  12:  * Limits imposed by this structure:
  13:  *
  14:  *		limit		     cur. size		fields
  15:  *	Physical memory*		64 Mb	c_next, c_prev, c_hlink
  16:  *	Mounted filesystems		255	c_mdev
  17:  *	size of a process segment	1 Gb	c_page
  18:  *	filesystem size			8 Gb	c_blkno
  19:  *	proc, text table size		64K	c_ndx
  20:  *
  21:  *	* memory can be expanded by converting first three entries
  22:  *	to bit fields of larger than 16 bits, shrinking c_ndx accordingly,
  23:  *	and increasing MAXMEM below.  Also, the type of cmhash
  24:  *	(below) must be changed to long.
  25:  */
  26: #ifndef LOCORE
  27: struct cmap
  28: {
  29: unsigned short  c_next,     /* index of next free list entry */
  30:         c_prev,     /* index of previous free list entry */
  31:         c_hlink;    /* hash link for <blkno,mdev> */
  32: unsigned short  c_ndx;      /* index of owner proc or text */
  33: unsigned int    c_page:21,  /* virtual page number in segment */
  34:         c_lock:1,   /* locked for raw i/o or pagein */
  35:         c_want:1,   /* wanted */
  36:         c_intrans:1,    /* intransit bit */
  37:         c_free:1,   /* on the free list */
  38:         c_gone:1,   /* associated page has been released */
  39:         c_type:2,   /* type CSYS or CTEXT or CSTACK or CDATA */
  40:         :4,     /* to longword boundary */
  41:         c_blkno:24, /* disk block this is a copy of */
  42:         c_mdev:8;   /* which mounted dev this is from */
  43: };
  44: #else   LOCORE
  45: /*
  46:  * bit offsets of elements in cmap
  47:  */
  48: #define C_INTRANS   87
  49: #define C_FREE      88
  50: #define SZ_CMAP     16      /* sizeof(struct cmap) */
  51: 
  52: #define MAXMEM      64*1024     /* maximum memory, in Kbytes */
  53: #endif	LOCORE
  54: 
  55: #define CMHEAD  0
  56: 
  57: /*
  58:  * Shared text pages are not totally abandoned when a process
  59:  * exits, but are remembered while in the free list hashed by <mdev,blkno>
  60:  * off the cmhash structure so that they can be reattached
  61:  * if another instance of the program runs again soon.
  62:  */
  63: #define CMHSIZ  2048        /* SHOULD BE DYNAMIC */
  64: #define CMHASH(bn)  ((bn)&(CMHSIZ-1))
  65: 
  66: #ifndef LOCORE
  67: #ifdef  KERNEL
  68: struct  cmap *cmap;
  69: struct  cmap *ecmap;
  70: int ncmap;
  71: struct  cmap *mfind();
  72: int firstfree, maxfree;
  73: int ecmx;           /* cmap index of ecmap */
  74: u_short cmhash[CMHSIZ];
  75: #endif
  76: 
  77: /* bits defined in c_type */
  78: 
  79: #define CSYS        0       /* none of below */
  80: #define CTEXT       1       /* belongs to shared text segment */
  81: #define CDATA       2       /* belongs to data segment */
  82: #define CSTACK      3       /* belongs to stack segment */
  83: 
  84: #define pgtocm(x)   (((int) ((x)-firstfree) / CLSIZE) + 1)
  85: #define cmtopg(x)   ((((x)-1) * CLSIZE) + firstfree)
  86: #endif	LOCORE

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Usage of this include