4.3BSD - /usr/src/sys/vax/vmparam.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:  *	@(#)vmparam.h	7.1 (Berkeley) 6/5/86
   7:  */
   8: 
   9: /*
  10:  * Machine dependent constants for VAX
  11:  */
  12: /*
  13:  * USRTEXT is the start of the user text/data space, while USRSTACK
  14:  * is the top (end) of the user stack.  LOWPAGES and HIGHPAGES are
  15:  * the number of pages from the beginning of the P0 region to the
  16:  * beginning of the text and from the beginning of the P1 region to the
  17:  * beginning of the stack respectively.
  18:  */
  19: #define USRTEXT     0
  20: #define USRSTACK    (0x80000000-UPAGES*NBPG) /* Start of user stack */
  21: #define BTOPUSRSTACK    (0x400000 - UPAGES)  /* btop(USRSTACK) */
  22: /* number of ptes per page */
  23: #define P1PAGES     0x200000    /* number of pages in P1 region */
  24: #define LOWPAGES    0
  25: #define HIGHPAGES   UPAGES
  26: 
  27: /*
  28:  * Virtual memory related constants, all in bytes
  29:  */
  30: #ifndef MAXTSIZ
  31: #define MAXTSIZ     (6*1024*1024)       /* max text size */
  32: #endif
  33: #ifndef DFLDSIZ
  34: #define DFLDSIZ     (6*1024*1024)       /* initial data size limit */
  35: #endif
  36: #ifndef MAXDSIZ
  37: #define MAXDSIZ     (16*1024*1024)      /* max data size */
  38: #endif
  39: #ifndef DFLSSIZ
  40: #define DFLSSIZ     (512*1024)      /* initial stack size limit */
  41: #endif
  42: #ifndef MAXSSIZ
  43: #define MAXSSIZ     MAXDSIZ         /* max stack size */
  44: #endif
  45: 
  46: /*
  47:  * Default sizes of swap allocation chunks (see dmap.h).
  48:  * The actual values may be changed in vminit() based on MAXDSIZ.
  49:  * With MAXDSIZ of 16Mb and NDMAP of 38, dmmax will be 1024.
  50:  */
  51: #define DMMIN   32          /* smallest swap allocation */
  52: #define DMMAX   4096            /* largest potential swap allocation */
  53: #define DMTEXT  1024            /* swap allocation for text */
  54: 
  55: /*
  56:  * Sizes of the system and user portions of the system page table.
  57:  */
  58: /* SYSPTSIZE IS SILLY; IT SHOULD BE COMPUTED AT BOOT TIME */
  59: #define SYSPTSIZE   ((20+MAXUSERS)*NPTEPG)
  60: #define USRPTSIZE   (32*NPTEPG)
  61: 
  62: /*
  63:  * The size of the clock loop.
  64:  */
  65: #define LOOPPAGES   (maxfree - firstfree)
  66: 
  67: /*
  68:  * The time for a process to be blocked before being very swappable.
  69:  * This is a number of seconds which the system takes as being a non-trivial
  70:  * amount of real time.  You probably shouldn't change this;
  71:  * it is used in subtle ways (fractions and multiples of it are, that is, like
  72:  * half of a ``long time'', almost a long time, etc.)
  73:  * It is related to human patience and other factors which don't really
  74:  * change over time.
  75:  */
  76: #define MAXSLP      20
  77: 
  78: /*
  79:  * A swapped in process is given a small amount of core without being bothered
  80:  * by the page replacement algorithm.  Basically this says that if you are
  81:  * swapped in you deserve some resources.  We protect the last SAFERSS
  82:  * pages against paging and will just swap you out rather than paging you.
  83:  * Note that each process has at least UPAGES+CLSIZE pages which are not
  84:  * paged anyways (this is currently 8+2=10 pages or 5k bytes), so this
  85:  * number just means a swapped in process is given around 25k bytes.
  86:  * Just for fun: current memory prices are 4600$ a megabyte on VAX (4/22/81),
  87:  * so we loan each swapped in process memory worth 100$, or just admit
  88:  * that we don't consider it worthwhile and swap it out to disk which costs
  89:  * $30/mb or about $0.75.
  90:  */
  91: #define SAFERSS     32      /* nominal ``small'' resident set size
  92: 					   protected against replacement */
  93: 
  94: /*
  95:  * DISKRPM is used to estimate the number of paging i/o operations
  96:  * which one can expect from a single disk controller.
  97:  */
  98: #define DISKRPM     60
  99: 
 100: /*
 101:  * Klustering constants.  Klustering is the gathering
 102:  * of pages together for pagein/pageout, while clustering
 103:  * is the treatment of hardware page size as though it were
 104:  * larger than it really is.
 105:  *
 106:  * KLMAX gives maximum cluster size in CLSIZE page (cluster-page)
 107:  * units.  Note that KLMAX*CLSIZE must be <= DMMIN in dmap.h.
 108:  */
 109: 
 110: #define KLMAX   (32/CLSIZE)
 111: #define KLSEQL  (16/CLSIZE)     /* in klust if vadvise(VA_SEQL) */
 112: #define KLIN    (8/CLSIZE)      /* default data/stack in klust */
 113: #define KLTXT   (4/CLSIZE)      /* default text in klust */
 114: #define KLOUT   (32/CLSIZE)
 115: 
 116: /*
 117:  * KLSDIST is the advance or retard of the fifo reclaim for sequential
 118:  * processes data space.
 119:  */
 120: #define KLSDIST 3       /* klusters advance/retard for seq. fifo */
 121: 
 122: /*
 123:  * Paging thresholds (see vm_sched.c).
 124:  * Strategy of 1/19/85:
 125:  *	lotsfree is 512k bytes, but at most 1/4 of memory
 126:  *	desfree is 200k bytes, but at most 1/8 of memory
 127:  *	minfree is 64k bytes, but at most 1/2 of desfree
 128:  */
 129: #define LOTSFREE    (512 * 1024)
 130: #define LOTSFREEFRACT   4
 131: #define DESFREE     (200 * 1024)
 132: #define DESFREEFRACT    8
 133: #define MINFREE     (64 * 1024)
 134: #define MINFREEFRACT    2
 135: 
 136: /*
 137:  * There are two clock hands, initially separated by HANDSPREAD bytes
 138:  * (but at most all of user memory).  The amount of time to reclaim
 139:  * a page once the pageout process examines it increases with this
 140:  * distance and decreases as the scan rate rises.
 141:  */
 142: #define HANDSPREAD  (2 * 1024 * 1024)
 143: 
 144: /*
 145:  * The number of times per second to recompute the desired paging rate
 146:  * and poke the pagedaemon.
 147:  */
 148: #define RATETOSCHEDPAGING   4
 149: 
 150: /*
 151:  * Believed threshold (in megabytes) for which interleaved
 152:  * swapping area is desirable.
 153:  */
 154: #define LOTSOFMEM   2
 155: 
 156: /*
 157:  * BEWARE THIS DEFINITION WORKS ONLY WITH COUNT OF 1
 158:  */
 159: #define mapin(pte, v, pfnum, count, prot) \
 160:     (*(int *)(pte) = (pfnum) | (prot), mtpr(TBIS, ptob(v)))

Defined macros

Usage of this include