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vmparam.h revision 1.15 
      1 /*	$NetBSD: vmparam.h,v 1.15 1997/01/18 18:58:21 gwr Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1994 Gordon W. Ross
      5  * Copyright (c) 1993 Adam Glass
      6  * Copyright (c) 1988 University of Utah.
      7  * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
      8  * All rights reserved.
      9  *
     10  * This code is derived from software contributed to Berkeley by
     11  * the Systems Programming Group of the University of Utah Computer
     12  * Science Department.
     13  *
     14  * Redistribution and use in source and binary forms, with or without
     15  * modification, are permitted provided that the following conditions
     16  * are met:
     17  * 1. Redistributions of source code must retain the above copyright
     18  *    notice, this list of conditions and the following disclaimer.
     19  * 2. Redistributions in binary form must reproduce the above copyright
     20  *    notice, this list of conditions and the following disclaimer in the
     21  *    documentation and/or other materials provided with the distribution.
     22  * 3. All advertising materials mentioning features or use of this software
     23  *    must display the following acknowledgement:
     24  *	This product includes software developed by the University of
     25  *	California, Berkeley and its contributors.
     26  * 4. Neither the name of the University nor the names of its contributors
     27  *    may be used to endorse or promote products derived from this software
     28  *    without specific prior written permission.
     29  *
     30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     40  * SUCH DAMAGE.
     41  *
     42  *	from: Utah $Hdr: vmparam.h 1.16 91/01/18$
     43  *	from: @(#)vmparam.h	7.3 (Berkeley) 5/7/91
     44  *	vmparam.h,v 1.2 1993/05/22 07:58:38 cgd Exp
     45  */
     46 
     47 /*
     48  * Machine dependent constants for Sun3
     49  *
     50  * The Sun3 has limited total kernel virtual space (32MB) and
     51  * can not use main memory for page tables.  (All active PTEs
     52  * must be installed in special translation RAM in the MMU).
     53  * Therefore, parameters that would normally configure the
     54  * size of various page tables are irrelevant.  Only things
     55  * that consume portions of kernel virtual (KV) space matter,
     56  * and those things should be chosen to conserve KV space.
     57  */
     58 
     59 /*
     60  * USRTEXT is the start of the user text/data space, while
     61  * USRSTACK is the top (end) of the user stack.
     62  */
     63 #define	USRTEXT 	NBPG		/* Start of user text */
     64 #define	USRSTACK	KERNBASE	/* High end of user stack */
     65 
     66 /*
     67  * Virtual memory related constants, all in bytes
     68  */
     69 #ifndef MAXTSIZ
     70 #define	MAXTSIZ		(8*1024*1024)		/* max text size */
     71 #endif
     72 #ifndef DFLDSIZ
     73 #define	DFLDSIZ		(8*1024*1024)		/* initial data size limit */
     74 #endif
     75 #ifndef MAXDSIZ
     76 #define	MAXDSIZ		(32*1024*1024)		/* max data size */
     77 #endif
     78 #ifndef	DFLSSIZ
     79 #define	DFLSSIZ		(512*1024)		/* initial stack size limit */
     80 #endif
     81 #ifndef	MAXSSIZ
     82 #define	MAXSSIZ		MAXDSIZ			/* max stack size */
     83 #endif
     84 
     85 /*
     86  * Default sizes of swap allocation chunks (see dmap.h).
     87  * The actual values may be changed in vminit() based on MAXDSIZ.
     88  * With MAXDSIZ of 16Mb and NDMAP of 38, dmmax will be 1024.
     89  * DMMIN should be at least ctod(1) so that vtod() works.
     90  * vminit() insures this.
     91  */
     92 #define	DMMIN	32			/* smallest swap allocation */
     93 #define	DMMAX	4096			/* largest potential swap allocation */
     94 
     95 /*
     96  * PTEs for mapping user space into the kernel for phyio operations.
     97  * The actual limitation for physio requests will be the DVMA space,
     98  * and that is fixed by hardware design at 1MB.  We could make the
     99  * physio map larger than that, but it would not buy us much.
    100  */
    101 #ifndef USRIOSIZE
    102 #define USRIOSIZE	128		/* 1 MB */
    103 #endif
    104 
    105 /*
    106  * PTEs for system V style shared memory.
    107  * This is basically slop for kmempt which we actually allocate (malloc) from.
    108  */
    109 #ifndef SHMMAXPGS
    110 #define SHMMAXPGS	512 	/* 4 MB */
    111 #endif
    112 
    113 /*
    114  * The time for a process to be blocked before being very swappable.
    115  * This is a number of seconds which the system takes as being a non-trivial
    116  * amount of real time.  You probably shouldn't change this;
    117  * it is used in subtle ways (fractions and multiples of it are, that is, like
    118  * half of a ``long time'', almost a long time, etc.)
    119  * It is related to human patience and other factors which don't really
    120  * change over time.
    121  */
    122 #define	MAXSLP 		20
    123 
    124 /*
    125  * A swapped in process is given a small amount of core without being bothered
    126  * by the page replacement algorithm.  Basically this says that if you are
    127  * swapped in you deserve some resources.  We protect the last SAFERSS
    128  * pages against paging and will just swap you out rather than paging you.
    129  * Note that each process has at least UPAGES+CLSIZE pages which are not
    130  * paged anyways (this is currently 8+2=10 pages or 5k bytes), so this
    131  * number just means a swapped in process is given around 25k bytes.
    132  * Just for fun: current memory prices are 4600$ a megabyte on VAX (4/22/81),
    133  * so we loan each swapped in process memory worth 100$, or just admit
    134  * that we don't consider it worthwhile and swap it out to disk which costs
    135  * $30/mb or about $0.75.
    136  */
    137 #define	SAFERSS		4		/* nominal ``small'' resident set size
    138 					   protected against replacement */
    139 
    140 /*
    141  * Mach-derived constants, virtual memory map:
    142  *
    143  * 0000.0000  user space
    144  * 0E00.0000  kernel space
    145  * 0FE0.0000  monitor map (devices)
    146  * 0FF0.0000  DVMA space
    147  * 0FFE.0000  monitor RAM seg.
    148  * 0FFF.E000  monitor RAM page
    149  */
    150 
    151 /* user/kernel map constants */
    152 #define VM_MIN_ADDRESS		((vm_offset_t)0)
    153 #define VM_MAX_ADDRESS		((vm_offset_t)KERNBASE)
    154 #define VM_MAXUSER_ADDRESS	((vm_offset_t)KERNBASE)
    155 #define VM_MIN_KERNEL_ADDRESS	((vm_offset_t)KERNBASE)
    156 #define VM_MAX_KERNEL_ADDRESS	((vm_offset_t)0x0FE00000)
    157 
    158 /* virtual sizes (bytes) for various kernel submaps */
    159 #define VM_MBUF_SIZE		(NMBCLUSTERS*MCLBYTES)
    160 #define VM_KMEM_SIZE		(NKMEMCLUSTERS*CLBYTES)
    161 #define VM_PHYS_SIZE		(USRIOSIZE*CLBYTES)
    162 
    163 #define MACHINE_NONCONTIG	/* VM <=> pmap interface modifier */
    164