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vmparam.h revision 1.23
      1 /*	$NetBSD: vmparam.h,v 1.23 1999/04/10 02:15:46 gwr Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *        This product includes software developed by the NetBSD
     18  *        Foundation, Inc. and its contributors.
     19  * 4. Neither the name of The NetBSD Foundation nor the names of its
     20  *    contributors may be used to endorse or promote products derived
     21  *    from this software without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     25  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     26  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     27  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     33  * POSSIBILITY OF SUCH DAMAGE.
     34  */
     35 
     36 #ifdef	_SUN3_
     37 #include <machine/vmparam3.h>
     38 #endif	/* SUN3 */
     39 #ifdef	_SUN3X_
     40 #include <machine/vmparam3x.h>
     41 #endif	/* SUN3X */
     42 #ifdef	_LKM
     43 #define	USRSTACK KERNBASE
     44 extern	char KERNBASE[];
     45 #endif	/* _LKM */
     46 
     47 /* This is needed by some LKMs. */
     48 #define VM_PHYSSEG_MAX		4
     49 struct pmap_physseg {
     50 	/* NULL */
     51 };
     52 
     53 /*
     54  * The time for a process to be blocked before being very swappable.
     55  * This is a number of seconds which the system takes as being a non-trivial
     56  * amount of real time.  You probably shouldn't change this;
     57  * it is used in subtle ways (fractions and multiples of it are, that is, like
     58  * half of a ``long time'', almost a long time, etc.)
     59  * It is related to human patience and other factors which don't really
     60  * change over time.
     61  */
     62 #define	MAXSLP 		20
     63 
     64 /*
     65  * A swapped in process is given a small amount of core without being bothered
     66  * by the page replacement algorithm.  Basically this says that if you are
     67  * swapped in you deserve some resources.  We protect the last SAFERSS
     68  * pages against paging and will just swap you out rather than paging you.
     69  * Note that each process has at least UPAGES+CLSIZE pages which are not
     70  * paged anyways (this is currently 8+2=10 pages or 5k bytes), so this
     71  * number just means a swapped in process is given around 25k bytes.
     72  * Just for fun: current memory prices are 4600$ a megabyte on VAX (4/22/81),
     73  * so we loan each swapped in process memory worth 100$, or just admit
     74  * that we don't consider it worthwhile and swap it out to disk which costs
     75  * $30/mb or about $0.75.
     76  * Update: memory prices have changed recently (9/96). At the current
     77  * value of $6 per megabyte, we lend each swapped in process memory worth
     78  * $0.15, or just admit that we don't consider it worthwhile and swap it out
     79  * to disk which costs $0.20/MB, or just under half a cent.
     80  */
     81 #define	SAFERSS		4		/* nominal ``small'' resident set size
     82 					   protected against replacement */
     83