/* * Copyright (c) 1982, 1986 Regents of the University of California. * All rights reserved. The Berkeley software License Agreement * specifies the terms and conditions for redistribution. * * @(#)vmparam.h 7.1 (Berkeley) 6/5/86 */ /* * RCS Info * $Header: vmparam.h,v 3.1 86/10/22 13:55:23 tadl Exp $ * $Locker: $ */ /* * Machine dependent constants for VAX */ /* * USRTEXT is the start of the user text/data space, while USRSTACK * is the top (end) of the user stack. LOWPAGES and HIGHPAGES are * the number of pages from the beginning of the P0 region to the * beginning of the text and from the beginning of the P1 region to the * beginning of the stack respectively. */ #define USRTEXT 0 #define USRSTACK (0x80000000-UPAGES*NBPG) /* Start of user stack */ #define BTOPUSRSTACK (0x400000 - UPAGES) /* btop(USRSTACK) */ /* number of ptes per page */ #define P1PAGES 0x200000 /* number of pages in P1 region */ #define LOWPAGES 0 #define HIGHPAGES UPAGES /* * Virtual memory related constants, all in bytes */ #ifndef MAXTSIZ #define MAXTSIZ (6*1024*1024) /* max text size */ #endif #ifndef DFLDSIZ #define DFLDSIZ (6*1024*1024) /* initial data size limit */ #endif #ifndef MAXDSIZ #define MAXDSIZ (16*1024*1024) /* max data size */ #endif #ifndef DFLSSIZ #define DFLSSIZ (512*1024) /* initial stack size limit */ #endif #ifndef MAXSSIZ #define MAXSSIZ MAXDSIZ /* max stack size */ #endif /* * Default sizes of swap allocation chunks (see dmap.h). * The actual values may be changed in vminit() based on MAXDSIZ. * With MAXDSIZ of 16Mb and NDMAP of 38, dmmax will be 1024. */ #define DMMIN 32 /* smallest swap allocation */ #define DMMAX 4096 /* largest potential swap allocation */ #define DMTEXT 1024 /* swap allocation for text */ /* * Sizes of the system and user portions of the system page table. */ /* SYSPTSIZE IS SILLY; IT SHOULD BE COMPUTED AT BOOT TIME */ #define SYSPTSIZE ((20+MAXUSERS)*NPTEPG) #define USRPTSIZE (32*NPTEPG) /* * The size of the clock loop. */ #define LOOPPAGES (maxfree - firstfree) /* * The time for a process to be blocked before being very swappable. * This is a number of seconds which the system takes as being a non-trivial * amount of real time. You probably shouldn't change this; * it is used in subtle ways (fractions and multiples of it are, that is, like * half of a ``long time'', almost a long time, etc.) * It is related to human patience and other factors which don't really * change over time. */ #define MAXSLP 20 /* * A swapped in process is given a small amount of core without being bothered * by the page replacement algorithm. Basically this says that if you are * swapped in you deserve some resources. We protect the last SAFERSS * pages against paging and will just swap you out rather than paging you. * Note that each process has at least UPAGES+CLSIZE pages which are not * paged anyways (this is currently 8+2=10 pages or 5k bytes), so this * number just means a swapped in process is given around 25k bytes. * Just for fun: current memory prices are 4600$ a megabyte on VAX (4/22/81), * so we loan each swapped in process memory worth 100$, or just admit * that we don't consider it worthwhile and swap it out to disk which costs * $30/mb or about $0.75. */ #define SAFERSS 32 /* nominal ``small'' resident set size protected against replacement */ /* * DISKRPM is used to estimate the number of paging i/o operations * which one can expect from a single disk controller. */ #define DISKRPM 60 /* * Klustering constants. Klustering is the gathering * of pages together for pagein/pageout, while clustering * is the treatment of hardware page size as though it were * larger than it really is. * * KLMAX gives maximum cluster size in CLSIZE page (cluster-page) * units. Note that KLMAX*CLSIZE must be <= DMMIN in dmap.h. */ #define KLMAX (32/CLSIZE) #define KLSEQL (16/CLSIZE) /* in klust if vadvise(VA_SEQL) */ #define KLIN (8/CLSIZE) /* default data/stack in klust */ #define KLTXT (4/CLSIZE) /* default text in klust */ #define KLOUT (32/CLSIZE) /* * KLSDIST is the advance or retard of the fifo reclaim for sequential * processes data space. */ #define KLSDIST 3 /* klusters advance/retard for seq. fifo */ /* * Paging thresholds (see vm_sched.c). * Strategy of 1/19/85: * lotsfree is 512k bytes, but at most 1/4 of memory * desfree is 200k bytes, but at most 1/8 of memory * minfree is 64k bytes, but at most 1/2 of desfree */ #define LOTSFREE (512 * 1024) #define LOTSFREEFRACT 4 #define DESFREE (200 * 1024) #define DESFREEFRACT 8 #define MINFREE (64 * 1024) #define MINFREEFRACT 2 /* * Paged text files that are less than PGTHRESH bytes may be swapped * in instead of paged in. */ #define PGTHRESH (100 * 1024) /* * There are two clock hands, initially separated by HANDSPREAD bytes * (but at most all of user memory). The amount of time to reclaim * a page once the pageout process examines it increases with this * distance and decreases as the scan rate rises. */ #define HANDSPREAD (2 * 1024 * 1024) /* * The number of times per second to recompute the desired paging rate * and poke the pagedaemon. */ #define RATETOSCHEDPAGING 4 /* * Believed threshold (in megabytes) for which interleaved * swapping area is desirable. */ #define LOTSOFMEM 2 /* * BEWARE THIS DEFINITION WORKS ONLY WITH COUNT OF 1 */ #define mapin(pte, v, pfnum, count, prot) \ (*(int *)(pte) = (pfnum) | (prot), mtpr(TBIS, ptob(v)))