/*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * William Jolitz. * * %sccs.include.redist.c% * * @(#)vmparam.h 8.2 (Berkeley) 04/22/94 */ /* * Machine dependent constants for 386. */ /* * Virtual address space arrangement. On 386, both user and kernel * share the address space, not unlike the vax. * USRTEXT is the start of the user text/data space, while USRSTACK * is the top (end) of the user stack. Immediately above the user stack * resides the user structure, which is UPAGES long and contains the * kernel stack. * * Immediately after the user structure is the page table map, and then * kernal address space. */ #define USRTEXT 0 #define USRSTACK 0xFDBFE000 #define BTOPUSRSTACK (0xFDC00-(UPAGES)) /* btop(USRSTACK) */ #define LOWPAGES 0 #define HIGHPAGES UPAGES /* * Virtual memory related constants, all in bytes */ #define MAXTSIZ (6*1024*1024) /* max text size */ #ifndef DFLDSIZ #define DFLDSIZ (6*1024*1024) /* initial data size limit */ #endif #ifndef MAXDSIZ #define MAXDSIZ (32*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. */ #define SYSPTSIZE (2*NPTEPG) #define USRPTSIZE (2*NPTEPG) /* * Size of User Raw I/O map */ #define USRIOSIZE 300 /* * 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. * { wfj 6/16/89: Retail AT memory expansion $800/megabyte, loan of $17 * on disk costing $7/mb or $0.18 (in memory still 100:1 in cost!) } */ #define SAFERSS 8 /* 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 (4/CLSIZE) #define KLSEQL (2/CLSIZE) /* in klust if vadvise(VA_SEQL) */ #define KLIN (4/CLSIZE) /* default data/stack in klust */ #define KLTXT (4/CLSIZE) /* default text in klust */ #define KLOUT (4/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 */ #define LOTSFREE (512 * 1024) #define LOTSFREEFRACT 4 #define DESFREE (200 * 1024) #define DESFREEFRACT 8 /* * 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 #define mapin(pte, v, pfnum, prot) \ {(*(int *)(pte) = ((pfnum)<p_addr) /* * Flush MMU TLB */ #ifndef I386_CR3PAT #define I386_CR3PAT 0x0 #endif #ifdef notyet #define _cr3() ({u_long rtn; \ asm (" movl %%cr3,%%eax; movl %%eax,%0 " \ : "=g" (rtn) \ : \ : "ax"); \ rtn; \ }) #define load_cr3(s) ({ u_long val; \ val = (s) | I386_CR3PAT; \ asm ("movl %0,%%eax; movl %%eax,%%cr3" \ : \ : "g" (val) \ : "ax"); \ }) #define tlbflush() ({ u_long val; \ val = u.u_pcb.pcb_ptd | I386_CR3PAT; \ asm ("movl %0,%%eax; movl %%eax,%%cr3" \ : \ : "g" (val) \ : "ax"); \ }) #endif