1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 7 * 8 * %sccs.include.redist.c% 9 * 10 * @(#)vmparam.h 8.2 (Berkeley) 04/22/94 11 */ 12 13 14 /* 15 * Machine dependent constants for 386. 16 */ 17 18 /* 19 * Virtual address space arrangement. On 386, both user and kernel 20 * share the address space, not unlike the vax. 21 * USRTEXT is the start of the user text/data space, while USRSTACK 22 * is the top (end) of the user stack. Immediately above the user stack 23 * resides the user structure, which is UPAGES long and contains the 24 * kernel stack. 25 * 26 * Immediately after the user structure is the page table map, and then 27 * kernal address space. 28 */ 29 #define USRTEXT 0 30 #define USRSTACK 0xFDBFE000 31 #define BTOPUSRSTACK (0xFDC00-(UPAGES)) /* btop(USRSTACK) */ 32 #define LOWPAGES 0 33 #define HIGHPAGES UPAGES 34 35 /* 36 * Virtual memory related constants, all in bytes 37 */ 38 #define MAXTSIZ (6*1024*1024) /* max text size */ 39 #ifndef DFLDSIZ 40 #define DFLDSIZ (6*1024*1024) /* initial data size limit */ 41 #endif 42 #ifndef MAXDSIZ 43 #define MAXDSIZ (32*1024*1024) /* max data size */ 44 #endif 45 #ifndef DFLSSIZ 46 #define DFLSSIZ (512*1024) /* initial stack size limit */ 47 #endif 48 #ifndef MAXSSIZ 49 #define MAXSSIZ MAXDSIZ /* max stack size */ 50 #endif 51 52 /* 53 * Default sizes of swap allocation chunks (see dmap.h). 54 * The actual values may be changed in vminit() based on MAXDSIZ. 55 * With MAXDSIZ of 16Mb and NDMAP of 38, dmmax will be 1024. 56 */ 57 #define DMMIN 32 /* smallest swap allocation */ 58 #define DMMAX 4096 /* largest potential swap allocation */ 59 #define DMTEXT 1024 /* swap allocation for text */ 60 61 /* 62 * Sizes of the system and user portions of the system page table. 63 */ 64 #define SYSPTSIZE (2*NPTEPG) 65 #define USRPTSIZE (2*NPTEPG) 66 67 /* 68 * Size of User Raw I/O map 69 */ 70 #define USRIOSIZE 300 71 72 /* 73 * The size of the clock loop. 74 */ 75 #define LOOPPAGES (maxfree - firstfree) 76 77 /* 78 * The time for a process to be blocked before being very swappable. 79 * This is a number of seconds which the system takes as being a non-trivial 80 * amount of real time. You probably shouldn't change this; 81 * it is used in subtle ways (fractions and multiples of it are, that is, like 82 * half of a ``long time'', almost a long time, etc.) 83 * It is related to human patience and other factors which don't really 84 * change over time. 85 */ 86 #define MAXSLP 20 87 88 /* 89 * A swapped in process is given a small amount of core without being bothered 90 * by the page replacement algorithm. Basically this says that if you are 91 * swapped in you deserve some resources. We protect the last SAFERSS 92 * pages against paging and will just swap you out rather than paging you. 93 * Note that each process has at least UPAGES+CLSIZE pages which are not 94 * paged anyways (this is currently 8+2=10 pages or 5k bytes), so this 95 * number just means a swapped in process is given around 25k bytes. 96 * Just for fun: current memory prices are 4600$ a megabyte on VAX (4/22/81), 97 * so we loan each swapped in process memory worth 100$, or just admit 98 * that we don't consider it worthwhile and swap it out to disk which costs 99 * $30/mb or about $0.75. 100 * { wfj 6/16/89: Retail AT memory expansion $800/megabyte, loan of $17 101 * on disk costing $7/mb or $0.18 (in memory still 100:1 in cost!) } 102 */ 103 #define SAFERSS 8 /* nominal ``small'' resident set size 104 protected against replacement */ 105 106 /* 107 * DISKRPM is used to estimate the number of paging i/o operations 108 * which one can expect from a single disk controller. 109 */ 110 #define DISKRPM 60 111 112 /* 113 * Klustering constants. Klustering is the gathering 114 * of pages together for pagein/pageout, while clustering 115 * is the treatment of hardware page size as though it were 116 * larger than it really is. 117 * 118 * KLMAX gives maximum cluster size in CLSIZE page (cluster-page) 119 * units. Note that KLMAX*CLSIZE must be <= DMMIN in dmap.h. 120 */ 121 122 #define KLMAX (4/CLSIZE) 123 #define KLSEQL (2/CLSIZE) /* in klust if vadvise(VA_SEQL) */ 124 #define KLIN (4/CLSIZE) /* default data/stack in klust */ 125 #define KLTXT (4/CLSIZE) /* default text in klust */ 126 #define KLOUT (4/CLSIZE) 127 128 /* 129 * KLSDIST is the advance or retard of the fifo reclaim for sequential 130 * processes data space. 131 */ 132 #define KLSDIST 3 /* klusters advance/retard for seq. fifo */ 133 134 /* 135 * Paging thresholds (see vm_sched.c). 136 * Strategy of 1/19/85: 137 * lotsfree is 512k bytes, but at most 1/4 of memory 138 * desfree is 200k bytes, but at most 1/8 of memory 139 */ 140 #define LOTSFREE (512 * 1024) 141 #define LOTSFREEFRACT 4 142 #define DESFREE (200 * 1024) 143 #define DESFREEFRACT 8 144 145 /* 146 * There are two clock hands, initially separated by HANDSPREAD bytes 147 * (but at most all of user memory). The amount of time to reclaim 148 * a page once the pageout process examines it increases with this 149 * distance and decreases as the scan rate rises. 150 */ 151 #define HANDSPREAD (2 * 1024 * 1024) 152 153 /* 154 * The number of times per second to recompute the desired paging rate 155 * and poke the pagedaemon. 156 */ 157 #define RATETOSCHEDPAGING 4 158 159 /* 160 * Believed threshold (in megabytes) for which interleaved 161 * swapping area is desirable. 162 */ 163 #define LOTSOFMEM 2 164 165 #define mapin(pte, v, pfnum, prot) \ 166 {(*(int *)(pte) = ((pfnum)<<PGSHIFT) | (prot)) ; } 167 168 /* 169 * Mach derived constants 170 */ 171 172 /* user/kernel map constants */ 173 #define VM_MIN_ADDRESS ((vm_offset_t)0) 174 #define VM_MAXUSER_ADDRESS ((vm_offset_t)0xFDBFD000) 175 #define UPT_MIN_ADDRESS ((vm_offset_t)0xFDC00000) 176 #define UPT_MAX_ADDRESS ((vm_offset_t)0xFDFF7000) 177 #define VM_MAX_ADDRESS UPT_MAX_ADDRESS 178 #define VM_MIN_KERNEL_ADDRESS ((vm_offset_t)0xFDFF7000) 179 #define UPDT VM_MIN_KERNEL_ADDRESS 180 #define KPT_MIN_ADDRESS ((vm_offset_t)0xFDFF8000) 181 #define KPT_MAX_ADDRESS ((vm_offset_t)0xFDFFF000) 182 #define VM_MAX_KERNEL_ADDRESS ((vm_offset_t)0xFF7FF000) 183 184 /* virtual sizes (bytes) for various kernel submaps */ 185 #define VM_MBUF_SIZE (NMBCLUSTERS*MCLBYTES) 186 #define VM_KMEM_SIZE (NKMEMCLUSTERS*CLBYTES) 187 #define VM_PHYS_SIZE (USRIOSIZE*CLBYTES) 188 189 /* # of kernel PT pages (initial only, can grow dynamically) */ 190 #define VM_KERNEL_PT_PAGES ((vm_size_t)2) /* XXX: SYSPTSIZE */ 191 192 /* pcb base */ 193 #define pcbb(p) ((u_int)(p)->p_addr) 194 195 /* 196 * Flush MMU TLB 197 */ 198 199 #ifndef I386_CR3PAT 200 #define I386_CR3PAT 0x0 201 #endif 202 203 #ifdef notyet 204 #define _cr3() ({u_long rtn; \ 205 asm (" movl %%cr3,%%eax; movl %%eax,%0 " \ 206 : "=g" (rtn) \ 207 : \ 208 : "ax"); \ 209 rtn; \ 210 }) 211 212 #define load_cr3(s) ({ u_long val; \ 213 val = (s) | I386_CR3PAT; \ 214 asm ("movl %0,%%eax; movl %%eax,%%cr3" \ 215 : \ 216 : "g" (val) \ 217 : "ax"); \ 218 }) 219 220 #define tlbflush() ({ u_long val; \ 221 val = u.u_pcb.pcb_ptd | I386_CR3PAT; \ 222 asm ("movl %0,%%eax; movl %%eax,%%cr3" \ 223 : \ 224 : "g" (val) \ 225 : "ax"); \ 226 }) 227 #endif 228