xref: /freebsd/sys/i386/include/vmparam.h (revision d42d25c451a6363140f28ee7a598ad9df304b475)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * William Jolitz.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	from: @(#)vmparam.h	5.9 (Berkeley) 5/12/91
37  *	$Id$
38  */
39 
40 
41 /*
42  * Machine dependent constants for 386.
43  */
44 
45 /*
46  * Virtual address space arrangement. On 386, both user and kernel
47  * share the address space, not unlike the vax.
48  * USRTEXT is the start of the user text/data space, while USRSTACK
49  * is the top (end) of the user stack. Immediately above the user stack
50  * resides the user structure, which is UPAGES long and contains the
51  * kernel stack.
52  *
53  * Immediately after the user structure is the page table map, and then
54  * kernal address space.
55  */
56 #define	USRTEXT		0
57 #define	USRSTACK	0xFDBFE000
58 #define	BTOPUSRSTACK	(0xFDC00-(UPAGES))	/* btop(USRSTACK) */
59 #define	LOWPAGES	0
60 #define HIGHPAGES	UPAGES
61 
62 /*
63  * Virtual memory related constants, all in bytes
64  */
65 #define	MAXTSIZ		(6*1024*1024)		/* max text size */
66 #ifndef DFLDSIZ
67 #define	DFLDSIZ		(16*1024*1024)		/* initial data size limit */
68 #endif
69 #ifndef MAXDSIZ
70 #define	MAXDSIZ		(32*1024*1024)		/* max data size */
71 #endif
72 #ifndef	DFLSSIZ
73 #define	DFLSSIZ		(512*1024)		/* initial stack size limit */
74 #endif
75 #ifndef	MAXSSIZ
76 #define	MAXSSIZ		(8*1024*1024)		/* max stack size */
77 #endif
78 
79 /*
80  * Default sizes of swap allocation chunks (see dmap.h).
81  * The actual values may be changed in vminit() based on MAXDSIZ.
82  * With MAXDSIZ of 16Mb and NDMAP of 38, dmmax will be 1024.
83  */
84 #define	DMMIN	32			/* smallest swap allocation */
85 #define	DMMAX	4096			/* largest potential swap allocation */
86 #define	DMTEXT	1024			/* swap allocation for text */
87 
88 /*
89  * Sizes of the system and user portions of the system page table.
90  */
91 #define	SYSPTSIZE 	(2*NPTEPG)
92 #define	USRPTSIZE 	(2*NPTEPG)
93 
94 /*
95  * Size of the Shared Memory Pages page table.
96  */
97 #ifndef	SHMMAXPGS
98 #define	SHMMAXPGS	512		/* XXX until we have more kmap space */
99 #endif
100 
101 /*
102  * Size of User Raw I/O map
103  */
104 #define	USRIOSIZE 	300
105 
106 /*
107  * The size of the clock loop.
108  */
109 #define	LOOPPAGES	(maxfree - firstfree)
110 
111 /*
112  * The time for a process to be blocked before being very swappable.
113  * This is a number of seconds which the system takes as being a non-trivial
114  * amount of real time.  You probably shouldn't change this;
115  * it is used in subtle ways (fractions and multiples of it are, that is, like
116  * half of a ``long time'', almost a long time, etc.)
117  * It is related to human patience and other factors which don't really
118  * change over time.
119  */
120 #define	MAXSLP 		20
121 
122 /*
123  * A swapped in process is given a small amount of core without being bothered
124  * by the page replacement algorithm.  Basically this says that if you are
125  * swapped in you deserve some resources.  We protect the last SAFERSS
126  * pages against paging and will just swap you out rather than paging you.
127  * Note that each process has at least UPAGES+CLSIZE pages which are not
128  * paged anyways (this is currently 8+2=10 pages or 5k bytes), so this
129  * number just means a swapped in process is given around 25k bytes.
130  * Just for fun: current memory prices are 4600$ a megabyte on VAX (4/22/81),
131  * so we loan each swapped in process memory worth 100$, or just admit
132  * that we don't consider it worthwhile and swap it out to disk which costs
133  * $30/mb or about $0.75.
134  * { wfj 6/16/89: Retail AT memory expansion $800/megabyte, loan of $17
135  *   on disk costing $7/mb or $0.18 (in memory still 100:1 in cost!) }
136  */
137 #define	SAFERSS		8		/* nominal ``small'' resident set size
138 					   protected against replacement */
139 
140 /*
141  * DISKRPM is used to estimate the number of paging i/o operations
142  * which one can expect from a single disk controller.
143  */
144 #define	DISKRPM		60
145 
146 /*
147  * Klustering constants.  Klustering is the gathering
148  * of pages together for pagein/pageout, while clustering
149  * is the treatment of hardware page size as though it were
150  * larger than it really is.
151  *
152  * KLMAX gives maximum cluster size in CLSIZE page (cluster-page)
153  * units.  Note that KLMAX*CLSIZE must be <= DMMIN in dmap.h.
154  */
155 
156 #define	KLMAX	(4/CLSIZE)
157 #define	KLSEQL	(2/CLSIZE)		/* in klust if vadvise(VA_SEQL) */
158 #define	KLIN	(4/CLSIZE)		/* default data/stack in klust */
159 #define	KLTXT	(4/CLSIZE)		/* default text in klust */
160 #define	KLOUT	(4/CLSIZE)
161 
162 /*
163  * KLSDIST is the advance or retard of the fifo reclaim for sequential
164  * processes data space.
165  */
166 #define	KLSDIST	3		/* klusters advance/retard for seq. fifo */
167 
168 /*
169  * Paging thresholds (see vm_sched.c).
170  * Strategy of 1/19/85:
171  *	lotsfree is 512k bytes, but at most 1/4 of memory
172  *	desfree is 200k bytes, but at most 1/8 of memory
173  *	minfree is 64k bytes, but at most 1/2 of desfree
174  */
175 #define	LOTSFREE	(512 * 1024)
176 #define	LOTSFREEFRACT	4
177 #define	DESFREE		(200 * 1024)
178 #define	DESFREEFRACT	8
179 #define	MINFREE		(64 * 1024)
180 #define	MINFREEFRACT	2
181 
182 /*
183  * There are two clock hands, initially separated by HANDSPREAD bytes
184  * (but at most all of user memory).  The amount of time to reclaim
185  * a page once the pageout process examines it increases with this
186  * distance and decreases as the scan rate rises.
187  */
188 #define	HANDSPREAD	(2 * 1024 * 1024)
189 
190 /*
191  * The number of times per second to recompute the desired paging rate
192  * and poke the pagedaemon.
193  */
194 #define	RATETOSCHEDPAGING	4
195 
196 /*
197  * Believed threshold (in megabytes) for which interleaved
198  * swapping area is desirable.
199  */
200 #define	LOTSOFMEM	2
201 
202 #define	mapin(pte, v, pfnum, prot) \
203 	{(*(int *)(pte) = ((pfnum)<<PGSHIFT) | (prot)) ; }
204 
205 /*
206  * Mach derived constants
207  */
208 
209 /* user/kernel map constants */
210 #define VM_MIN_ADDRESS		((vm_offset_t)0)
211 #define VM_MAXUSER_ADDRESS	((vm_offset_t)0xFDBFE000)
212 #define UPT_MIN_ADDRESS		((vm_offset_t)0xFDC00000)
213 #define UPT_MAX_ADDRESS		((vm_offset_t)0xFDFF7000)
214 #define VM_MAX_ADDRESS		UPT_MAX_ADDRESS
215 #define VM_MIN_KERNEL_ADDRESS	((vm_offset_t)0xFDFF7000)
216 #define UPDT			VM_MIN_KERNEL_ADDRESS
217 #define KPT_MIN_ADDRESS		((vm_offset_t)0xFDFF8000)
218 #define KPT_MAX_ADDRESS		((vm_offset_t)0xFDFFF000)
219 #define VM_MAX_KERNEL_ADDRESS	((vm_offset_t)0xFF7FF000)
220 
221 /* virtual sizes (bytes) for various kernel submaps */
222 #define VM_MBUF_SIZE		(NMBCLUSTERS*MCLBYTES)
223 #define VM_KMEM_SIZE		(16 * 1024 * 1024)
224 #define VM_PHYS_SIZE		(USRIOSIZE*CLBYTES)
225 
226 /* pcb base */
227 #define	pcbb(p)		((u_int)(p)->p_addr)
228 
229 /*
230  * Flush MMU TLB
231  */
232 
233 #ifndef I386_CR3PAT
234 #define	I386_CR3PAT	0x0
235 #endif
236 
237 #ifdef notyet
238 #define _cr3() ({u_long rtn; \
239 	asm (" movl %%cr3,%%eax; movl %%eax,%0 " \
240 		: "=g" (rtn) \
241 		: \
242 		: "ax"); \
243 	rtn; \
244 })
245 
246 #define load_cr3(s) ({ u_long val; \
247 	val = (s) | I386_CR3PAT; \
248 	asm ("movl %0,%%eax; movl %%eax,%%cr3" \
249 		:  \
250 		: "g" (val) \
251 		: "ax"); \
252 })
253 
254 #define tlbflush() ({ u_long val; \
255 	val = u.u_pcb.pcb_ptd | I386_CR3PAT; \
256 	asm ("movl %0,%%eax; movl %%eax,%%cr3" \
257 		:  \
258 		: "g" (val) \
259 		: "ax"); \
260 })
261 #endif
262