xref: /csrg-svn/sys/tahoe/include/vmparam.h (revision 49429)
1*49429Sbostic /*-
2*49429Sbostic  * Copyright (c) 1988 The Regents of the University of California.
3*49429Sbostic  * All rights reserved.
434408Skarels  *
5*49429Sbostic  * This code is derived from software contributed to Berkeley by
6*49429Sbostic  * Computer Consoles Inc.
7*49429Sbostic  *
8*49429Sbostic  * %sccs.include.proprietary.c%
9*49429Sbostic  *
10*49429Sbostic  *	@(#)vmparam.h	7.3 (Berkeley) 05/08/91
1134408Skarels  */
1224010Ssam 
13*49429Sbostic /*-
1425926Ssam  * Machine dependent constants for tahoe.
1524010Ssam  */
1625926Ssam 
1724010Ssam /*
1824010Ssam  * USRTEXT is the start of the user text/data space, while USRSTACK
1924010Ssam  * is the top (end) of the user stack.  LOWPAGES and HIGHPAGES are
2024010Ssam  * the number of pages from the beginning of the P0 region to the
2124010Ssam  * beginning of the text and from the beginning of the P2 region to the
2224010Ssam  * beginning of the stack respectively.
2324010Ssam  */
2424010Ssam #define	USRTEXT		0
2525678Ssam #define	USRSTACK	(0xc0000000-UPAGES*NBPG) /* Start of user stack */
2625678Ssam #define	BTOPUSRSTACK	(0x300000 - UPAGES)	 /* btop(USRSTACK) */
2724010Ssam #define	P2PAGES		0x100000	/* number of pages in P2 region */
2824010Ssam #define	LOWPAGES	0
2924010Ssam #define	HIGHPAGES	UPAGES
3024010Ssam 
3124010Ssam /*
3225854Ssam  * Virtual memory related constants, all in bytes
3324010Ssam  */
3425854Ssam #define	MAXTSIZ		(6*1024*1024)		/* max text size */
3525678Ssam #ifndef DFLDSIZ
3625854Ssam #define	DFLDSIZ		(6*1024*1024)		/* initial data size limit */
3725678Ssam #endif
3825678Ssam #ifndef MAXDSIZ
3927184Ssam #define	MAXDSIZ		(32*1024*1024)		/* max data size */
4025678Ssam #endif
4125678Ssam #ifndef	DFLSSIZ
4225854Ssam #define	DFLSSIZ		(512*1024)		/* initial stack size limit */
4325678Ssam #endif
4425678Ssam #ifndef	MAXSSIZ
4525678Ssam #define	MAXSSIZ		MAXDSIZ			/* max stack size */
4625678Ssam #endif
4724010Ssam 
4824010Ssam /*
4925678Ssam  * Default sizes of swap allocation chunks (see dmap.h).
5025678Ssam  * The actual values may be changed in vminit() based on MAXDSIZ.
5125678Ssam  * With MAXDSIZ of 16Mb and NDMAP of 38, dmmax will be 1024.
5241521Smckusick  * DMMIN should be at least ctod(1) so that vtod() works.
5341521Smckusick  * vminit() ensures this.
5425678Ssam  */
5525678Ssam #define	DMMIN	32			/* smallest swap allocation */
5625678Ssam #define	DMMAX	4096			/* largest potential swap allocation */
5725678Ssam #define	DMTEXT	1024			/* swap allocation for text */
5825678Ssam 
5925678Ssam /*
6024010Ssam  * Sizes of the system and user portions of the system page table.
6124010Ssam  */
6224010Ssam /* SYSPTSIZE IS SILLY; IT SHOULD BE COMPUTED AT BOOT TIME */
6331317Skarels #define	SYSPTSIZE	((20+MAXUSERS/2)*NPTEPG)
6425678Ssam #define	USRPTSIZE 	(4*NPTEPG)
6524010Ssam 
6624010Ssam /*
6741521Smckusick  * PTEs for system V compatible shared memory.
6841521Smckusick  * This is basically slop for kmempt which we actually allocate (malloc) from.
6941521Smckusick  */
7041521Smckusick #define SHMMAXPGS	512
7141521Smckusick 
7241521Smckusick /*
7341521Smckusick  * Boundary at which to place first MAPMEM segment if not explicitly
7441521Smckusick  * specified.  Should be a power of two.  This allows some slop for
7541521Smckusick  * the data segment to grow underneath the first mapped segment.
7641521Smckusick  */
7741521Smckusick #define MMSEG		0x200000
7841521Smckusick 
7941521Smckusick /*
8024010Ssam  * The size of the clock loop.
8124010Ssam  */
8224010Ssam #define	LOOPPAGES	(maxfree - firstfree)
8324010Ssam 
8424010Ssam /*
8524010Ssam  * The time for a process to be blocked before being very swappable.
8624010Ssam  * This is a number of seconds which the system takes as being a non-trivial
8724010Ssam  * amount of real time.  You probably shouldn't change this;
8824010Ssam  * it is used in subtle ways (fractions and multiples of it are, that is, like
8924010Ssam  * half of a ``long time'', almost a long time, etc.)
9024010Ssam  * It is related to human patience and other factors which don't really
9124010Ssam  * change over time.
9224010Ssam  */
9324010Ssam #define	MAXSLP 		20
9424010Ssam 
9524010Ssam /*
9624010Ssam  * A swapped in process is given a small amount of core without being bothered
9724010Ssam  * by the page replacement algorithm.  Basically this says that if you are
9824010Ssam  * swapped in you deserve some resources.  We protect the last SAFERSS
9924010Ssam  * pages against paging and will just swap you out rather than paging you.
10024010Ssam  * Note that each process has at least UPAGES+CLSIZE pages which are not
10124010Ssam  * paged anyways (this is currently 8+2=10 pages or 5k bytes), so this
10224010Ssam  * number just means a swapped in process is given around 25k bytes.
10324010Ssam  * Just for fun: current memory prices are 4600$ a megabyte on VAX (4/22/81),
10424010Ssam  * so we loan each swapped in process memory worth 100$, or just admit
10524010Ssam  * that we don't consider it worthwhile and swap it out to disk which costs
10624010Ssam  * $30/mb or about $0.75.
10724010Ssam  */
10825678Ssam #define	SAFERSS		32		/* nominal ``small'' resident set size
10924010Ssam 					   protected against replacement */
11024010Ssam 
11124010Ssam /*
11224010Ssam  * DISKRPM is used to estimate the number of paging i/o operations
11324010Ssam  * which one can expect from a single disk controller.
11424010Ssam  */
11524010Ssam #define	DISKRPM		60
11624010Ssam 
11724010Ssam /*
11824010Ssam  * Klustering constants.  Klustering is the gathering
11924010Ssam  * of pages together for pagein/pageout, while clustering
12024010Ssam  * is the treatment of hardware page size as though it were
12124010Ssam  * larger than it really is.
12224010Ssam  *
12324010Ssam  * KLMAX gives maximum cluster size in CLSIZE page (cluster-page)
12441521Smckusick  * units.  Note that ctod(KLMAX*CLSIZE) must be <= DMMIN in dmap.h.
12541521Smckusick  * ctob(KLMAX) should also be less than MAXPHYS (in vm_swp.c) to
12641521Smckusick  * avoid "big push" panics.
12724010Ssam  */
12824010Ssam 
12924010Ssam #define	KLMAX	(32/CLSIZE)
13024010Ssam #define	KLSEQL	(16/CLSIZE)		/* in klust if vadvise(VA_SEQL) */
13124010Ssam #define	KLIN	(8/CLSIZE)		/* default data/stack in klust */
13224010Ssam #define	KLTXT	(4/CLSIZE)		/* default text in klust */
13324010Ssam #define	KLOUT	(32/CLSIZE)
13424010Ssam 
13524010Ssam /*
13624010Ssam  * KLSDIST is the advance or retard of the fifo reclaim for sequential
13724010Ssam  * processes data space.
13824010Ssam  */
13924010Ssam #define	KLSDIST	3		/* klusters advance/retard for seq. fifo */
14024010Ssam 
14124010Ssam /*
14224010Ssam  * Paging thresholds (see vm_sched.c).
14325678Ssam  * Strategy of 1/19/85:
14425678Ssam  *	lotsfree is 512k bytes, but at most 1/4 of memory
14524010Ssam  *	desfree is 200k bytes, but at most 1/8 of memory
14624010Ssam  *	minfree is 64k bytes, but at most 1/2 of desfree
14724010Ssam  */
14825678Ssam #define	LOTSFREE	(512 * 1024)
14924010Ssam #define	LOTSFREEFRACT	4
15024010Ssam #define	DESFREE		(200 * 1024)
15124010Ssam #define	DESFREEFRACT	8
15224010Ssam #define	MINFREE		(64 * 1024)
15324010Ssam #define	MINFREEFRACT	2
15424010Ssam 
15524010Ssam /*
15625678Ssam  * There are two clock hands, initially separated by HANDSPREAD bytes
15725678Ssam  * (but at most all of user memory).  The amount of time to reclaim
15825678Ssam  * a page once the pageout process examines it increases with this
15925678Ssam  * distance and decreases as the scan rate rises.
16025678Ssam  */
16125678Ssam #define	HANDSPREAD	(2 * 1024 * 1024)
16225678Ssam 
16325678Ssam /*
16425678Ssam  * The number of times per second to recompute the desired paging rate
16525678Ssam  * and poke the pagedaemon.
16625678Ssam  */
16725678Ssam #define	RATETOSCHEDPAGING	4
16825678Ssam 
16925678Ssam /*
17024010Ssam  * Believed threshold (in megabytes) for which interleaved
17124010Ssam  * swapping area is desirable.
17224010Ssam  */
17324010Ssam #define	LOTSOFMEM	2
17424010Ssam 
17533285Skarels #define	mapin(pte, v, pfnum, prot) \
17633285Skarels 	(*(int *)(pte) = (pfnum) | (prot), mtpr(TBIS, v))
17724010Ssam 
17825678Ssam /*
17925678Ssam  * Invalidate a cluster (optimized here for standard CLSIZE).
18025678Ssam  */
18125678Ssam #if CLSIZE == 1
18225678Ssam #define	tbiscl(v)	mtpr(TBIS, ptob(v))
18325678Ssam #endif
184