xref: /original-bsd/sys/sys/param.h (revision 64716fc5)
165a1cfb1Smckusick /*
20c67d176Skarels  * Copyright (c) 1982, 1986, 1989 Regents of the University of California.
365a1cfb1Smckusick  * All rights reserved.  The Berkeley software License Agreement
465a1cfb1Smckusick  * specifies the terms and conditions for redistribution.
565a1cfb1Smckusick  *
6*64716fc5Sbostic  *	@(#)param.h	7.19 (Berkeley) 12/16/90
765a1cfb1Smckusick  */
85db792e4Sbill 
9c2520f22Skarels #define	BSD	199006		/* June, 1990 system version (year & month) */
101a9e6e3cSkarels #define BSD4_3	1
1157ce53b7Skarels #define BSD4_4	0.5
122867d692Sbloom 
134a9959f4Sbostic #include <sys/syslimits.h>
144a9959f4Sbostic 
155db792e4Sbill /*
16b481cdefSroot  * Machine-independent constants
17b481cdefSroot  */
184a9959f4Sbostic #define	MAXUPRC		CHILD_MAX	/* max processes per user */
194a9959f4Sbostic #define	NOFILE		OPEN_MAX	/* max open files per process */
204a9959f4Sbostic #define	NCARGS		ARG_MAX		/* # characters in exec arglist */
2157ce53b7Skarels #define	MAXINTERP	32		/* max interpreter file name length */
224a9959f4Sbostic #define	NGROUPS		NGROUPS_MAX	/* max number groups */
2377caf3abSkarels #define MAXHOSTNAMELEN	256		/* maximum hostname size */
2477caf3abSkarels #define	MAXCOMLEN	16		/* maximum command name remembered */
2577caf3abSkarels 	/* MAXCOMLEN should be >= sizeof(ac_comm) (acct.h)  */
2677caf3abSkarels #define	MAXLOGNAME	12		/* maximum login name length */
2777caf3abSkarels 	/* MAXLOGNAME must be >= UT_NAMESIZE (<utmp.h>) */
2845ac661dSwnj 
29ebd4ffb8Skarels #define	NOGROUP		65535		/* marker for empty group set member */
30e74c57f3Ssam 
315db792e4Sbill /*
32b481cdefSroot  * Priorities
335db792e4Sbill  */
345db792e4Sbill #define	PSWP	0
358ec93d38Smckusick #define	PVM	1
365db792e4Sbill #define	PINOD	10
375db792e4Sbill #define	PRIBIO	20
38c9c63310Smckusick #define	PVFS	22
395db792e4Sbill #define	PZERO	25
4057ce53b7Skarels #define	PSOCK	26
415db792e4Sbill #define	PWAIT	30
42bea46c20Ssam #define	PLOCK	35
4357ce53b7Skarels #define	PPAUSE	40
445db792e4Sbill #define	PUSER	50
4557ce53b7Skarels #define	PRIMASK	0x0ff
4657ce53b7Skarels #define	PCATCH	0x100		/* or'd with pri for tsleep to check signals */
475db792e4Sbill 
4874c6c69bSkarels #define	NZERO	0
495db792e4Sbill 
50f520e942Skarels #ifndef LOCORE
51*64716fc5Sbostic #include	<sys/types.h>
52f520e942Skarels #endif
53f520e942Skarels 
545db792e4Sbill /*
55b481cdefSroot  * Signals
565db792e4Sbill  */
570c67d176Skarels #include <sys/signal.h>
5803c2128fSroot 
59f520e942Skarels /*
60f520e942Skarels  * Machine type dependent parameters.
61f520e942Skarels  */
62*64716fc5Sbostic #include <machine/param.h>
63*64716fc5Sbostic #include <machine/endian.h>
64*64716fc5Sbostic #include <machine/limits.h>
65f520e942Skarels 
665db792e4Sbill #define	NBPW	sizeof(int)	/* number of bytes in an integer */
675db792e4Sbill 
680c67d176Skarels #ifndef NULL
695db792e4Sbill #define	NULL	0
700c67d176Skarels #endif
71f0028148Skarels #define	CMASK	022		/* default mask for file creation */
725db792e4Sbill #define	NODEV	(dev_t)(-1)
735db792e4Sbill 
745db792e4Sbill /*
755db792e4Sbill  * Clustering of hardware pages on machines with ridiculously small
765db792e4Sbill  * page sizes is done here.  The paging subsystem deals with units of
77f520e942Skarels  * CLSIZE pte's describing NBPG (from machine/machparam.h) pages each.
785db792e4Sbill  *
795db792e4Sbill  * NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE
805db792e4Sbill  */
81248881f8Swnj #define	CLBYTES		(CLSIZE*NBPG)
82e163c03cSwnj #define	CLOFSET		(CLSIZE*NBPG-1)	/* for clusters, like PGOFSET */
83248881f8Swnj #define	claligned(x)	((((int)(x))&CLOFSET)==0)
84248881f8Swnj #define	CLOFF		CLOFSET
85b481cdefSroot #define	CLSHIFT		(PGSHIFT+CLSIZELOG2)
865db792e4Sbill 
87b481cdefSroot #if CLSIZE==1
88b481cdefSroot #define	clbase(i)	(i)
89b481cdefSroot #define	clrnd(i)	(i)
90b481cdefSroot #else
915db792e4Sbill /* give the base virtual address (first of CLSIZE) */
925db792e4Sbill #define	clbase(i)	((i) &~ (CLSIZE-1))
935db792e4Sbill /* round a number of clicks up to a whole cluster */
945db792e4Sbill #define	clrnd(i)	(((i) + (CLSIZE-1)) &~ (CLSIZE-1))
95b481cdefSroot #endif
965db792e4Sbill 
974bda8b2fSkarels /* CBLOCK is the size of a clist block, must be power of 2 */
984bda8b2fSkarels #define	CBLOCK	64
992a0e599eSmarc #define CBQSIZE	(CBLOCK/NBBY)	/* quote bytes/cblock - can do better */
1002a0e599eSmarc #define	CBSIZE	(CBLOCK - sizeof(struct cblock *) - CBQSIZE) /* data chars/clist */
1014bda8b2fSkarels #define	CROUND	(CBLOCK - 1)				/* clist rounding */
1025db792e4Sbill 
1035db792e4Sbill /*
104389af1dfSmckusic  * File system parameters and macros.
105389af1dfSmckusic  *
106389af1dfSmckusic  * The file system is made out of blocks of at most MAXBSIZE units,
107389af1dfSmckusic  * with smaller units (fragments) only in the last direct block.
108389af1dfSmckusic  * MAXBSIZE primarily determines the size of buffers in the buffer
109389af1dfSmckusic  * pool. It may be made larger without any effect on existing
110389af1dfSmckusic  * file systems; however making it smaller make make some file
111389af1dfSmckusic  * systems unmountable.
112389af1dfSmckusic  */
113389af1dfSmckusic #define	MAXBSIZE	8192
114389af1dfSmckusic #define MAXFRAG 	8
115389af1dfSmckusic 
116edc472f6Skre /*
117389af1dfSmckusic  * MAXPATHLEN defines the longest permissable path length
118389af1dfSmckusic  * after expanding symbolic links. It is used to allocate
119389af1dfSmckusic  * a temporary buffer from the buffer pool in which to do the
120389af1dfSmckusic  * name expansion, hence should be a power of two, and must
121389af1dfSmckusic  * be less than or equal to MAXBSIZE.
122389af1dfSmckusic  * MAXSYMLINKS defines the maximum number of symbolic links
123389af1dfSmckusic  * that may be expanded in a path name. It should be set high
124389af1dfSmckusic  * enough to allow all legitimate uses, but halt infinite loops
125389af1dfSmckusic  * reasonably quickly.
126389af1dfSmckusic  */
1274a9959f4Sbostic #define	MAXPATHLEN	PATH_MAX
128389af1dfSmckusic #define MAXSYMLINKS	8
129389af1dfSmckusic 
130389af1dfSmckusic /*
131ab090aa7Skarels  * bit map related macros
132ab090aa7Skarels  */
133ab090aa7Skarels #define	setbit(a,i)	((a)[(i)/NBBY] |= 1<<((i)%NBBY))
134ab090aa7Skarels #define	clrbit(a,i)	((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
135ab090aa7Skarels #define	isset(a,i)	((a)[(i)/NBBY] & (1<<((i)%NBBY)))
136ab090aa7Skarels #define	isclr(a,i)	(((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
137ab090aa7Skarels 
138ab090aa7Skarels /*
139ab090aa7Skarels  * Macros for counting and rounding.
140ab090aa7Skarels  */
141ab090aa7Skarels #ifndef howmany
142ab090aa7Skarels #define	howmany(x, y)	(((x)+((y)-1))/(y))
143ab090aa7Skarels #endif
144ab090aa7Skarels #define	roundup(x, y)	((((x)+((y)-1))/(y))*(y))
145ab090aa7Skarels #define powerof2(x)	((((x)-1)&(x))==0)
146ab090aa7Skarels 
147ab090aa7Skarels /*
148ab090aa7Skarels  * Macros for fast min/max:
149ab090aa7Skarels  * with inline expansion, the "function" is faster.
150ab090aa7Skarels  */
151ab090aa7Skarels #ifdef KERNEL
152ab090aa7Skarels #define	MIN(a,b) min((a), (b))
153ab090aa7Skarels #define	MAX(a,b) max((a), (b))
154ab090aa7Skarels #else
155ab090aa7Skarels #define	MIN(a,b) (((a)<(b))?(a):(b))
156ab090aa7Skarels #define	MAX(a,b) (((a)>(b))?(a):(b))
157ab090aa7Skarels #endif
158ab090aa7Skarels 
159ab090aa7Skarels /*
1602fe64d92Smckusick  * Constants for setting the parameters of the kernel memory allocator.
1612fe64d92Smckusick  *
1622fe64d92Smckusick  * 2 ** MINBUCKET is the smallest unit of memory that will be
1632fe64d92Smckusick  * allocated. It must be at least large enough to hold a pointer.
1642fe64d92Smckusick  *
1652fe64d92Smckusick  * Units of memory less or equal to MAXALLOCSAVE will permanently
1662fe64d92Smckusick  * allocate physical memory; requests for these size pieces of
1672fe64d92Smckusick  * memory are quite fast. Allocations greater than MAXALLOCSAVE must
1682fe64d92Smckusick  * always allocate and free physical memory; requests for these
1692fe64d92Smckusick  * size allocations should be done infrequently as they will be slow.
1702fe64d92Smckusick  * Constraints: CLBYTES <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14)
1712fe64d92Smckusick  * and MAXALLOCSIZE must be a power of two.
1722fe64d92Smckusick  */
1732fe64d92Smckusick #define MINBUCKET	4		/* 4 => min allocation of 16 bytes */
1742fe64d92Smckusick #define MAXALLOCSAVE	(2 * CLBYTES)
1752fe64d92Smckusick 
1762fe64d92Smckusick /*
1774233ee38Smckusick  * Scale factor for scaled integers used to count %cpu time and load avgs.
1784233ee38Smckusick  *
1794233ee38Smckusick  * The number of CPU `tick's that map to a unique `%age' can be expressed
1804233ee38Smckusick  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
1814233ee38Smckusick  * can be calculated (assuming 32 bits) can be closely approximated using
1824233ee38Smckusick  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
1834233ee38Smckusick  *
1844233ee38Smckusick  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
1854233ee38Smckusick  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
1864233ee38Smckusick  */
1874233ee38Smckusick #define	FSHIFT	11		/* bits to right of fixed binary point */
1884233ee38Smckusick #define FSCALE	(1<<FSHIFT)
189