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38 * @(#)param.h 8.3 (Berkeley) 4/4/95
39 * $FreeBSD: src/sys/sys/param.h,v 1.61.2.38 2003/05/22 17:12:01 fjoe Exp $
40 * $DragonFly: src/sys/sys/param.h,v 1.20 2005/01/14 02:20:24 dillon Exp $
46 #define BSD 200307 /* XXX kern.osrevision */
47 #define BSD4_3 1 /* XXX obsolete */
48 #define BSD4_4 1 /* XXX obsolete */
51 * __DragonFly_version number. Note that the name and comment are pattern
52 * searched from conf/newvers.sh.
54 * Version changes should be documented in:
55 * doc/en_US.ISO8859-1/books/porters-handbook/book.sgml
57 #undef __DragonFly_version
58 #define __DragonFly_version 110000 /* Master, propagated to newvers */
62 * __FreeBSD_version numbers for source compatibility. This is temporary
63 * along with the __FreeBSD__ define in gcc2. Note that gcc3 does not
64 * define __FreeBSD__ by default, only __DragonFly__.
66 #undef __FreeBSD_version
67 #define __FreeBSD_version 480101
75 #include <sys/types.h>
79 * Machine-independent constants (some used in following include files).
80 * Redefined constants are from POSIX 1003.1 limits file.
82 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
83 * MAXLOGNAME should be == UT_NAMESIZE+1 (see <utmp.h>)
85 #include <sys/syslimits.h>
87 #define MAXCOMLEN 16 /* max command name remembered */
88 #define MAXINTERP 32 /* max interpreter file name length */
89 #define MAXLOGNAME 17 /* max login name length (incl. NUL) */
90 #define MAXUPRC CHILD_MAX /* max simultaneous processes */
91 #define NCARGS ARG_MAX /* max bytes for an exec function */
92 #define NGROUPS NGROUPS_MAX /* max number groups */
93 #define NOFILE OPEN_MAX /* max open files per process */
94 #define NOGROUP 65535 /* marker for empty group set member */
95 #define MAXHOSTNAMELEN 256 /* max hostname size */
97 /* More types and definitions used throughout the kernel. */
99 #include <sys/cdefs.h>
100 #include <sys/errno.h>
101 #include <sys/time.h>
109 #include <sys/signal.h>
112 /* Machine type dependent parameters. */
113 #include <machine/param.h>
115 #include <machine/limits.h>
119 * Priorities. Note that with 32 run queues, differences less than 4 are
122 #define MAXPRI 127 /* Priorities range from 0 through MAXPRI. */
125 #define PRIBASE_REALTIME 0
126 #define PRIBASE_NORMAL 128
127 #define PRIBASE_IDLE 256
128 #define PRIBASE_THREAD 384 /* huh? */
129 #define PRIBASE_NULL 512
131 #define PCATCH 0x00000100 /* tsleep checks signals */
132 #define PUSRFLAG1 0x00000200 /* Subsystem specific flag */
133 #define PNORESCHED 0x00000400 /* No reschedule on wakeup */
134 #define PDOMAIN_MASK 0xFFFF0000 /* address domains for wakeup */
135 #define PDOMAIN_UMTX 0x00010000 /* independant domain for UMTX */
137 #define NZERO 0 /* default "nice" */
139 #define NBPW sizeof(int) /* number of bytes per word (integer) */
141 #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
143 #define NODEV (dev_t)(-1) /* non-existent device */
144 #define NOUDEV (udev_t)(-1) /* non-existent device */
145 #define NOMAJ 256 /* non-existent device */
147 #define NODEV (dev_t)(-1) /* non-existent device */
151 * File system parameters and macros.
153 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes
154 * per block. MAXBSIZE may be made larger without effecting
155 * any existing filesystems as long as it does not exceed MAXPHYS,
156 * and may be made smaller at the risk of not being able to use
157 * filesystems which require a block size exceeding MAXBSIZE.
159 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the
160 * minimum KVM memory reservation the kernel is willing to make.
161 * Filesystems can of course request smaller chunks. Actual
162 * backing memory uses a chunk size of a page (PAGE_SIZE).
164 * If you make BKVASIZE too small you risk seriously fragmenting
165 * the buffer KVM map which may slow things down a bit. If you
166 * make it too big the kernel will not be able to optimally use
167 * the KVM memory reserved for the buffer cache and will wind
168 * up with too-few buffers.
170 * The default is 16384, roughly 2x the block size used by a
171 * normal UFS filesystem.
173 #define MAXBSIZE 65536 /* must be power of 2 */
174 #define BKVASIZE 16384 /* must be power of 2 */
175 #define BKVAMASK (BKVASIZE-1)
179 * MAXPATHLEN defines the longest permissible path length after expanding
180 * symbolic links. It is used to allocate a temporary buffer from the buffer
181 * pool in which to do the name expansion, hence should be a power of two,
182 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
183 * maximum number of symbolic links that may be expanded in a path name.
184 * It should be set high enough to allow all legitimate uses, but halt
185 * infinite loops reasonably quickly.
187 #define MAXPATHLEN PATH_MAX
188 #define MAXSYMLINKS 32
190 /* Bit map related macros. */
191 #define setbit(a,i) ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
192 #define clrbit(a,i) ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
193 #define isset(a,i) ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
194 #define isclr(a,i) (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
196 /* Macros for counting and rounding. */
198 #define howmany(x, y) (((x)+((y)-1))/(y))
200 #define rounddown(x, y) (((x)/(y))*(y))
201 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
202 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
203 #define powerof2(x) ((((x)-1)&(x))==0)
205 /* Macros for min/max. */
206 #define MIN(a,b) (((a)<(b))?(a):(b))
207 #define MAX(a,b) (((a)>(b))?(a):(b))
210 * Constants for setting the parameters of the kernel memory allocator.
212 * 2 ** MINBUCKET is the smallest unit of memory that will be
213 * allocated. It must be at least large enough to hold a pointer.
215 * Units of memory less or equal to MAXALLOCSAVE will permanently
216 * allocate physical memory; requests for these size pieces of
217 * memory are quite fast. Allocations greater than MAXALLOCSAVE must
218 * always allocate and free physical memory; requests for these
219 * size allocations should be done infrequently as they will be slow.
221 * Constraints: PAGE_SIZE <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
222 * MAXALLOCSIZE must be a power of two.
224 #if defined(__alpha__)
225 #define MINBUCKET 5 /* 5 => min allocation of 32 bytes */
227 #define MINBUCKET 4 /* 4 => min allocation of 16 bytes */
229 #define MAXALLOCSAVE (2 * PAGE_SIZE)
232 * Scale factor for scaled integers used to count %cpu time and load avgs.
234 * The number of CPU `tick's that map to a unique `%age' can be expressed
235 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
236 * can be calculated (assuming 32 bits) can be closely approximated using
237 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
239 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
240 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
242 #define FSHIFT 11 /* bits to right of fixed binary point */
243 #define FSCALE (1<<FSHIFT)
245 #define dbtoc(db) /* calculates devblks to pages */ \
246 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
248 #define ctodb(db) /* calculates pages to devblks */ \
249 ((db) << (PAGE_SHIFT - DEV_BSHIFT))
253 * Make this available for most of the kernel. There were too many
254 * things that included sys/systm.h just for panic().
257 void panic (const char *, ...) __dead2 __printflike(1, 2);
261 #define htonl(x) __htonl(x)
264 #define htons(x) __htons(x)
267 #define ntohl(x) __ntohl(x)
270 #define ntohs(x) __ntohs(x)
273 #endif /* _SYS_PARAM_H_ */