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34 * @(#)param.h 8.3 (Berkeley) 4/4/95
41 #include <sys/_null.h>
43 #define BSD 199506 /* System version (year & month). */
48 * __FreeBSD_version numbers are documented in the Porter's Handbook.
49 * If you bump the version for any reason, you should update the documentation
51 * Currently this lives here:
53 * doc/en_US.ISO8859-1/books/porters-handbook/book.sgml
55 * scheme is: <major><two digit minor>Rxx
56 * 'R' is in the range 0 to 4 if this is a release branch or
57 * x.0-CURRENT before RELENG_*_0 is created, otherwise 'R' is
58 * in the range 5 to 9.
60 #undef __FreeBSD_version
61 #define __FreeBSD_version 900044 /* Master, propagated to newvers */
64 #define P_OSREL_SIGSEGV 700004
65 #define P_OSREL_MAP_ANON 800104
69 #include <sys/types.h>
73 * Machine-independent constants (some used in following include files).
74 * Redefined constants are from POSIX 1003.1 limits file.
76 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
78 #include <sys/syslimits.h>
80 #define MAXCOMLEN 19 /* max command name remembered */
81 #define MAXINTERP PATH_MAX /* max interpreter file name length */
82 #define MAXLOGNAME 17 /* max login name length (incl. NUL) */
83 #define MAXUPRC CHILD_MAX /* max simultaneous processes */
84 #define NCARGS ARG_MAX /* max bytes for an exec function */
85 #define NGROUPS (NGROUPS_MAX+1) /* max number groups */
86 #define NOFILE OPEN_MAX /* max open files per process */
87 #define NOGROUP 65535 /* marker for empty group set member */
88 #define MAXHOSTNAMELEN 256 /* max hostname size */
89 #define SPECNAMELEN 63 /* max length of devicename */
91 /* More types and definitions used throughout the kernel. */
93 #include <sys/cdefs.h>
94 #include <sys/errno.h>
97 #include <sys/priority.h>
110 #include <sys/signal.h>
113 /* Machine type dependent parameters. */
114 #include <machine/param.h>
116 #include <sys/limits.h>
120 #define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */
122 #define DEV_BSIZE (1<<DEV_BSHIFT)
124 #ifndef BLKDEV_IOSIZE
125 #define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */
128 #define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */
131 #define MAXPHYS (128 * 1024) /* max raw I/O transfer size */
134 #define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE)
138 * Constants related to network buffer management.
139 * MCLBYTES must be no larger than PAGE_SIZE.
142 #define MSIZE 256 /* size of an mbuf */
146 #define MCLSHIFT 11 /* convert bytes to mbuf clusters */
147 #endif /* MCLSHIFT */
149 #define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */
152 #define MJUMPAGESIZE MCLBYTES
153 #elif PAGE_SIZE <= 8192
154 #define MJUMPAGESIZE PAGE_SIZE
156 #define MJUMPAGESIZE (8 * 1024)
159 #define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */
160 #define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */
163 * Some macros for units conversion
166 /* clicks to bytes */
168 #define ctob(x) ((x)<<PAGE_SHIFT)
171 /* bytes to clicks */
173 #define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
177 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We
178 * want to shift an unsigned type to avoid sign extension and we don't
179 * want to widen `bytes' unnecessarily. Assume that the result fits in
183 #define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \
184 (sizeof (bytes) > sizeof(long) \
185 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
186 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
190 #define dbtob(db) /* calculates (db * DEV_BSIZE) */ \
191 ((off_t)(db) << DEV_BSHIFT)
194 #define PRIMASK 0x0ff
195 #define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */
196 #define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */
197 #define PBDRY 0x400 /* for PCATCH stop is done on the user boundary */
199 #define NZERO 0 /* default "nice" */
201 #define NBBY 8 /* number of bits in a byte */
202 #define NBPW sizeof(int) /* number of bytes per word (integer) */
204 #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
206 #define NODEV (dev_t)(-1) /* non-existent device */
209 * File system parameters and macros.
211 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes
212 * per block. MAXBSIZE may be made larger without effecting
213 * any existing filesystems as long as it does not exceed MAXPHYS,
214 * and may be made smaller at the risk of not being able to use
215 * filesystems which require a block size exceeding MAXBSIZE.
217 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the
218 * minimum KVM memory reservation the kernel is willing to make.
219 * Filesystems can of course request smaller chunks. Actual
220 * backing memory uses a chunk size of a page (PAGE_SIZE).
222 * If you make BKVASIZE too small you risk seriously fragmenting
223 * the buffer KVM map which may slow things down a bit. If you
224 * make it too big the kernel will not be able to optimally use
225 * the KVM memory reserved for the buffer cache and will wind
226 * up with too-few buffers.
228 * The default is 16384, roughly 2x the block size used by a
229 * normal UFS filesystem.
231 #define MAXBSIZE 65536 /* must be power of 2 */
232 #define BKVASIZE 16384 /* must be power of 2 */
233 #define BKVAMASK (BKVASIZE-1)
236 * MAXPATHLEN defines the longest permissible path length after expanding
237 * symbolic links. It is used to allocate a temporary buffer from the buffer
238 * pool in which to do the name expansion, hence should be a power of two,
239 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
240 * maximum number of symbolic links that may be expanded in a path name.
241 * It should be set high enough to allow all legitimate uses, but halt
242 * infinite loops reasonably quickly.
244 #define MAXPATHLEN PATH_MAX
245 #define MAXSYMLINKS 32
247 /* Bit map related macros. */
248 #define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
249 #define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
251 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
253 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
255 /* Macros for counting and rounding. */
257 #define howmany(x, y) (((x)+((y)-1))/(y))
259 #define rounddown(x, y) (((x)/(y))*(y))
260 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
261 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
262 #define powerof2(x) ((((x)-1)&(x))==0)
264 /* Macros for min/max. */
265 #define MIN(a,b) (((a)<(b))?(a):(b))
266 #define MAX(a,b) (((a)>(b))?(a):(b))
270 * Basic byte order function prototypes for non-inline functions.
273 #ifndef _BYTEORDER_PROTOTYPED
274 #define _BYTEORDER_PROTOTYPED
276 __uint32_t htonl(__uint32_t);
277 __uint16_t htons(__uint16_t);
278 __uint32_t ntohl(__uint32_t);
279 __uint16_t ntohs(__uint16_t);
285 #ifndef _BYTEORDER_FUNC_DEFINED
286 #define _BYTEORDER_FUNC_DEFINED
287 #define htonl(x) __htonl(x)
288 #define htons(x) __htons(x)
289 #define ntohl(x) __ntohl(x)
290 #define ntohs(x) __ntohs(x)
291 #endif /* !_BYTEORDER_FUNC_DEFINED */
296 * Scale factor for scaled integers used to count %cpu time and load avgs.
298 * The number of CPU `tick's that map to a unique `%age' can be expressed
299 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
300 * can be calculated (assuming 32 bits) can be closely approximated using
301 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
303 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
304 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
306 #define FSHIFT 11 /* bits to right of fixed binary point */
307 #define FSCALE (1<<FSHIFT)
309 #define dbtoc(db) /* calculates devblks to pages */ \
310 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
312 #define ctodb(db) /* calculates pages to devblks */ \
313 ((db) << (PAGE_SHIFT - DEV_BSHIFT))
316 * Given the pointer x to the member m of the struct s, return
317 * a pointer to the containing structure.
319 #define member2struct(s, m, x) \
320 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))
323 * Access a variable length array that has been declared as a fixed
326 #define __PAST_END(array, offset) (((typeof(*(array)) *)(array))[offset])
328 #endif /* _SYS_PARAM_H_ */