xref: /illumos-gate/usr/src/uts/common/conf/param.c (revision acd07c6b871cfa70bc42c9278037a17c430897b6)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 1983, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright 2012 Milan Jurik. All rights reserved.
24  */
25 
26 #include <sys/types.h>
27 #include <sys/time.h>
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/signal.h>
31 #include <sys/sysmacros.h>
32 #include <sys/cmn_err.h>
33 #include <sys/user.h>
34 #include <sys/proc.h>
35 #include <sys/task.h>
36 #include <sys/project.h>
37 #include <sys/klwp.h>
38 #include <sys/vnode.h>
39 #include <sys/file.h>
40 #include <sys/fcntl.h>
41 #include <sys/flock.h>
42 #include <sys/var.h>
43 #include <sys/stream.h>
44 #include <sys/strsubr.h>
45 #include <sys/conf.h>
46 #include <sys/class.h>
47 #include <sys/ts.h>
48 #include <sys/rt.h>
49 #include <sys/exec.h>
50 #include <sys/exechdr.h>
51 #include <sys/buf.h>
52 #include <sys/resource.h>
53 #include <vm/seg.h>
54 #include <vm/pvn.h>
55 #include <vm/seg_kmem.h>
56 #include <sys/vmparam.h>
57 #include <sys/machparam.h>
58 #include <sys/utsname.h>
59 #include <sys/kmem.h>
60 #include <sys/stack.h>
61 #include <sys/modctl.h>
62 #include <sys/fdbuffer.h>
63 #include <sys/cyclic_impl.h>
64 #include <sys/disp.h>
65 #include <sys/tuneable.h>
66 #include <sys/systeminfo.h>
67 
68 #include <sys/vmem.h>
69 #include <sys/clock.h>
70 #include <sys/clock_impl.h>
71 #include <sys/serializer.h>
72 
73 /*
74  * The following few lines describe generic things that must be compiled
75  * into the booted executable (unix) rather than genunix or any other
76  * module because they're required by crash dump readers, etc.
77  */
78 struct modctl modules;		/* head of linked list of modules */
79 char *default_path;		/* default module loading path */
80 struct swapinfo *swapinfo;	/* protected by the swapinfo_lock */
81 proc_t *practive;		/* active process list */
82 uint_t nproc;			/* current number of processes */
83 proc_t p0;			/* process 0 */
84 struct plock p0lock;		/* p0's p_lock */
85 klwp_t lwp0;			/* t0's lwp */
86 task_t *task0p;			/* task 0 */
87 kproject_t *proj0p;		/* location of project 0 */
88 
89 /*
90  * The following are "implementation architecture" dependent constants made
91  * available here in the form of initialized data for use by "implementation
92  * architecture" independent modules. See machparam.h.
93  */
94 const unsigned long	_pagesize	= (unsigned long)PAGESIZE;
95 const unsigned int	_pageshift	= (unsigned int)PAGESHIFT;
96 const unsigned long	_pageoffset	= (unsigned long)PAGEOFFSET;
97 /*
98  * XXX - This value pagemask has to be a 64bit size because
99  * large file support uses this mask on offsets which are 64 bit size.
100  * using unsigned leaves the higher 32 bits value as zero thus
101  * corrupting offset calculations in the file system and VM.
102  */
103 const u_longlong_t	_pagemask	= (u_longlong_t)PAGEMASK;
104 const unsigned long	_mmu_pagesize	= (unsigned long)MMU_PAGESIZE;
105 const unsigned int	_mmu_pageshift	= (unsigned int)MMU_PAGESHIFT;
106 const unsigned long	_mmu_pageoffset	= (unsigned long)MMU_PAGEOFFSET;
107 const unsigned long	_mmu_pagemask	= (unsigned long)MMU_PAGEMASK;
108 uintptr_t		_kernelbase	= (uintptr_t)KERNELBASE;
109 uintptr_t		_userlimit	= (uintptr_t)USERLIMIT;
110 uintptr_t		_userlimit32	= (uintptr_t)USERLIMIT32;
111 const uintptr_t		_argsbase	= (uintptr_t)ARGSBASE;
112 const unsigned int	_diskrpm	= (unsigned int)DISKRPM;
113 const unsigned long	_pgthresh	= (unsigned long)PGTHRESH;
114 const unsigned int	_maxslp		= (unsigned int)MAXSLP;
115 const unsigned long	_maxhandspreadpages = (unsigned long)MAXHANDSPREADPAGES;
116 const int		_ncpu 		= (int)NCPU;
117 const int		_ncpu_log2	= (int)NCPU_LOG2;
118 const int		_ncpu_p2	= (int)NCPU_P2;
119 const unsigned long	_defaultstksz	= (unsigned long)DEFAULTSTKSZ;
120 const unsigned int	_nbpg		= (unsigned int)MMU_PAGESIZE;
121 
122 /*
123  * System parameter formulae.
124  *
125  * This file is copied into each directory where we compile
126  * the kernel; it should be modified there to suit local taste
127  * if necessary.
128  */
129 
130 /*
131  * Default hz is 100, but if we set hires_tick we get higher resolution
132  * clock behavior (currently defined to be 1000 hz).  Higher values seem
133  * to work, but are not supported.
134  *
135  * If we do decide to play with higher values, remember that hz should
136  * satisfy the following constraints to avoid integer round-off problems:
137  *
138  * (1) hz should be in the range 100 <= hz <= MICROSEC.  If hz exceeds
139  *     MICROSEC, usec_per_tick will be zero and lots of stuff will break.
140  *     Similarly, if hz < 100 then hz / 100 == 0 and stuff will break.
141  *
142  * (2) If hz <= 1000, it should be both a multiple of 100 and a
143  *	divisor of 1000.
144  *
145  * (3) If hz > 1000, it should be both a multiple of 1000 and a
146  *	divisor of MICROSEC.
147  *
148  * Thus the only reasonable values of hz (i.e. the values that won't
149  * cause roundoff error) are: 100, 200, 500, 1000, 2000, 4000, 5000,
150  * 8000, 10000, 20000, 25000, 40000, 50000, 100000, 125000, 200000,
151  * 250000, 500000, 1000000.  As of this writing (1996) a clock rate
152  * of more than about 10 kHz seems utterly ridiculous, although
153  * this observation will no doubt seem quaintly amusing one day.
154  */
155 #define	HIRES_HZ_DEFAULT	1000
156 
157 int hz = HZ_DEFAULT;
158 int hires_hz = HIRES_HZ_DEFAULT;
159 
160 int hires_tick = 0;
161 int cpu_decay_factor = 10;	/* this is no longer tied to clock */
162 int max_hres_adj;	/* maximum adjustment of hrtime per tick */
163 int tick_per_msec;	/* clock ticks per millisecond (zero if hz < 1000) */
164 
165 /*
166  * Milliseconds, Microseconds, and Nanoseconds per clock tick
167  *
168  * Note:
169  *  msec_per_tick is zero if hz > 1000
170  */
171 int msec_per_tick;
172 int usec_per_tick;
173 int nsec_per_tick;
174 
175 /*
176  * Time Resolution values. These are defined in condvar.h and initialized in
177  * param_init(). Consumers of cv_reltimedwait() and cv_reltimedwait_sig()
178  * need to specify how accurate the timeout argument should be through
179  * one of these values. The intention is to allow the underlying implementation
180  * to anticipate or defer the expiration of timeouts, preventing unnecessary
181  * wakeups by batch processing similarly expiring events.
182  */
183 time_res_t time_res[TR_COUNT];
184 
185 /*
186  * Setting "snooping" to a non-zero value will cause a deadman panic if
187  * snoop_interval microseconds elapse without lbolt increasing.  The default
188  * snoop_interval is 50 seconds.
189  */
190 #define	SNOOP_INTERVAL_MIN	(MICROSEC)
191 #define	SNOOP_INTERVAL_DEFAULT	(50 * MICROSEC)
192 
193 int snooping = 0;
194 uint_t snoop_interval = SNOOP_INTERVAL_DEFAULT;
195 
196 /*
197  * Tables of initialization functions, called from main().
198  */
199 
200 extern void system_taskq_init(void);
201 extern void binit(void);
202 extern void space_init(void);
203 extern void dnlc_init(void);
204 extern void vfsinit(void);
205 extern void finit(void);
206 extern void strinit(void);
207 extern void flk_init(void);
208 extern void ftrace_init(void);
209 extern void softcall_init(void);
210 extern void ttyinit(void);
211 extern void schedctl_init(void);
212 extern void deadman_init(void);
213 extern void clock_timer_init(void);
214 extern void clock_realtime_init(void);
215 extern void clock_highres_init(void);
216 extern void clock_tick_mp_init(void);
217 extern void cu_init(void);
218 extern void callout_mp_init(void);
219 extern void cpu_seq_tbl_init(void);
220 
221 void	(*init_tbl[])(void) = {
222 	system_taskq_init,
223 	binit,
224 	space_init,
225 	dnlc_init,
226 	vfsinit,
227 	finit,
228 	strinit,
229 	serializer_init,
230 	softcall_init,
231 	ttyinit,
232 	as_init,
233 	pvn_init,
234 	anon_init,
235 	segvn_init,
236 	flk_init,
237 	cpu_seq_tbl_init,
238 	schedctl_init,
239 	fdb_init,
240 	deadman_init,
241 	clock_timer_init,
242 	clock_realtime_init,
243 	clock_highres_init,
244 	0
245 };
246 
247 
248 #if defined(__sparc)
249 	extern void siron_mp_init();
250 #endif
251 
252 /*
253  * Any per cpu resources should be initialized via
254  * an entry in mp_init_tbl().
255  */
256 void	(*mp_init_tbl[])(void) = {
257 	ftrace_init,
258 	cyclic_mp_init,
259 #if defined(__sparc)
260 	siron_mp_init,
261 #endif
262 	clock_tick_mp_init,
263 	cu_init,
264 	callout_mp_init,
265 	0
266 };
267 
268 int maxusers;		/* kitchen-sink knob for dynamic configuration */
269 
270 /*
271  * pidmax -- highest pid value assigned by the system
272  * Settable in /etc/system
273  */
274 int pidmax = DEFAULT_MAXPID;
275 
276 /*
277  * jump_pid - if set, this value is where pid numbers should start
278  * after the first few system pids (0-3) are used.  If 0, pids are
279  * chosen in the usual way. This variable can be used to quickly
280  * create large pids (by setting it to 100000, for example). pids
281  * less than this value will never be chosen.
282  */
283 pid_t jump_pid = DEFAULT_JUMPPID;
284 
285 /*
286  * autoup -- used in struct var for dynamic config of the age a delayed-write
287  * buffer must be in seconds before bdflush will write it out.
288  */
289 #define	DEFAULT_AUTOUP	30
290 int autoup = DEFAULT_AUTOUP;
291 
292 /*
293  * bufhwm -- tuneable variable for struct var for v_bufhwm.
294  * high water mark for buffer cache mem usage in units of K bytes.
295  *
296  * bufhwm_pct -- ditto, but given in % of physmem.
297  */
298 int bufhwm = 0;
299 int bufhwm_pct = 0;
300 
301 /*
302  * Process table.
303  */
304 int maxpid;
305 int max_nprocs;		/* set in param_init() */
306 int maxuprc;		/* set in param_init() */
307 int reserved_procs;
308 int nthread = 1;
309 
310 /*
311  * UFS tunables
312  */
313 int ufs_ninode;		/* declared here due to backwards compatibility */
314 int ndquot;		/* declared here due to backwards compatibility */
315 
316 /*
317  * Exec switch table. This is used by the generic exec module
318  * to switch out to the desired executable type, based on the
319  * magic number. The currently supported types are ELF, a.out
320  * (both NMAGIC and ZMAGIC), interpreter (#!) files,
321  * and Java executables.
322  */
323 /*
324  * Magic numbers
325  */
326 short elfmagic = 0x7f45;
327 short intpmagic = 0x2321;
328 short jmagic = 0x504b;
329 
330 #if defined(__sparc)
331 short aout_nmagic = NMAGIC;
332 short aout_zmagic = ZMAGIC;
333 short aout_omagic = OMAGIC;
334 #endif
335 short nomagic = 0;
336 
337 /*
338  * Magic strings
339  */
340 #define	ELF32MAGIC_STRING	"\x7f""ELF\x1"
341 #define	ELF64MAGIC_STRING	"\x7f""ELF\x2"
342 #define	INTPMAGIC_STRING	"#!"
343 #define	JAVAMAGIC_STRING	"PK\003\004"
344 #define	AOUT_OMAGIC_STRING	"\x1""\x07"	/* 0407 */
345 #define	AOUT_NMAGIC_STRING	"\x1""\x08"	/* 0410 */
346 #define	AOUT_ZMAGIC_STRING	"\x1""\x0b"	/* 0413 */
347 #define	NOMAGIC_STRING		""
348 
349 #define	SHBIN_CNTL(x)	((x)&037)
350 #define	SHBINMAGIC_STRING {SHBIN_CNTL('k'), SHBIN_CNTL('s'), SHBIN_CNTL('h'), 0}
351 #define	SHBINMAGIC_LEN	4
352 
353 char elf32magicstr[] = ELF32MAGIC_STRING;
354 char elf64magicstr[] = ELF64MAGIC_STRING;
355 char intpmagicstr[] = INTPMAGIC_STRING;
356 char shbinmagicstr[] = SHBINMAGIC_STRING;
357 char javamagicstr[] = JAVAMAGIC_STRING;
358 #if defined(__sparc)
359 char aout_nmagicstr[] = AOUT_NMAGIC_STRING;
360 char aout_zmagicstr[] = AOUT_ZMAGIC_STRING;
361 char aout_omagicstr[] = AOUT_OMAGIC_STRING;
362 #endif
363 char nomagicstr[] = NOMAGIC_STRING;
364 
365 char *execswnames[] = {
366 	"elfexec",	/* Elf32 */
367 #ifdef _LP64
368 	"elfexec",	/* Elf64 */
369 #endif
370 	"intpexec",
371 	"shbinexec",
372 	"javaexec",
373 #if defined(__sparc)
374 	"aoutexec",
375 	"aoutexec",
376 	"aoutexec",
377 #endif
378 	NULL,
379 	NULL,
380 	NULL
381 };
382 
383 struct execsw execsw[] = {
384 	{ elf32magicstr, 0, 5, NULL, NULL, NULL },
385 #ifdef _LP64
386 	{ elf64magicstr, 0, 5, NULL, NULL, NULL },
387 #endif
388 	{ intpmagicstr, 0, 2, NULL, NULL, NULL },
389 	{ shbinmagicstr, 0, SHBINMAGIC_LEN, NULL, NULL, NULL },
390 	{ javamagicstr, 0, 4, NULL, NULL, NULL },
391 #if defined(__sparc)
392 	{ aout_zmagicstr, 2, 2, NULL, NULL, NULL },
393 	{ aout_nmagicstr, 2, 2, NULL, NULL, NULL },
394 	{ aout_omagicstr, 2, 2, NULL, NULL, NULL },
395 #endif
396 	{ nomagicstr, 0, 0, NULL, NULL, NULL },
397 	{ nomagicstr, 0, 0, NULL, NULL, NULL },
398 	{ nomagicstr, 0, 0, NULL, NULL, NULL },
399 	{ nomagicstr, 0, 0, NULL, NULL, NULL }
400 };
401 int nexectype = sizeof (execsw) / sizeof (execsw[0]);	/* # of exec types */
402 kmutex_t execsw_lock;	/* Used for allocation of execsw entries */
403 
404 /*
405  * symbols added to make changing max-file-descriptors
406  * simple via /etc/system
407  */
408 #define	RLIM_FD_CUR 0x100
409 #define	RLIM_FD_MAX 0x10000
410 
411 uint_t rlim_fd_cur = RLIM_FD_CUR;
412 uint_t rlim_fd_max = RLIM_FD_MAX;
413 
414 /*
415  * (Default resource limits were formerly declared here, but are now provided by
416  * the more general resource controls framework.)
417  */
418 
419 /*
420  * STREAMS tunables
421  */
422 int	nstrpush = 9;		/* maximum # of modules/drivers on a stream */
423 ssize_t	strctlsz = 1024;	/* maximum size of user-generated M_PROTO */
424 ssize_t	strmsgsz = 0x10000;	/* maximum size of user-generated M_DATA */
425 				/* for `strmsgsz', zero means unlimited */
426 /*
427  * Filesystem tunables
428  */
429 int	rstchown = 1;		/* POSIX_CHOWN_RESTRICTED is enabled */
430 int	ngroups_max = NGROUPS_MAX_DEFAULT;
431 
432 /*
433  * generic scheduling stuff
434  *
435  * Configurable parameters for RT and TS are in the respective
436  * scheduling class modules.
437  */
438 
439 pri_t maxclsyspri = MAXCLSYSPRI;
440 pri_t minclsyspri = MINCLSYSPRI;
441 char sys_name[] = "SYS";
442 
443 extern pri_t sys_init(id_t, int, classfuncs_t **);
444 extern classfuncs_t sys_classfuncs;
445 
446 sclass_t sclass[] = {
447 	{ "SYS",	sys_init,	&sys_classfuncs, STATIC_SCHED, 0 },
448 	{ "",	NULL,	NULL,	NULL, 0 },
449 	{ "",	NULL,	NULL,	NULL, 0 },
450 	{ "",	NULL,	NULL,	NULL, 0 },
451 	{ "",	NULL,	NULL,	NULL, 0 },
452 	{ "",	NULL,	NULL,	NULL, 0 },
453 	{ "",	NULL,	NULL,	NULL, 0 },
454 	{ "",	NULL,	NULL,	NULL, 0 },
455 	{ "",	NULL,	NULL,	NULL, 0 },
456 	{ "",	NULL,	NULL,	NULL, 0 }
457 };
458 
459 int loaded_classes = 1;		/* for loaded classes */
460 kmutex_t class_lock;		/* lock for class[] */
461 
462 int nclass = sizeof (sclass) / sizeof (sclass_t);
463 char initcls[] = "TS";
464 char *defaultclass = initcls;
465 
466 /*
467  * Tunable system parameters.
468  */
469 
470 /*
471  * The integers tune_* are done this way so that the tune
472  * data structure may be "tuned" if necessary from the /etc/system
473  * file. The tune data structure is initialized in param_init();
474  */
475 
476 tune_t tune;
477 
478 /*
479  * If freemem < t_getpgslow, then start to steal pages from processes.
480  */
481 int tune_t_gpgslo = 25;
482 
483 /*
484  * Rate at which fsflush is run, in seconds.
485  */
486 #define	DEFAULT_TUNE_T_FSFLUSHR	1
487 int tune_t_fsflushr = DEFAULT_TUNE_T_FSFLUSHR;
488 
489 /*
490  * The minimum available resident (not swappable) memory to maintain
491  * in order to avoid deadlock.  In pages.
492  */
493 int tune_t_minarmem = 25;
494 
495 /*
496  * The minimum available swappable memory to maintain in order to avoid
497  * deadlock.  In pages.
498  */
499 int tune_t_minasmem = 25;
500 
501 int tune_t_flckrec = 512;	/* max # of active frlocks */
502 
503 /*
504  * Number of currently available pages that cannot be 'locked'
505  * This is set in init_pages_pp_maximum, and must be initialized
506  * to zero here to detect an override in /etc/system
507  */
508 pgcnt_t pages_pp_maximum = 0;
509 
510 int boothowto;			/* boot flags passed to kernel */
511 struct var v;			/* System Configuration Information */
512 
513 /*
514  * System Configuration Information
515  */
516 
517 /*
518  * The physical system's host identifier, expressed as a decimal string.
519  * Code should only directly access this value when writing to it (setting the
520  * physical system's host identifier).  Code that reads the physical system's
521  * host identifier should use zone_get_hostid(NULL) instead.
522  */
523 char hw_serial[HW_HOSTID_LEN] = "0";
524 
525 #if defined(__sparc)
526 
527 /*
528  * On sparc machines, read hw_serial from the firmware at boot time
529  * and simply assert Oracle is the hardware provider.
530  */
531 char architecture[] = "sparcv9";
532 char architecture_32[] = "sparc";
533 char hw_provider[] = "Oracle Corporation";
534 
535 #elif defined(__i386)
536 
537 char architecture[] = "i386";
538 char architecture_32[] = "i386";
539 char hw_provider[SYS_NMLN] = "";
540 
541 #elif defined(__amd64)
542 
543 char architecture[] = "amd64";
544 char architecture_32[] = "i386";
545 char hw_provider[SYS_NMLN] = "";
546 
547 #else
548 #error "unknown processor architecture"
549 #endif
550 
551 char srpc_domain[SYS_NMLN] = "";
552 char platform[SYS_NMLN] = "";	/* read from the devinfo root node */
553 
554 /* Initialize isa_list */
555 char *isa_list = architecture;
556 
557 static pgcnt_t original_physmem = 0;
558 
559 #define	MIN_DEFAULT_MAXUSERS	8u
560 #define	MAX_DEFAULT_MAXUSERS	2048u
561 #define	MAX_MAXUSERS		4096u
562 
563 void
564 param_preset(void)
565 {
566 	original_physmem = physmem;
567 }
568 
569 void
570 param_calc(int platform_max_nprocs)
571 {
572 	/*
573 	 * Default to about one "user" per megabyte, taking into
574 	 * account both physical and virtual constraints.
575 	 * Note: 2^20 is a meg; shifting right by (20 - PAGESHIFT)
576 	 * converts pages to megs without integer overflow.
577 	 */
578 #if defined(__sparc)
579 	if (physmem > original_physmem) {
580 		physmem = original_physmem;
581 		cmn_err(CE_NOTE, "physmem limited to %ld", physmem);
582 	}
583 #endif
584 	if (maxusers == 0) {
585 		pgcnt_t physmegs = physmem >> (20 - PAGESHIFT);
586 		pgcnt_t virtmegs = vmem_size(heap_arena, VMEM_FREE) >> 20;
587 		maxusers = MIN(MAX(MIN(physmegs, virtmegs),
588 		    MIN_DEFAULT_MAXUSERS), MAX_DEFAULT_MAXUSERS);
589 	}
590 	if (maxusers > MAX_MAXUSERS) {
591 		maxusers = MAX_MAXUSERS;
592 		cmn_err(CE_NOTE, "maxusers limited to %d", MAX_MAXUSERS);
593 	}
594 
595 	if (ngroups_max > NGROUPS_MAX_DEFAULT)
596 		cmn_err(CE_WARN, "ngroups_max of %d > %d, NFS AUTH_SYS will"
597 		    " not work properly", ngroups_max, NGROUPS_MAX_DEFAULT);
598 
599 #ifdef DEBUG
600 	/*
601 	 * The purpose of maxusers is to prevent memory overcommit.
602 	 * DEBUG kernels take more space, so reduce maxusers a bit.
603 	 */
604 	maxusers = (3 * maxusers) / 4;
605 #endif
606 
607 	/*
608 	 * We need to dynamically change any variables now so that
609 	 * the setting of maxusers and pidmax propagate to the other
610 	 * variables that are dependent on them.
611 	 */
612 	if (reserved_procs == 0)
613 		reserved_procs = 5;
614 	if (pidmax < reserved_procs || pidmax > MAX_MAXPID)
615 		maxpid = MAX_MAXPID;
616 	else
617 		maxpid = pidmax;
618 
619 	/*
620 	 * This allows platform-dependent code to constrain the maximum
621 	 * number of processes allowed in case there are e.g. VM limitations
622 	 * with how many contexts are available.
623 	 */
624 	if (max_nprocs == 0)
625 		max_nprocs = (10 + 16 * maxusers);
626 	if (platform_max_nprocs > 0 && max_nprocs > platform_max_nprocs)
627 		max_nprocs = platform_max_nprocs;
628 	if (max_nprocs > maxpid)
629 		max_nprocs = maxpid;
630 
631 	if (maxuprc == 0)
632 		maxuprc = (max_nprocs - reserved_procs);
633 }
634 
635 void
636 param_init(void)
637 {
638 	/*
639 	 * Set each individual element of struct var v to be the
640 	 * default value. This is done this way
641 	 * so that a user can set the assigned integer value in the
642 	 * /etc/system file *IF* tuning is needed.
643 	 */
644 	v.v_proc = max_nprocs;	/* v_proc - max # of processes system wide */
645 	v.v_maxupttl = max_nprocs - reserved_procs;
646 	v.v_maxsyspri = (int)maxclsyspri;  /* max global pri for sysclass */
647 	v.v_maxup = MIN(maxuprc, v.v_maxupttl); /* max procs per user */
648 	v.v_autoup = autoup;	/* v_autoup - delay for delayed writes */
649 
650 	/*
651 	 * Set each individual element of struct tune to be the
652 	 * default value. Each struct element This is done this way
653 	 *  so that a user can set the assigned integer value in the
654 	 * /etc/system file *IF* tuning is needed.
655 	 */
656 	tune.t_gpgslo = tune_t_gpgslo;
657 	tune.t_fsflushr = tune_t_fsflushr;
658 	tune.t_minarmem = tune_t_minarmem;
659 	tune.t_minasmem = tune_t_minasmem;
660 	tune.t_flckrec = tune_t_flckrec;
661 
662 	/*
663 	 * Initialization for file descriptors to correct mistaken settings in
664 	 * /etc/system.  Initialization of limits performed by resource control
665 	 * system.
666 	 */
667 	if (rlim_fd_cur > rlim_fd_max)
668 		rlim_fd_cur = rlim_fd_max;
669 
670 	/*
671 	 * calculations needed if hz was set in /etc/system
672 	 */
673 	if (hires_tick)
674 		hz = hires_hz;
675 
676 	tick_per_msec = hz / MILLISEC;
677 	msec_per_tick = MILLISEC / hz;
678 	usec_per_tick = MICROSEC / hz;
679 	nsec_per_tick = NANOSEC / hz;
680 	max_hres_adj = nsec_per_tick >> ADJ_SHIFT;
681 
682 	/*
683 	 * Consumers of relative timedwait functions must specify how accurately
684 	 * the given timeout must expire. This is currently TR_CLOCK_TICK for
685 	 * the vast majority of consumers, but nsec_per_tick becomes an
686 	 * artificial value in a tickless world. Each caller of such routines
687 	 * should re-evaluate their usage and specify the appropriate
688 	 * resolution.
689 	 */
690 	time_res[TR_NANOSEC] = NANOSEC / NANOSEC;
691 	time_res[TR_MICROSEC] = NANOSEC / MICROSEC;
692 	time_res[TR_MILLISEC] = NANOSEC / MILLISEC;
693 	time_res[TR_SEC] = NANOSEC / SEC;
694 	time_res[TR_CLOCK_TICK] = nsec_per_tick;
695 }
696 
697 /*
698  * Validate tuneable parameters following /etc/system processing,
699  * but prior to param_init().
700  */
701 void
702 param_check(void)
703 {
704 #if defined(__x86)
705 	if (physmem != original_physmem) {
706 		cmn_err(CE_NOTE, "physmem cannot be modified to 0x%lx"
707 		    " via /etc/system. Please use eeprom(1M) instead.",
708 		    physmem);
709 		physmem = original_physmem;
710 	}
711 #endif
712 	if (ngroups_max < NGROUPS_UMIN)
713 		ngroups_max = NGROUPS_UMIN;
714 	if (ngroups_max > NGROUPS_UMAX)
715 		ngroups_max = NGROUPS_UMAX;
716 
717 	/* If we have many groups then the ucred proto message also grows. */
718 	if (ngroups_max > NGROUPS_OLDMAX &&
719 	    strctlsz < (ngroups_max - NGROUPS_OLDMAX) * sizeof (gid_t) + 1024) {
720 		strctlsz = (ngroups_max - NGROUPS_OLDMAX) * sizeof (gid_t) +
721 		    1024;
722 	}
723 
724 	if (autoup <= 0) {
725 		autoup = DEFAULT_AUTOUP;
726 		cmn_err(CE_WARN, "autoup <= 0; defaulting to %d", autoup);
727 	}
728 
729 	if (tune_t_fsflushr <= 0) {
730 		tune_t_fsflushr = DEFAULT_TUNE_T_FSFLUSHR;
731 		cmn_err(CE_WARN, "tune_t_fsflushr <= 0; defaulting to %d",
732 		    tune_t_fsflushr);
733 	}
734 
735 	if (jump_pid < 0 || jump_pid >= pidmax) {
736 		jump_pid = 0;
737 		cmn_err(CE_WARN, "jump_pid < 0 or >= pidmax; ignored");
738 	}
739 
740 	if (snoop_interval < SNOOP_INTERVAL_MIN) {
741 		snoop_interval = SNOOP_INTERVAL_DEFAULT;
742 		cmn_err(CE_WARN, "snoop_interval < minimum (%d); defaulting"
743 		    " to %d", SNOOP_INTERVAL_MIN, SNOOP_INTERVAL_DEFAULT);
744 	}
745 }
746