xref: /freebsd/sys/cddl/dev/profile/profile.c (revision ce6a89e27cd190313be39bb479880aeda4778436)
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  * Portions Copyright 2006-2008 John Birrell jb@freebsd.org
22  *
23  * $FreeBSD$
24  *
25  */
26 
27 /*
28  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
29  * Use is subject to license terms.
30  */
31 
32 #include <sys/cdefs.h>
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/conf.h>
36 #include <sys/cpuvar.h>
37 #include <sys/fcntl.h>
38 #include <sys/filio.h>
39 #include <sys/kdb.h>
40 #include <sys/kernel.h>
41 #include <sys/kmem.h>
42 #include <sys/kthread.h>
43 #include <sys/limits.h>
44 #include <sys/linker.h>
45 #include <sys/lock.h>
46 #include <sys/malloc.h>
47 #include <sys/module.h>
48 #include <sys/mutex.h>
49 #include <sys/poll.h>
50 #include <sys/proc.h>
51 #include <sys/selinfo.h>
52 #include <sys/smp.h>
53 #include <sys/sysctl.h>
54 #include <sys/uio.h>
55 #include <sys/unistd.h>
56 #include <machine/cpu.h>
57 #include <machine/stdarg.h>
58 
59 #include <sys/dtrace.h>
60 #include <sys/dtrace_bsd.h>
61 
62 #define	PROF_NAMELEN		15
63 
64 #define	PROF_PROFILE		0
65 #define	PROF_TICK		1
66 #define	PROF_PREFIX_PROFILE	"profile-"
67 #define	PROF_PREFIX_TICK	"tick-"
68 
69 /*
70  * Regardless of platform, there are five artificial frames in the case of the
71  * profile provider:
72  *
73  *	profile_fire
74  *	cyclic_expire
75  *	cyclic_fire
76  *	[ cbe ]
77  *	[ locore ]
78  *
79  * On amd64, there are two frames associated with locore:  one in locore, and
80  * another in common interrupt dispatch code.  (i386 has not been modified to
81  * use this common layer.)  Further, on i386, the interrupted instruction
82  * appears as its own stack frame.  All of this means that we need to add one
83  * frame for amd64, and then take one away for both amd64 and i386.
84  *
85  * On SPARC, the picture is further complicated because the compiler
86  * optimizes away tail-calls -- so the following frames are optimized away:
87  *
88  * 	profile_fire
89  *	cyclic_expire
90  *
91  * This gives three frames.  However, on DEBUG kernels, the cyclic_expire
92  * frame cannot be tail-call eliminated, yielding four frames in this case.
93  *
94  * All of the above constraints lead to the mess below.  Yes, the profile
95  * provider should ideally figure this out on-the-fly by hiting one of its own
96  * probes and then walking its own stack trace.  This is complicated, however,
97  * and the static definition doesn't seem to be overly brittle.  Still, we
98  * allow for a manual override in case we get it completely wrong.
99  */
100 #ifdef __amd64
101 #define	PROF_ARTIFICIAL_FRAMES	10
102 #else
103 #ifdef __i386
104 #define	PROF_ARTIFICIAL_FRAMES	6
105 #else
106 #ifdef __sparc
107 #ifdef DEBUG
108 #define	PROF_ARTIFICIAL_FRAMES	4
109 #else
110 #define	PROF_ARTIFICIAL_FRAMES	3
111 #endif
112 #endif
113 #endif
114 #endif
115 
116 #ifdef __mips
117 /*
118  * This value is bogus just to make module compilable on mips
119  */
120 #define	PROF_ARTIFICIAL_FRAMES	3
121 #endif
122 
123 #ifdef __powerpc__
124 /*
125  * This value is bogus just to make module compilable on powerpc
126  */
127 #define	PROF_ARTIFICIAL_FRAMES	3
128 #endif
129 
130 struct profile_probe_percpu;
131 
132 #ifdef __mips
133 /* bogus */
134 #define	PROF_ARTIFICIAL_FRAMES	3
135 #endif
136 
137 #ifdef __arm__
138 #define	PROF_ARTIFICIAL_FRAMES	3
139 #endif
140 
141 #ifdef __aarch64__
142 /* TODO: verify */
143 #define	PROF_ARTIFICIAL_FRAMES	10
144 #endif
145 
146 #ifdef __riscv
147 /* TODO: verify */
148 #define	PROF_ARTIFICIAL_FRAMES	10
149 #endif
150 
151 typedef struct profile_probe {
152 	char		prof_name[PROF_NAMELEN];
153 	dtrace_id_t	prof_id;
154 	int		prof_kind;
155 #ifdef illumos
156 	hrtime_t	prof_interval;
157 	cyclic_id_t	prof_cyclic;
158 #else
159 	sbintime_t	prof_interval;
160 	struct callout	prof_cyclic;
161 	sbintime_t	prof_expected;
162 	struct profile_probe_percpu **prof_pcpus;
163 #endif
164 } profile_probe_t;
165 
166 typedef struct profile_probe_percpu {
167 	hrtime_t	profc_expected;
168 	hrtime_t	profc_interval;
169 	profile_probe_t	*profc_probe;
170 #ifdef __FreeBSD__
171 	struct callout	profc_cyclic;
172 #endif
173 } profile_probe_percpu_t;
174 
175 static d_open_t	profile_open;
176 static int	profile_unload(void);
177 static void	profile_create(hrtime_t, char *, int);
178 static void	profile_destroy(void *, dtrace_id_t, void *);
179 static void	profile_enable(void *, dtrace_id_t, void *);
180 static void	profile_disable(void *, dtrace_id_t, void *);
181 static void	profile_load(void *);
182 static void	profile_provide(void *, dtrace_probedesc_t *);
183 
184 static int profile_rates[] = {
185     97, 199, 499, 997, 1999,
186     4001, 4999, 0, 0, 0,
187     0, 0, 0, 0, 0,
188     0, 0, 0, 0, 0
189 };
190 
191 static int profile_ticks[] = {
192     1, 10, 100, 500, 1000,
193     5000, 0, 0, 0, 0,
194     0, 0, 0, 0, 0
195 };
196 
197 /*
198  * profile_max defines the upper bound on the number of profile probes that
199  * can exist (this is to prevent malicious or clumsy users from exhausing
200  * system resources by creating a slew of profile probes). At mod load time,
201  * this gets its value from PROFILE_MAX_DEFAULT or profile-max-probes if it's
202  * present in the profile.conf file.
203  */
204 #define	PROFILE_MAX_DEFAULT	1000	/* default max. number of probes */
205 static uint32_t profile_max = PROFILE_MAX_DEFAULT;
206 					/* maximum number of profile probes */
207 static uint32_t profile_total;		/* current number of profile probes */
208 
209 static struct cdevsw profile_cdevsw = {
210 	.d_version	= D_VERSION,
211 	.d_open		= profile_open,
212 	.d_name		= "profile",
213 };
214 
215 static dtrace_pattr_t profile_attr = {
216 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
217 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
218 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
219 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
220 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
221 };
222 
223 static dtrace_pops_t profile_pops = {
224 	.dtps_provide =		profile_provide,
225 	.dtps_provide_module =	NULL,
226 	.dtps_enable =		profile_enable,
227 	.dtps_disable =		profile_disable,
228 	.dtps_suspend =		NULL,
229 	.dtps_resume =		NULL,
230 	.dtps_getargdesc =	NULL,
231 	.dtps_getargval =	NULL,
232 	.dtps_usermode =	NULL,
233 	.dtps_destroy =		profile_destroy
234 };
235 
236 static struct cdev		*profile_cdev;
237 static dtrace_provider_id_t	profile_id;
238 static hrtime_t			profile_interval_min = NANOSEC / 5000;	/* 5000 hz */
239 static int			profile_aframes = PROF_ARTIFICIAL_FRAMES;
240 
241 SYSCTL_DECL(_kern_dtrace);
242 SYSCTL_NODE(_kern_dtrace, OID_AUTO, profile, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
243     "DTrace profile parameters");
244 SYSCTL_INT(_kern_dtrace_profile, OID_AUTO, aframes, CTLFLAG_RW, &profile_aframes,
245     0, "Skipped frames for profile provider");
246 
247 static sbintime_t
248 nsec_to_sbt(hrtime_t nsec)
249 {
250 	time_t sec;
251 
252 	/*
253 	 * We need to calculate nsec * 2^32 / 10^9
254 	 * Seconds and nanoseconds are split to avoid overflow.
255 	 */
256 	sec = nsec / NANOSEC;
257 	nsec = nsec % NANOSEC;
258 	return (((sbintime_t)sec << 32) | ((sbintime_t)nsec << 32) / NANOSEC);
259 }
260 
261 static hrtime_t
262 sbt_to_nsec(sbintime_t sbt)
263 {
264 
265 	return ((sbt >> 32) * NANOSEC +
266 	    (((uint32_t)sbt * (hrtime_t)NANOSEC) >> 32));
267 }
268 
269 static void
270 profile_probe(profile_probe_t *prof, hrtime_t late)
271 {
272 	struct thread *td;
273 	struct trapframe *frame;
274 	uintfptr_t pc, upc;
275 
276 	td = curthread;
277 	pc = upc = 0;
278 
279 	/*
280 	 * td_intr_frame can be unset if this is a catch-up event upon waking up
281 	 * from idle sleep. This can only happen on a CPU idle thread. Use a
282 	 * representative arg0 value in this case so that one of the probe
283 	 * arguments is non-zero.
284 	 */
285 	frame = td->td_intr_frame;
286 	if (frame != NULL) {
287 		if (TRAPF_USERMODE(frame))
288 			upc = TRAPF_PC(frame);
289 		else
290 			pc = TRAPF_PC(frame);
291 	} else if (TD_IS_IDLETHREAD(td))
292 		pc = (uintfptr_t)&cpu_idle;
293 
294 	dtrace_probe(prof->prof_id, pc, upc, late, 0, 0);
295 }
296 
297 static void
298 profile_fire(void *arg)
299 {
300 	profile_probe_percpu_t *pcpu = arg;
301 	profile_probe_t *prof = pcpu->profc_probe;
302 	hrtime_t late;
303 
304 	late = sbt_to_nsec(sbinuptime() - pcpu->profc_expected);
305 
306 	profile_probe(prof, late);
307 	pcpu->profc_expected += pcpu->profc_interval;
308 	callout_schedule_sbt_curcpu(&pcpu->profc_cyclic,
309 	    pcpu->profc_expected, 0, C_DIRECT_EXEC | C_ABSOLUTE);
310 }
311 
312 static void
313 profile_tick(void *arg)
314 {
315 	profile_probe_t *prof = arg;
316 
317 	profile_probe(prof, 0);
318 	prof->prof_expected += prof->prof_interval;
319 	callout_schedule_sbt(&prof->prof_cyclic,
320 	    prof->prof_expected, 0, C_DIRECT_EXEC | C_ABSOLUTE);
321 }
322 
323 static void
324 profile_create(hrtime_t interval, char *name, int kind)
325 {
326 	profile_probe_t *prof;
327 
328 	if (interval < profile_interval_min)
329 		return;
330 
331 	if (dtrace_probe_lookup(profile_id, NULL, NULL, name) != 0)
332 		return;
333 
334 	atomic_add_32(&profile_total, 1);
335 	if (profile_total > profile_max) {
336 		atomic_add_32(&profile_total, -1);
337 		return;
338 	}
339 
340 	prof = kmem_zalloc(sizeof (profile_probe_t), KM_SLEEP);
341 	(void) strcpy(prof->prof_name, name);
342 #ifdef illumos
343 	prof->prof_interval = interval;
344 	prof->prof_cyclic = CYCLIC_NONE;
345 #else
346 	prof->prof_interval = nsec_to_sbt(interval);
347 	callout_init(&prof->prof_cyclic, 1);
348 #endif
349 	prof->prof_kind = kind;
350 	prof->prof_id = dtrace_probe_create(profile_id,
351 	    NULL, NULL, name,
352 	    profile_aframes, prof);
353 }
354 
355 /*ARGSUSED*/
356 static void
357 profile_provide(void *arg, dtrace_probedesc_t *desc)
358 {
359 	int i, j, rate, kind;
360 	hrtime_t val = 0, mult = 1, len = 0;
361 	char *name, *suffix = NULL;
362 
363 	const struct {
364 		char *prefix;
365 		int kind;
366 	} types[] = {
367 		{ PROF_PREFIX_PROFILE, PROF_PROFILE },
368 		{ PROF_PREFIX_TICK, PROF_TICK },
369 		{ 0, 0 }
370 	};
371 
372 	const struct {
373 		char *name;
374 		hrtime_t mult;
375 	} suffixes[] = {
376 		{ "ns", 	NANOSEC / NANOSEC },
377 		{ "nsec",	NANOSEC / NANOSEC },
378 		{ "us",		NANOSEC / MICROSEC },
379 		{ "usec",	NANOSEC / MICROSEC },
380 		{ "ms",		NANOSEC / MILLISEC },
381 		{ "msec",	NANOSEC / MILLISEC },
382 		{ "s",		NANOSEC / SEC },
383 		{ "sec",	NANOSEC / SEC },
384 		{ "m",		NANOSEC * (hrtime_t)60 },
385 		{ "min",	NANOSEC * (hrtime_t)60 },
386 		{ "h",		NANOSEC * (hrtime_t)(60 * 60) },
387 		{ "hour",	NANOSEC * (hrtime_t)(60 * 60) },
388 		{ "d",		NANOSEC * (hrtime_t)(24 * 60 * 60) },
389 		{ "day",	NANOSEC * (hrtime_t)(24 * 60 * 60) },
390 		{ "hz",		0 },
391 		{ NULL }
392 	};
393 
394 	if (desc == NULL) {
395 		char n[PROF_NAMELEN];
396 
397 		/*
398 		 * If no description was provided, provide all of our probes.
399 		 */
400 		for (i = 0; i < sizeof (profile_rates) / sizeof (int); i++) {
401 			if ((rate = profile_rates[i]) == 0)
402 				continue;
403 
404 			(void) snprintf(n, PROF_NAMELEN, "%s%d",
405 			    PROF_PREFIX_PROFILE, rate);
406 			profile_create(NANOSEC / rate, n, PROF_PROFILE);
407 		}
408 
409 		for (i = 0; i < sizeof (profile_ticks) / sizeof (int); i++) {
410 			if ((rate = profile_ticks[i]) == 0)
411 				continue;
412 
413 			(void) snprintf(n, PROF_NAMELEN, "%s%d",
414 			    PROF_PREFIX_TICK, rate);
415 			profile_create(NANOSEC / rate, n, PROF_TICK);
416 		}
417 
418 		return;
419 	}
420 
421 	name = desc->dtpd_name;
422 
423 	for (i = 0; types[i].prefix != NULL; i++) {
424 		len = strlen(types[i].prefix);
425 
426 		if (strncmp(name, types[i].prefix, len) != 0)
427 			continue;
428 		break;
429 	}
430 
431 	if (types[i].prefix == NULL)
432 		return;
433 
434 	kind = types[i].kind;
435 	j = strlen(name) - len;
436 
437 	/*
438 	 * We need to start before any time suffix.
439 	 */
440 	for (j = strlen(name); j >= len; j--) {
441 		if (name[j] >= '0' && name[j] <= '9')
442 			break;
443 		suffix = &name[j];
444 	}
445 
446 	ASSERT(suffix != NULL);
447 
448 	/*
449 	 * Now determine the numerical value present in the probe name.
450 	 */
451 	for (; j >= len; j--) {
452 		if (name[j] < '0' || name[j] > '9')
453 			return;
454 
455 		val += (name[j] - '0') * mult;
456 		mult *= (hrtime_t)10;
457 	}
458 
459 	if (val == 0)
460 		return;
461 
462 	/*
463 	 * Look-up the suffix to determine the multiplier.
464 	 */
465 	for (i = 0, mult = 0; suffixes[i].name != NULL; i++) {
466 		if (strcasecmp(suffixes[i].name, suffix) == 0) {
467 			mult = suffixes[i].mult;
468 			break;
469 		}
470 	}
471 
472 	if (suffixes[i].name == NULL && *suffix != '\0')
473 		return;
474 
475 	if (mult == 0) {
476 		/*
477 		 * The default is frequency-per-second.
478 		 */
479 		val = NANOSEC / val;
480 	} else {
481 		val *= mult;
482 	}
483 
484 	profile_create(val, name, kind);
485 }
486 
487 /* ARGSUSED */
488 static void
489 profile_destroy(void *arg, dtrace_id_t id, void *parg)
490 {
491 	profile_probe_t *prof = parg;
492 
493 #ifdef illumos
494 	ASSERT(prof->prof_cyclic == CYCLIC_NONE);
495 #else
496 	ASSERT(!callout_active(&prof->prof_cyclic) && prof->prof_pcpus == NULL);
497 #endif
498 	kmem_free(prof, sizeof (profile_probe_t));
499 
500 	ASSERT(profile_total >= 1);
501 	atomic_add_32(&profile_total, -1);
502 }
503 
504 #ifdef illumos
505 /*ARGSUSED*/
506 static void
507 profile_online(void *arg, cpu_t *cpu, cyc_handler_t *hdlr, cyc_time_t *when)
508 {
509 	profile_probe_t *prof = arg;
510 	profile_probe_percpu_t *pcpu;
511 
512 	pcpu = kmem_zalloc(sizeof (profile_probe_percpu_t), KM_SLEEP);
513 	pcpu->profc_probe = prof;
514 
515 	hdlr->cyh_func = profile_fire;
516 	hdlr->cyh_arg = pcpu;
517 
518 	when->cyt_interval = prof->prof_interval;
519 	when->cyt_when = gethrtime() + when->cyt_interval;
520 
521 	pcpu->profc_expected = when->cyt_when;
522 	pcpu->profc_interval = when->cyt_interval;
523 }
524 
525 /*ARGSUSED*/
526 static void
527 profile_offline(void *arg, cpu_t *cpu, void *oarg)
528 {
529 	profile_probe_percpu_t *pcpu = oarg;
530 
531 	ASSERT(pcpu->profc_probe == arg);
532 	kmem_free(pcpu, sizeof (profile_probe_percpu_t));
533 }
534 
535 /* ARGSUSED */
536 static void
537 profile_enable(void *arg, dtrace_id_t id, void *parg)
538 {
539 	profile_probe_t *prof = parg;
540 	cyc_omni_handler_t omni;
541 	cyc_handler_t hdlr;
542 	cyc_time_t when;
543 
544 	ASSERT(prof->prof_interval != 0);
545 	ASSERT(MUTEX_HELD(&cpu_lock));
546 
547 	if (prof->prof_kind == PROF_TICK) {
548 		hdlr.cyh_func = profile_tick;
549 		hdlr.cyh_arg = prof;
550 
551 		when.cyt_interval = prof->prof_interval;
552 		when.cyt_when = gethrtime() + when.cyt_interval;
553 	} else {
554 		ASSERT(prof->prof_kind == PROF_PROFILE);
555 		omni.cyo_online = profile_online;
556 		omni.cyo_offline = profile_offline;
557 		omni.cyo_arg = prof;
558 	}
559 
560 	if (prof->prof_kind == PROF_TICK) {
561 		prof->prof_cyclic = cyclic_add(&hdlr, &when);
562 	} else {
563 		prof->prof_cyclic = cyclic_add_omni(&omni);
564 	}
565 }
566 
567 /* ARGSUSED */
568 static void
569 profile_disable(void *arg, dtrace_id_t id, void *parg)
570 {
571 	profile_probe_t *prof = parg;
572 
573 	ASSERT(prof->prof_cyclic != CYCLIC_NONE);
574 	ASSERT(MUTEX_HELD(&cpu_lock));
575 
576 	cyclic_remove(prof->prof_cyclic);
577 	prof->prof_cyclic = CYCLIC_NONE;
578 }
579 
580 #else
581 
582 static void
583 profile_enable_omni(profile_probe_t *prof)
584 {
585 	profile_probe_percpu_t *pcpu;
586 	int cpu;
587 
588 	prof->prof_pcpus = kmem_zalloc((mp_maxid + 1) * sizeof(pcpu), KM_SLEEP);
589 	CPU_FOREACH(cpu) {
590 		pcpu = kmem_zalloc(sizeof(profile_probe_percpu_t), KM_SLEEP);
591 		prof->prof_pcpus[cpu] = pcpu;
592 		pcpu->profc_probe = prof;
593 		pcpu->profc_expected = sbinuptime() + prof->prof_interval;
594 		pcpu->profc_interval = prof->prof_interval;
595 		callout_init(&pcpu->profc_cyclic, 1);
596 		callout_reset_sbt_on(&pcpu->profc_cyclic,
597 		    pcpu->profc_expected, 0, profile_fire, pcpu,
598 		    cpu, C_DIRECT_EXEC | C_ABSOLUTE);
599 	}
600 }
601 
602 static void
603 profile_disable_omni(profile_probe_t *prof)
604 {
605 	profile_probe_percpu_t *pcpu;
606 	int cpu;
607 
608 	ASSERT(prof->prof_pcpus != NULL);
609 	CPU_FOREACH(cpu) {
610 		pcpu = prof->prof_pcpus[cpu];
611 		ASSERT(pcpu->profc_probe == prof);
612 		ASSERT(callout_active(&pcpu->profc_cyclic));
613 		callout_stop(&pcpu->profc_cyclic);
614 		callout_drain(&pcpu->profc_cyclic);
615 		kmem_free(pcpu, sizeof(profile_probe_percpu_t));
616 	}
617 	kmem_free(prof->prof_pcpus, (mp_maxid + 1) * sizeof(pcpu));
618 	prof->prof_pcpus = NULL;
619 }
620 
621 /* ARGSUSED */
622 static void
623 profile_enable(void *arg, dtrace_id_t id, void *parg)
624 {
625 	profile_probe_t *prof = parg;
626 
627 	if (prof->prof_kind == PROF_TICK) {
628 		prof->prof_expected = sbinuptime() + prof->prof_interval;
629 		callout_reset_sbt(&prof->prof_cyclic,
630 		    prof->prof_expected, 0, profile_tick, prof,
631 		    C_DIRECT_EXEC | C_ABSOLUTE);
632 	} else {
633 		ASSERT(prof->prof_kind == PROF_PROFILE);
634 		profile_enable_omni(prof);
635 	}
636 }
637 
638 /* ARGSUSED */
639 static void
640 profile_disable(void *arg, dtrace_id_t id, void *parg)
641 {
642 	profile_probe_t *prof = parg;
643 
644 	if (prof->prof_kind == PROF_TICK) {
645 		ASSERT(callout_active(&prof->prof_cyclic));
646 		callout_stop(&prof->prof_cyclic);
647 		callout_drain(&prof->prof_cyclic);
648 	} else {
649 		ASSERT(prof->prof_kind == PROF_PROFILE);
650 		profile_disable_omni(prof);
651 	}
652 }
653 #endif
654 
655 static void
656 profile_load(void *dummy)
657 {
658 	/* Create the /dev/dtrace/profile entry. */
659 	profile_cdev = make_dev(&profile_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
660 	    "dtrace/profile");
661 
662 	if (dtrace_register("profile", &profile_attr, DTRACE_PRIV_USER,
663 	    NULL, &profile_pops, NULL, &profile_id) != 0)
664 		return;
665 }
666 
667 
668 static int
669 profile_unload()
670 {
671 	int error = 0;
672 
673 	if ((error = dtrace_unregister(profile_id)) != 0)
674 		return (error);
675 
676 	destroy_dev(profile_cdev);
677 
678 	return (error);
679 }
680 
681 /* ARGSUSED */
682 static int
683 profile_modevent(module_t mod __unused, int type, void *data __unused)
684 {
685 	int error = 0;
686 
687 	switch (type) {
688 	case MOD_LOAD:
689 		break;
690 
691 	case MOD_UNLOAD:
692 		break;
693 
694 	case MOD_SHUTDOWN:
695 		break;
696 
697 	default:
698 		error = EOPNOTSUPP;
699 		break;
700 
701 	}
702 	return (error);
703 }
704 
705 /* ARGSUSED */
706 static int
707 profile_open(struct cdev *dev __unused, int oflags __unused, int devtype __unused, struct thread *td __unused)
708 {
709 	return (0);
710 }
711 
712 SYSINIT(profile_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, profile_load, NULL);
713 SYSUNINIT(profile_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, profile_unload, NULL);
714 
715 DEV_MODULE(profile, profile_modevent, NULL);
716 MODULE_VERSION(profile, 1);
717 MODULE_DEPEND(profile, dtrace, 1, 1, 1);
718 MODULE_DEPEND(profile, opensolaris, 1, 1, 1);
719