xref: /freebsd/usr.sbin/pmcstat/pmcstat.c (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
1 /*-
2  * Copyright (c) 2003-2007, Joseph Koshy
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/types.h>
31 #include <sys/event.h>
32 #include <sys/param.h>
33 #include <sys/queue.h>
34 #include <sys/socket.h>
35 #include <sys/stat.h>
36 #include <sys/sysctl.h>
37 #include <sys/time.h>
38 #include <sys/ttycom.h>
39 #include <sys/user.h>
40 #include <sys/wait.h>
41 
42 #include <assert.h>
43 #include <err.h>
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <kvm.h>
47 #include <libgen.h>
48 #include <limits.h>
49 #include <math.h>
50 #include <pmc.h>
51 #include <pmclog.h>
52 #include <regex.h>
53 #include <signal.h>
54 #include <stdarg.h>
55 #include <stdint.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <sysexits.h>
60 #include <unistd.h>
61 
62 #include "pmcstat.h"
63 
64 /*
65  * A given invocation of pmcstat(8) can manage multiple PMCs of both
66  * the system-wide and per-process variety.  Each of these could be in
67  * 'counting mode' or in 'sampling mode'.
68  *
69  * For 'counting mode' PMCs, pmcstat(8) will periodically issue a
70  * pmc_read() at the configured time interval and print out the value
71  * of the requested PMCs.
72  *
73  * For 'sampling mode' PMCs it can log to a file for offline analysis,
74  * or can analyse sampling data "on the fly", either by converting
75  * samples to printed textual form or by creating gprof(1) compatible
76  * profiles, one per program executed.  When creating gprof(1)
77  * profiles it can optionally merge entries from multiple processes
78  * for a given executable into a single profile file.
79  *
80  * pmcstat(8) can also execute a command line and attach PMCs to the
81  * resulting child process.  The protocol used is as follows:
82  *
83  * - parent creates a socketpair for two way communication and
84  *   fork()s.
85  * - subsequently:
86  *
87  *   /Parent/				/Child/
88  *
89  *   - Wait for childs token.
90  *					- Sends token.
91  *					- Awaits signal to start.
92  *  - Attaches PMCs to the child's pid
93  *    and starts them. Sets up
94  *    monitoring for the child.
95  *  - Signals child to start.
96  *					- Recieves signal, attempts exec().
97  *
98  * After this point normal processing can happen.
99  */
100 
101 /* Globals */
102 
103 int	pmcstat_interrupt = 0;
104 int	pmcstat_displayheight = DEFAULT_DISPLAY_HEIGHT;
105 int	pmcstat_sockpair[NSOCKPAIRFD];
106 int	pmcstat_kq;
107 kvm_t	*pmcstat_kvm;
108 struct kinfo_proc *pmcstat_plist;
109 
110 void
111 pmcstat_attach_pmcs(struct pmcstat_args *a)
112 {
113 	struct pmcstat_ev *ev;
114 	struct pmcstat_target *pt;
115 	int count;
116 
117 	/* Attach all process PMCs to target processes. */
118 	count = 0;
119 	STAILQ_FOREACH(ev, &a->pa_events, ev_next) {
120 		if (PMC_IS_SYSTEM_MODE(ev->ev_mode))
121 			continue;
122 		SLIST_FOREACH(pt, &a->pa_targets, pt_next)
123 			if (pmc_attach(ev->ev_pmcid, pt->pt_pid) == 0)
124 				count++;
125 			else if (errno != ESRCH)
126 				err(EX_OSERR, "ERROR: cannot attach pmc "
127 				    "\"%s\" to process %d", ev->ev_name,
128 				    (int) pt->pt_pid);
129 	}
130 
131 	if (count == 0)
132 		errx(EX_DATAERR, "ERROR: No processes were attached to.");
133 }
134 
135 
136 void
137 pmcstat_cleanup(struct pmcstat_args *a)
138 {
139 	struct pmcstat_ev *ev, *tmp;
140 
141 	/* release allocated PMCs. */
142 	STAILQ_FOREACH_SAFE(ev, &a->pa_events, ev_next, tmp)
143 	    if (ev->ev_pmcid != PMC_ID_INVALID) {
144 		if (pmc_release(ev->ev_pmcid) < 0)
145 			err(EX_OSERR, "ERROR: cannot release pmc "
146 			    "0x%x \"%s\"", ev->ev_pmcid, ev->ev_name);
147 		free(ev->ev_name);
148 		free(ev->ev_spec);
149 		STAILQ_REMOVE(&a->pa_events, ev, pmcstat_ev, ev_next);
150 		free(ev);
151 	    }
152 
153 	/* de-configure the log file if present. */
154 	if (a->pa_flags & (FLAG_HAS_PIPE | FLAG_HAS_OUTPUT_LOGFILE))
155 		(void) pmc_configure_logfile(-1);
156 
157 	if (a->pa_logparser) {
158 		pmclog_close(a->pa_logparser);
159 		a->pa_logparser = NULL;
160 	}
161 
162 	if (a->pa_flags & (FLAG_HAS_PIPE | FLAG_HAS_OUTPUT_LOGFILE))
163 		pmcstat_shutdown_logging(a);
164 }
165 
166 void
167 pmcstat_clone_event_descriptor(struct pmcstat_args *a, struct pmcstat_ev *ev,
168     uint32_t cpumask)
169 {
170 	int cpu;
171 	struct pmcstat_ev *ev_clone;
172 
173 	while ((cpu = ffs(cpumask)) > 0) {
174 		cpu--;
175 
176 		if ((ev_clone = malloc(sizeof(*ev_clone))) == NULL)
177 			errx(EX_SOFTWARE, "ERROR: Out of memory");
178 		(void) memset(ev_clone, 0, sizeof(*ev_clone));
179 
180 		ev_clone->ev_count = ev->ev_count;
181 		ev_clone->ev_cpu   = cpu;
182 		ev_clone->ev_cumulative = ev->ev_cumulative;
183 		ev_clone->ev_flags = ev->ev_flags;
184 		ev_clone->ev_mode  = ev->ev_mode;
185 		ev_clone->ev_name  = strdup(ev->ev_name);
186 		ev_clone->ev_pmcid = ev->ev_pmcid;
187 		ev_clone->ev_saved = ev->ev_saved;
188 		ev_clone->ev_spec  = strdup(ev->ev_spec);
189 
190 		STAILQ_INSERT_TAIL(&a->pa_events, ev_clone, ev_next);
191 
192 		cpumask &= ~(1 << cpu);
193 	}
194 }
195 
196 void
197 pmcstat_create_process(struct pmcstat_args *a)
198 {
199 	char token;
200 	pid_t pid;
201 	struct kevent kev;
202 	struct pmcstat_target *pt;
203 
204 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, pmcstat_sockpair) < 0)
205 		err(EX_OSERR, "ERROR: cannot create socket pair");
206 
207 	switch (pid = fork()) {
208 	case -1:
209 		err(EX_OSERR, "ERROR: cannot fork");
210 		/*NOTREACHED*/
211 
212 	case 0:		/* child */
213 		(void) close(pmcstat_sockpair[PARENTSOCKET]);
214 
215 		/* Write a token to tell our parent we've started executing. */
216 		if (write(pmcstat_sockpair[CHILDSOCKET], "+", 1) != 1)
217 			err(EX_OSERR, "ERROR (child): cannot write token");
218 
219 		/* Wait for our parent to signal us to start. */
220 		if (read(pmcstat_sockpair[CHILDSOCKET], &token, 1) < 0)
221 			err(EX_OSERR, "ERROR (child): cannot read token");
222 		(void) close(pmcstat_sockpair[CHILDSOCKET]);
223 
224 		/* exec() the program requested */
225 		execvp(*a->pa_argv, a->pa_argv);
226 		/* and if that fails, notify the parent */
227 		kill(getppid(), SIGCHLD);
228 		err(EX_OSERR, "ERROR: execvp \"%s\" failed", *a->pa_argv);
229 		/*NOTREACHED*/
230 
231 	default:	/* parent */
232 		(void) close(pmcstat_sockpair[CHILDSOCKET]);
233 		break;
234 	}
235 
236 	/* Ask to be notified via a kevent when the target process exits. */
237 	EV_SET(&kev, pid, EVFILT_PROC, EV_ADD|EV_ONESHOT, NOTE_EXIT, 0,
238 	    NULL);
239 	if (kevent(pmcstat_kq, &kev, 1, NULL, 0, NULL) < 0)
240 		err(EX_OSERR, "ERROR: cannot monitor child process %d", pid);
241 
242 	if ((pt = malloc(sizeof(*pt))) == NULL)
243 		errx(EX_SOFTWARE, "ERROR: Out of memory.");
244 
245 	pt->pt_pid = pid;
246 	SLIST_INSERT_HEAD(&a->pa_targets, pt, pt_next);
247 
248 	/* Wait for the child to signal that its ready to go. */
249 	if (read(pmcstat_sockpair[PARENTSOCKET], &token, 1) < 0)
250 		err(EX_OSERR, "ERROR (parent): cannot read token");
251 
252 	return;
253 }
254 
255 void
256 pmcstat_find_targets(struct pmcstat_args *a, const char *spec)
257 {
258 	int n, nproc, pid, rv;
259 	struct pmcstat_target *pt;
260 	char errbuf[_POSIX2_LINE_MAX], *end;
261 	static struct kinfo_proc *kp;
262 	regex_t reg;
263 	regmatch_t regmatch;
264 
265 	/* First check if we've been given a process id. */
266       	pid = strtol(spec, &end, 0);
267 	if (end != spec && pid >= 0) {
268 		if ((pt = malloc(sizeof(*pt))) == NULL)
269 			goto outofmemory;
270 		pt->pt_pid = pid;
271 		SLIST_INSERT_HEAD(&a->pa_targets, pt, pt_next);
272 		return;
273 	}
274 
275 	/* Otherwise treat arg as a regular expression naming processes. */
276 	if (pmcstat_kvm == NULL) {
277 		if ((pmcstat_kvm = kvm_openfiles(NULL, "/dev/null", NULL, 0,
278 		    errbuf)) == NULL)
279 			err(EX_OSERR, "ERROR: Cannot open kernel \"%s\"",
280 			    errbuf);
281 		if ((pmcstat_plist = kvm_getprocs(pmcstat_kvm, KERN_PROC_PROC,
282 		    0, &nproc)) == NULL)
283 			err(EX_OSERR, "ERROR: Cannot get process list: %s",
284 			    kvm_geterr(pmcstat_kvm));
285 	}
286 
287 	if ((rv = regcomp(&reg, spec, REG_EXTENDED|REG_NOSUB)) != 0) {
288 		regerror(rv, &reg, errbuf, sizeof(errbuf));
289 		err(EX_DATAERR, "ERROR: Failed to compile regex \"%s\": %s",
290 		    spec, errbuf);
291 	}
292 
293 	for (n = 0, kp = pmcstat_plist; n < nproc; n++, kp++) {
294 		if ((rv = regexec(&reg, kp->ki_comm, 1, &regmatch, 0)) == 0) {
295 			if ((pt = malloc(sizeof(*pt))) == NULL)
296 				goto outofmemory;
297 			pt->pt_pid = kp->ki_pid;
298 			SLIST_INSERT_HEAD(&a->pa_targets, pt, pt_next);
299 		} else if (rv != REG_NOMATCH) {
300 			regerror(rv, &reg, errbuf, sizeof(errbuf));
301 			errx(EX_SOFTWARE, "ERROR: Regex evalation failed: %s",
302 			    errbuf);
303 		}
304 	}
305 
306 	regfree(&reg);
307 
308 	return;
309 
310  outofmemory:
311 	errx(EX_SOFTWARE, "Out of memory.");
312 	/*NOTREACHED*/
313 }
314 
315 uint32_t
316 pmcstat_get_cpumask(const char *cpuspec)
317 {
318 	uint32_t cpumask;
319 	int cpu;
320 	const char *s;
321 	char *end;
322 
323 	s = cpuspec;
324 	cpumask = 0ULL;
325 
326 	do {
327 		cpu = strtol(s, &end, 0);
328 		if (cpu < 0 || end == s)
329 			errx(EX_USAGE, "ERROR: Illegal CPU specification "
330 			    "\"%s\".", cpuspec);
331 		cpumask |= (1 << cpu);
332 		s = end + strspn(end, ", \t");
333 	} while (*s);
334 
335 	return (cpumask);
336 }
337 
338 void
339 pmcstat_kill_process(struct pmcstat_args *a)
340 {
341 	struct pmcstat_target *pt;
342 
343 	assert(a->pa_flags & FLAG_HAS_COMMANDLINE);
344 
345 	/*
346 	 * If a command line was specified, it would be the very first
347 	 * in the list, before any other processes specified by -t.
348 	 */
349 	pt = SLIST_FIRST(&a->pa_targets);
350 	assert(pt != NULL);
351 
352 	if (kill(pt->pt_pid, SIGINT) != 0)
353 		err(EX_OSERR, "ERROR: cannot signal child process");
354 }
355 
356 void
357 pmcstat_start_pmcs(struct pmcstat_args *a)
358 {
359 	struct pmcstat_ev *ev;
360 
361 	STAILQ_FOREACH(ev, &args.pa_events, ev_next) {
362 
363 	    assert(ev->ev_pmcid != PMC_ID_INVALID);
364 
365 	    if (pmc_start(ev->ev_pmcid) < 0) {
366 	        warn("ERROR: Cannot start pmc 0x%x \"%s\"",
367 		    ev->ev_pmcid, ev->ev_name);
368 		pmcstat_cleanup(a);
369 		exit(EX_OSERR);
370 	    }
371 	}
372 
373 }
374 
375 void
376 pmcstat_print_headers(struct pmcstat_args *a)
377 {
378 	struct pmcstat_ev *ev;
379 	int c, w;
380 
381 	(void) fprintf(a->pa_printfile, PRINT_HEADER_PREFIX);
382 
383 	STAILQ_FOREACH(ev, &a->pa_events, ev_next) {
384 		if (PMC_IS_SAMPLING_MODE(ev->ev_mode))
385 			continue;
386 
387 		c = PMC_IS_SYSTEM_MODE(ev->ev_mode) ? 's' : 'p';
388 
389 		if (ev->ev_fieldskip != 0)
390 			(void) fprintf(a->pa_printfile, "%*s",
391 			    ev->ev_fieldskip, "");
392 		w = ev->ev_fieldwidth - ev->ev_fieldskip - 2;
393 
394 		if (c == 's')
395 			(void) fprintf(a->pa_printfile, "s/%02d/%-*s ",
396 			    ev->ev_cpu, w-3, ev->ev_name);
397 		else
398 			(void) fprintf(a->pa_printfile, "p/%*s ", w,
399 			    ev->ev_name);
400 	}
401 
402 	(void) fflush(a->pa_printfile);
403 }
404 
405 void
406 pmcstat_print_counters(struct pmcstat_args *a)
407 {
408 	int extra_width;
409 	struct pmcstat_ev *ev;
410 	pmc_value_t value;
411 
412 	extra_width = sizeof(PRINT_HEADER_PREFIX) - 1;
413 
414 	STAILQ_FOREACH(ev, &a->pa_events, ev_next) {
415 
416 		/* skip sampling mode counters */
417 		if (PMC_IS_SAMPLING_MODE(ev->ev_mode))
418 			continue;
419 
420 		if (pmc_read(ev->ev_pmcid, &value) < 0)
421 			err(EX_OSERR, "ERROR: Cannot read pmc "
422 			    "\"%s\"", ev->ev_name);
423 
424 		(void) fprintf(a->pa_printfile, "%*ju ",
425 		    ev->ev_fieldwidth + extra_width,
426 		    (uintmax_t) ev->ev_cumulative ? value :
427 		    (value - ev->ev_saved));
428 
429 		if (ev->ev_cumulative == 0)
430 			ev->ev_saved = value;
431 		extra_width = 0;
432 	}
433 
434 	(void) fflush(a->pa_printfile);
435 }
436 
437 /*
438  * Print output
439  */
440 
441 void
442 pmcstat_print_pmcs(struct pmcstat_args *a)
443 {
444 	static int linecount = 0;
445 
446 	/* check if we need to print a header line */
447 	if (++linecount > pmcstat_displayheight) {
448 		(void) fprintf(a->pa_printfile, "\n");
449 		linecount = 1;
450 	}
451 	if (linecount == 1)
452 		pmcstat_print_headers(a);
453 	(void) fprintf(a->pa_printfile, "\n");
454 
455 	pmcstat_print_counters(a);
456 
457 	return;
458 }
459 
460 /*
461  * Do process profiling
462  *
463  * If a pid was specified, attach each allocated PMC to the target
464  * process.  Otherwise, fork a child and attach the PMCs to the child,
465  * and have the child exec() the target program.
466  */
467 
468 void
469 pmcstat_start_process(void)
470 {
471 	/* Signal the child to proceed. */
472 	if (write(pmcstat_sockpair[PARENTSOCKET], "!", 1) != 1)
473 		err(EX_OSERR, "ERROR (parent): write of token failed");
474 
475 	(void) close(pmcstat_sockpair[PARENTSOCKET]);
476 }
477 
478 void
479 pmcstat_show_usage(void)
480 {
481 	errx(EX_USAGE,
482 	    "[options] [commandline]\n"
483 	    "\t Measure process and/or system performance using hardware\n"
484 	    "\t performance monitoring counters.\n"
485 	    "\t Options include:\n"
486 	    "\t -C\t\t (toggle) show cumulative counts\n"
487 	    "\t -D path\t create profiles in directory \"path\"\n"
488 	    "\t -E\t\t (toggle) show counts at process exit\n"
489 	    "\t -M file\t print executable/gmon file map to \"file\"\n"
490 	    "\t -O file\t send log output to \"file\"\n"
491 	    "\t -P spec\t allocate a process-private sampling PMC\n"
492 	    "\t -R file\t read events from \"file\"\n"
493 	    "\t -S spec\t allocate a system-wide sampling PMC\n"
494 	    "\t -W\t\t (toggle) show counts per context switch\n"
495 	    "\t -c cpu-list\t set cpus for subsequent system-wide PMCs\n"
496 	    "\t -d\t\t (toggle) track descendants\n"
497 	    "\t -g\t\t produce gprof(1) compatible profiles\n"
498 	    "\t -k dir\t\t set the path to the kernel\n"
499 	    "\t -n rate\t set sampling rate\n"
500 	    "\t -o file\t send print output to \"file\"\n"
501 	    "\t -p spec\t allocate a process-private counting PMC\n"
502 	    "\t -q\t\t suppress verbosity\n"
503 	    "\t -r fsroot\t specify FS root directory\n"
504 	    "\t -s spec\t allocate a system-wide counting PMC\n"
505 	    "\t -t pid\t\t attach to running process with pid \"pid\"\n"
506 	    "\t -v\t\t increase verbosity\n"
507 	    "\t -w secs\t set printing time interval"
508 	);
509 }
510 
511 /*
512  * Main
513  */
514 
515 int
516 main(int argc, char **argv)
517 {
518 	double interval;
519 	int option, npmc, ncpu;
520 	int c, check_driver_stats, current_cpu, current_sampling_count;
521 	int do_print, do_descendants;
522 	int do_logproccsw, do_logprocexit;
523 	size_t dummy;
524 	int pipefd[2];
525 	int use_cumulative_counts;
526 	uint32_t cpumask;
527 	char *end, *tmp;
528 	const char *errmsg;
529 	enum pmcstat_state runstate;
530 	struct pmc_driverstats ds_start, ds_end;
531 	struct pmcstat_ev *ev;
532 	struct sigaction sa;
533 	struct kevent kev;
534 	struct winsize ws;
535 	struct stat sb;
536 	char buffer[PATH_MAX];
537 
538 	check_driver_stats      = 0;
539 	current_cpu 		= 0;
540 	current_sampling_count  = DEFAULT_SAMPLE_COUNT;
541 	do_descendants          = 0;
542 	do_logproccsw           = 0;
543 	do_logprocexit          = 0;
544 	use_cumulative_counts   = 0;
545 	args.pa_required	= 0;
546 	args.pa_flags		= 0;
547 	args.pa_verbosity	= 1;
548 	args.pa_logfd		= -1;
549 	args.pa_fsroot		= "";
550 	args.pa_kernel		= strdup("/boot/kernel");
551 	args.pa_samplesdir	= ".";
552 	args.pa_printfile	= stderr;
553 	args.pa_interval	= DEFAULT_WAIT_INTERVAL;
554 	args.pa_mapfilename	= NULL;
555 	STAILQ_INIT(&args.pa_events);
556 	SLIST_INIT(&args.pa_targets);
557 	bzero(&ds_start, sizeof(ds_start));
558 	bzero(&ds_end, sizeof(ds_end));
559 	ev = NULL;
560 
561 	dummy = sizeof(ncpu);
562 	if (sysctlbyname("hw.ncpu", &ncpu, &dummy, NULL, 0) < 0)
563 		err(EX_OSERR, "ERROR: Cannot determine #cpus");
564 	cpumask = (1 << ncpu) - 1;
565 
566 	while ((option = getopt(argc, argv,
567 	    "CD:EM:O:P:R:S:Wc:dgk:n:o:p:qr:s:t:vw:")) != -1)
568 		switch (option) {
569 		case 'C':	/* cumulative values */
570 			use_cumulative_counts = !use_cumulative_counts;
571 			args.pa_required |= FLAG_HAS_COUNTING_PMCS;
572 			break;
573 
574 		case 'c':	/* CPU */
575 
576 			if (optarg[0] == '*' && optarg[1] == '\0')
577 				cpumask = (1 << ncpu) - 1;
578 			else
579 				cpumask = pmcstat_get_cpumask(optarg);
580 
581 			args.pa_required |= FLAG_HAS_SYSTEM_PMCS;
582 			break;
583 
584 		case 'D':
585 			if (stat(optarg, &sb) < 0)
586 				err(EX_OSERR, "ERROR: Cannot stat \"%s\"",
587 				    optarg);
588 			if (!S_ISDIR(sb.st_mode))
589 				errx(EX_USAGE, "ERROR: \"%s\" is not a "
590 				    "directory.", optarg);
591 			args.pa_samplesdir = optarg;
592 			args.pa_flags     |= FLAG_HAS_SAMPLESDIR;
593 			args.pa_required  |= FLAG_DO_GPROF;
594 			break;
595 
596 		case 'd':	/* toggle descendents */
597 			do_descendants = !do_descendants;
598 			args.pa_required |= FLAG_HAS_PROCESS_PMCS;
599 			break;
600 
601 		case 'g':	/* produce gprof compatible profiles */
602 			args.pa_flags |= FLAG_DO_GPROF;
603 			break;
604 
605 		case 'k':	/* pathname to the kernel */
606 			free(args.pa_kernel);
607 			args.pa_kernel = strdup(optarg);
608 			args.pa_required |= FLAG_DO_GPROF;
609 			args.pa_flags    |= FLAG_HAS_KERNELPATH;
610 			break;
611 
612 		case 'E':	/* log process exit */
613 			do_logprocexit = !do_logprocexit;
614 			args.pa_required |= (FLAG_HAS_PROCESS_PMCS |
615 			    FLAG_HAS_COUNTING_PMCS | FLAG_HAS_OUTPUT_LOGFILE);
616 			break;
617 
618 		case 'M':	/* mapfile */
619 			args.pa_mapfilename = optarg;
620 			break;
621 
622 		case 'p':	/* process virtual counting PMC */
623 		case 's':	/* system-wide counting PMC */
624 		case 'P':	/* process virtual sampling PMC */
625 		case 'S':	/* system-wide sampling PMC */
626 			if ((ev = malloc(sizeof(*ev))) == NULL)
627 				errx(EX_SOFTWARE, "ERROR: Out of memory.");
628 
629 			switch (option) {
630 			case 'p': ev->ev_mode = PMC_MODE_TC; break;
631 			case 's': ev->ev_mode = PMC_MODE_SC; break;
632 			case 'P': ev->ev_mode = PMC_MODE_TS; break;
633 			case 'S': ev->ev_mode = PMC_MODE_SS; break;
634 			}
635 
636 			if (option == 'P' || option == 'p') {
637 				args.pa_flags |= FLAG_HAS_PROCESS_PMCS;
638 				args.pa_required |= (FLAG_HAS_COMMANDLINE |
639 				    FLAG_HAS_TARGET);
640 			}
641 
642 			if (option == 'P' || option == 'S') {
643 				args.pa_flags |= FLAG_HAS_SAMPLING_PMCS;
644 				args.pa_required |= (FLAG_HAS_PIPE |
645 				    FLAG_HAS_OUTPUT_LOGFILE);
646 			}
647 
648 			if (option == 'p' || option == 's')
649 				args.pa_flags |= FLAG_HAS_COUNTING_PMCS;
650 
651 			if (option == 's' || option == 'S')
652 				args.pa_flags |= FLAG_HAS_SYSTEM_PMCS;
653 
654 			ev->ev_spec  = strdup(optarg);
655 
656 			if (option == 'S' || option == 'P')
657 				ev->ev_count = current_sampling_count;
658 			else
659 				ev->ev_count = -1;
660 
661 			if (option == 'S' || option == 's')
662 				ev->ev_cpu = ffs(cpumask) - 1;
663 			else
664 				ev->ev_cpu = PMC_CPU_ANY;
665 
666 			ev->ev_flags = 0;
667 			if (do_descendants)
668 				ev->ev_flags |= PMC_F_DESCENDANTS;
669 			if (do_logprocexit)
670 				ev->ev_flags |= PMC_F_LOG_PROCEXIT;
671 			if (do_logproccsw)
672 				ev->ev_flags |= PMC_F_LOG_PROCCSW;
673 
674 			ev->ev_cumulative  = use_cumulative_counts;
675 
676 			ev->ev_saved = 0LL;
677 			ev->ev_pmcid = PMC_ID_INVALID;
678 
679 			/* extract event name */
680 			c = strcspn(optarg, ", \t");
681 			ev->ev_name = malloc(c + 1);
682 			(void) strncpy(ev->ev_name, optarg, c);
683 			*(ev->ev_name + c) = '\0';
684 
685 			STAILQ_INSERT_TAIL(&args.pa_events, ev, ev_next);
686 
687 			if (option == 's' || option == 'S')
688 				pmcstat_clone_event_descriptor(&args, ev,
689 				    cpumask & ~(1 << ev->ev_cpu));
690 
691 			break;
692 
693 		case 'n':	/* sampling count */
694 			current_sampling_count = strtol(optarg, &end, 0);
695 			if (*end != '\0' || current_sampling_count <= 0)
696 				errx(EX_USAGE,
697 				    "ERROR: Illegal count value \"%s\".",
698 				    optarg);
699 			args.pa_required |= FLAG_HAS_SAMPLING_PMCS;
700 			break;
701 
702 		case 'o':	/* outputfile */
703 			if (args.pa_printfile != NULL)
704 				(void) fclose(args.pa_printfile);
705 			if ((args.pa_printfile = fopen(optarg, "w")) == NULL)
706 				errx(EX_OSERR, "ERROR: cannot open \"%s\" for "
707 				    "writing.", optarg);
708 			args.pa_flags |= FLAG_DO_PRINT;
709 			break;
710 
711 		case 'O':	/* sampling output */
712 			if (args.pa_outputpath)
713 				errx(EX_USAGE, "ERROR: option -O may only be "
714 				    "specified once.");
715 			args.pa_outputpath = optarg;
716 			args.pa_flags |= FLAG_HAS_OUTPUT_LOGFILE;
717 			break;
718 
719 		case 'q':	/* quiet mode */
720 			args.pa_verbosity = 0;
721 			break;
722 
723 		case 'r':	/* root FS path */
724 			args.pa_fsroot = optarg;
725 			break;
726 
727 		case 'R':	/* read an existing log file */
728 			if (args.pa_logparser != NULL)
729 				errx(EX_USAGE, "ERROR: option -R may only be "
730 				    "specified once.");
731 			args.pa_inputpath = optarg;
732 			if (args.pa_printfile == stderr)
733 				args.pa_printfile = stdout;
734 			args.pa_flags |= FLAG_READ_LOGFILE;
735 			break;
736 
737 		case 't':	/* target pid or process name */
738 			pmcstat_find_targets(&args, optarg);
739 
740 			args.pa_flags |= FLAG_HAS_TARGET;
741 			args.pa_required |= FLAG_HAS_PROCESS_PMCS;
742 			break;
743 
744 		case 'v':	/* verbose */
745 			args.pa_verbosity++;
746 			break;
747 
748 		case 'w':	/* wait interval */
749 			interval = strtod(optarg, &end);
750 			if (*end != '\0' || interval <= 0)
751 				errx(EX_USAGE, "ERROR: Illegal wait interval "
752 				    "value \"%s\".", optarg);
753 			args.pa_flags |= FLAG_HAS_WAIT_INTERVAL;
754 			args.pa_required |= FLAG_HAS_COUNTING_PMCS;
755 			args.pa_interval = interval;
756 			break;
757 
758 		case 'W':	/* toggle LOG_CSW */
759 			do_logproccsw = !do_logproccsw;
760 			args.pa_required |= (FLAG_HAS_PROCESS_PMCS |
761 			    FLAG_HAS_COUNTING_PMCS | FLAG_HAS_OUTPUT_LOGFILE);
762 			break;
763 
764 		case '?':
765 		default:
766 			pmcstat_show_usage();
767 			break;
768 
769 		}
770 
771 	args.pa_argc = (argc -= optind);
772 	args.pa_argv = (argv += optind);
773 
774 	if (argc)	/* command line present */
775 		args.pa_flags |= FLAG_HAS_COMMANDLINE;
776 
777 	/*
778 	 * Check invocation syntax.
779 	 */
780 
781 	/* disallow -O and -R together */
782 	if (args.pa_outputpath && args.pa_inputpath)
783 		errx(EX_USAGE, "ERROR: options -O and -R are mutually "
784 		    "exclusive.");
785 
786 	if (args.pa_flags & FLAG_READ_LOGFILE) {
787 		errmsg = NULL;
788 		if (args.pa_flags & FLAG_HAS_COMMANDLINE)
789 			errmsg = "a command line specification";
790 		else if (args.pa_flags & FLAG_HAS_TARGET)
791 			errmsg = "option -t";
792 		else if (!STAILQ_EMPTY(&args.pa_events))
793 			errmsg = "a PMC event specification";
794 		if (errmsg)
795 			errx(EX_USAGE, "ERROR: option -R may not be used with "
796 			    "%s.", errmsg);
797 	} else if (STAILQ_EMPTY(&args.pa_events))
798 		/* All other uses require a PMC spec. */
799 		pmcstat_show_usage();
800 
801 	/* check for -t pid without a process PMC spec */
802 	if ((args.pa_required & FLAG_HAS_TARGET) &&
803 	    (args.pa_flags & FLAG_HAS_PROCESS_PMCS) == 0)
804 		errx(EX_USAGE, "ERROR: option -t requires a process mode PMC "
805 		    "to be specified.");
806 
807 	/* check for process-mode options without a command or -t pid */
808 	if ((args.pa_required & FLAG_HAS_PROCESS_PMCS) &&
809 	    (args.pa_flags & (FLAG_HAS_COMMANDLINE | FLAG_HAS_TARGET)) == 0)
810 		errx(EX_USAGE, "ERROR: options -d, -E, -p, -P, and -W require "
811 		    "a command line or target process.");
812 
813 	/* check for -p | -P without a target process of some sort */
814 	if ((args.pa_required & (FLAG_HAS_COMMANDLINE | FLAG_HAS_TARGET)) &&
815 	    (args.pa_flags & (FLAG_HAS_COMMANDLINE | FLAG_HAS_TARGET)) == 0)
816 		errx(EX_USAGE, "ERROR: options -P and -p require a "
817 		    "target process or a command line.");
818 
819 	/* check for process-mode options without a process-mode PMC */
820 	if ((args.pa_required & FLAG_HAS_PROCESS_PMCS) &&
821 	    (args.pa_flags & FLAG_HAS_PROCESS_PMCS) == 0)
822 		errx(EX_USAGE, "ERROR: options -d, -E, and -W require a "
823 		    "process mode PMC to be specified.");
824 
825 	/* check for -c cpu and not system mode PMCs */
826 	if ((args.pa_required & FLAG_HAS_SYSTEM_PMCS) &&
827 	    (args.pa_flags & FLAG_HAS_SYSTEM_PMCS) == 0)
828 		errx(EX_USAGE, "ERROR: option -c requires at least one "
829 		    "system mode PMC to be specified.");
830 
831 	/* check for counting mode options without a counting PMC */
832 	if ((args.pa_required & FLAG_HAS_COUNTING_PMCS) &&
833 	    (args.pa_flags & FLAG_HAS_COUNTING_PMCS) == 0)
834 		errx(EX_USAGE, "ERROR: options -C, -W, -o and -w require at "
835 		    "least one counting mode PMC to be specified.");
836 
837 	/* check for sampling mode options without a sampling PMC spec */
838 	if ((args.pa_required & FLAG_HAS_SAMPLING_PMCS) &&
839 	    (args.pa_flags & FLAG_HAS_SAMPLING_PMCS) == 0)
840 		errx(EX_USAGE, "ERROR: options -n and -O require at least "
841 		    "one sampling mode PMC to be specified.");
842 
843 	/* check if -g is being used correctly */
844 	if ((args.pa_flags & FLAG_DO_GPROF) &&
845 	    !(args.pa_flags & (FLAG_HAS_SAMPLING_PMCS|FLAG_READ_LOGFILE)))
846 		errx(EX_USAGE, "ERROR: option -g requires sampling PMCs or -R "
847 		    "to be specified.");
848 
849 	/* check if -O was spuriously specified */
850 	if ((args.pa_flags & FLAG_HAS_OUTPUT_LOGFILE) &&
851 	    (args.pa_required & FLAG_HAS_OUTPUT_LOGFILE) == 0)
852 		errx(EX_USAGE,
853 		    "ERROR: option -O is used only with options "
854 		    "-E, -P, -S and -W.");
855 
856 	/* -D dir and -k kernel path require -g or -R */
857 	if ((args.pa_flags & FLAG_HAS_KERNELPATH) &&
858 	    (args.pa_flags & FLAG_DO_GPROF) == 0 &&
859 	    (args.pa_flags & FLAG_READ_LOGFILE) == 0)
860 	    errx(EX_USAGE, "ERROR: option -k is only used with -g/-R.");
861 
862 	if ((args.pa_flags & FLAG_HAS_SAMPLESDIR) &&
863 	    (args.pa_flags & FLAG_DO_GPROF) == 0 &&
864 	    (args.pa_flags & FLAG_READ_LOGFILE) == 0)
865 	    errx(EX_USAGE, "ERROR: option -D is only used with -g/-R.");
866 
867 	/* -M mapfile requires -g or -R */
868 	if (args.pa_mapfilename != NULL &&
869 	    (args.pa_flags & FLAG_DO_GPROF) == 0 &&
870 	    (args.pa_flags & FLAG_READ_LOGFILE) == 0)
871 	    errx(EX_USAGE, "ERROR: option -M is only used with -g/-R.");
872 
873 	/*
874 	 * Disallow textual output of sampling PMCs if counting PMCs
875 	 * have also been asked for, mostly because the combined output
876 	 * is difficult to make sense of.
877 	 */
878 	if ((args.pa_flags & FLAG_HAS_COUNTING_PMCS) &&
879 	    (args.pa_flags & FLAG_HAS_SAMPLING_PMCS) &&
880 	    ((args.pa_flags & FLAG_HAS_OUTPUT_LOGFILE) == 0))
881 		errx(EX_USAGE, "ERROR: option -O is required if counting and "
882 		    "sampling PMCs are specified together.");
883 
884 	/*
885 	 * Check if "-k kerneldir" was specified, and if whether 'kerneldir'
886 	 * actually refers to a a file.  If so, use `dirname path` to determine
887 	 * the kernel directory.
888 	 */
889 	if (args.pa_flags & FLAG_HAS_KERNELPATH) {
890 		(void) snprintf(buffer, sizeof(buffer), "%s%s", args.pa_fsroot,
891 		    args.pa_kernel);
892 		if (stat(buffer, &sb) < 0)
893 			err(EX_OSERR, "ERROR: Cannot locate kernel \"%s\"",
894 			    buffer);
895 		if (!S_ISREG(sb.st_mode) && !S_ISDIR(sb.st_mode))
896 			errx(EX_USAGE, "ERROR: \"%s\": Unsupported file type.",
897 			    buffer);
898 		if (!S_ISDIR(sb.st_mode)) {
899 			tmp = args.pa_kernel;
900 			args.pa_kernel = strdup(dirname(args.pa_kernel));
901 			free(tmp);
902 			(void) snprintf(buffer, sizeof(buffer), "%s%s",
903 			    args.pa_fsroot, args.pa_kernel);
904 			if (stat(buffer, &sb) < 0)
905 				err(EX_OSERR, "ERROR: Cannot stat \"%s\"",
906 				    buffer);
907 			if (!S_ISDIR(sb.st_mode))
908 				errx(EX_USAGE, "ERROR: \"%s\" is not a "
909 				    "directory.", buffer);
910 		}
911 	}
912 
913 	/* if we've been asked to process a log file, do that and exit */
914 	if (args.pa_flags & FLAG_READ_LOGFILE) {
915 		/*
916 		 * Print the log in textual form if we haven't been
917 		 * asked to generate gmon.out files.
918 		 */
919 		if ((args.pa_flags & FLAG_DO_GPROF) == 0)
920 			args.pa_flags |= FLAG_DO_PRINT;
921 
922 		pmcstat_initialize_logging(&args);
923 		args.pa_logfd = pmcstat_open_log(args.pa_inputpath,
924 		    PMCSTAT_OPEN_FOR_READ);
925 		if ((args.pa_logparser = pmclog_open(args.pa_logfd)) == NULL)
926 			err(EX_OSERR, "ERROR: Cannot create parser");
927 		pmcstat_process_log(&args);
928 		pmcstat_shutdown_logging(&args);
929 		exit(EX_OK);
930 	}
931 
932 	/* otherwise, we've been asked to collect data */
933 	if (pmc_init() < 0)
934 		err(EX_UNAVAILABLE,
935 		    "ERROR: Initialization of the pmc(3) library failed");
936 
937 	if ((npmc = pmc_npmc(0)) < 0) /* assume all CPUs are identical */
938 		err(EX_OSERR, "ERROR: Cannot determine the number of PMCs "
939 		    "on CPU %d", 0);
940 
941 	/* Allocate a kqueue */
942 	if ((pmcstat_kq = kqueue()) < 0)
943 		err(EX_OSERR, "ERROR: Cannot allocate kqueue");
944 
945 	/*
946 	 * Configure the specified log file or setup a default log
947 	 * consumer via a pipe.
948 	 */
949 	if (args.pa_required & FLAG_HAS_OUTPUT_LOGFILE) {
950 		if (args.pa_outputpath)
951 			args.pa_logfd = pmcstat_open_log(args.pa_outputpath,
952 			    PMCSTAT_OPEN_FOR_WRITE);
953 		else {
954 			/*
955 			 * process the log on the fly by reading it in
956 			 * through a pipe.
957 			 */
958 			if (pipe(pipefd) < 0)
959 				err(EX_OSERR, "ERROR: pipe(2) failed");
960 
961 			if (fcntl(pipefd[READPIPEFD], F_SETFL, O_NONBLOCK) < 0)
962 				err(EX_OSERR, "ERROR: fcntl(2) failed");
963 
964 			EV_SET(&kev, pipefd[READPIPEFD], EVFILT_READ, EV_ADD,
965 			    0, 0, NULL);
966 
967 			if (kevent(pmcstat_kq, &kev, 1, NULL, 0, NULL) < 0)
968 				err(EX_OSERR, "ERROR: Cannot register kevent");
969 
970 			args.pa_logfd = pipefd[WRITEPIPEFD];
971 
972 			args.pa_flags |= (FLAG_HAS_PIPE | FLAG_DO_PRINT);
973 			args.pa_logparser = pmclog_open(pipefd[READPIPEFD]);
974 		}
975 
976 		if (pmc_configure_logfile(args.pa_logfd) < 0)
977 			err(EX_OSERR, "ERROR: Cannot configure log file");
978 	}
979 
980 	/* remember to check for driver errors if we are sampling or logging */
981 	check_driver_stats = (args.pa_flags & FLAG_HAS_SAMPLING_PMCS) ||
982 	    (args.pa_flags & FLAG_HAS_OUTPUT_LOGFILE);
983 
984 	/*
985 	 * Allocate PMCs.
986 	 */
987 
988 	STAILQ_FOREACH(ev, &args.pa_events, ev_next) {
989 	    if (pmc_allocate(ev->ev_spec, ev->ev_mode,
990 		    ev->ev_flags, ev->ev_cpu, &ev->ev_pmcid) < 0)
991 		    err(EX_OSERR, "ERROR: Cannot allocate %s-mode pmc with "
992 			"specification \"%s\"",
993 			PMC_IS_SYSTEM_MODE(ev->ev_mode) ? "system" : "process",
994 			ev->ev_spec);
995 
996 	    if (PMC_IS_SAMPLING_MODE(ev->ev_mode) &&
997 		pmc_set(ev->ev_pmcid, ev->ev_count) < 0)
998 		    err(EX_OSERR, "ERROR: Cannot set sampling count "
999 			"for PMC \"%s\"", ev->ev_name);
1000 	}
1001 
1002 	/* compute printout widths */
1003 	STAILQ_FOREACH(ev, &args.pa_events, ev_next) {
1004 		int counter_width;
1005 		int display_width;
1006 		int header_width;
1007 
1008 		(void) pmc_width(ev->ev_pmcid, &counter_width);
1009 		header_width = strlen(ev->ev_name) + 2; /* prefix '%c/' */
1010 		display_width = (int) floor(counter_width / 3.32193) + 1;
1011 
1012 		if (PMC_IS_SYSTEM_MODE(ev->ev_mode))
1013 			header_width += 3; /* 2 digit CPU number + '/' */
1014 
1015 		if (header_width > display_width) {
1016 			ev->ev_fieldskip = 0;
1017 			ev->ev_fieldwidth = header_width;
1018 		} else {
1019 			ev->ev_fieldskip = display_width -
1020 			    header_width;
1021 			ev->ev_fieldwidth = display_width;
1022 		}
1023 	}
1024 
1025 	/*
1026 	 * If our output is being set to a terminal, register a handler
1027 	 * for window size changes.
1028 	 */
1029 
1030 	if (isatty(fileno(args.pa_printfile))) {
1031 
1032 		if (ioctl(fileno(args.pa_printfile), TIOCGWINSZ, &ws) < 0)
1033 			err(EX_OSERR, "ERROR: Cannot determine window size");
1034 
1035 		pmcstat_displayheight = ws.ws_row - 1;
1036 
1037 		EV_SET(&kev, SIGWINCH, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL);
1038 
1039 		if (kevent(pmcstat_kq, &kev, 1, NULL, 0, NULL) < 0)
1040 			err(EX_OSERR, "ERROR: Cannot register kevent for "
1041 			    "SIGWINCH");
1042 	}
1043 
1044 	EV_SET(&kev, SIGINT, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL);
1045 	if (kevent(pmcstat_kq, &kev, 1, NULL, 0, NULL) < 0)
1046 		err(EX_OSERR, "ERROR: Cannot register kevent for SIGINT");
1047 
1048 	EV_SET(&kev, SIGIO, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL);
1049 	if (kevent(pmcstat_kq, &kev, 1, NULL, 0, NULL) < 0)
1050 		err(EX_OSERR, "ERROR: Cannot register kevent for SIGIO");
1051 
1052 	/*
1053 	 * An exec() failure of a forked child is signalled by the
1054 	 * child sending the parent a SIGCHLD.  We don't register an
1055 	 * actual signal handler for SIGCHLD, but instead use our
1056 	 * kqueue to pick up the signal.
1057 	 */
1058 	EV_SET(&kev, SIGCHLD, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL);
1059 	if (kevent(pmcstat_kq, &kev, 1, NULL, 0, NULL) < 0)
1060 		err(EX_OSERR, "ERROR: Cannot register kevent for SIGCHLD");
1061 
1062 	/* setup a timer if we have counting mode PMCs needing to be printed */
1063 	if ((args.pa_flags & FLAG_HAS_COUNTING_PMCS) &&
1064 	    (args.pa_required & FLAG_HAS_OUTPUT_LOGFILE) == 0) {
1065 		EV_SET(&kev, 0, EVFILT_TIMER, EV_ADD, 0,
1066 		    args.pa_interval * 1000, NULL);
1067 
1068 		if (kevent(pmcstat_kq, &kev, 1, NULL, 0, NULL) < 0)
1069 			err(EX_OSERR, "ERROR: Cannot register kevent for "
1070 			    "timer");
1071 	}
1072 
1073 	/* attach PMCs to the target process, starting it if specified */
1074 	if (args.pa_flags & FLAG_HAS_COMMANDLINE)
1075 		pmcstat_create_process(&args);
1076 
1077 	if (check_driver_stats && pmc_get_driver_stats(&ds_start) < 0)
1078 		err(EX_OSERR, "ERROR: Cannot retrieve driver statistics");
1079 
1080 	/* Attach process pmcs to the target process. */
1081 	if (args.pa_flags & FLAG_HAS_TARGET) {
1082 		if (SLIST_EMPTY(&args.pa_targets))
1083 			errx(EX_DATAERR, "ERROR: No matching target "
1084 			    "processes.");
1085 		else
1086 			pmcstat_attach_pmcs(&args);
1087 
1088 		if (pmcstat_kvm) {
1089 			kvm_close(pmcstat_kvm);
1090 			pmcstat_kvm = NULL;
1091 		}
1092 	}
1093 
1094 	/* start the pmcs */
1095 	pmcstat_start_pmcs(&args);
1096 
1097 	/* start the (commandline) process if needed */
1098 	if (args.pa_flags & FLAG_HAS_COMMANDLINE)
1099 		pmcstat_start_process();
1100 
1101 	/* initialize logging if printing the configured log */
1102 	if ((args.pa_flags & FLAG_DO_PRINT) &&
1103 	    (args.pa_flags & (FLAG_HAS_PIPE | FLAG_HAS_OUTPUT_LOGFILE)))
1104 		pmcstat_initialize_logging(&args);
1105 
1106 	/* Handle SIGINT using the kqueue loop */
1107 	sa.sa_handler = SIG_IGN;
1108 	sa.sa_flags   = 0;
1109 	(void) sigemptyset(&sa.sa_mask);
1110 
1111 	if (sigaction(SIGINT, &sa, NULL) < 0)
1112 		err(EX_OSERR, "ERROR: Cannot install signal handler");
1113 
1114 	/*
1115 	 * loop till either the target process (if any) exits, or we
1116 	 * are killed by a SIGINT.
1117 	 */
1118 	runstate = PMCSTAT_RUNNING;
1119 	do_print = 0;
1120 	do {
1121 		if ((c = kevent(pmcstat_kq, NULL, 0, &kev, 1, NULL)) <= 0) {
1122 			if (errno != EINTR)
1123 				err(EX_OSERR, "ERROR: kevent failed");
1124 			else
1125 				continue;
1126 		}
1127 
1128 		if (kev.flags & EV_ERROR)
1129 			errc(EX_OSERR, kev.data, "ERROR: kevent failed");
1130 
1131 		switch (kev.filter) {
1132 		case EVFILT_PROC:  /* target has exited */
1133 			if (args.pa_flags & (FLAG_HAS_OUTPUT_LOGFILE |
1134 				FLAG_HAS_PIPE))
1135 				runstate = pmcstat_close_log(&args);
1136 			else
1137 				runstate = PMCSTAT_FINISHED;
1138 			do_print = 1;
1139 			break;
1140 
1141 		case EVFILT_READ:  /* log file data is present */
1142 			runstate = pmcstat_process_log(&args);
1143 			break;
1144 
1145 		case EVFILT_SIGNAL:
1146 			if (kev.ident == SIGCHLD) {
1147 				/*
1148 				 * The child process sends us a
1149 				 * SIGCHLD if its exec() failed.  We
1150 				 * wait for it to exit and then exit
1151 				 * ourselves.
1152 				 */
1153 				(void) wait(&c);
1154 				runstate = PMCSTAT_FINISHED;
1155 			} else if (kev.ident == SIGIO) {
1156 				/*
1157 				 * We get a SIGIO if a PMC loses all
1158 				 * of its targets, or if logfile
1159 				 * writes encounter an error.
1160 				 */
1161 				if (args.pa_flags & (FLAG_HAS_OUTPUT_LOGFILE |
1162 				    FLAG_HAS_PIPE)) {
1163 					runstate = pmcstat_close_log(&args);
1164 					if (args.pa_flags &
1165 					    (FLAG_DO_PRINT|FLAG_DO_GPROF))
1166 						pmcstat_process_log(&args);
1167 				}
1168 				do_print = 1; /* print PMCs at exit */
1169 				runstate = PMCSTAT_FINISHED;
1170 			} else if (kev.ident == SIGINT) {
1171 				/* Kill the child process if we started it */
1172 				if (args.pa_flags & FLAG_HAS_COMMANDLINE)
1173 					pmcstat_kill_process(&args);
1174 				runstate = PMCSTAT_FINISHED;
1175 			} else if (kev.ident == SIGWINCH) {
1176 				if (ioctl(fileno(args.pa_printfile),
1177 					TIOCGWINSZ, &ws) < 0)
1178 				    err(EX_OSERR, "ERROR: Cannot determine "
1179 					"window size");
1180 				pmcstat_displayheight = ws.ws_row - 1;
1181 			} else
1182 				assert(0);
1183 
1184 			break;
1185 
1186 		case EVFILT_TIMER: /* print out counting PMCs */
1187 			do_print = 1;
1188 			break;
1189 
1190 		}
1191 
1192 		if (do_print &&
1193 		    (args.pa_required & FLAG_HAS_OUTPUT_LOGFILE) == 0) {
1194 			pmcstat_print_pmcs(&args);
1195 			if (runstate == PMCSTAT_FINISHED && /* final newline */
1196 			    (args.pa_flags & FLAG_DO_PRINT) == 0)
1197 				(void) fprintf(args.pa_printfile, "\n");
1198 			do_print = 0;
1199 		}
1200 
1201 	} while (runstate != PMCSTAT_FINISHED);
1202 
1203 	/* flush any pending log entries */
1204 	if (args.pa_flags & (FLAG_HAS_OUTPUT_LOGFILE | FLAG_HAS_PIPE))
1205 		pmc_flush_logfile();
1206 
1207 	pmcstat_cleanup(&args);
1208 
1209 	free(args.pa_kernel);
1210 
1211 	/* check if the driver lost any samples or events */
1212 	if (check_driver_stats) {
1213 		if (pmc_get_driver_stats(&ds_end) < 0)
1214 			err(EX_OSERR, "ERROR: Cannot retrieve driver "
1215 			    "statistics");
1216 		if (ds_start.pm_intr_bufferfull != ds_end.pm_intr_bufferfull &&
1217 		    args.pa_verbosity > 0)
1218 			warnx("WARNING: some samples were dropped.  Please "
1219 			    "consider tuning the \"kern.hwpmc.nsamples\" "
1220 			    "tunable.");
1221 		if (ds_start.pm_buffer_requests_failed !=
1222 		    ds_end.pm_buffer_requests_failed &&
1223 		    args.pa_verbosity > 0)
1224 			warnx("WARNING: some events were discarded.  Please "
1225 			    "consider tuning the \"kern.hwpmc.nbuffers\" "
1226 			    "tunable.");
1227 	}
1228 
1229 	exit(EX_OK);
1230 }
1231