FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_clock.c
1 /*-
2 * Copyright (c) 1982, 1986, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/8.4/sys/kern/kern_clock.c 247556 2013-03-01 17:10:52Z jhb $");
39
40 #include "opt_kdb.h"
41 #include "opt_device_polling.h"
42 #include "opt_hwpmc_hooks.h"
43 #include "opt_kdtrace.h"
44 #include "opt_ntp.h"
45 #include "opt_watchdog.h"
46
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/callout.h>
50 #include <sys/kdb.h>
51 #include <sys/kernel.h>
52 #include <sys/kthread.h>
53 #include <sys/ktr.h>
54 #include <sys/lock.h>
55 #include <sys/mutex.h>
56 #include <sys/proc.h>
57 #include <sys/resource.h>
58 #include <sys/resourcevar.h>
59 #include <sys/sched.h>
60 #include <sys/sdt.h>
61 #include <sys/signalvar.h>
62 #include <sys/sleepqueue.h>
63 #include <sys/smp.h>
64 #include <vm/vm.h>
65 #include <vm/pmap.h>
66 #include <vm/vm_map.h>
67 #include <sys/sysctl.h>
68 #include <sys/bus.h>
69 #include <sys/interrupt.h>
70 #include <sys/limits.h>
71 #include <sys/timetc.h>
72
73 #ifdef GPROF
74 #include <sys/gmon.h>
75 #endif
76
77 #ifdef HWPMC_HOOKS
78 #include <sys/pmckern.h>
79 #endif
80
81 #ifdef DEVICE_POLLING
82 extern void hardclock_device_poll(void);
83 #endif /* DEVICE_POLLING */
84
85 static void initclocks(void *dummy);
86 SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL);
87
88 /* Spin-lock protecting profiling statistics. */
89 static struct mtx time_lock;
90
91 SDT_PROVIDER_DECLARE(sched);
92 SDT_PROBE_DEFINE2(sched, , , tick, tick, "struct thread *", "struct proc *");
93
94 static int
95 sysctl_kern_cp_time(SYSCTL_HANDLER_ARGS)
96 {
97 int error;
98 long cp_time[CPUSTATES];
99 #ifdef SCTL_MASK32
100 int i;
101 unsigned int cp_time32[CPUSTATES];
102 #endif
103
104 read_cpu_time(cp_time);
105 #ifdef SCTL_MASK32
106 if (req->flags & SCTL_MASK32) {
107 if (!req->oldptr)
108 return SYSCTL_OUT(req, 0, sizeof(cp_time32));
109 for (i = 0; i < CPUSTATES; i++)
110 cp_time32[i] = (unsigned int)cp_time[i];
111 error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32));
112 } else
113 #endif
114 {
115 if (!req->oldptr)
116 return SYSCTL_OUT(req, 0, sizeof(cp_time));
117 error = SYSCTL_OUT(req, cp_time, sizeof(cp_time));
118 }
119 return error;
120 }
121
122 SYSCTL_PROC(_kern, OID_AUTO, cp_time, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE,
123 0,0, sysctl_kern_cp_time, "LU", "CPU time statistics");
124
125 static long empty[CPUSTATES];
126
127 static int
128 sysctl_kern_cp_times(SYSCTL_HANDLER_ARGS)
129 {
130 struct pcpu *pcpu;
131 int error;
132 int c;
133 long *cp_time;
134 #ifdef SCTL_MASK32
135 unsigned int cp_time32[CPUSTATES];
136 int i;
137 #endif
138
139 if (!req->oldptr) {
140 #ifdef SCTL_MASK32
141 if (req->flags & SCTL_MASK32)
142 return SYSCTL_OUT(req, 0, sizeof(cp_time32) * (mp_maxid + 1));
143 else
144 #endif
145 return SYSCTL_OUT(req, 0, sizeof(long) * CPUSTATES * (mp_maxid + 1));
146 }
147 for (error = 0, c = 0; error == 0 && c <= mp_maxid; c++) {
148 if (!CPU_ABSENT(c)) {
149 pcpu = pcpu_find(c);
150 cp_time = pcpu->pc_cp_time;
151 } else {
152 cp_time = empty;
153 }
154 #ifdef SCTL_MASK32
155 if (req->flags & SCTL_MASK32) {
156 for (i = 0; i < CPUSTATES; i++)
157 cp_time32[i] = (unsigned int)cp_time[i];
158 error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32));
159 } else
160 #endif
161 error = SYSCTL_OUT(req, cp_time, sizeof(long) * CPUSTATES);
162 }
163 return error;
164 }
165
166 SYSCTL_PROC(_kern, OID_AUTO, cp_times, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE,
167 0,0, sysctl_kern_cp_times, "LU", "per-CPU time statistics");
168
169 #ifdef DEADLKRES
170 static const char *blessed[] = {
171 "getblk",
172 "so_snd_sx",
173 "so_rcv_sx",
174 NULL
175 };
176 static int slptime_threshold = 1800;
177 static int blktime_threshold = 900;
178 static int sleepfreq = 3;
179
180 static void
181 deadlkres(void)
182 {
183 struct proc *p;
184 struct thread *td;
185 void *wchan;
186 int blkticks, i, slpticks, slptype, tryl, tticks;
187
188 tryl = 0;
189 for (;;) {
190 blkticks = blktime_threshold * hz;
191 slpticks = slptime_threshold * hz;
192
193 /*
194 * Avoid to sleep on the sx_lock in order to avoid a possible
195 * priority inversion problem leading to starvation.
196 * If the lock can't be held after 100 tries, panic.
197 */
198 if (!sx_try_slock(&allproc_lock)) {
199 if (tryl > 100)
200 panic("%s: possible deadlock detected on allproc_lock\n",
201 __func__);
202 tryl++;
203 pause("allproc", sleepfreq * hz);
204 continue;
205 }
206 tryl = 0;
207 FOREACH_PROC_IN_SYSTEM(p) {
208 PROC_LOCK(p);
209 if (p->p_state == PRS_NEW) {
210 PROC_UNLOCK(p);
211 continue;
212 }
213 FOREACH_THREAD_IN_PROC(p, td) {
214
215 /*
216 * Once a thread is found in "interesting"
217 * state a possible ticks wrap-up needs to be
218 * checked.
219 */
220 thread_lock(td);
221 if (TD_ON_LOCK(td) && ticks < td->td_blktick) {
222
223 /*
224 * The thread should be blocked on a
225 * turnstile, simply check if the
226 * turnstile channel is in good state.
227 */
228 MPASS(td->td_blocked != NULL);
229
230 tticks = ticks - td->td_blktick;
231 thread_unlock(td);
232 if (tticks > blkticks) {
233
234 /*
235 * Accordingly with provided
236 * thresholds, this thread is
237 * stuck for too long on a
238 * turnstile.
239 */
240 PROC_UNLOCK(p);
241 sx_sunlock(&allproc_lock);
242 panic("%s: possible deadlock detected for %p, blocked for %d ticks\n",
243 __func__, td, tticks);
244 }
245 } else if (TD_IS_SLEEPING(td) &&
246 TD_ON_SLEEPQ(td) &&
247 ticks < td->td_blktick) {
248
249 /*
250 * Check if the thread is sleeping on a
251 * lock, otherwise skip the check.
252 * Drop the thread lock in order to
253 * avoid a LOR with the sleepqueue
254 * spinlock.
255 */
256 wchan = td->td_wchan;
257 tticks = ticks - td->td_slptick;
258 thread_unlock(td);
259 slptype = sleepq_type(wchan);
260 if ((slptype == SLEEPQ_SX ||
261 slptype == SLEEPQ_LK) &&
262 tticks > slpticks) {
263
264 /*
265 * Accordingly with provided
266 * thresholds, this thread is
267 * stuck for too long on a
268 * sleepqueue.
269 * However, being on a
270 * sleepqueue, we might still
271 * check for the blessed
272 * list.
273 */
274 tryl = 0;
275 for (i = 0; blessed[i] != NULL;
276 i++) {
277 if (!strcmp(blessed[i],
278 td->td_wmesg)) {
279 tryl = 1;
280 break;
281 }
282 }
283 if (tryl != 0) {
284 tryl = 0;
285 continue;
286 }
287 PROC_UNLOCK(p);
288 sx_sunlock(&allproc_lock);
289 panic("%s: possible deadlock detected for %p, blocked for %d ticks\n",
290 __func__, td, tticks);
291 }
292 } else
293 thread_unlock(td);
294 }
295 PROC_UNLOCK(p);
296 }
297 sx_sunlock(&allproc_lock);
298
299 /* Sleep for sleepfreq seconds. */
300 pause("-", sleepfreq * hz);
301 }
302 }
303
304 static struct kthread_desc deadlkres_kd = {
305 "deadlkres",
306 deadlkres,
307 (struct thread **)NULL
308 };
309
310 SYSINIT(deadlkres, SI_SUB_CLOCKS, SI_ORDER_ANY, kthread_start, &deadlkres_kd);
311
312 SYSCTL_NODE(_debug, OID_AUTO, deadlkres, CTLFLAG_RW, 0, "Deadlock resolver");
313 SYSCTL_INT(_debug_deadlkres, OID_AUTO, slptime_threshold, CTLFLAG_RW,
314 &slptime_threshold, 0,
315 "Number of seconds within is valid to sleep on a sleepqueue");
316 SYSCTL_INT(_debug_deadlkres, OID_AUTO, blktime_threshold, CTLFLAG_RW,
317 &blktime_threshold, 0,
318 "Number of seconds within is valid to block on a turnstile");
319 SYSCTL_INT(_debug_deadlkres, OID_AUTO, sleepfreq, CTLFLAG_RW, &sleepfreq, 0,
320 "Number of seconds between any deadlock resolver thread run");
321 #endif /* DEADLKRES */
322
323 void
324 read_cpu_time(long *cp_time)
325 {
326 struct pcpu *pc;
327 int i, j;
328
329 /* Sum up global cp_time[]. */
330 bzero(cp_time, sizeof(long) * CPUSTATES);
331 CPU_FOREACH(i) {
332 pc = pcpu_find(i);
333 for (j = 0; j < CPUSTATES; j++)
334 cp_time[j] += pc->pc_cp_time[j];
335 }
336 }
337
338 #ifdef SW_WATCHDOG
339 #include <sys/watchdog.h>
340
341 static int watchdog_ticks;
342 static int watchdog_enabled;
343 static void watchdog_fire(void);
344 static void watchdog_config(void *, u_int, int *);
345 #endif /* SW_WATCHDOG */
346
347 /*
348 * Clock handling routines.
349 *
350 * This code is written to operate with two timers that run independently of
351 * each other.
352 *
353 * The main timer, running hz times per second, is used to trigger interval
354 * timers, timeouts and rescheduling as needed.
355 *
356 * The second timer handles kernel and user profiling,
357 * and does resource use estimation. If the second timer is programmable,
358 * it is randomized to avoid aliasing between the two clocks. For example,
359 * the randomization prevents an adversary from always giving up the cpu
360 * just before its quantum expires. Otherwise, it would never accumulate
361 * cpu ticks. The mean frequency of the second timer is stathz.
362 *
363 * If no second timer exists, stathz will be zero; in this case we drive
364 * profiling and statistics off the main clock. This WILL NOT be accurate;
365 * do not do it unless absolutely necessary.
366 *
367 * The statistics clock may (or may not) be run at a higher rate while
368 * profiling. This profile clock runs at profhz. We require that profhz
369 * be an integral multiple of stathz.
370 *
371 * If the statistics clock is running fast, it must be divided by the ratio
372 * profhz/stathz for statistics. (For profiling, every tick counts.)
373 *
374 * Time-of-day is maintained using a "timecounter", which may or may
375 * not be related to the hardware generating the above mentioned
376 * interrupts.
377 */
378
379 int stathz;
380 int profhz;
381 int profprocs;
382 volatile int ticks;
383 int psratio;
384
385 /*
386 * Initialize clock frequencies and start both clocks running.
387 */
388 /* ARGSUSED*/
389 static void
390 initclocks(dummy)
391 void *dummy;
392 {
393 register int i;
394
395 /*
396 * Set divisors to 1 (normal case) and let the machine-specific
397 * code do its bit.
398 */
399 mtx_init(&time_lock, "time lock", NULL, MTX_SPIN);
400 cpu_initclocks();
401
402 /*
403 * Compute profhz/stathz, and fix profhz if needed.
404 */
405 i = stathz ? stathz : hz;
406 if (profhz == 0)
407 profhz = i;
408 psratio = profhz / i;
409 #ifdef SW_WATCHDOG
410 EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0);
411 #endif
412 }
413
414 /*
415 * Each time the real-time timer fires, this function is called on all CPUs.
416 * Note that hardclock() calls hardclock_cpu() for the boot CPU, so only
417 * the other CPUs in the system need to call this function.
418 */
419 void
420 hardclock_cpu(int usermode)
421 {
422 struct pstats *pstats;
423 struct thread *td = curthread;
424 struct proc *p = td->td_proc;
425 int flags;
426
427 /*
428 * Run current process's virtual and profile time, as needed.
429 */
430 pstats = p->p_stats;
431 flags = 0;
432 if (usermode &&
433 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) {
434 PROC_SLOCK(p);
435 if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0)
436 flags |= TDF_ALRMPEND | TDF_ASTPENDING;
437 PROC_SUNLOCK(p);
438 }
439 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) {
440 PROC_SLOCK(p);
441 if (itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0)
442 flags |= TDF_PROFPEND | TDF_ASTPENDING;
443 PROC_SUNLOCK(p);
444 }
445 thread_lock(td);
446 sched_tick();
447 td->td_flags |= flags;
448 thread_unlock(td);
449
450 #ifdef HWPMC_HOOKS
451 if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid)))
452 PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL);
453 #endif
454 callout_tick();
455 }
456
457 /*
458 * The real-time timer, interrupting hz times per second.
459 */
460 void
461 hardclock(int usermode, uintfptr_t pc)
462 {
463
464 atomic_add_int(&ticks, 1);
465 hardclock_cpu(usermode);
466 tc_ticktock();
467 /*
468 * If no separate statistics clock is available, run it from here.
469 *
470 * XXX: this only works for UP
471 */
472 if (stathz == 0) {
473 profclock(usermode, pc);
474 statclock(usermode);
475 }
476 #ifdef DEVICE_POLLING
477 hardclock_device_poll(); /* this is very short and quick */
478 #endif /* DEVICE_POLLING */
479 #ifdef SW_WATCHDOG
480 if (watchdog_enabled > 0 && --watchdog_ticks <= 0)
481 watchdog_fire();
482 #endif /* SW_WATCHDOG */
483 }
484
485 /*
486 * Compute number of ticks in the specified amount of time.
487 */
488 int
489 tvtohz(tv)
490 struct timeval *tv;
491 {
492 register unsigned long ticks;
493 register long sec, usec;
494
495 /*
496 * If the number of usecs in the whole seconds part of the time
497 * difference fits in a long, then the total number of usecs will
498 * fit in an unsigned long. Compute the total and convert it to
499 * ticks, rounding up and adding 1 to allow for the current tick
500 * to expire. Rounding also depends on unsigned long arithmetic
501 * to avoid overflow.
502 *
503 * Otherwise, if the number of ticks in the whole seconds part of
504 * the time difference fits in a long, then convert the parts to
505 * ticks separately and add, using similar rounding methods and
506 * overflow avoidance. This method would work in the previous
507 * case but it is slightly slower and assumes that hz is integral.
508 *
509 * Otherwise, round the time difference down to the maximum
510 * representable value.
511 *
512 * If ints have 32 bits, then the maximum value for any timeout in
513 * 10ms ticks is 248 days.
514 */
515 sec = tv->tv_sec;
516 usec = tv->tv_usec;
517 if (usec < 0) {
518 sec--;
519 usec += 1000000;
520 }
521 if (sec < 0) {
522 #ifdef DIAGNOSTIC
523 if (usec > 0) {
524 sec++;
525 usec -= 1000000;
526 }
527 printf("tvotohz: negative time difference %ld sec %ld usec\n",
528 sec, usec);
529 #endif
530 ticks = 1;
531 } else if (sec <= LONG_MAX / 1000000)
532 ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1))
533 / tick + 1;
534 else if (sec <= LONG_MAX / hz)
535 ticks = sec * hz
536 + ((unsigned long)usec + (tick - 1)) / tick + 1;
537 else
538 ticks = LONG_MAX;
539 if (ticks > INT_MAX)
540 ticks = INT_MAX;
541 return ((int)ticks);
542 }
543
544 /*
545 * Start profiling on a process.
546 *
547 * Kernel profiling passes proc0 which never exits and hence
548 * keeps the profile clock running constantly.
549 */
550 void
551 startprofclock(p)
552 register struct proc *p;
553 {
554
555 PROC_LOCK_ASSERT(p, MA_OWNED);
556 if (p->p_flag & P_STOPPROF)
557 return;
558 if ((p->p_flag & P_PROFIL) == 0) {
559 p->p_flag |= P_PROFIL;
560 mtx_lock_spin(&time_lock);
561 if (++profprocs == 1)
562 cpu_startprofclock();
563 mtx_unlock_spin(&time_lock);
564 }
565 }
566
567 /*
568 * Stop profiling on a process.
569 */
570 void
571 stopprofclock(p)
572 register struct proc *p;
573 {
574
575 PROC_LOCK_ASSERT(p, MA_OWNED);
576 if (p->p_flag & P_PROFIL) {
577 if (p->p_profthreads != 0) {
578 p->p_flag |= P_STOPPROF;
579 while (p->p_profthreads != 0)
580 msleep(&p->p_profthreads, &p->p_mtx, PPAUSE,
581 "stopprof", 0);
582 p->p_flag &= ~P_STOPPROF;
583 }
584 if ((p->p_flag & P_PROFIL) == 0)
585 return;
586 p->p_flag &= ~P_PROFIL;
587 mtx_lock_spin(&time_lock);
588 if (--profprocs == 0)
589 cpu_stopprofclock();
590 mtx_unlock_spin(&time_lock);
591 }
592 }
593
594 /*
595 * Statistics clock. Updates rusage information and calls the scheduler
596 * to adjust priorities of the active thread.
597 *
598 * This should be called by all active processors.
599 */
600 void
601 statclock(int usermode)
602 {
603 struct rusage *ru;
604 struct vmspace *vm;
605 struct thread *td;
606 struct proc *p;
607 long rss;
608 long *cp_time;
609
610 td = curthread;
611 p = td->td_proc;
612
613 cp_time = (long *)PCPU_PTR(cp_time);
614 if (usermode) {
615 /*
616 * Charge the time as appropriate.
617 */
618 td->td_uticks++;
619 if (p->p_nice > NZERO)
620 cp_time[CP_NICE]++;
621 else
622 cp_time[CP_USER]++;
623 } else {
624 /*
625 * Came from kernel mode, so we were:
626 * - handling an interrupt,
627 * - doing syscall or trap work on behalf of the current
628 * user process, or
629 * - spinning in the idle loop.
630 * Whichever it is, charge the time as appropriate.
631 * Note that we charge interrupts to the current process,
632 * regardless of whether they are ``for'' that process,
633 * so that we know how much of its real time was spent
634 * in ``non-process'' (i.e., interrupt) work.
635 */
636 if ((td->td_pflags & TDP_ITHREAD) ||
637 td->td_intr_nesting_level >= 2) {
638 td->td_iticks++;
639 cp_time[CP_INTR]++;
640 } else {
641 td->td_pticks++;
642 td->td_sticks++;
643 if (!TD_IS_IDLETHREAD(td))
644 cp_time[CP_SYS]++;
645 else
646 cp_time[CP_IDLE]++;
647 }
648 }
649
650 /* Update resource usage integrals and maximums. */
651 MPASS(p->p_vmspace != NULL);
652 vm = p->p_vmspace;
653 ru = &td->td_ru;
654 ru->ru_ixrss += pgtok(vm->vm_tsize);
655 ru->ru_idrss += pgtok(vm->vm_dsize);
656 ru->ru_isrss += pgtok(vm->vm_ssize);
657 rss = pgtok(vmspace_resident_count(vm));
658 if (ru->ru_maxrss < rss)
659 ru->ru_maxrss = rss;
660 KTR_POINT2(KTR_SCHED, "thread", sched_tdname(td), "statclock",
661 "prio:%d", td->td_priority, "stathz:%d", (stathz)?stathz:hz);
662 SDT_PROBE2(sched, , , tick, td, td->td_proc);
663 thread_lock_flags(td, MTX_QUIET);
664 sched_clock(td);
665 thread_unlock(td);
666 }
667
668 void
669 profclock(int usermode, uintfptr_t pc)
670 {
671 struct thread *td;
672 #ifdef GPROF
673 struct gmonparam *g;
674 uintfptr_t i;
675 #endif
676
677 td = curthread;
678 if (usermode) {
679 /*
680 * Came from user mode; CPU was in user state.
681 * If this process is being profiled, record the tick.
682 * if there is no related user location yet, don't
683 * bother trying to count it.
684 */
685 if (td->td_proc->p_flag & P_PROFIL)
686 addupc_intr(td, pc, 1);
687 }
688 #ifdef GPROF
689 else {
690 /*
691 * Kernel statistics are just like addupc_intr, only easier.
692 */
693 g = &_gmonparam;
694 if (g->state == GMON_PROF_ON && pc >= g->lowpc) {
695 i = PC_TO_I(g, pc);
696 if (i < g->textsize) {
697 KCOUNT(g, i)++;
698 }
699 }
700 }
701 #endif
702 }
703
704 /*
705 * Return information about system clocks.
706 */
707 static int
708 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
709 {
710 struct clockinfo clkinfo;
711 /*
712 * Construct clockinfo structure.
713 */
714 bzero(&clkinfo, sizeof(clkinfo));
715 clkinfo.hz = hz;
716 clkinfo.tick = tick;
717 clkinfo.profhz = profhz;
718 clkinfo.stathz = stathz ? stathz : hz;
719 return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
720 }
721
722 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate,
723 CTLTYPE_STRUCT|CTLFLAG_RD|CTLFLAG_MPSAFE,
724 0, 0, sysctl_kern_clockrate, "S,clockinfo",
725 "Rate and period of various kernel clocks");
726
727 #ifdef SW_WATCHDOG
728
729 static void
730 watchdog_config(void *unused __unused, u_int cmd, int *error)
731 {
732 u_int u;
733
734 u = cmd & WD_INTERVAL;
735 if (u >= WD_TO_1SEC) {
736 watchdog_ticks = (1 << (u - WD_TO_1SEC)) * hz;
737 watchdog_enabled = 1;
738 *error = 0;
739 } else {
740 watchdog_enabled = 0;
741 }
742 }
743
744 /*
745 * Handle a watchdog timeout by dumping interrupt information and
746 * then either dropping to DDB or panicking.
747 */
748 static void
749 watchdog_fire(void)
750 {
751 int nintr;
752 u_int64_t inttotal;
753 u_long *curintr;
754 char *curname;
755
756 curintr = intrcnt;
757 curname = intrnames;
758 inttotal = 0;
759 nintr = eintrcnt - intrcnt;
760
761 printf("interrupt total\n");
762 while (--nintr >= 0) {
763 if (*curintr)
764 printf("%-12s %20lu\n", curname, *curintr);
765 curname += strlen(curname) + 1;
766 inttotal += *curintr++;
767 }
768 printf("Total %20ju\n", (uintmax_t)inttotal);
769
770 #if defined(KDB) && !defined(KDB_UNATTENDED)
771 kdb_backtrace();
772 kdb_enter(KDB_WHY_WATCHDOG, "watchdog timeout");
773 #else
774 panic("watchdog timeout");
775 #endif
776 }
777
778 #endif /* SW_WATCHDOG */
Cache object: bfd97d6cb2be035009577439e66b2696
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