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/8.3/sys/kern/kern_clock.c 222868 2011-06-08 19:58:20Z jhb $");
39
40 #include "opt_kdb.h"
41 #include "opt_device_polling.h"
42 #include "opt_hwpmc_hooks.h"
43 #include "opt_ntp.h"
44 #include "opt_watchdog.h"
45
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/callout.h>
49 #include <sys/kdb.h>
50 #include <sys/kernel.h>
51 #include <sys/kthread.h>
52 #include <sys/ktr.h>
53 #include <sys/lock.h>
54 #include <sys/mutex.h>
55 #include <sys/proc.h>
56 #include <sys/resource.h>
57 #include <sys/resourcevar.h>
58 #include <sys/sched.h>
59 #include <sys/signalvar.h>
60 #include <sys/sleepqueue.h>
61 #include <sys/smp.h>
62 #include <vm/vm.h>
63 #include <vm/pmap.h>
64 #include <vm/vm_map.h>
65 #include <sys/sysctl.h>
66 #include <sys/bus.h>
67 #include <sys/interrupt.h>
68 #include <sys/limits.h>
69 #include <sys/timetc.h>
70
71 #ifdef GPROF
72 #include <sys/gmon.h>
73 #endif
74
75 #ifdef HWPMC_HOOKS
76 #include <sys/pmckern.h>
77 #endif
78
79 #ifdef DEVICE_POLLING
80 extern void hardclock_device_poll(void);
81 #endif /* DEVICE_POLLING */
82
83 static void initclocks(void *dummy);
84 SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL);
85
86 /* Spin-lock protecting profiling statistics. */
87 static struct mtx time_lock;
88
89 static int
90 sysctl_kern_cp_time(SYSCTL_HANDLER_ARGS)
91 {
92 int error;
93 long cp_time[CPUSTATES];
94 #ifdef SCTL_MASK32
95 int i;
96 unsigned int cp_time32[CPUSTATES];
97 #endif
98
99 read_cpu_time(cp_time);
100 #ifdef SCTL_MASK32
101 if (req->flags & SCTL_MASK32) {
102 if (!req->oldptr)
103 return SYSCTL_OUT(req, 0, sizeof(cp_time32));
104 for (i = 0; i < CPUSTATES; i++)
105 cp_time32[i] = (unsigned int)cp_time[i];
106 error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32));
107 } else
108 #endif
109 {
110 if (!req->oldptr)
111 return SYSCTL_OUT(req, 0, sizeof(cp_time));
112 error = SYSCTL_OUT(req, cp_time, sizeof(cp_time));
113 }
114 return error;
115 }
116
117 SYSCTL_PROC(_kern, OID_AUTO, cp_time, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE,
118 0,0, sysctl_kern_cp_time, "LU", "CPU time statistics");
119
120 static long empty[CPUSTATES];
121
122 static int
123 sysctl_kern_cp_times(SYSCTL_HANDLER_ARGS)
124 {
125 struct pcpu *pcpu;
126 int error;
127 int c;
128 long *cp_time;
129 #ifdef SCTL_MASK32
130 unsigned int cp_time32[CPUSTATES];
131 int i;
132 #endif
133
134 if (!req->oldptr) {
135 #ifdef SCTL_MASK32
136 if (req->flags & SCTL_MASK32)
137 return SYSCTL_OUT(req, 0, sizeof(cp_time32) * (mp_maxid + 1));
138 else
139 #endif
140 return SYSCTL_OUT(req, 0, sizeof(long) * CPUSTATES * (mp_maxid + 1));
141 }
142 for (error = 0, c = 0; error == 0 && c <= mp_maxid; c++) {
143 if (!CPU_ABSENT(c)) {
144 pcpu = pcpu_find(c);
145 cp_time = pcpu->pc_cp_time;
146 } else {
147 cp_time = empty;
148 }
149 #ifdef SCTL_MASK32
150 if (req->flags & SCTL_MASK32) {
151 for (i = 0; i < CPUSTATES; i++)
152 cp_time32[i] = (unsigned int)cp_time[i];
153 error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32));
154 } else
155 #endif
156 error = SYSCTL_OUT(req, cp_time, sizeof(long) * CPUSTATES);
157 }
158 return error;
159 }
160
161 SYSCTL_PROC(_kern, OID_AUTO, cp_times, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE,
162 0,0, sysctl_kern_cp_times, "LU", "per-CPU time statistics");
163
164 #ifdef DEADLKRES
165 static const char *blessed[] = {
166 "getblk",
167 "so_snd_sx",
168 "so_rcv_sx",
169 NULL
170 };
171 static int slptime_threshold = 1800;
172 static int blktime_threshold = 900;
173 static int sleepfreq = 3;
174
175 static void
176 deadlkres(void)
177 {
178 struct proc *p;
179 struct thread *td;
180 void *wchan;
181 int blkticks, i, slpticks, slptype, tryl, tticks;
182
183 tryl = 0;
184 for (;;) {
185 blkticks = blktime_threshold * hz;
186 slpticks = slptime_threshold * hz;
187
188 /*
189 * Avoid to sleep on the sx_lock in order to avoid a possible
190 * priority inversion problem leading to starvation.
191 * If the lock can't be held after 100 tries, panic.
192 */
193 if (!sx_try_slock(&allproc_lock)) {
194 if (tryl > 100)
195 panic("%s: possible deadlock detected on allproc_lock\n",
196 __func__);
197 tryl++;
198 pause("allproc", sleepfreq * hz);
199 continue;
200 }
201 tryl = 0;
202 FOREACH_PROC_IN_SYSTEM(p) {
203 PROC_LOCK(p);
204 if (p->p_state == PRS_NEW) {
205 PROC_UNLOCK(p);
206 continue;
207 }
208 FOREACH_THREAD_IN_PROC(p, td) {
209
210 /*
211 * Once a thread is found in "interesting"
212 * state a possible ticks wrap-up needs to be
213 * checked.
214 */
215 thread_lock(td);
216 if (TD_ON_LOCK(td) && ticks < td->td_blktick) {
217
218 /*
219 * The thread should be blocked on a
220 * turnstile, simply check if the
221 * turnstile channel is in good state.
222 */
223 MPASS(td->td_blocked != NULL);
224
225 tticks = ticks - td->td_blktick;
226 thread_unlock(td);
227 if (tticks > blkticks) {
228
229 /*
230 * Accordingly with provided
231 * thresholds, this thread is
232 * stuck for too long on a
233 * turnstile.
234 */
235 PROC_UNLOCK(p);
236 sx_sunlock(&allproc_lock);
237 panic("%s: possible deadlock detected for %p, blocked for %d ticks\n",
238 __func__, td, tticks);
239 }
240 } else if (TD_IS_SLEEPING(td) &&
241 TD_ON_SLEEPQ(td) &&
242 ticks < td->td_blktick) {
243
244 /*
245 * Check if the thread is sleeping on a
246 * lock, otherwise skip the check.
247 * Drop the thread lock in order to
248 * avoid a LOR with the sleepqueue
249 * spinlock.
250 */
251 wchan = td->td_wchan;
252 tticks = ticks - td->td_slptick;
253 thread_unlock(td);
254 slptype = sleepq_type(wchan);
255 if ((slptype == SLEEPQ_SX ||
256 slptype == SLEEPQ_LK) &&
257 tticks > slpticks) {
258
259 /*
260 * Accordingly with provided
261 * thresholds, this thread is
262 * stuck for too long on a
263 * sleepqueue.
264 * However, being on a
265 * sleepqueue, we might still
266 * check for the blessed
267 * list.
268 */
269 tryl = 0;
270 for (i = 0; blessed[i] != NULL;
271 i++) {
272 if (!strcmp(blessed[i],
273 td->td_wmesg)) {
274 tryl = 1;
275 break;
276 }
277 }
278 if (tryl != 0) {
279 tryl = 0;
280 continue;
281 }
282 PROC_UNLOCK(p);
283 sx_sunlock(&allproc_lock);
284 panic("%s: possible deadlock detected for %p, blocked for %d ticks\n",
285 __func__, td, tticks);
286 }
287 } else
288 thread_unlock(td);
289 }
290 PROC_UNLOCK(p);
291 }
292 sx_sunlock(&allproc_lock);
293
294 /* Sleep for sleepfreq seconds. */
295 pause("-", sleepfreq * hz);
296 }
297 }
298
299 static struct kthread_desc deadlkres_kd = {
300 "deadlkres",
301 deadlkres,
302 (struct thread **)NULL
303 };
304
305 SYSINIT(deadlkres, SI_SUB_CLOCKS, SI_ORDER_ANY, kthread_start, &deadlkres_kd);
306
307 SYSCTL_NODE(_debug, OID_AUTO, deadlkres, CTLFLAG_RW, 0, "Deadlock resolver");
308 SYSCTL_INT(_debug_deadlkres, OID_AUTO, slptime_threshold, CTLFLAG_RW,
309 &slptime_threshold, 0,
310 "Number of seconds within is valid to sleep on a sleepqueue");
311 SYSCTL_INT(_debug_deadlkres, OID_AUTO, blktime_threshold, CTLFLAG_RW,
312 &blktime_threshold, 0,
313 "Number of seconds within is valid to block on a turnstile");
314 SYSCTL_INT(_debug_deadlkres, OID_AUTO, sleepfreq, CTLFLAG_RW, &sleepfreq, 0,
315 "Number of seconds between any deadlock resolver thread run");
316 #endif /* DEADLKRES */
317
318 void
319 read_cpu_time(long *cp_time)
320 {
321 struct pcpu *pc;
322 int i, j;
323
324 /* Sum up global cp_time[]. */
325 bzero(cp_time, sizeof(long) * CPUSTATES);
326 CPU_FOREACH(i) {
327 pc = pcpu_find(i);
328 for (j = 0; j < CPUSTATES; j++)
329 cp_time[j] += pc->pc_cp_time[j];
330 }
331 }
332
333 #ifdef SW_WATCHDOG
334 #include <sys/watchdog.h>
335
336 static int watchdog_ticks;
337 static int watchdog_enabled;
338 static void watchdog_fire(void);
339 static void watchdog_config(void *, u_int, int *);
340 #endif /* SW_WATCHDOG */
341
342 /*
343 * Clock handling routines.
344 *
345 * This code is written to operate with two timers that run independently of
346 * each other.
347 *
348 * The main timer, running hz times per second, is used to trigger interval
349 * timers, timeouts and rescheduling as needed.
350 *
351 * The second timer handles kernel and user profiling,
352 * and does resource use estimation. If the second timer is programmable,
353 * it is randomized to avoid aliasing between the two clocks. For example,
354 * the randomization prevents an adversary from always giving up the cpu
355 * just before its quantum expires. Otherwise, it would never accumulate
356 * cpu ticks. The mean frequency of the second timer is stathz.
357 *
358 * If no second timer exists, stathz will be zero; in this case we drive
359 * profiling and statistics off the main clock. This WILL NOT be accurate;
360 * do not do it unless absolutely necessary.
361 *
362 * The statistics clock may (or may not) be run at a higher rate while
363 * profiling. This profile clock runs at profhz. We require that profhz
364 * be an integral multiple of stathz.
365 *
366 * If the statistics clock is running fast, it must be divided by the ratio
367 * profhz/stathz for statistics. (For profiling, every tick counts.)
368 *
369 * Time-of-day is maintained using a "timecounter", which may or may
370 * not be related to the hardware generating the above mentioned
371 * interrupts.
372 */
373
374 int stathz;
375 int profhz;
376 int profprocs;
377 int ticks;
378 int psratio;
379
380 /*
381 * Initialize clock frequencies and start both clocks running.
382 */
383 /* ARGSUSED*/
384 static void
385 initclocks(dummy)
386 void *dummy;
387 {
388 register int i;
389
390 /*
391 * Set divisors to 1 (normal case) and let the machine-specific
392 * code do its bit.
393 */
394 mtx_init(&time_lock, "time lock", NULL, MTX_SPIN);
395 cpu_initclocks();
396
397 /*
398 * Compute profhz/stathz, and fix profhz if needed.
399 */
400 i = stathz ? stathz : hz;
401 if (profhz == 0)
402 profhz = i;
403 psratio = profhz / i;
404 #ifdef SW_WATCHDOG
405 EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0);
406 #endif
407 }
408
409 /*
410 * Each time the real-time timer fires, this function is called on all CPUs.
411 * Note that hardclock() calls hardclock_cpu() for the boot CPU, so only
412 * the other CPUs in the system need to call this function.
413 */
414 void
415 hardclock_cpu(int usermode)
416 {
417 struct pstats *pstats;
418 struct thread *td = curthread;
419 struct proc *p = td->td_proc;
420 int flags;
421
422 /*
423 * Run current process's virtual and profile time, as needed.
424 */
425 pstats = p->p_stats;
426 flags = 0;
427 if (usermode &&
428 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) {
429 PROC_SLOCK(p);
430 if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0)
431 flags |= TDF_ALRMPEND | TDF_ASTPENDING;
432 PROC_SUNLOCK(p);
433 }
434 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) {
435 PROC_SLOCK(p);
436 if (itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0)
437 flags |= TDF_PROFPEND | TDF_ASTPENDING;
438 PROC_SUNLOCK(p);
439 }
440 thread_lock(td);
441 sched_tick();
442 td->td_flags |= flags;
443 thread_unlock(td);
444
445 #ifdef HWPMC_HOOKS
446 if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid)))
447 PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL);
448 #endif
449 callout_tick();
450 }
451
452 /*
453 * The real-time timer, interrupting hz times per second.
454 */
455 void
456 hardclock(int usermode, uintfptr_t pc)
457 {
458
459 atomic_add_int((volatile int *)&ticks, 1);
460 hardclock_cpu(usermode);
461 tc_ticktock();
462 /*
463 * If no separate statistics clock is available, run it from here.
464 *
465 * XXX: this only works for UP
466 */
467 if (stathz == 0) {
468 profclock(usermode, pc);
469 statclock(usermode);
470 }
471 #ifdef DEVICE_POLLING
472 hardclock_device_poll(); /* this is very short and quick */
473 #endif /* DEVICE_POLLING */
474 #ifdef SW_WATCHDOG
475 if (watchdog_enabled > 0 && --watchdog_ticks <= 0)
476 watchdog_fire();
477 #endif /* SW_WATCHDOG */
478 }
479
480 /*
481 * Compute number of ticks in the specified amount of time.
482 */
483 int
484 tvtohz(tv)
485 struct timeval *tv;
486 {
487 register unsigned long ticks;
488 register long sec, usec;
489
490 /*
491 * If the number of usecs in the whole seconds part of the time
492 * difference fits in a long, then the total number of usecs will
493 * fit in an unsigned long. Compute the total and convert it to
494 * ticks, rounding up and adding 1 to allow for the current tick
495 * to expire. Rounding also depends on unsigned long arithmetic
496 * to avoid overflow.
497 *
498 * Otherwise, if the number of ticks in the whole seconds part of
499 * the time difference fits in a long, then convert the parts to
500 * ticks separately and add, using similar rounding methods and
501 * overflow avoidance. This method would work in the previous
502 * case but it is slightly slower and assumes that hz is integral.
503 *
504 * Otherwise, round the time difference down to the maximum
505 * representable value.
506 *
507 * If ints have 32 bits, then the maximum value for any timeout in
508 * 10ms ticks is 248 days.
509 */
510 sec = tv->tv_sec;
511 usec = tv->tv_usec;
512 if (usec < 0) {
513 sec--;
514 usec += 1000000;
515 }
516 if (sec < 0) {
517 #ifdef DIAGNOSTIC
518 if (usec > 0) {
519 sec++;
520 usec -= 1000000;
521 }
522 printf("tvotohz: negative time difference %ld sec %ld usec\n",
523 sec, usec);
524 #endif
525 ticks = 1;
526 } else if (sec <= LONG_MAX / 1000000)
527 ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1))
528 / tick + 1;
529 else if (sec <= LONG_MAX / hz)
530 ticks = sec * hz
531 + ((unsigned long)usec + (tick - 1)) / tick + 1;
532 else
533 ticks = LONG_MAX;
534 if (ticks > INT_MAX)
535 ticks = INT_MAX;
536 return ((int)ticks);
537 }
538
539 /*
540 * Start profiling on a process.
541 *
542 * Kernel profiling passes proc0 which never exits and hence
543 * keeps the profile clock running constantly.
544 */
545 void
546 startprofclock(p)
547 register struct proc *p;
548 {
549
550 PROC_LOCK_ASSERT(p, MA_OWNED);
551 if (p->p_flag & P_STOPPROF)
552 return;
553 if ((p->p_flag & P_PROFIL) == 0) {
554 p->p_flag |= P_PROFIL;
555 mtx_lock_spin(&time_lock);
556 if (++profprocs == 1)
557 cpu_startprofclock();
558 mtx_unlock_spin(&time_lock);
559 }
560 }
561
562 /*
563 * Stop profiling on a process.
564 */
565 void
566 stopprofclock(p)
567 register struct proc *p;
568 {
569
570 PROC_LOCK_ASSERT(p, MA_OWNED);
571 if (p->p_flag & P_PROFIL) {
572 if (p->p_profthreads != 0) {
573 p->p_flag |= P_STOPPROF;
574 while (p->p_profthreads != 0)
575 msleep(&p->p_profthreads, &p->p_mtx, PPAUSE,
576 "stopprof", 0);
577 p->p_flag &= ~P_STOPPROF;
578 }
579 if ((p->p_flag & P_PROFIL) == 0)
580 return;
581 p->p_flag &= ~P_PROFIL;
582 mtx_lock_spin(&time_lock);
583 if (--profprocs == 0)
584 cpu_stopprofclock();
585 mtx_unlock_spin(&time_lock);
586 }
587 }
588
589 /*
590 * Statistics clock. Updates rusage information and calls the scheduler
591 * to adjust priorities of the active thread.
592 *
593 * This should be called by all active processors.
594 */
595 void
596 statclock(int usermode)
597 {
598 struct rusage *ru;
599 struct vmspace *vm;
600 struct thread *td;
601 struct proc *p;
602 long rss;
603 long *cp_time;
604
605 td = curthread;
606 p = td->td_proc;
607
608 cp_time = (long *)PCPU_PTR(cp_time);
609 if (usermode) {
610 /*
611 * Charge the time as appropriate.
612 */
613 td->td_uticks++;
614 if (p->p_nice > NZERO)
615 cp_time[CP_NICE]++;
616 else
617 cp_time[CP_USER]++;
618 } else {
619 /*
620 * Came from kernel mode, so we were:
621 * - handling an interrupt,
622 * - doing syscall or trap work on behalf of the current
623 * user process, or
624 * - spinning in the idle loop.
625 * Whichever it is, charge the time as appropriate.
626 * Note that we charge interrupts to the current process,
627 * regardless of whether they are ``for'' that process,
628 * so that we know how much of its real time was spent
629 * in ``non-process'' (i.e., interrupt) work.
630 */
631 if ((td->td_pflags & TDP_ITHREAD) ||
632 td->td_intr_nesting_level >= 2) {
633 td->td_iticks++;
634 cp_time[CP_INTR]++;
635 } else {
636 td->td_pticks++;
637 td->td_sticks++;
638 if (!TD_IS_IDLETHREAD(td))
639 cp_time[CP_SYS]++;
640 else
641 cp_time[CP_IDLE]++;
642 }
643 }
644
645 /* Update resource usage integrals and maximums. */
646 MPASS(p->p_vmspace != NULL);
647 vm = p->p_vmspace;
648 ru = &td->td_ru;
649 ru->ru_ixrss += pgtok(vm->vm_tsize);
650 ru->ru_idrss += pgtok(vm->vm_dsize);
651 ru->ru_isrss += pgtok(vm->vm_ssize);
652 rss = pgtok(vmspace_resident_count(vm));
653 if (ru->ru_maxrss < rss)
654 ru->ru_maxrss = rss;
655 KTR_POINT2(KTR_SCHED, "thread", sched_tdname(td), "statclock",
656 "prio:%d", td->td_priority, "stathz:%d", (stathz)?stathz:hz);
657 thread_lock_flags(td, MTX_QUIET);
658 sched_clock(td);
659 thread_unlock(td);
660 }
661
662 void
663 profclock(int usermode, uintfptr_t pc)
664 {
665 struct thread *td;
666 #ifdef GPROF
667 struct gmonparam *g;
668 uintfptr_t i;
669 #endif
670
671 td = curthread;
672 if (usermode) {
673 /*
674 * Came from user mode; CPU was in user state.
675 * If this process is being profiled, record the tick.
676 * if there is no related user location yet, don't
677 * bother trying to count it.
678 */
679 if (td->td_proc->p_flag & P_PROFIL)
680 addupc_intr(td, pc, 1);
681 }
682 #ifdef GPROF
683 else {
684 /*
685 * Kernel statistics are just like addupc_intr, only easier.
686 */
687 g = &_gmonparam;
688 if (g->state == GMON_PROF_ON && pc >= g->lowpc) {
689 i = PC_TO_I(g, pc);
690 if (i < g->textsize) {
691 KCOUNT(g, i)++;
692 }
693 }
694 }
695 #endif
696 }
697
698 /*
699 * Return information about system clocks.
700 */
701 static int
702 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
703 {
704 struct clockinfo clkinfo;
705 /*
706 * Construct clockinfo structure.
707 */
708 bzero(&clkinfo, sizeof(clkinfo));
709 clkinfo.hz = hz;
710 clkinfo.tick = tick;
711 clkinfo.profhz = profhz;
712 clkinfo.stathz = stathz ? stathz : hz;
713 return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
714 }
715
716 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate,
717 CTLTYPE_STRUCT|CTLFLAG_RD|CTLFLAG_MPSAFE,
718 0, 0, sysctl_kern_clockrate, "S,clockinfo",
719 "Rate and period of various kernel clocks");
720
721 #ifdef SW_WATCHDOG
722
723 static void
724 watchdog_config(void *unused __unused, u_int cmd, int *error)
725 {
726 u_int u;
727
728 u = cmd & WD_INTERVAL;
729 if (u >= WD_TO_1SEC) {
730 watchdog_ticks = (1 << (u - WD_TO_1SEC)) * hz;
731 watchdog_enabled = 1;
732 *error = 0;
733 } else {
734 watchdog_enabled = 0;
735 }
736 }
737
738 /*
739 * Handle a watchdog timeout by dumping interrupt information and
740 * then either dropping to DDB or panicking.
741 */
742 static void
743 watchdog_fire(void)
744 {
745 int nintr;
746 u_int64_t inttotal;
747 u_long *curintr;
748 char *curname;
749
750 curintr = intrcnt;
751 curname = intrnames;
752 inttotal = 0;
753 nintr = eintrcnt - intrcnt;
754
755 printf("interrupt total\n");
756 while (--nintr >= 0) {
757 if (*curintr)
758 printf("%-12s %20lu\n", curname, *curintr);
759 curname += strlen(curname) + 1;
760 inttotal += *curintr++;
761 }
762 printf("Total %20ju\n", (uintmax_t)inttotal);
763
764 #if defined(KDB) && !defined(KDB_UNATTENDED)
765 kdb_backtrace();
766 kdb_enter(KDB_WHY_WATCHDOG, "watchdog timeout");
767 #else
768 panic("watchdog timeout");
769 #endif
770 }
771
772 #endif /* SW_WATCHDOG */
Cache object: f238d3f36ccb548f71e6d30ab86381ba
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