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