Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_clock.c
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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_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 */
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