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 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_kdb.h" 43 #include "opt_device_polling.h" 44 #include "opt_hwpmc_hooks.h" 45 #include "opt_ntp.h" 46 #include "opt_watchdog.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/callout.h> 51 #include <sys/epoch.h> 52 #include <sys/eventhandler.h> 53 #include <sys/gtaskqueue.h> 54 #include <sys/kdb.h> 55 #include <sys/kernel.h> 56 #include <sys/kthread.h> 57 #include <sys/ktr.h> 58 #include <sys/lock.h> 59 #include <sys/mutex.h> 60 #include <sys/proc.h> 61 #include <sys/resource.h> 62 #include <sys/resourcevar.h> 63 #include <sys/sched.h> 64 #include <sys/sdt.h> 65 #include <sys/signalvar.h> 66 #include <sys/sleepqueue.h> 67 #include <sys/smp.h> 68 #include <vm/vm.h> 69 #include <vm/pmap.h> 70 #include <vm/vm_map.h> 71 #include <sys/sysctl.h> 72 #include <sys/bus.h> 73 #include <sys/interrupt.h> 74 #include <sys/limits.h> 75 #include <sys/timetc.h> 76 77 #ifdef GPROF 78 #include <sys/gmon.h> 79 #endif 80 81 #ifdef HWPMC_HOOKS 82 #include <sys/pmckern.h> 83 PMC_SOFT_DEFINE( , , clock, hard); 84 PMC_SOFT_DEFINE( , , clock, stat); 85 PMC_SOFT_DEFINE_EX( , , clock, prof, \ 86 cpu_startprofclock, cpu_stopprofclock); 87 #endif 88 89 #ifdef DEVICE_POLLING 90 extern void hardclock_device_poll(void); 91 #endif /* DEVICE_POLLING */ 92 93 static void initclocks(void *dummy); 94 SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL); 95 96 /* Spin-lock protecting profiling statistics. */ 97 static struct mtx time_lock; 98 99 SDT_PROVIDER_DECLARE(sched); 100 SDT_PROBE_DEFINE2(sched, , , tick, "struct thread *", "struct proc *"); 101 102 static int 103 sysctl_kern_cp_time(SYSCTL_HANDLER_ARGS) 104 { 105 int error; 106 long cp_time[CPUSTATES]; 107 #ifdef SCTL_MASK32 108 int i; 109 unsigned int cp_time32[CPUSTATES]; 110 #endif 111 112 read_cpu_time(cp_time); 113 #ifdef SCTL_MASK32 114 if (req->flags & SCTL_MASK32) { 115 if (!req->oldptr) 116 return SYSCTL_OUT(req, 0, sizeof(cp_time32)); 117 for (i = 0; i < CPUSTATES; i++) 118 cp_time32[i] = (unsigned int)cp_time[i]; 119 error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32)); 120 } else 121 #endif 122 { 123 if (!req->oldptr) 124 return SYSCTL_OUT(req, 0, sizeof(cp_time)); 125 error = SYSCTL_OUT(req, cp_time, sizeof(cp_time)); 126 } 127 return error; 128 } 129 130 SYSCTL_PROC(_kern, OID_AUTO, cp_time, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE, 131 0,0, sysctl_kern_cp_time, "LU", "CPU time statistics"); 132 133 static long empty[CPUSTATES]; 134 135 static int 136 sysctl_kern_cp_times(SYSCTL_HANDLER_ARGS) 137 { 138 struct pcpu *pcpu; 139 int error; 140 int c; 141 long *cp_time; 142 #ifdef SCTL_MASK32 143 unsigned int cp_time32[CPUSTATES]; 144 int i; 145 #endif 146 147 if (!req->oldptr) { 148 #ifdef SCTL_MASK32 149 if (req->flags & SCTL_MASK32) 150 return SYSCTL_OUT(req, 0, sizeof(cp_time32) * (mp_maxid + 1)); 151 else 152 #endif 153 return SYSCTL_OUT(req, 0, sizeof(long) * CPUSTATES * (mp_maxid + 1)); 154 } 155 for (error = 0, c = 0; error == 0 && c <= mp_maxid; c++) { 156 if (!CPU_ABSENT(c)) { 157 pcpu = pcpu_find(c); 158 cp_time = pcpu->pc_cp_time; 159 } else { 160 cp_time = empty; 161 } 162 #ifdef SCTL_MASK32 163 if (req->flags & SCTL_MASK32) { 164 for (i = 0; i < CPUSTATES; i++) 165 cp_time32[i] = (unsigned int)cp_time[i]; 166 error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32)); 167 } else 168 #endif 169 error = SYSCTL_OUT(req, cp_time, sizeof(long) * CPUSTATES); 170 } 171 return error; 172 } 173 174 SYSCTL_PROC(_kern, OID_AUTO, cp_times, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE, 175 0,0, sysctl_kern_cp_times, "LU", "per-CPU time statistics"); 176 177 #ifdef DEADLKRES 178 static const char *blessed[] = { 179 "getblk", 180 "so_snd_sx", 181 "so_rcv_sx", 182 NULL 183 }; 184 static int slptime_threshold = 1800; 185 static int blktime_threshold = 900; 186 static int sleepfreq = 3; 187 188 static void 189 deadlres_td_on_lock(struct proc *p, struct thread *td, int blkticks) 190 { 191 int tticks; 192 193 sx_assert(&allproc_lock, SX_LOCKED); 194 PROC_LOCK_ASSERT(p, MA_OWNED); 195 THREAD_LOCK_ASSERT(td, MA_OWNED); 196 /* 197 * The thread should be blocked on a turnstile, simply check 198 * if the turnstile channel is in good state. 199 */ 200 MPASS(td->td_blocked != NULL); 201 202 tticks = ticks - td->td_blktick; 203 if (tticks > blkticks) 204 /* 205 * Accordingly with provided thresholds, this thread is stuck 206 * for too long on a turnstile. 207 */ 208 panic("%s: possible deadlock detected for %p (%s), " 209 "blocked for %d ticks\n", __func__, 210 td, sched_tdname(td), tticks); 211 } 212 213 static void 214 deadlres_td_sleep_q(struct proc *p, struct thread *td, int slpticks) 215 { 216 const void *wchan; 217 int i, slptype, tticks; 218 219 sx_assert(&allproc_lock, SX_LOCKED); 220 PROC_LOCK_ASSERT(p, MA_OWNED); 221 THREAD_LOCK_ASSERT(td, MA_OWNED); 222 /* 223 * Check if the thread is sleeping on a lock, otherwise skip the check. 224 * Drop the thread lock in order to avoid a LOR with the sleepqueue 225 * spinlock. 226 */ 227 wchan = td->td_wchan; 228 tticks = ticks - td->td_slptick; 229 slptype = sleepq_type(wchan); 230 if ((slptype == SLEEPQ_SX || slptype == SLEEPQ_LK) && 231 tticks > slpticks) { 232 /* 233 * Accordingly with provided thresholds, this thread is stuck 234 * for too long on a sleepqueue. 235 * However, being on a sleepqueue, we might still check for the 236 * blessed list. 237 */ 238 for (i = 0; blessed[i] != NULL; i++) 239 if (!strcmp(blessed[i], td->td_wmesg)) 240 return; 241 242 panic("%s: possible deadlock detected for %p (%s), " 243 "blocked for %d ticks\n", __func__, 244 td, sched_tdname(td), tticks); 245 } 246 } 247 248 static void 249 deadlkres(void) 250 { 251 struct proc *p; 252 struct thread *td; 253 int blkticks, slpticks, tryl; 254 255 tryl = 0; 256 for (;;) { 257 blkticks = blktime_threshold * hz; 258 slpticks = slptime_threshold * hz; 259 260 /* 261 * Avoid to sleep on the sx_lock in order to avoid a 262 * possible priority inversion problem leading to 263 * starvation. 264 * If the lock can't be held after 100 tries, panic. 265 */ 266 if (!sx_try_slock(&allproc_lock)) { 267 if (tryl > 100) 268 panic("%s: possible deadlock detected " 269 "on allproc_lock\n", __func__); 270 tryl++; 271 pause("allproc", sleepfreq * hz); 272 continue; 273 } 274 tryl = 0; 275 FOREACH_PROC_IN_SYSTEM(p) { 276 PROC_LOCK(p); 277 if (p->p_state == PRS_NEW) { 278 PROC_UNLOCK(p); 279 continue; 280 } 281 FOREACH_THREAD_IN_PROC(p, td) { 282 thread_lock(td); 283 if (TD_ON_LOCK(td)) 284 deadlres_td_on_lock(p, td, 285 blkticks); 286 else if (TD_IS_SLEEPING(td)) 287 deadlres_td_sleep_q(p, td, 288 slpticks); 289 thread_unlock(td); 290 } 291 PROC_UNLOCK(p); 292 } 293 sx_sunlock(&allproc_lock); 294 295 /* Sleep for sleepfreq seconds. */ 296 pause("-", sleepfreq * hz); 297 } 298 } 299 300 static struct kthread_desc deadlkres_kd = { 301 "deadlkres", 302 deadlkres, 303 (struct thread **)NULL 304 }; 305 306 SYSINIT(deadlkres, SI_SUB_CLOCKS, SI_ORDER_ANY, kthread_start, &deadlkres_kd); 307 308 static SYSCTL_NODE(_debug, OID_AUTO, deadlkres, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 309 "Deadlock resolver"); 310 SYSCTL_INT(_debug_deadlkres, OID_AUTO, slptime_threshold, CTLFLAG_RW, 311 &slptime_threshold, 0, 312 "Number of seconds within is valid to sleep on a sleepqueue"); 313 SYSCTL_INT(_debug_deadlkres, OID_AUTO, blktime_threshold, CTLFLAG_RW, 314 &blktime_threshold, 0, 315 "Number of seconds within is valid to block on a turnstile"); 316 SYSCTL_INT(_debug_deadlkres, OID_AUTO, sleepfreq, CTLFLAG_RW, &sleepfreq, 0, 317 "Number of seconds between any deadlock resolver thread run"); 318 #endif /* DEADLKRES */ 319 320 void 321 read_cpu_time(long *cp_time) 322 { 323 struct pcpu *pc; 324 int i, j; 325 326 /* Sum up global cp_time[]. */ 327 bzero(cp_time, sizeof(long) * CPUSTATES); 328 CPU_FOREACH(i) { 329 pc = pcpu_find(i); 330 for (j = 0; j < CPUSTATES; j++) 331 cp_time[j] += pc->pc_cp_time[j]; 332 } 333 } 334 335 #include <sys/watchdog.h> 336 337 static int watchdog_ticks; 338 static int watchdog_enabled; 339 static void watchdog_fire(void); 340 static void watchdog_config(void *, u_int, int *); 341 342 static void 343 watchdog_attach(void) 344 { 345 EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0); 346 } 347 348 /* 349 * Clock handling routines. 350 * 351 * This code is written to operate with two timers that run independently of 352 * each other. 353 * 354 * The main timer, running hz times per second, is used to trigger interval 355 * timers, timeouts and rescheduling as needed. 356 * 357 * The second timer handles kernel and user profiling, 358 * and does resource use estimation. If the second timer is programmable, 359 * it is randomized to avoid aliasing between the two clocks. For example, 360 * the randomization prevents an adversary from always giving up the cpu 361 * just before its quantum expires. Otherwise, it would never accumulate 362 * cpu ticks. The mean frequency of the second timer is stathz. 363 * 364 * If no second timer exists, stathz will be zero; in this case we drive 365 * profiling and statistics off the main clock. This WILL NOT be accurate; 366 * do not do it unless absolutely necessary. 367 * 368 * The statistics clock may (or may not) be run at a higher rate while 369 * profiling. This profile clock runs at profhz. We require that profhz 370 * be an integral multiple of stathz. 371 * 372 * If the statistics clock is running fast, it must be divided by the ratio 373 * profhz/stathz for statistics. (For profiling, every tick counts.) 374 * 375 * Time-of-day is maintained using a "timecounter", which may or may 376 * not be related to the hardware generating the above mentioned 377 * interrupts. 378 */ 379 380 int stathz; 381 int profhz; 382 int profprocs; 383 volatile int ticks; 384 int psratio; 385 386 DPCPU_DEFINE_STATIC(int, pcputicks); /* Per-CPU version of ticks. */ 387 #ifdef DEVICE_POLLING 388 static int devpoll_run = 0; 389 #endif 390 391 /* 392 * Initialize clock frequencies and start both clocks running. 393 */ 394 /* ARGSUSED*/ 395 static void 396 initclocks(void *dummy) 397 { 398 int i; 399 400 /* 401 * Set divisors to 1 (normal case) and let the machine-specific 402 * code do its bit. 403 */ 404 mtx_init(&time_lock, "time lock", NULL, MTX_DEF); 405 cpu_initclocks(); 406 407 /* 408 * Compute profhz/stathz, and fix profhz if needed. 409 */ 410 i = stathz ? stathz : hz; 411 if (profhz == 0) 412 profhz = i; 413 psratio = profhz / i; 414 415 #ifdef SW_WATCHDOG 416 /* Enable hardclock watchdog now, even if a hardware watchdog exists. */ 417 watchdog_attach(); 418 #else 419 /* Volunteer to run a software watchdog. */ 420 if (wdog_software_attach == NULL) 421 wdog_software_attach = watchdog_attach; 422 #endif 423 } 424 425 static __noinline void 426 hardclock_itimer(struct thread *td, struct pstats *pstats, int cnt, int usermode) 427 { 428 struct proc *p; 429 int flags; 430 431 flags = 0; 432 p = td->td_proc; 433 if (usermode && 434 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) { 435 PROC_ITIMLOCK(p); 436 if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], 437 tick * cnt) == 0) 438 flags |= TDF_ALRMPEND | TDF_ASTPENDING; 439 PROC_ITIMUNLOCK(p); 440 } 441 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) { 442 PROC_ITIMLOCK(p); 443 if (itimerdecr(&pstats->p_timer[ITIMER_PROF], 444 tick * cnt) == 0) 445 flags |= TDF_PROFPEND | TDF_ASTPENDING; 446 PROC_ITIMUNLOCK(p); 447 } 448 if (flags != 0) { 449 thread_lock(td); 450 td->td_flags |= flags; 451 thread_unlock(td); 452 } 453 } 454 455 void 456 hardclock(int cnt, int usermode) 457 { 458 struct pstats *pstats; 459 struct thread *td = curthread; 460 struct proc *p = td->td_proc; 461 int *t = DPCPU_PTR(pcputicks); 462 int global, i, newticks; 463 464 /* 465 * Update per-CPU and possibly global ticks values. 466 */ 467 *t += cnt; 468 global = ticks; 469 do { 470 newticks = *t - global; 471 if (newticks <= 0) { 472 if (newticks < -1) 473 *t = global - 1; 474 newticks = 0; 475 break; 476 } 477 } while (!atomic_fcmpset_int(&ticks, &global, *t)); 478 479 /* 480 * Run current process's virtual and profile time, as needed. 481 */ 482 pstats = p->p_stats; 483 if (__predict_false( 484 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value) || 485 timevalisset(&pstats->p_timer[ITIMER_PROF].it_value))) 486 hardclock_itimer(td, pstats, cnt, usermode); 487 488 #ifdef HWPMC_HOOKS 489 if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid))) 490 PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL); 491 if (td->td_intr_frame != NULL) 492 PMC_SOFT_CALL_TF( , , clock, hard, td->td_intr_frame); 493 #endif 494 /* We are in charge to handle this tick duty. */ 495 if (newticks > 0) { 496 tc_ticktock(newticks); 497 #ifdef DEVICE_POLLING 498 /* Dangerous and no need to call these things concurrently. */ 499 if (atomic_cmpset_acq_int(&devpoll_run, 0, 1)) { 500 /* This is very short and quick. */ 501 hardclock_device_poll(); 502 atomic_store_rel_int(&devpoll_run, 0); 503 } 504 #endif /* DEVICE_POLLING */ 505 if (watchdog_enabled > 0) { 506 i = atomic_fetchadd_int(&watchdog_ticks, -newticks); 507 if (i > 0 && i <= newticks) 508 watchdog_fire(); 509 } 510 intr_event_handle(clk_intr_event, NULL); 511 } 512 if (curcpu == CPU_FIRST()) 513 cpu_tick_calibration(); 514 if (__predict_false(DPCPU_GET(epoch_cb_count))) 515 GROUPTASK_ENQUEUE(DPCPU_PTR(epoch_cb_task)); 516 } 517 518 void 519 hardclock_sync(int cpu) 520 { 521 int *t; 522 KASSERT(!CPU_ABSENT(cpu), ("Absent CPU %d", cpu)); 523 t = DPCPU_ID_PTR(cpu, pcputicks); 524 525 *t = ticks; 526 } 527 528 /* 529 * Compute number of ticks in the specified amount of time. 530 */ 531 int 532 tvtohz(struct timeval *tv) 533 { 534 unsigned long ticks; 535 long sec, usec; 536 537 /* 538 * If the number of usecs in the whole seconds part of the time 539 * difference fits in a long, then the total number of usecs will 540 * fit in an unsigned long. Compute the total and convert it to 541 * ticks, rounding up and adding 1 to allow for the current tick 542 * to expire. Rounding also depends on unsigned long arithmetic 543 * to avoid overflow. 544 * 545 * Otherwise, if the number of ticks in the whole seconds part of 546 * the time difference fits in a long, then convert the parts to 547 * ticks separately and add, using similar rounding methods and 548 * overflow avoidance. This method would work in the previous 549 * case but it is slightly slower and assumes that hz is integral. 550 * 551 * Otherwise, round the time difference down to the maximum 552 * representable value. 553 * 554 * If ints have 32 bits, then the maximum value for any timeout in 555 * 10ms ticks is 248 days. 556 */ 557 sec = tv->tv_sec; 558 usec = tv->tv_usec; 559 if (usec < 0) { 560 sec--; 561 usec += 1000000; 562 } 563 if (sec < 0) { 564 #ifdef DIAGNOSTIC 565 if (usec > 0) { 566 sec++; 567 usec -= 1000000; 568 } 569 printf("tvotohz: negative time difference %ld sec %ld usec\n", 570 sec, usec); 571 #endif 572 ticks = 1; 573 } else if (sec <= LONG_MAX / 1000000) 574 ticks = howmany(sec * 1000000 + (unsigned long)usec, tick) + 1; 575 else if (sec <= LONG_MAX / hz) 576 ticks = sec * hz 577 + howmany((unsigned long)usec, tick) + 1; 578 else 579 ticks = LONG_MAX; 580 if (ticks > INT_MAX) 581 ticks = INT_MAX; 582 return ((int)ticks); 583 } 584 585 /* 586 * Start profiling on a process. 587 * 588 * Kernel profiling passes proc0 which never exits and hence 589 * keeps the profile clock running constantly. 590 */ 591 void 592 startprofclock(struct proc *p) 593 { 594 595 PROC_LOCK_ASSERT(p, MA_OWNED); 596 if (p->p_flag & P_STOPPROF) 597 return; 598 if ((p->p_flag & P_PROFIL) == 0) { 599 p->p_flag |= P_PROFIL; 600 mtx_lock(&time_lock); 601 if (++profprocs == 1) 602 cpu_startprofclock(); 603 mtx_unlock(&time_lock); 604 } 605 } 606 607 /* 608 * Stop profiling on a process. 609 */ 610 void 611 stopprofclock(struct proc *p) 612 { 613 614 PROC_LOCK_ASSERT(p, MA_OWNED); 615 if (p->p_flag & P_PROFIL) { 616 if (p->p_profthreads != 0) { 617 while (p->p_profthreads != 0) { 618 p->p_flag |= P_STOPPROF; 619 msleep(&p->p_profthreads, &p->p_mtx, PPAUSE, 620 "stopprof", 0); 621 } 622 } 623 if ((p->p_flag & P_PROFIL) == 0) 624 return; 625 p->p_flag &= ~P_PROFIL; 626 mtx_lock(&time_lock); 627 if (--profprocs == 0) 628 cpu_stopprofclock(); 629 mtx_unlock(&time_lock); 630 } 631 } 632 633 /* 634 * Statistics clock. Updates rusage information and calls the scheduler 635 * to adjust priorities of the active thread. 636 * 637 * This should be called by all active processors. 638 */ 639 void 640 statclock(int cnt, int usermode) 641 { 642 struct rusage *ru; 643 struct vmspace *vm; 644 struct thread *td; 645 struct proc *p; 646 long rss; 647 long *cp_time; 648 uint64_t runtime, new_switchtime; 649 650 td = curthread; 651 p = td->td_proc; 652 653 cp_time = (long *)PCPU_PTR(cp_time); 654 if (usermode) { 655 /* 656 * Charge the time as appropriate. 657 */ 658 td->td_uticks += cnt; 659 if (p->p_nice > NZERO) 660 cp_time[CP_NICE] += cnt; 661 else 662 cp_time[CP_USER] += cnt; 663 } else { 664 /* 665 * Came from kernel mode, so we were: 666 * - handling an interrupt, 667 * - doing syscall or trap work on behalf of the current 668 * user process, or 669 * - spinning in the idle loop. 670 * Whichever it is, charge the time as appropriate. 671 * Note that we charge interrupts to the current process, 672 * regardless of whether they are ``for'' that process, 673 * so that we know how much of its real time was spent 674 * in ``non-process'' (i.e., interrupt) work. 675 */ 676 if ((td->td_pflags & TDP_ITHREAD) || 677 td->td_intr_nesting_level >= 2) { 678 td->td_iticks += cnt; 679 cp_time[CP_INTR] += cnt; 680 } else { 681 td->td_pticks += cnt; 682 td->td_sticks += cnt; 683 if (!TD_IS_IDLETHREAD(td)) 684 cp_time[CP_SYS] += cnt; 685 else 686 cp_time[CP_IDLE] += cnt; 687 } 688 } 689 690 /* Update resource usage integrals and maximums. */ 691 MPASS(p->p_vmspace != NULL); 692 vm = p->p_vmspace; 693 ru = &td->td_ru; 694 ru->ru_ixrss += pgtok(vm->vm_tsize) * cnt; 695 ru->ru_idrss += pgtok(vm->vm_dsize) * cnt; 696 ru->ru_isrss += pgtok(vm->vm_ssize) * cnt; 697 rss = pgtok(vmspace_resident_count(vm)); 698 if (ru->ru_maxrss < rss) 699 ru->ru_maxrss = rss; 700 KTR_POINT2(KTR_SCHED, "thread", sched_tdname(td), "statclock", 701 "prio:%d", td->td_priority, "stathz:%d", (stathz)?stathz:hz); 702 SDT_PROBE2(sched, , , tick, td, td->td_proc); 703 thread_lock_flags(td, MTX_QUIET); 704 705 /* 706 * Compute the amount of time during which the current 707 * thread was running, and add that to its total so far. 708 */ 709 new_switchtime = cpu_ticks(); 710 runtime = new_switchtime - PCPU_GET(switchtime); 711 td->td_runtime += runtime; 712 td->td_incruntime += runtime; 713 PCPU_SET(switchtime, new_switchtime); 714 715 sched_clock(td, cnt); 716 thread_unlock(td); 717 #ifdef HWPMC_HOOKS 718 if (td->td_intr_frame != NULL) 719 PMC_SOFT_CALL_TF( , , clock, stat, td->td_intr_frame); 720 #endif 721 } 722 723 void 724 profclock(int cnt, int usermode, uintfptr_t pc) 725 { 726 struct thread *td; 727 #ifdef GPROF 728 struct gmonparam *g; 729 uintfptr_t i; 730 #endif 731 732 td = curthread; 733 if (usermode) { 734 /* 735 * Came from user mode; CPU was in user state. 736 * If this process is being profiled, record the tick. 737 * if there is no related user location yet, don't 738 * bother trying to count it. 739 */ 740 if (td->td_proc->p_flag & P_PROFIL) 741 addupc_intr(td, pc, cnt); 742 } 743 #ifdef GPROF 744 else { 745 /* 746 * Kernel statistics are just like addupc_intr, only easier. 747 */ 748 g = &_gmonparam; 749 if (g->state == GMON_PROF_ON && pc >= g->lowpc) { 750 i = PC_TO_I(g, pc); 751 if (i < g->textsize) { 752 KCOUNT(g, i) += cnt; 753 } 754 } 755 } 756 #endif 757 #ifdef HWPMC_HOOKS 758 if (td->td_intr_frame != NULL) 759 PMC_SOFT_CALL_TF( , , clock, prof, td->td_intr_frame); 760 #endif 761 } 762 763 /* 764 * Return information about system clocks. 765 */ 766 static int 767 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS) 768 { 769 struct clockinfo clkinfo; 770 /* 771 * Construct clockinfo structure. 772 */ 773 bzero(&clkinfo, sizeof(clkinfo)); 774 clkinfo.hz = hz; 775 clkinfo.tick = tick; 776 clkinfo.profhz = profhz; 777 clkinfo.stathz = stathz ? stathz : hz; 778 return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req)); 779 } 780 781 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, 782 CTLTYPE_STRUCT|CTLFLAG_RD|CTLFLAG_MPSAFE, 783 0, 0, sysctl_kern_clockrate, "S,clockinfo", 784 "Rate and period of various kernel clocks"); 785 786 static void 787 watchdog_config(void *unused __unused, u_int cmd, int *error) 788 { 789 u_int u; 790 791 u = cmd & WD_INTERVAL; 792 if (u >= WD_TO_1SEC) { 793 watchdog_ticks = (1 << (u - WD_TO_1SEC)) * hz; 794 watchdog_enabled = 1; 795 *error = 0; 796 } else { 797 watchdog_enabled = 0; 798 } 799 } 800 801 /* 802 * Handle a watchdog timeout by dumping interrupt information and 803 * then either dropping to DDB or panicking. 804 */ 805 static void 806 watchdog_fire(void) 807 { 808 int nintr; 809 uint64_t inttotal; 810 u_long *curintr; 811 char *curname; 812 813 curintr = intrcnt; 814 curname = intrnames; 815 inttotal = 0; 816 nintr = sintrcnt / sizeof(u_long); 817 818 printf("interrupt total\n"); 819 while (--nintr >= 0) { 820 if (*curintr) 821 printf("%-12s %20lu\n", curname, *curintr); 822 curname += strlen(curname) + 1; 823 inttotal += *curintr++; 824 } 825 printf("Total %20ju\n", (uintmax_t)inttotal); 826 827 #if defined(KDB) && !defined(KDB_UNATTENDED) 828 kdb_backtrace(); 829 kdb_enter(KDB_WHY_WATCHDOG, "watchdog timeout"); 830 #else 831 panic("watchdog timeout"); 832 #endif 833 }
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