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/kdb.h> 52 #include <sys/kernel.h> 53 #include <sys/kthread.h> 54 #include <sys/ktr.h> 55 #include <sys/lock.h> 56 #include <sys/mutex.h> 57 #include <sys/proc.h> 58 #include <sys/resource.h> 59 #include <sys/resourcevar.h> 60 #include <sys/sched.h> 61 #include <sys/sdt.h> 62 #include <sys/signalvar.h> 63 #include <sys/sleepqueue.h> 64 #include <sys/smp.h> 65 #include <vm/vm.h> 66 #include <vm/pmap.h> 67 #include <vm/vm_map.h> 68 #include <sys/sysctl.h> 69 #include <sys/bus.h> 70 #include <sys/interrupt.h> 71 #include <sys/limits.h> 72 #include <sys/timetc.h> 73 74 #ifdef GPROF 75 #include <sys/gmon.h> 76 #endif 77 78 #ifdef HWPMC_HOOKS 79 #include <sys/pmckern.h> 80 PMC_SOFT_DEFINE( , , clock, hard); 81 PMC_SOFT_DEFINE( , , clock, stat); 82 PMC_SOFT_DEFINE_EX( , , clock, prof, \ 83 cpu_startprofclock, cpu_stopprofclock); 84 #endif 85 86 #ifdef DEVICE_POLLING 87 extern void hardclock_device_poll(void); 88 #endif /* DEVICE_POLLING */ 89 90 static void initclocks(void *dummy); 91 SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL); 92 93 /* Spin-lock protecting profiling statistics. */ 94 static struct mtx time_lock; 95 96 SDT_PROVIDER_DECLARE(sched); 97 SDT_PROBE_DEFINE2(sched, , , tick, "struct thread *", "struct proc *"); 98 99 static int 100 sysctl_kern_cp_time(SYSCTL_HANDLER_ARGS) 101 { 102 int error; 103 long cp_time[CPUSTATES]; 104 #ifdef SCTL_MASK32 105 int i; 106 unsigned int cp_time32[CPUSTATES]; 107 #endif 108 109 read_cpu_time(cp_time); 110 #ifdef SCTL_MASK32 111 if (req->flags & SCTL_MASK32) { 112 if (!req->oldptr) 113 return SYSCTL_OUT(req, 0, sizeof(cp_time32)); 114 for (i = 0; i < CPUSTATES; i++) 115 cp_time32[i] = (unsigned int)cp_time[i]; 116 error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32)); 117 } else 118 #endif 119 { 120 if (!req->oldptr) 121 return SYSCTL_OUT(req, 0, sizeof(cp_time)); 122 error = SYSCTL_OUT(req, cp_time, sizeof(cp_time)); 123 } 124 return error; 125 } 126 127 SYSCTL_PROC(_kern, OID_AUTO, cp_time, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE, 128 0,0, sysctl_kern_cp_time, "LU", "CPU time statistics"); 129 130 static long empty[CPUSTATES]; 131 132 static int 133 sysctl_kern_cp_times(SYSCTL_HANDLER_ARGS) 134 { 135 struct pcpu *pcpu; 136 int error; 137 int c; 138 long *cp_time; 139 #ifdef SCTL_MASK32 140 unsigned int cp_time32[CPUSTATES]; 141 int i; 142 #endif 143 144 if (!req->oldptr) { 145 #ifdef SCTL_MASK32 146 if (req->flags & SCTL_MASK32) 147 return SYSCTL_OUT(req, 0, sizeof(cp_time32) * (mp_maxid + 1)); 148 else 149 #endif 150 return SYSCTL_OUT(req, 0, sizeof(long) * CPUSTATES * (mp_maxid + 1)); 151 } 152 for (error = 0, c = 0; error == 0 && c <= mp_maxid; c++) { 153 if (!CPU_ABSENT(c)) { 154 pcpu = pcpu_find(c); 155 cp_time = pcpu->pc_cp_time; 156 } else { 157 cp_time = empty; 158 } 159 #ifdef SCTL_MASK32 160 if (req->flags & SCTL_MASK32) { 161 for (i = 0; i < CPUSTATES; i++) 162 cp_time32[i] = (unsigned int)cp_time[i]; 163 error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32)); 164 } else 165 #endif 166 error = SYSCTL_OUT(req, cp_time, sizeof(long) * CPUSTATES); 167 } 168 return error; 169 } 170 171 SYSCTL_PROC(_kern, OID_AUTO, cp_times, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE, 172 0,0, sysctl_kern_cp_times, "LU", "per-CPU time statistics"); 173 174 #ifdef DEADLKRES 175 static const char *blessed[] = { 176 "getblk", 177 "so_snd_sx", 178 "so_rcv_sx", 179 NULL 180 }; 181 static int slptime_threshold = 1800; 182 static int blktime_threshold = 900; 183 static int sleepfreq = 3; 184 185 static void 186 deadlkres(void) 187 { 188 struct proc *p; 189 struct thread *td; 190 void *wchan; 191 int blkticks, i, slpticks, slptype, tryl, tticks; 192 193 tryl = 0; 194 for (;;) { 195 blkticks = blktime_threshold * hz; 196 slpticks = slptime_threshold * hz; 197 198 /* 199 * Avoid to sleep on the sx_lock in order to avoid a possible 200 * priority inversion problem leading to starvation. 201 * If the lock can't be held after 100 tries, panic. 202 */ 203 if (!sx_try_slock(&allproc_lock)) { 204 if (tryl > 100) 205 panic("%s: possible deadlock detected on allproc_lock\n", 206 __func__); 207 tryl++; 208 pause("allproc", sleepfreq * hz); 209 continue; 210 } 211 tryl = 0; 212 FOREACH_PROC_IN_SYSTEM(p) { 213 PROC_LOCK(p); 214 if (p->p_state == PRS_NEW) { 215 PROC_UNLOCK(p); 216 continue; 217 } 218 FOREACH_THREAD_IN_PROC(p, td) { 219 220 thread_lock(td); 221 if (TD_ON_LOCK(td)) { 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)) { 247 248 /* 249 * Check if the thread is sleeping on a 250 * lock, otherwise skip the check. 251 * Drop the thread lock in order to 252 * avoid a LOR with the sleepqueue 253 * spinlock. 254 */ 255 wchan = td->td_wchan; 256 tticks = ticks - td->td_slptick; 257 thread_unlock(td); 258 slptype = sleepq_type(wchan); 259 if ((slptype == SLEEPQ_SX || 260 slptype == SLEEPQ_LK) && 261 tticks > slpticks) { 262 263 /* 264 * Accordingly with provided 265 * thresholds, this thread is 266 * stuck for too long on a 267 * sleepqueue. 268 * However, being on a 269 * sleepqueue, we might still 270 * check for the blessed 271 * list. 272 */ 273 tryl = 0; 274 for (i = 0; blessed[i] != NULL; 275 i++) { 276 if (!strcmp(blessed[i], 277 td->td_wmesg)) { 278 tryl = 1; 279 break; 280 } 281 } 282 if (tryl != 0) { 283 tryl = 0; 284 continue; 285 } 286 PROC_UNLOCK(p); 287 sx_sunlock(&allproc_lock); 288 panic("%s: possible deadlock detected for %p, blocked for %d ticks\n", 289 __func__, td, tticks); 290 } 291 } else 292 thread_unlock(td); 293 } 294 PROC_UNLOCK(p); 295 } 296 sx_sunlock(&allproc_lock); 297 298 /* Sleep for sleepfreq seconds. */ 299 pause("-", sleepfreq * hz); 300 } 301 } 302 303 static struct kthread_desc deadlkres_kd = { 304 "deadlkres", 305 deadlkres, 306 (struct thread **)NULL 307 }; 308 309 SYSINIT(deadlkres, SI_SUB_CLOCKS, SI_ORDER_ANY, kthread_start, &deadlkres_kd); 310 311 static SYSCTL_NODE(_debug, OID_AUTO, deadlkres, CTLFLAG_RW, 0, 312 "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 #include <sys/watchdog.h> 339 340 static int watchdog_ticks; 341 static int watchdog_enabled; 342 static void watchdog_fire(void); 343 static void watchdog_config(void *, u_int, int *); 344 345 static void 346 watchdog_attach(void) 347 { 348 EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0); 349 } 350 351 /* 352 * Clock handling routines. 353 * 354 * This code is written to operate with two timers that run independently of 355 * each other. 356 * 357 * The main timer, running hz times per second, is used to trigger interval 358 * timers, timeouts and rescheduling as needed. 359 * 360 * The second timer handles kernel and user profiling, 361 * and does resource use estimation. If the second timer is programmable, 362 * it is randomized to avoid aliasing between the two clocks. For example, 363 * the randomization prevents an adversary from always giving up the cpu 364 * just before its quantum expires. Otherwise, it would never accumulate 365 * cpu ticks. The mean frequency of the second timer is stathz. 366 * 367 * If no second timer exists, stathz will be zero; in this case we drive 368 * profiling and statistics off the main clock. This WILL NOT be accurate; 369 * do not do it unless absolutely necessary. 370 * 371 * The statistics clock may (or may not) be run at a higher rate while 372 * profiling. This profile clock runs at profhz. We require that profhz 373 * be an integral multiple of stathz. 374 * 375 * If the statistics clock is running fast, it must be divided by the ratio 376 * profhz/stathz for statistics. (For profiling, every tick counts.) 377 * 378 * Time-of-day is maintained using a "timecounter", which may or may 379 * not be related to the hardware generating the above mentioned 380 * interrupts. 381 */ 382 383 int stathz; 384 int profhz; 385 int profprocs; 386 volatile int ticks; 387 int psratio; 388 389 static DPCPU_DEFINE(int, pcputicks); /* Per-CPU version of ticks. */ 390 #ifdef DEVICE_POLLING 391 static int devpoll_run = 0; 392 #endif 393 394 /* 395 * Initialize clock frequencies and start both clocks running. 396 */ 397 /* ARGSUSED*/ 398 static void 399 initclocks(void *dummy) 400 { 401 int i; 402 403 /* 404 * Set divisors to 1 (normal case) and let the machine-specific 405 * code do its bit. 406 */ 407 mtx_init(&time_lock, "time lock", NULL, MTX_DEF); 408 cpu_initclocks(); 409 410 /* 411 * Compute profhz/stathz, and fix profhz if needed. 412 */ 413 i = stathz ? stathz : hz; 414 if (profhz == 0) 415 profhz = i; 416 psratio = profhz / i; 417 418 #ifdef SW_WATCHDOG 419 /* Enable hardclock watchdog now, even if a hardware watchdog exists. */ 420 watchdog_attach(); 421 #else 422 /* Volunteer to run a software watchdog. */ 423 if (wdog_software_attach == NULL) 424 wdog_software_attach = watchdog_attach; 425 #endif 426 } 427 428 /* 429 * Each time the real-time timer fires, this function is called on all CPUs. 430 * Note that hardclock() calls hardclock_cpu() for the boot CPU, so only 431 * the other CPUs in the system need to call this function. 432 */ 433 void 434 hardclock_cpu(int usermode) 435 { 436 struct pstats *pstats; 437 struct thread *td = curthread; 438 struct proc *p = td->td_proc; 439 int flags; 440 441 /* 442 * Run current process's virtual and profile time, as needed. 443 */ 444 pstats = p->p_stats; 445 flags = 0; 446 if (usermode && 447 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) { 448 PROC_ITIMLOCK(p); 449 if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0) 450 flags |= TDF_ALRMPEND | TDF_ASTPENDING; 451 PROC_ITIMUNLOCK(p); 452 } 453 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) { 454 PROC_ITIMLOCK(p); 455 if (itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0) 456 flags |= TDF_PROFPEND | TDF_ASTPENDING; 457 PROC_ITIMUNLOCK(p); 458 } 459 thread_lock(td); 460 td->td_flags |= flags; 461 thread_unlock(td); 462 463 #ifdef HWPMC_HOOKS 464 if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid))) 465 PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL); 466 if (td->td_intr_frame != NULL) 467 PMC_SOFT_CALL_TF( , , clock, hard, td->td_intr_frame); 468 #endif 469 callout_process(sbinuptime()); 470 } 471 472 /* 473 * The real-time timer, interrupting hz times per second. 474 */ 475 void 476 hardclock(int usermode, uintfptr_t pc) 477 { 478 479 atomic_add_int(&ticks, 1); 480 hardclock_cpu(usermode); 481 tc_ticktock(1); 482 cpu_tick_calibration(); 483 /* 484 * If no separate statistics clock is available, run it from here. 485 * 486 * XXX: this only works for UP 487 */ 488 if (stathz == 0) { 489 profclock(usermode, pc); 490 statclock(usermode); 491 } 492 #ifdef DEVICE_POLLING 493 hardclock_device_poll(); /* this is very short and quick */ 494 #endif /* DEVICE_POLLING */ 495 if (watchdog_enabled > 0 && --watchdog_ticks <= 0) 496 watchdog_fire(); 497 } 498 499 void 500 hardclock_cnt(int cnt, int usermode) 501 { 502 struct pstats *pstats; 503 struct thread *td = curthread; 504 struct proc *p = td->td_proc; 505 int *t = DPCPU_PTR(pcputicks); 506 int flags, global, newticks; 507 int i; 508 509 /* 510 * Update per-CPU and possibly global ticks values. 511 */ 512 *t += cnt; 513 do { 514 global = ticks; 515 newticks = *t - global; 516 if (newticks <= 0) { 517 if (newticks < -1) 518 *t = global - 1; 519 newticks = 0; 520 break; 521 } 522 } while (!atomic_cmpset_int(&ticks, global, *t)); 523 524 /* 525 * Run current process's virtual and profile time, as needed. 526 */ 527 pstats = p->p_stats; 528 flags = 0; 529 if (usermode && 530 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) { 531 PROC_ITIMLOCK(p); 532 if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], 533 tick * cnt) == 0) 534 flags |= TDF_ALRMPEND | TDF_ASTPENDING; 535 PROC_ITIMUNLOCK(p); 536 } 537 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) { 538 PROC_ITIMLOCK(p); 539 if (itimerdecr(&pstats->p_timer[ITIMER_PROF], 540 tick * cnt) == 0) 541 flags |= TDF_PROFPEND | TDF_ASTPENDING; 542 PROC_ITIMUNLOCK(p); 543 } 544 if (flags != 0) { 545 thread_lock(td); 546 td->td_flags |= flags; 547 thread_unlock(td); 548 } 549 550 #ifdef HWPMC_HOOKS 551 if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid))) 552 PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL); 553 if (td->td_intr_frame != NULL) 554 PMC_SOFT_CALL_TF( , , clock, hard, td->td_intr_frame); 555 #endif 556 /* We are in charge to handle this tick duty. */ 557 if (newticks > 0) { 558 tc_ticktock(newticks); 559 #ifdef DEVICE_POLLING 560 /* Dangerous and no need to call these things concurrently. */ 561 if (atomic_cmpset_acq_int(&devpoll_run, 0, 1)) { 562 /* This is very short and quick. */ 563 hardclock_device_poll(); 564 atomic_store_rel_int(&devpoll_run, 0); 565 } 566 #endif /* DEVICE_POLLING */ 567 if (watchdog_enabled > 0) { 568 i = atomic_fetchadd_int(&watchdog_ticks, -newticks); 569 if (i > 0 && i <= newticks) 570 watchdog_fire(); 571 } 572 } 573 if (curcpu == CPU_FIRST()) 574 cpu_tick_calibration(); 575 } 576 577 void 578 hardclock_sync(int cpu) 579 { 580 int *t; 581 KASSERT(!CPU_ABSENT(cpu), ("Absent CPU %d", cpu)); 582 t = DPCPU_ID_PTR(cpu, pcputicks); 583 584 *t = ticks; 585 } 586 587 /* 588 * Compute number of ticks in the specified amount of time. 589 */ 590 int 591 tvtohz(struct timeval *tv) 592 { 593 unsigned long ticks; 594 long sec, usec; 595 596 /* 597 * If the number of usecs in the whole seconds part of the time 598 * difference fits in a long, then the total number of usecs will 599 * fit in an unsigned long. Compute the total and convert it to 600 * ticks, rounding up and adding 1 to allow for the current tick 601 * to expire. Rounding also depends on unsigned long arithmetic 602 * to avoid overflow. 603 * 604 * Otherwise, if the number of ticks in the whole seconds part of 605 * the time difference fits in a long, then convert the parts to 606 * ticks separately and add, using similar rounding methods and 607 * overflow avoidance. This method would work in the previous 608 * case but it is slightly slower and assumes that hz is integral. 609 * 610 * Otherwise, round the time difference down to the maximum 611 * representable value. 612 * 613 * If ints have 32 bits, then the maximum value for any timeout in 614 * 10ms ticks is 248 days. 615 */ 616 sec = tv->tv_sec; 617 usec = tv->tv_usec; 618 if (usec < 0) { 619 sec--; 620 usec += 1000000; 621 } 622 if (sec < 0) { 623 #ifdef DIAGNOSTIC 624 if (usec > 0) { 625 sec++; 626 usec -= 1000000; 627 } 628 printf("tvotohz: negative time difference %ld sec %ld usec\n", 629 sec, usec); 630 #endif 631 ticks = 1; 632 } else if (sec <= LONG_MAX / 1000000) 633 ticks = howmany(sec * 1000000 + (unsigned long)usec, tick) + 1; 634 else if (sec <= LONG_MAX / hz) 635 ticks = sec * hz 636 + howmany((unsigned long)usec, tick) + 1; 637 else 638 ticks = LONG_MAX; 639 if (ticks > INT_MAX) 640 ticks = INT_MAX; 641 return ((int)ticks); 642 } 643 644 /* 645 * Start profiling on a process. 646 * 647 * Kernel profiling passes proc0 which never exits and hence 648 * keeps the profile clock running constantly. 649 */ 650 void 651 startprofclock(struct proc *p) 652 { 653 654 PROC_LOCK_ASSERT(p, MA_OWNED); 655 if (p->p_flag & P_STOPPROF) 656 return; 657 if ((p->p_flag & P_PROFIL) == 0) { 658 p->p_flag |= P_PROFIL; 659 mtx_lock(&time_lock); 660 if (++profprocs == 1) 661 cpu_startprofclock(); 662 mtx_unlock(&time_lock); 663 } 664 } 665 666 /* 667 * Stop profiling on a process. 668 */ 669 void 670 stopprofclock(struct proc *p) 671 { 672 673 PROC_LOCK_ASSERT(p, MA_OWNED); 674 if (p->p_flag & P_PROFIL) { 675 if (p->p_profthreads != 0) { 676 while (p->p_profthreads != 0) { 677 p->p_flag |= P_STOPPROF; 678 msleep(&p->p_profthreads, &p->p_mtx, PPAUSE, 679 "stopprof", 0); 680 } 681 } 682 if ((p->p_flag & P_PROFIL) == 0) 683 return; 684 p->p_flag &= ~P_PROFIL; 685 mtx_lock(&time_lock); 686 if (--profprocs == 0) 687 cpu_stopprofclock(); 688 mtx_unlock(&time_lock); 689 } 690 } 691 692 /* 693 * Statistics clock. Updates rusage information and calls the scheduler 694 * to adjust priorities of the active thread. 695 * 696 * This should be called by all active processors. 697 */ 698 void 699 statclock(int usermode) 700 { 701 702 statclock_cnt(1, usermode); 703 } 704 705 void 706 statclock_cnt(int cnt, int usermode) 707 { 708 struct rusage *ru; 709 struct vmspace *vm; 710 struct thread *td; 711 struct proc *p; 712 long rss; 713 long *cp_time; 714 715 td = curthread; 716 p = td->td_proc; 717 718 cp_time = (long *)PCPU_PTR(cp_time); 719 if (usermode) { 720 /* 721 * Charge the time as appropriate. 722 */ 723 td->td_uticks += cnt; 724 if (p->p_nice > NZERO) 725 cp_time[CP_NICE] += cnt; 726 else 727 cp_time[CP_USER] += cnt; 728 } else { 729 /* 730 * Came from kernel mode, so we were: 731 * - handling an interrupt, 732 * - doing syscall or trap work on behalf of the current 733 * user process, or 734 * - spinning in the idle loop. 735 * Whichever it is, charge the time as appropriate. 736 * Note that we charge interrupts to the current process, 737 * regardless of whether they are ``for'' that process, 738 * so that we know how much of its real time was spent 739 * in ``non-process'' (i.e., interrupt) work. 740 */ 741 if ((td->td_pflags & TDP_ITHREAD) || 742 td->td_intr_nesting_level >= 2) { 743 td->td_iticks += cnt; 744 cp_time[CP_INTR] += cnt; 745 } else { 746 td->td_pticks += cnt; 747 td->td_sticks += cnt; 748 if (!TD_IS_IDLETHREAD(td)) 749 cp_time[CP_SYS] += cnt; 750 else 751 cp_time[CP_IDLE] += cnt; 752 } 753 } 754 755 /* Update resource usage integrals and maximums. */ 756 MPASS(p->p_vmspace != NULL); 757 vm = p->p_vmspace; 758 ru = &td->td_ru; 759 ru->ru_ixrss += pgtok(vm->vm_tsize) * cnt; 760 ru->ru_idrss += pgtok(vm->vm_dsize) * cnt; 761 ru->ru_isrss += pgtok(vm->vm_ssize) * cnt; 762 rss = pgtok(vmspace_resident_count(vm)); 763 if (ru->ru_maxrss < rss) 764 ru->ru_maxrss = rss; 765 KTR_POINT2(KTR_SCHED, "thread", sched_tdname(td), "statclock", 766 "prio:%d", td->td_priority, "stathz:%d", (stathz)?stathz:hz); 767 SDT_PROBE2(sched, , , tick, td, td->td_proc); 768 thread_lock_flags(td, MTX_QUIET); 769 for ( ; cnt > 0; cnt--) 770 sched_clock(td); 771 thread_unlock(td); 772 #ifdef HWPMC_HOOKS 773 if (td->td_intr_frame != NULL) 774 PMC_SOFT_CALL_TF( , , clock, stat, td->td_intr_frame); 775 #endif 776 } 777 778 void 779 profclock(int usermode, uintfptr_t pc) 780 { 781 782 profclock_cnt(1, usermode, pc); 783 } 784 785 void 786 profclock_cnt(int cnt, int usermode, uintfptr_t pc) 787 { 788 struct thread *td; 789 #ifdef GPROF 790 struct gmonparam *g; 791 uintfptr_t i; 792 #endif 793 794 td = curthread; 795 if (usermode) { 796 /* 797 * Came from user mode; CPU was in user state. 798 * If this process is being profiled, record the tick. 799 * if there is no related user location yet, don't 800 * bother trying to count it. 801 */ 802 if (td->td_proc->p_flag & P_PROFIL) 803 addupc_intr(td, pc, cnt); 804 } 805 #ifdef GPROF 806 else { 807 /* 808 * Kernel statistics are just like addupc_intr, only easier. 809 */ 810 g = &_gmonparam; 811 if (g->state == GMON_PROF_ON && pc >= g->lowpc) { 812 i = PC_TO_I(g, pc); 813 if (i < g->textsize) { 814 KCOUNT(g, i) += cnt; 815 } 816 } 817 } 818 #endif 819 #ifdef HWPMC_HOOKS 820 if (td->td_intr_frame != NULL) 821 PMC_SOFT_CALL_TF( , , clock, prof, td->td_intr_frame); 822 #endif 823 } 824 825 /* 826 * Return information about system clocks. 827 */ 828 static int 829 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS) 830 { 831 struct clockinfo clkinfo; 832 /* 833 * Construct clockinfo structure. 834 */ 835 bzero(&clkinfo, sizeof(clkinfo)); 836 clkinfo.hz = hz; 837 clkinfo.tick = tick; 838 clkinfo.profhz = profhz; 839 clkinfo.stathz = stathz ? stathz : hz; 840 return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req)); 841 } 842 843 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, 844 CTLTYPE_STRUCT|CTLFLAG_RD|CTLFLAG_MPSAFE, 845 0, 0, sysctl_kern_clockrate, "S,clockinfo", 846 "Rate and period of various kernel clocks"); 847 848 static void 849 watchdog_config(void *unused __unused, u_int cmd, int *error) 850 { 851 u_int u; 852 853 u = cmd & WD_INTERVAL; 854 if (u >= WD_TO_1SEC) { 855 watchdog_ticks = (1 << (u - WD_TO_1SEC)) * hz; 856 watchdog_enabled = 1; 857 *error = 0; 858 } else { 859 watchdog_enabled = 0; 860 } 861 } 862 863 /* 864 * Handle a watchdog timeout by dumping interrupt information and 865 * then either dropping to DDB or panicking. 866 */ 867 static void 868 watchdog_fire(void) 869 { 870 int nintr; 871 uint64_t inttotal; 872 u_long *curintr; 873 char *curname; 874 875 curintr = intrcnt; 876 curname = intrnames; 877 inttotal = 0; 878 nintr = sintrcnt / sizeof(u_long); 879 880 printf("interrupt total\n"); 881 while (--nintr >= 0) { 882 if (*curintr) 883 printf("%-12s %20lu\n", curname, *curintr); 884 curname += strlen(curname) + 1; 885 inttotal += *curintr++; 886 } 887 printf("Total %20ju\n", (uintmax_t)inttotal); 888 889 #if defined(KDB) && !defined(KDB_UNATTENDED) 890 kdb_backtrace(); 891 kdb_enter(KDB_WHY_WATCHDOG, "watchdog timeout"); 892 #else 893 panic("watchdog timeout"); 894 #endif 895 } 896