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: releng/9.0/sys/kern/kern_clock.c 225799 2011-09-27 15:08:59Z mav $"); 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 static DPCPU_DEFINE(int, pcputicks); /* Per-CPU version of ticks. */ 381 static int global_hardclock_run = 0; 382 383 /* 384 * Initialize clock frequencies and start both clocks running. 385 */ 386 /* ARGSUSED*/ 387 static void 388 initclocks(dummy) 389 void *dummy; 390 { 391 register int i; 392 393 /* 394 * Set divisors to 1 (normal case) and let the machine-specific 395 * code do its bit. 396 */ 397 mtx_init(&time_lock, "time lock", NULL, MTX_DEF); 398 cpu_initclocks(); 399 400 /* 401 * Compute profhz/stathz, and fix profhz if needed. 402 */ 403 i = stathz ? stathz : hz; 404 if (profhz == 0) 405 profhz = i; 406 psratio = profhz / i; 407 #ifdef SW_WATCHDOG 408 EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0); 409 #endif 410 } 411 412 /* 413 * Each time the real-time timer fires, this function is called on all CPUs. 414 * Note that hardclock() calls hardclock_cpu() for the boot CPU, so only 415 * the other CPUs in the system need to call this function. 416 */ 417 void 418 hardclock_cpu(int usermode) 419 { 420 struct pstats *pstats; 421 struct thread *td = curthread; 422 struct proc *p = td->td_proc; 423 int flags; 424 425 /* 426 * Run current process's virtual and profile time, as needed. 427 */ 428 pstats = p->p_stats; 429 flags = 0; 430 if (usermode && 431 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) { 432 PROC_SLOCK(p); 433 if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0) 434 flags |= TDF_ALRMPEND | TDF_ASTPENDING; 435 PROC_SUNLOCK(p); 436 } 437 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) { 438 PROC_SLOCK(p); 439 if (itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0) 440 flags |= TDF_PROFPEND | TDF_ASTPENDING; 441 PROC_SUNLOCK(p); 442 } 443 thread_lock(td); 444 sched_tick(1); 445 td->td_flags |= flags; 446 thread_unlock(td); 447 448 #ifdef HWPMC_HOOKS 449 if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid))) 450 PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL); 451 #endif 452 callout_tick(); 453 } 454 455 /* 456 * The real-time timer, interrupting hz times per second. 457 */ 458 void 459 hardclock(int usermode, uintfptr_t pc) 460 { 461 462 atomic_add_int((volatile int *)&ticks, 1); 463 hardclock_cpu(usermode); 464 tc_ticktock(1); 465 cpu_tick_calibration(); 466 /* 467 * If no separate statistics clock is available, run it from here. 468 * 469 * XXX: this only works for UP 470 */ 471 if (stathz == 0) { 472 profclock(usermode, pc); 473 statclock(usermode); 474 } 475 #ifdef DEVICE_POLLING 476 hardclock_device_poll(); /* this is very short and quick */ 477 #endif /* DEVICE_POLLING */ 478 #ifdef SW_WATCHDOG 479 if (watchdog_enabled > 0 && --watchdog_ticks <= 0) 480 watchdog_fire(); 481 #endif /* SW_WATCHDOG */ 482 } 483 484 void 485 hardclock_anycpu(int cnt, int usermode) 486 { 487 struct pstats *pstats; 488 struct thread *td = curthread; 489 struct proc *p = td->td_proc; 490 int *t = DPCPU_PTR(pcputicks); 491 int flags, global, newticks; 492 #ifdef SW_WATCHDOG 493 int i; 494 #endif /* SW_WATCHDOG */ 495 496 /* 497 * Update per-CPU and possibly global ticks values. 498 */ 499 *t += cnt; 500 do { 501 global = ticks; 502 newticks = *t - global; 503 if (newticks <= 0) { 504 if (newticks < -1) 505 *t = global - 1; 506 newticks = 0; 507 break; 508 } 509 } while (!atomic_cmpset_int(&ticks, global, *t)); 510 511 /* 512 * Run current process's virtual and profile time, as needed. 513 */ 514 pstats = p->p_stats; 515 flags = 0; 516 if (usermode && 517 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) { 518 PROC_SLOCK(p); 519 if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], 520 tick * cnt) == 0) 521 flags |= TDF_ALRMPEND | TDF_ASTPENDING; 522 PROC_SUNLOCK(p); 523 } 524 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) { 525 PROC_SLOCK(p); 526 if (itimerdecr(&pstats->p_timer[ITIMER_PROF], 527 tick * cnt) == 0) 528 flags |= TDF_PROFPEND | TDF_ASTPENDING; 529 PROC_SUNLOCK(p); 530 } 531 thread_lock(td); 532 sched_tick(cnt); 533 td->td_flags |= flags; 534 thread_unlock(td); 535 536 #ifdef HWPMC_HOOKS 537 if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid))) 538 PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL); 539 #endif 540 callout_tick(); 541 /* We are in charge to handle this tick duty. */ 542 if (newticks > 0) { 543 /* Dangerous and no need to call these things concurrently. */ 544 if (atomic_cmpset_acq_int(&global_hardclock_run, 0, 1)) { 545 tc_ticktock(newticks); 546 #ifdef DEVICE_POLLING 547 /* This is very short and quick. */ 548 hardclock_device_poll(); 549 #endif /* DEVICE_POLLING */ 550 atomic_store_rel_int(&global_hardclock_run, 0); 551 } 552 #ifdef SW_WATCHDOG 553 if (watchdog_enabled > 0) { 554 i = atomic_fetchadd_int(&watchdog_ticks, -newticks); 555 if (i > 0 && i <= newticks) 556 watchdog_fire(); 557 } 558 #endif /* SW_WATCHDOG */ 559 } 560 if (curcpu == CPU_FIRST()) 561 cpu_tick_calibration(); 562 } 563 564 void 565 hardclock_sync(int cpu) 566 { 567 int *t = DPCPU_ID_PTR(cpu, pcputicks); 568 569 *t = ticks; 570 } 571 572 /* 573 * Compute number of ticks in the specified amount of time. 574 */ 575 int 576 tvtohz(tv) 577 struct timeval *tv; 578 { 579 register unsigned long ticks; 580 register long sec, usec; 581 582 /* 583 * If the number of usecs in the whole seconds part of the time 584 * difference fits in a long, then the total number of usecs will 585 * fit in an unsigned long. Compute the total and convert it to 586 * ticks, rounding up and adding 1 to allow for the current tick 587 * to expire. Rounding also depends on unsigned long arithmetic 588 * to avoid overflow. 589 * 590 * Otherwise, if the number of ticks in the whole seconds part of 591 * the time difference fits in a long, then convert the parts to 592 * ticks separately and add, using similar rounding methods and 593 * overflow avoidance. This method would work in the previous 594 * case but it is slightly slower and assumes that hz is integral. 595 * 596 * Otherwise, round the time difference down to the maximum 597 * representable value. 598 * 599 * If ints have 32 bits, then the maximum value for any timeout in 600 * 10ms ticks is 248 days. 601 */ 602 sec = tv->tv_sec; 603 usec = tv->tv_usec; 604 if (usec < 0) { 605 sec--; 606 usec += 1000000; 607 } 608 if (sec < 0) { 609 #ifdef DIAGNOSTIC 610 if (usec > 0) { 611 sec++; 612 usec -= 1000000; 613 } 614 printf("tvotohz: negative time difference %ld sec %ld usec\n", 615 sec, usec); 616 #endif 617 ticks = 1; 618 } else if (sec <= LONG_MAX / 1000000) 619 ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1)) 620 / tick + 1; 621 else if (sec <= LONG_MAX / hz) 622 ticks = sec * hz 623 + ((unsigned long)usec + (tick - 1)) / tick + 1; 624 else 625 ticks = LONG_MAX; 626 if (ticks > INT_MAX) 627 ticks = INT_MAX; 628 return ((int)ticks); 629 } 630 631 /* 632 * Start profiling on a process. 633 * 634 * Kernel profiling passes proc0 which never exits and hence 635 * keeps the profile clock running constantly. 636 */ 637 void 638 startprofclock(p) 639 register struct proc *p; 640 { 641 642 PROC_LOCK_ASSERT(p, MA_OWNED); 643 if (p->p_flag & P_STOPPROF) 644 return; 645 if ((p->p_flag & P_PROFIL) == 0) { 646 p->p_flag |= P_PROFIL; 647 mtx_lock(&time_lock); 648 if (++profprocs == 1) 649 cpu_startprofclock(); 650 mtx_unlock(&time_lock); 651 } 652 } 653 654 /* 655 * Stop profiling on a process. 656 */ 657 void 658 stopprofclock(p) 659 register struct proc *p; 660 { 661 662 PROC_LOCK_ASSERT(p, MA_OWNED); 663 if (p->p_flag & P_PROFIL) { 664 if (p->p_profthreads != 0) { 665 p->p_flag |= P_STOPPROF; 666 while (p->p_profthreads != 0) 667 msleep(&p->p_profthreads, &p->p_mtx, PPAUSE, 668 "stopprof", 0); 669 p->p_flag &= ~P_STOPPROF; 670 } 671 if ((p->p_flag & P_PROFIL) == 0) 672 return; 673 p->p_flag &= ~P_PROFIL; 674 mtx_lock(&time_lock); 675 if (--profprocs == 0) 676 cpu_stopprofclock(); 677 mtx_unlock(&time_lock); 678 } 679 } 680 681 /* 682 * Statistics clock. Updates rusage information and calls the scheduler 683 * to adjust priorities of the active thread. 684 * 685 * This should be called by all active processors. 686 */ 687 void 688 statclock(int usermode) 689 { 690 struct rusage *ru; 691 struct vmspace *vm; 692 struct thread *td; 693 struct proc *p; 694 long rss; 695 long *cp_time; 696 697 td = curthread; 698 p = td->td_proc; 699 700 cp_time = (long *)PCPU_PTR(cp_time); 701 if (usermode) { 702 /* 703 * Charge the time as appropriate. 704 */ 705 td->td_uticks++; 706 if (p->p_nice > NZERO) 707 cp_time[CP_NICE]++; 708 else 709 cp_time[CP_USER]++; 710 } else { 711 /* 712 * Came from kernel mode, so we were: 713 * - handling an interrupt, 714 * - doing syscall or trap work on behalf of the current 715 * user process, or 716 * - spinning in the idle loop. 717 * Whichever it is, charge the time as appropriate. 718 * Note that we charge interrupts to the current process, 719 * regardless of whether they are ``for'' that process, 720 * so that we know how much of its real time was spent 721 * in ``non-process'' (i.e., interrupt) work. 722 */ 723 if ((td->td_pflags & TDP_ITHREAD) || 724 td->td_intr_nesting_level >= 2) { 725 td->td_iticks++; 726 cp_time[CP_INTR]++; 727 } else { 728 td->td_pticks++; 729 td->td_sticks++; 730 if (!TD_IS_IDLETHREAD(td)) 731 cp_time[CP_SYS]++; 732 else 733 cp_time[CP_IDLE]++; 734 } 735 } 736 737 /* Update resource usage integrals and maximums. */ 738 MPASS(p->p_vmspace != NULL); 739 vm = p->p_vmspace; 740 ru = &td->td_ru; 741 ru->ru_ixrss += pgtok(vm->vm_tsize); 742 ru->ru_idrss += pgtok(vm->vm_dsize); 743 ru->ru_isrss += pgtok(vm->vm_ssize); 744 rss = pgtok(vmspace_resident_count(vm)); 745 if (ru->ru_maxrss < rss) 746 ru->ru_maxrss = rss; 747 KTR_POINT2(KTR_SCHED, "thread", sched_tdname(td), "statclock", 748 "prio:%d", td->td_priority, "stathz:%d", (stathz)?stathz:hz); 749 thread_lock_flags(td, MTX_QUIET); 750 sched_clock(td); 751 thread_unlock(td); 752 } 753 754 void 755 profclock(int usermode, uintfptr_t pc) 756 { 757 struct thread *td; 758 #ifdef GPROF 759 struct gmonparam *g; 760 uintfptr_t i; 761 #endif 762 763 td = curthread; 764 if (usermode) { 765 /* 766 * Came from user mode; CPU was in user state. 767 * If this process is being profiled, record the tick. 768 * if there is no related user location yet, don't 769 * bother trying to count it. 770 */ 771 if (td->td_proc->p_flag & P_PROFIL) 772 addupc_intr(td, pc, 1); 773 } 774 #ifdef GPROF 775 else { 776 /* 777 * Kernel statistics are just like addupc_intr, only easier. 778 */ 779 g = &_gmonparam; 780 if (g->state == GMON_PROF_ON && pc >= g->lowpc) { 781 i = PC_TO_I(g, pc); 782 if (i < g->textsize) { 783 KCOUNT(g, i)++; 784 } 785 } 786 } 787 #endif 788 } 789 790 /* 791 * Return information about system clocks. 792 */ 793 static int 794 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS) 795 { 796 struct clockinfo clkinfo; 797 /* 798 * Construct clockinfo structure. 799 */ 800 bzero(&clkinfo, sizeof(clkinfo)); 801 clkinfo.hz = hz; 802 clkinfo.tick = tick; 803 clkinfo.profhz = profhz; 804 clkinfo.stathz = stathz ? stathz : hz; 805 return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req)); 806 } 807 808 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, 809 CTLTYPE_STRUCT|CTLFLAG_RD|CTLFLAG_MPSAFE, 810 0, 0, sysctl_kern_clockrate, "S,clockinfo", 811 "Rate and period of various kernel clocks"); 812 813 #ifdef SW_WATCHDOG 814 815 static void 816 watchdog_config(void *unused __unused, u_int cmd, int *error) 817 { 818 u_int u; 819 820 u = cmd & WD_INTERVAL; 821 if (u >= WD_TO_1SEC) { 822 watchdog_ticks = (1 << (u - WD_TO_1SEC)) * hz; 823 watchdog_enabled = 1; 824 *error = 0; 825 } else { 826 watchdog_enabled = 0; 827 } 828 } 829 830 /* 831 * Handle a watchdog timeout by dumping interrupt information and 832 * then either dropping to DDB or panicking. 833 */ 834 static void 835 watchdog_fire(void) 836 { 837 int nintr; 838 uint64_t inttotal; 839 u_long *curintr; 840 char *curname; 841 842 curintr = intrcnt; 843 curname = intrnames; 844 inttotal = 0; 845 nintr = sintrcnt / sizeof(u_long); 846 847 printf("interrupt total\n"); 848 while (--nintr >= 0) { 849 if (*curintr) 850 printf("%-12s %20lu\n", curname, *curintr); 851 curname += strlen(curname) + 1; 852 inttotal += *curintr++; 853 } 854 printf("Total %20ju\n", (uintmax_t)inttotal); 855 856 #if defined(KDB) && !defined(KDB_UNATTENDED) 857 kdb_backtrace(); 858 kdb_enter(KDB_WHY_WATCHDOG, "watchdog timeout"); 859 #else 860 panic("watchdog timeout"); 861 #endif 862 } 863 864 #endif /* SW_WATCHDOG */
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