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/9.1/sys/kern/kern_clock.c 236344 2012-05-30 23:22:52Z rstone $"); 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 PMC_SOFT_DEFINE( , , clock, hard); 80 PMC_SOFT_DEFINE( , , clock, stat); 81 #endif 82 83 #ifdef DEVICE_POLLING 84 extern void hardclock_device_poll(void); 85 #endif /* DEVICE_POLLING */ 86 87 static void initclocks(void *dummy); 88 SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL); 89 90 /* Spin-lock protecting profiling statistics. */ 91 static struct mtx time_lock; 92 93 SDT_PROVIDER_DECLARE(sched); 94 SDT_PROBE_DEFINE2(sched, , , tick, tick, "struct thread *", "struct proc *"); 95 96 static int 97 sysctl_kern_cp_time(SYSCTL_HANDLER_ARGS) 98 { 99 int error; 100 long cp_time[CPUSTATES]; 101 #ifdef SCTL_MASK32 102 int i; 103 unsigned int cp_time32[CPUSTATES]; 104 #endif 105 106 read_cpu_time(cp_time); 107 #ifdef SCTL_MASK32 108 if (req->flags & SCTL_MASK32) { 109 if (!req->oldptr) 110 return SYSCTL_OUT(req, 0, sizeof(cp_time32)); 111 for (i = 0; i < CPUSTATES; i++) 112 cp_time32[i] = (unsigned int)cp_time[i]; 113 error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32)); 114 } else 115 #endif 116 { 117 if (!req->oldptr) 118 return SYSCTL_OUT(req, 0, sizeof(cp_time)); 119 error = SYSCTL_OUT(req, cp_time, sizeof(cp_time)); 120 } 121 return error; 122 } 123 124 SYSCTL_PROC(_kern, OID_AUTO, cp_time, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE, 125 0,0, sysctl_kern_cp_time, "LU", "CPU time statistics"); 126 127 static long empty[CPUSTATES]; 128 129 static int 130 sysctl_kern_cp_times(SYSCTL_HANDLER_ARGS) 131 { 132 struct pcpu *pcpu; 133 int error; 134 int c; 135 long *cp_time; 136 #ifdef SCTL_MASK32 137 unsigned int cp_time32[CPUSTATES]; 138 int i; 139 #endif 140 141 if (!req->oldptr) { 142 #ifdef SCTL_MASK32 143 if (req->flags & SCTL_MASK32) 144 return SYSCTL_OUT(req, 0, sizeof(cp_time32) * (mp_maxid + 1)); 145 else 146 #endif 147 return SYSCTL_OUT(req, 0, sizeof(long) * CPUSTATES * (mp_maxid + 1)); 148 } 149 for (error = 0, c = 0; error == 0 && c <= mp_maxid; c++) { 150 if (!CPU_ABSENT(c)) { 151 pcpu = pcpu_find(c); 152 cp_time = pcpu->pc_cp_time; 153 } else { 154 cp_time = empty; 155 } 156 #ifdef SCTL_MASK32 157 if (req->flags & SCTL_MASK32) { 158 for (i = 0; i < CPUSTATES; i++) 159 cp_time32[i] = (unsigned int)cp_time[i]; 160 error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32)); 161 } else 162 #endif 163 error = SYSCTL_OUT(req, cp_time, sizeof(long) * CPUSTATES); 164 } 165 return error; 166 } 167 168 SYSCTL_PROC(_kern, OID_AUTO, cp_times, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE, 169 0,0, sysctl_kern_cp_times, "LU", "per-CPU time statistics"); 170 171 #ifdef DEADLKRES 172 static const char *blessed[] = { 173 "getblk", 174 "so_snd_sx", 175 "so_rcv_sx", 176 NULL 177 }; 178 static int slptime_threshold = 1800; 179 static int blktime_threshold = 900; 180 static int sleepfreq = 3; 181 182 static void 183 deadlkres(void) 184 { 185 struct proc *p; 186 struct thread *td; 187 void *wchan; 188 int blkticks, i, slpticks, slptype, tryl, tticks; 189 190 tryl = 0; 191 for (;;) { 192 blkticks = blktime_threshold * hz; 193 slpticks = slptime_threshold * hz; 194 195 /* 196 * Avoid to sleep on the sx_lock in order to avoid a possible 197 * priority inversion problem leading to starvation. 198 * If the lock can't be held after 100 tries, panic. 199 */ 200 if (!sx_try_slock(&allproc_lock)) { 201 if (tryl > 100) 202 panic("%s: possible deadlock detected on allproc_lock\n", 203 __func__); 204 tryl++; 205 pause("allproc", sleepfreq * hz); 206 continue; 207 } 208 tryl = 0; 209 FOREACH_PROC_IN_SYSTEM(p) { 210 PROC_LOCK(p); 211 if (p->p_state == PRS_NEW) { 212 PROC_UNLOCK(p); 213 continue; 214 } 215 FOREACH_THREAD_IN_PROC(p, td) { 216 217 /* 218 * Once a thread is found in "interesting" 219 * state a possible ticks wrap-up needs to be 220 * checked. 221 */ 222 thread_lock(td); 223 if (TD_ON_LOCK(td) && ticks < td->td_blktick) { 224 225 /* 226 * The thread should be blocked on a 227 * turnstile, simply check if the 228 * turnstile channel is in good state. 229 */ 230 MPASS(td->td_blocked != NULL); 231 232 tticks = ticks - td->td_blktick; 233 thread_unlock(td); 234 if (tticks > blkticks) { 235 236 /* 237 * Accordingly with provided 238 * thresholds, this thread is 239 * stuck for too long on a 240 * turnstile. 241 */ 242 PROC_UNLOCK(p); 243 sx_sunlock(&allproc_lock); 244 panic("%s: possible deadlock detected for %p, blocked for %d ticks\n", 245 __func__, td, tticks); 246 } 247 } else if (TD_IS_SLEEPING(td) && 248 TD_ON_SLEEPQ(td) && 249 ticks < td->td_blktick) { 250 251 /* 252 * Check if the thread is sleeping on a 253 * lock, otherwise skip the check. 254 * Drop the thread lock in order to 255 * avoid a LOR with the sleepqueue 256 * spinlock. 257 */ 258 wchan = td->td_wchan; 259 tticks = ticks - td->td_slptick; 260 thread_unlock(td); 261 slptype = sleepq_type(wchan); 262 if ((slptype == SLEEPQ_SX || 263 slptype == SLEEPQ_LK) && 264 tticks > slpticks) { 265 266 /* 267 * Accordingly with provided 268 * thresholds, this thread is 269 * stuck for too long on a 270 * sleepqueue. 271 * However, being on a 272 * sleepqueue, we might still 273 * check for the blessed 274 * list. 275 */ 276 tryl = 0; 277 for (i = 0; blessed[i] != NULL; 278 i++) { 279 if (!strcmp(blessed[i], 280 td->td_wmesg)) { 281 tryl = 1; 282 break; 283 } 284 } 285 if (tryl != 0) { 286 tryl = 0; 287 continue; 288 } 289 PROC_UNLOCK(p); 290 sx_sunlock(&allproc_lock); 291 panic("%s: possible deadlock detected for %p, blocked for %d ticks\n", 292 __func__, td, tticks); 293 } 294 } else 295 thread_unlock(td); 296 } 297 PROC_UNLOCK(p); 298 } 299 sx_sunlock(&allproc_lock); 300 301 /* Sleep for sleepfreq seconds. */ 302 pause("-", sleepfreq * hz); 303 } 304 } 305 306 static struct kthread_desc deadlkres_kd = { 307 "deadlkres", 308 deadlkres, 309 (struct thread **)NULL 310 }; 311 312 SYSINIT(deadlkres, SI_SUB_CLOCKS, SI_ORDER_ANY, kthread_start, &deadlkres_kd); 313 314 SYSCTL_NODE(_debug, OID_AUTO, deadlkres, CTLFLAG_RW, 0, "Deadlock resolver"); 315 SYSCTL_INT(_debug_deadlkres, OID_AUTO, slptime_threshold, CTLFLAG_RW, 316 &slptime_threshold, 0, 317 "Number of seconds within is valid to sleep on a sleepqueue"); 318 SYSCTL_INT(_debug_deadlkres, OID_AUTO, blktime_threshold, CTLFLAG_RW, 319 &blktime_threshold, 0, 320 "Number of seconds within is valid to block on a turnstile"); 321 SYSCTL_INT(_debug_deadlkres, OID_AUTO, sleepfreq, CTLFLAG_RW, &sleepfreq, 0, 322 "Number of seconds between any deadlock resolver thread run"); 323 #endif /* DEADLKRES */ 324 325 void 326 read_cpu_time(long *cp_time) 327 { 328 struct pcpu *pc; 329 int i, j; 330 331 /* Sum up global cp_time[]. */ 332 bzero(cp_time, sizeof(long) * CPUSTATES); 333 CPU_FOREACH(i) { 334 pc = pcpu_find(i); 335 for (j = 0; j < CPUSTATES; j++) 336 cp_time[j] += pc->pc_cp_time[j]; 337 } 338 } 339 340 #ifdef SW_WATCHDOG 341 #include <sys/watchdog.h> 342 343 static int watchdog_ticks; 344 static int watchdog_enabled; 345 static void watchdog_fire(void); 346 static void watchdog_config(void *, u_int, int *); 347 #endif /* SW_WATCHDOG */ 348 349 /* 350 * Clock handling routines. 351 * 352 * This code is written to operate with two timers that run independently of 353 * each other. 354 * 355 * The main timer, running hz times per second, is used to trigger interval 356 * timers, timeouts and rescheduling as needed. 357 * 358 * The second timer handles kernel and user profiling, 359 * and does resource use estimation. If the second timer is programmable, 360 * it is randomized to avoid aliasing between the two clocks. For example, 361 * the randomization prevents an adversary from always giving up the cpu 362 * just before its quantum expires. Otherwise, it would never accumulate 363 * cpu ticks. The mean frequency of the second timer is stathz. 364 * 365 * If no second timer exists, stathz will be zero; in this case we drive 366 * profiling and statistics off the main clock. This WILL NOT be accurate; 367 * do not do it unless absolutely necessary. 368 * 369 * The statistics clock may (or may not) be run at a higher rate while 370 * profiling. This profile clock runs at profhz. We require that profhz 371 * be an integral multiple of stathz. 372 * 373 * If the statistics clock is running fast, it must be divided by the ratio 374 * profhz/stathz for statistics. (For profiling, every tick counts.) 375 * 376 * Time-of-day is maintained using a "timecounter", which may or may 377 * not be related to the hardware generating the above mentioned 378 * interrupts. 379 */ 380 381 int stathz; 382 int profhz; 383 int profprocs; 384 int ticks; 385 int psratio; 386 387 static DPCPU_DEFINE(int, pcputicks); /* Per-CPU version of ticks. */ 388 static int global_hardclock_run = 0; 389 390 /* 391 * Initialize clock frequencies and start both clocks running. 392 */ 393 /* ARGSUSED*/ 394 static void 395 initclocks(dummy) 396 void *dummy; 397 { 398 register 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 #ifdef SW_WATCHDOG 415 EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0); 416 #endif 417 } 418 419 /* 420 * Each time the real-time timer fires, this function is called on all CPUs. 421 * Note that hardclock() calls hardclock_cpu() for the boot CPU, so only 422 * the other CPUs in the system need to call this function. 423 */ 424 void 425 hardclock_cpu(int usermode) 426 { 427 struct pstats *pstats; 428 struct thread *td = curthread; 429 struct proc *p = td->td_proc; 430 int flags; 431 432 /* 433 * Run current process's virtual and profile time, as needed. 434 */ 435 pstats = p->p_stats; 436 flags = 0; 437 if (usermode && 438 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) { 439 PROC_SLOCK(p); 440 if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0) 441 flags |= TDF_ALRMPEND | TDF_ASTPENDING; 442 PROC_SUNLOCK(p); 443 } 444 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) { 445 PROC_SLOCK(p); 446 if (itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0) 447 flags |= TDF_PROFPEND | TDF_ASTPENDING; 448 PROC_SUNLOCK(p); 449 } 450 thread_lock(td); 451 sched_tick(1); 452 td->td_flags |= flags; 453 thread_unlock(td); 454 455 #ifdef HWPMC_HOOKS 456 if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid))) 457 PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL); 458 if (td->td_intr_frame != NULL) 459 PMC_SOFT_CALL_TF( , , clock, hard, td->td_intr_frame); 460 #endif 461 callout_tick(); 462 } 463 464 /* 465 * The real-time timer, interrupting hz times per second. 466 */ 467 void 468 hardclock(int usermode, uintfptr_t pc) 469 { 470 471 atomic_add_int((volatile int *)&ticks, 1); 472 hardclock_cpu(usermode); 473 tc_ticktock(1); 474 cpu_tick_calibration(); 475 /* 476 * If no separate statistics clock is available, run it from here. 477 * 478 * XXX: this only works for UP 479 */ 480 if (stathz == 0) { 481 profclock(usermode, pc); 482 statclock(usermode); 483 } 484 #ifdef DEVICE_POLLING 485 hardclock_device_poll(); /* this is very short and quick */ 486 #endif /* DEVICE_POLLING */ 487 #ifdef SW_WATCHDOG 488 if (watchdog_enabled > 0 && --watchdog_ticks <= 0) 489 watchdog_fire(); 490 #endif /* SW_WATCHDOG */ 491 } 492 493 void 494 hardclock_cnt(int cnt, int usermode) 495 { 496 struct pstats *pstats; 497 struct thread *td = curthread; 498 struct proc *p = td->td_proc; 499 int *t = DPCPU_PTR(pcputicks); 500 int flags, global, newticks; 501 #ifdef SW_WATCHDOG 502 int i; 503 #endif /* SW_WATCHDOG */ 504 505 /* 506 * Update per-CPU and possibly global ticks values. 507 */ 508 *t += cnt; 509 do { 510 global = ticks; 511 newticks = *t - global; 512 if (newticks <= 0) { 513 if (newticks < -1) 514 *t = global - 1; 515 newticks = 0; 516 break; 517 } 518 } while (!atomic_cmpset_int(&ticks, global, *t)); 519 520 /* 521 * Run current process's virtual and profile time, as needed. 522 */ 523 pstats = p->p_stats; 524 flags = 0; 525 if (usermode && 526 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) { 527 PROC_SLOCK(p); 528 if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], 529 tick * cnt) == 0) 530 flags |= TDF_ALRMPEND | TDF_ASTPENDING; 531 PROC_SUNLOCK(p); 532 } 533 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) { 534 PROC_SLOCK(p); 535 if (itimerdecr(&pstats->p_timer[ITIMER_PROF], 536 tick * cnt) == 0) 537 flags |= TDF_PROFPEND | TDF_ASTPENDING; 538 PROC_SUNLOCK(p); 539 } 540 thread_lock(td); 541 sched_tick(cnt); 542 td->td_flags |= flags; 543 thread_unlock(td); 544 545 #ifdef HWPMC_HOOKS 546 if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid))) 547 PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL); 548 if (td->td_intr_frame != NULL) 549 PMC_SOFT_CALL_TF( , , clock, hard, td->td_intr_frame); 550 #endif 551 callout_tick(); 552 /* We are in charge to handle this tick duty. */ 553 if (newticks > 0) { 554 /* Dangerous and no need to call these things concurrently. */ 555 if (atomic_cmpset_acq_int(&global_hardclock_run, 0, 1)) { 556 tc_ticktock(newticks); 557 #ifdef DEVICE_POLLING 558 /* This is very short and quick. */ 559 hardclock_device_poll(); 560 #endif /* DEVICE_POLLING */ 561 atomic_store_rel_int(&global_hardclock_run, 0); 562 } 563 #ifdef SW_WATCHDOG 564 if (watchdog_enabled > 0) { 565 i = atomic_fetchadd_int(&watchdog_ticks, -newticks); 566 if (i > 0 && i <= newticks) 567 watchdog_fire(); 568 } 569 #endif /* SW_WATCHDOG */ 570 } 571 if (curcpu == CPU_FIRST()) 572 cpu_tick_calibration(); 573 } 574 575 void 576 hardclock_sync(int cpu) 577 { 578 int *t = DPCPU_ID_PTR(cpu, pcputicks); 579 580 *t = ticks; 581 } 582 583 /* 584 * Compute number of ticks in the specified amount of time. 585 */ 586 int 587 tvtohz(tv) 588 struct timeval *tv; 589 { 590 register unsigned long ticks; 591 register long sec, usec; 592 593 /* 594 * If the number of usecs in the whole seconds part of the time 595 * difference fits in a long, then the total number of usecs will 596 * fit in an unsigned long. Compute the total and convert it to 597 * ticks, rounding up and adding 1 to allow for the current tick 598 * to expire. Rounding also depends on unsigned long arithmetic 599 * to avoid overflow. 600 * 601 * Otherwise, if the number of ticks in the whole seconds part of 602 * the time difference fits in a long, then convert the parts to 603 * ticks separately and add, using similar rounding methods and 604 * overflow avoidance. This method would work in the previous 605 * case but it is slightly slower and assumes that hz is integral. 606 * 607 * Otherwise, round the time difference down to the maximum 608 * representable value. 609 * 610 * If ints have 32 bits, then the maximum value for any timeout in 611 * 10ms ticks is 248 days. 612 */ 613 sec = tv->tv_sec; 614 usec = tv->tv_usec; 615 if (usec < 0) { 616 sec--; 617 usec += 1000000; 618 } 619 if (sec < 0) { 620 #ifdef DIAGNOSTIC 621 if (usec > 0) { 622 sec++; 623 usec -= 1000000; 624 } 625 printf("tvotohz: negative time difference %ld sec %ld usec\n", 626 sec, usec); 627 #endif 628 ticks = 1; 629 } else if (sec <= LONG_MAX / 1000000) 630 ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1)) 631 / tick + 1; 632 else if (sec <= LONG_MAX / hz) 633 ticks = sec * hz 634 + ((unsigned long)usec + (tick - 1)) / tick + 1; 635 else 636 ticks = LONG_MAX; 637 if (ticks > INT_MAX) 638 ticks = INT_MAX; 639 return ((int)ticks); 640 } 641 642 /* 643 * Start profiling on a process. 644 * 645 * Kernel profiling passes proc0 which never exits and hence 646 * keeps the profile clock running constantly. 647 */ 648 void 649 startprofclock(p) 650 register struct proc *p; 651 { 652 653 PROC_LOCK_ASSERT(p, MA_OWNED); 654 if (p->p_flag & P_STOPPROF) 655 return; 656 if ((p->p_flag & P_PROFIL) == 0) { 657 p->p_flag |= P_PROFIL; 658 mtx_lock(&time_lock); 659 if (++profprocs == 1) 660 cpu_startprofclock(); 661 mtx_unlock(&time_lock); 662 } 663 } 664 665 /* 666 * Stop profiling on a process. 667 */ 668 void 669 stopprofclock(p) 670 register 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 p->p_flag |= P_STOPPROF; 677 while (p->p_profthreads != 0) 678 msleep(&p->p_profthreads, &p->p_mtx, PPAUSE, 679 "stopprof", 0); 680 p->p_flag &= ~P_STOPPROF; 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 } 820 821 /* 822 * Return information about system clocks. 823 */ 824 static int 825 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS) 826 { 827 struct clockinfo clkinfo; 828 /* 829 * Construct clockinfo structure. 830 */ 831 bzero(&clkinfo, sizeof(clkinfo)); 832 clkinfo.hz = hz; 833 clkinfo.tick = tick; 834 clkinfo.profhz = profhz; 835 clkinfo.stathz = stathz ? stathz : hz; 836 return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req)); 837 } 838 839 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, 840 CTLTYPE_STRUCT|CTLFLAG_RD|CTLFLAG_MPSAFE, 841 0, 0, sysctl_kern_clockrate, "S,clockinfo", 842 "Rate and period of various kernel clocks"); 843 844 #ifdef SW_WATCHDOG 845 846 static void 847 watchdog_config(void *unused __unused, u_int cmd, int *error) 848 { 849 u_int u; 850 851 u = cmd & WD_INTERVAL; 852 if (u >= WD_TO_1SEC) { 853 watchdog_ticks = (1 << (u - WD_TO_1SEC)) * hz; 854 watchdog_enabled = 1; 855 *error = 0; 856 } else { 857 watchdog_enabled = 0; 858 } 859 } 860 861 /* 862 * Handle a watchdog timeout by dumping interrupt information and 863 * then either dropping to DDB or panicking. 864 */ 865 static void 866 watchdog_fire(void) 867 { 868 int nintr; 869 uint64_t inttotal; 870 u_long *curintr; 871 char *curname; 872 873 curintr = intrcnt; 874 curname = intrnames; 875 inttotal = 0; 876 nintr = sintrcnt / sizeof(u_long); 877 878 printf("interrupt total\n"); 879 while (--nintr >= 0) { 880 if (*curintr) 881 printf("%-12s %20lu\n", curname, *curintr); 882 curname += strlen(curname) + 1; 883 inttotal += *curintr++; 884 } 885 printf("Total %20ju\n", (uintmax_t)inttotal); 886 887 #if defined(KDB) && !defined(KDB_UNATTENDED) 888 kdb_backtrace(); 889 kdb_enter(KDB_WHY_WATCHDOG, "watchdog timeout"); 890 #else 891 panic("watchdog timeout"); 892 #endif 893 } 894 895 #endif /* SW_WATCHDOG */
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