1 /*- 2 * Copyright (c) 1982, 1986, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_hwpmc_hooks.h" 41 #include "opt_ntp.h" 42 #include "opt_watchdog.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/callout.h> 47 #include <sys/kdb.h> 48 #include <sys/kernel.h> 49 #include <sys/lock.h> 50 #include <sys/ktr.h> 51 #include <sys/mutex.h> 52 #include <sys/proc.h> 53 #include <sys/resource.h> 54 #include <sys/resourcevar.h> 55 #include <sys/sched.h> 56 #include <sys/signalvar.h> 57 #include <sys/smp.h> 58 #include <vm/vm.h> 59 #include <vm/pmap.h> 60 #include <vm/vm_map.h> 61 #include <sys/sysctl.h> 62 #include <sys/bus.h> 63 #include <sys/interrupt.h> 64 #include <sys/limits.h> 65 #include <sys/timetc.h> 66 67 #include <machine/cpu.h> 68 69 #ifdef GPROF 70 #include <sys/gmon.h> 71 #endif 72 73 #ifdef HWPMC_HOOKS 74 #include <sys/pmckern.h> 75 #endif 76 77 #ifdef DEVICE_POLLING 78 extern void hardclock_device_poll(void); 79 #endif /* DEVICE_POLLING */ 80 81 static void initclocks(void *dummy); 82 SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL) 83 84 /* Some of these don't belong here, but it's easiest to concentrate them. */ 85 long cp_time[CPUSTATES]; 86 87 static int 88 sysctl_kern_cp_time(SYSCTL_HANDLER_ARGS) 89 { 90 int error; 91 #ifdef SCTL_MASK32 92 int i; 93 unsigned int cp_time32[CPUSTATES]; 94 95 if (req->flags & SCTL_MASK32) { 96 if (!req->oldptr) 97 return SYSCTL_OUT(req, 0, sizeof(cp_time32)); 98 for (i = 0; i < CPUSTATES; i++) 99 cp_time32[i] = (unsigned int)cp_time[i]; 100 error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32)); 101 } else 102 #endif 103 { 104 if (!req->oldptr) 105 return SYSCTL_OUT(req, 0, sizeof(cp_time)); 106 error = SYSCTL_OUT(req, cp_time, sizeof(cp_time)); 107 } 108 return error; 109 } 110 111 SYSCTL_PROC(_kern, OID_AUTO, cp_time, CTLTYPE_LONG|CTLFLAG_RD, 112 0,0, sysctl_kern_cp_time, "LU", "CPU time statistics"); 113 114 #ifdef SW_WATCHDOG 115 #include <sys/watchdog.h> 116 117 static int watchdog_ticks; 118 static int watchdog_enabled; 119 static void watchdog_fire(void); 120 static void watchdog_config(void *, u_int, int *); 121 #endif /* SW_WATCHDOG */ 122 123 /* 124 * Clock handling routines. 125 * 126 * This code is written to operate with two timers that run independently of 127 * each other. 128 * 129 * The main timer, running hz times per second, is used to trigger interval 130 * timers, timeouts and rescheduling as needed. 131 * 132 * The second timer handles kernel and user profiling, 133 * and does resource use estimation. If the second timer is programmable, 134 * it is randomized to avoid aliasing between the two clocks. For example, 135 * the randomization prevents an adversary from always giving up the cpu 136 * just before its quantum expires. Otherwise, it would never accumulate 137 * cpu ticks. The mean frequency of the second timer is stathz. 138 * 139 * If no second timer exists, stathz will be zero; in this case we drive 140 * profiling and statistics off the main clock. This WILL NOT be accurate; 141 * do not do it unless absolutely necessary. 142 * 143 * The statistics clock may (or may not) be run at a higher rate while 144 * profiling. This profile clock runs at profhz. We require that profhz 145 * be an integral multiple of stathz. 146 * 147 * If the statistics clock is running fast, it must be divided by the ratio 148 * profhz/stathz for statistics. (For profiling, every tick counts.) 149 * 150 * Time-of-day is maintained using a "timecounter", which may or may 151 * not be related to the hardware generating the above mentioned 152 * interrupts. 153 */ 154 155 int stathz; 156 int profhz; 157 int profprocs; 158 int ticks; 159 int psratio; 160 161 /* 162 * Initialize clock frequencies and start both clocks running. 163 */ 164 /* ARGSUSED*/ 165 static void 166 initclocks(dummy) 167 void *dummy; 168 { 169 register int i; 170 171 /* 172 * Set divisors to 1 (normal case) and let the machine-specific 173 * code do its bit. 174 */ 175 cpu_initclocks(); 176 177 /* 178 * Compute profhz/stathz, and fix profhz if needed. 179 */ 180 i = stathz ? stathz : hz; 181 if (profhz == 0) 182 profhz = i; 183 psratio = profhz / i; 184 #ifdef SW_WATCHDOG 185 EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0); 186 #endif 187 } 188 189 /* 190 * Each time the real-time timer fires, this function is called on all CPUs. 191 * Note that hardclock() calls hardclock_process() for the boot CPU, so only 192 * the other CPUs in the system need to call this function. 193 */ 194 void 195 hardclock_process(frame) 196 register struct clockframe *frame; 197 { 198 struct pstats *pstats; 199 struct thread *td = curthread; 200 struct proc *p = td->td_proc; 201 202 /* 203 * Run current process's virtual and profile time, as needed. 204 */ 205 mtx_lock_spin_flags(&sched_lock, MTX_QUIET); 206 if (p->p_flag & P_SA) { 207 /* XXXKSE What to do? */ 208 } else { 209 pstats = p->p_stats; 210 if (CLKF_USERMODE(frame) && 211 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value) && 212 itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0) { 213 p->p_sflag |= PS_ALRMPEND; 214 td->td_flags |= TDF_ASTPENDING; 215 } 216 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value) && 217 itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0) { 218 p->p_sflag |= PS_PROFPEND; 219 td->td_flags |= TDF_ASTPENDING; 220 } 221 } 222 mtx_unlock_spin_flags(&sched_lock, MTX_QUIET); 223 224 #ifdef HWPMC_HOOKS 225 if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid))) 226 PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL); 227 #endif 228 } 229 230 /* 231 * The real-time timer, interrupting hz times per second. 232 */ 233 void 234 hardclock(frame) 235 register struct clockframe *frame; 236 { 237 int need_softclock = 0; 238 239 CTR0(KTR_CLK, "hardclock fired"); 240 hardclock_process(frame); 241 242 tc_ticktock(); 243 /* 244 * If no separate statistics clock is available, run it from here. 245 * 246 * XXX: this only works for UP 247 */ 248 if (stathz == 0) { 249 profclock(frame); 250 statclock(frame); 251 } 252 253 #ifdef DEVICE_POLLING 254 hardclock_device_poll(); /* this is very short and quick */ 255 #endif /* DEVICE_POLLING */ 256 257 /* 258 * Process callouts at a very low cpu priority, so we don't keep the 259 * relatively high clock interrupt priority any longer than necessary. 260 */ 261 mtx_lock_spin_flags(&callout_lock, MTX_QUIET); 262 ticks++; 263 if (TAILQ_FIRST(&callwheel[ticks & callwheelmask]) != NULL) { 264 need_softclock = 1; 265 } else if (softticks + 1 == ticks) 266 ++softticks; 267 mtx_unlock_spin_flags(&callout_lock, MTX_QUIET); 268 269 /* 270 * swi_sched acquires sched_lock, so we don't want to call it with 271 * callout_lock held; incorrect locking order. 272 */ 273 if (need_softclock) 274 swi_sched(softclock_ih, 0); 275 276 #ifdef SW_WATCHDOG 277 if (watchdog_enabled > 0 && --watchdog_ticks <= 0) 278 watchdog_fire(); 279 #endif /* SW_WATCHDOG */ 280 } 281 282 /* 283 * Compute number of ticks in the specified amount of time. 284 */ 285 int 286 tvtohz(tv) 287 struct timeval *tv; 288 { 289 register unsigned long ticks; 290 register long sec, usec; 291 292 /* 293 * If the number of usecs in the whole seconds part of the time 294 * difference fits in a long, then the total number of usecs will 295 * fit in an unsigned long. Compute the total and convert it to 296 * ticks, rounding up and adding 1 to allow for the current tick 297 * to expire. Rounding also depends on unsigned long arithmetic 298 * to avoid overflow. 299 * 300 * Otherwise, if the number of ticks in the whole seconds part of 301 * the time difference fits in a long, then convert the parts to 302 * ticks separately and add, using similar rounding methods and 303 * overflow avoidance. This method would work in the previous 304 * case but it is slightly slower and assumes that hz is integral. 305 * 306 * Otherwise, round the time difference down to the maximum 307 * representable value. 308 * 309 * If ints have 32 bits, then the maximum value for any timeout in 310 * 10ms ticks is 248 days. 311 */ 312 sec = tv->tv_sec; 313 usec = tv->tv_usec; 314 if (usec < 0) { 315 sec--; 316 usec += 1000000; 317 } 318 if (sec < 0) { 319 #ifdef DIAGNOSTIC 320 if (usec > 0) { 321 sec++; 322 usec -= 1000000; 323 } 324 printf("tvotohz: negative time difference %ld sec %ld usec\n", 325 sec, usec); 326 #endif 327 ticks = 1; 328 } else if (sec <= LONG_MAX / 1000000) 329 ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1)) 330 / tick + 1; 331 else if (sec <= LONG_MAX / hz) 332 ticks = sec * hz 333 + ((unsigned long)usec + (tick - 1)) / tick + 1; 334 else 335 ticks = LONG_MAX; 336 if (ticks > INT_MAX) 337 ticks = INT_MAX; 338 return ((int)ticks); 339 } 340 341 /* 342 * Start profiling on a process. 343 * 344 * Kernel profiling passes proc0 which never exits and hence 345 * keeps the profile clock running constantly. 346 */ 347 void 348 startprofclock(p) 349 register struct proc *p; 350 { 351 352 /* 353 * XXX; Right now sched_lock protects statclock(), but perhaps 354 * it should be protected later on by a time_lock, which would 355 * cover psdiv, etc. as well. 356 */ 357 PROC_LOCK_ASSERT(p, MA_OWNED); 358 if (p->p_flag & P_STOPPROF) 359 return; 360 if ((p->p_flag & P_PROFIL) == 0) { 361 mtx_lock_spin(&sched_lock); 362 p->p_flag |= P_PROFIL; 363 if (++profprocs == 1) 364 cpu_startprofclock(); 365 mtx_unlock_spin(&sched_lock); 366 } 367 } 368 369 /* 370 * Stop profiling on a process. 371 */ 372 void 373 stopprofclock(p) 374 register struct proc *p; 375 { 376 377 PROC_LOCK_ASSERT(p, MA_OWNED); 378 if (p->p_flag & P_PROFIL) { 379 if (p->p_profthreads != 0) { 380 p->p_flag |= P_STOPPROF; 381 while (p->p_profthreads != 0) 382 msleep(&p->p_profthreads, &p->p_mtx, PPAUSE, 383 "stopprof", 0); 384 p->p_flag &= ~P_STOPPROF; 385 } 386 if ((p->p_flag & P_PROFIL) == 0) 387 return; 388 mtx_lock_spin(&sched_lock); 389 p->p_flag &= ~P_PROFIL; 390 if (--profprocs == 0) 391 cpu_stopprofclock(); 392 mtx_unlock_spin(&sched_lock); 393 } 394 } 395 396 /* 397 * Statistics clock. Grab profile sample, and if divider reaches 0, 398 * do process and kernel statistics. Most of the statistics are only 399 * used by user-level statistics programs. The main exceptions are 400 * ke->ke_uticks, p->p_rux.rux_sticks, p->p_rux.rux_iticks, and p->p_estcpu. 401 * This should be called by all active processors. 402 */ 403 void 404 statclock(frame) 405 register struct clockframe *frame; 406 { 407 struct rusage *ru; 408 struct vmspace *vm; 409 struct thread *td; 410 struct proc *p; 411 long rss; 412 413 td = curthread; 414 p = td->td_proc; 415 416 mtx_lock_spin_flags(&sched_lock, MTX_QUIET); 417 if (CLKF_USERMODE(frame)) { 418 /* 419 * Charge the time as appropriate. 420 */ 421 if (p->p_flag & P_SA) 422 thread_statclock(1); 423 p->p_rux.rux_uticks++; 424 if (p->p_nice > NZERO) 425 cp_time[CP_NICE]++; 426 else 427 cp_time[CP_USER]++; 428 } else { 429 /* 430 * Came from kernel mode, so we were: 431 * - handling an interrupt, 432 * - doing syscall or trap work on behalf of the current 433 * user process, or 434 * - spinning in the idle loop. 435 * Whichever it is, charge the time as appropriate. 436 * Note that we charge interrupts to the current process, 437 * regardless of whether they are ``for'' that process, 438 * so that we know how much of its real time was spent 439 * in ``non-process'' (i.e., interrupt) work. 440 */ 441 if ((td->td_ithd != NULL) || td->td_intr_nesting_level >= 2) { 442 p->p_rux.rux_iticks++; 443 cp_time[CP_INTR]++; 444 } else { 445 if (p->p_flag & P_SA) 446 thread_statclock(0); 447 td->td_sticks++; 448 p->p_rux.rux_sticks++; 449 if (p != PCPU_GET(idlethread)->td_proc) 450 cp_time[CP_SYS]++; 451 else 452 cp_time[CP_IDLE]++; 453 } 454 } 455 CTR4(KTR_SCHED, "statclock: %p(%s) prio %d stathz %d", 456 td, td->td_proc->p_comm, td->td_priority, (stathz)?stathz:hz); 457 458 sched_clock(td); 459 460 /* Update resource usage integrals and maximums. */ 461 MPASS(p->p_stats != NULL); 462 MPASS(p->p_vmspace != NULL); 463 vm = p->p_vmspace; 464 ru = &p->p_stats->p_ru; 465 ru->ru_ixrss += pgtok(vm->vm_tsize); 466 ru->ru_idrss += pgtok(vm->vm_dsize); 467 ru->ru_isrss += pgtok(vm->vm_ssize); 468 rss = pgtok(vmspace_resident_count(vm)); 469 if (ru->ru_maxrss < rss) 470 ru->ru_maxrss = rss; 471 mtx_unlock_spin_flags(&sched_lock, MTX_QUIET); 472 } 473 474 void 475 profclock(frame) 476 register struct clockframe *frame; 477 { 478 struct thread *td; 479 #ifdef GPROF 480 struct gmonparam *g; 481 int i; 482 #endif 483 484 td = curthread; 485 if (CLKF_USERMODE(frame)) { 486 /* 487 * Came from user mode; CPU was in user state. 488 * If this process is being profiled, record the tick. 489 * if there is no related user location yet, don't 490 * bother trying to count it. 491 */ 492 if (td->td_proc->p_flag & P_PROFIL) 493 addupc_intr(td, CLKF_PC(frame), 1); 494 } 495 #ifdef GPROF 496 else { 497 /* 498 * Kernel statistics are just like addupc_intr, only easier. 499 */ 500 g = &_gmonparam; 501 if (g->state == GMON_PROF_ON) { 502 i = CLKF_PC(frame) - g->lowpc; 503 if (i < g->textsize) { 504 i /= HISTFRACTION * sizeof(*g->kcount); 505 g->kcount[i]++; 506 } 507 } 508 } 509 #endif 510 } 511 512 /* 513 * Return information about system clocks. 514 */ 515 static int 516 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS) 517 { 518 struct clockinfo clkinfo; 519 /* 520 * Construct clockinfo structure. 521 */ 522 bzero(&clkinfo, sizeof(clkinfo)); 523 clkinfo.hz = hz; 524 clkinfo.tick = tick; 525 clkinfo.profhz = profhz; 526 clkinfo.stathz = stathz ? stathz : hz; 527 return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req)); 528 } 529 530 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD, 531 0, 0, sysctl_kern_clockrate, "S,clockinfo", 532 "Rate and period of various kernel clocks"); 533 534 #ifdef SW_WATCHDOG 535 536 static void 537 watchdog_config(void *unused __unused, u_int cmd, int *err) 538 { 539 u_int u; 540 541 u = cmd & WD_INTERVAL; 542 if (cmd && u >= WD_TO_1SEC) { 543 u = cmd & WD_INTERVAL; 544 watchdog_ticks = (1 << (u - WD_TO_1SEC)) * hz; 545 watchdog_enabled = 1; 546 *err = 0; 547 } else { 548 watchdog_enabled = 0; 549 } 550 } 551 552 /* 553 * Handle a watchdog timeout by dumping interrupt information and 554 * then either dropping to DDB or panicing. 555 */ 556 static void 557 watchdog_fire(void) 558 { 559 int nintr; 560 u_int64_t inttotal; 561 u_long *curintr; 562 char *curname; 563 564 curintr = intrcnt; 565 curname = intrnames; 566 inttotal = 0; 567 nintr = eintrcnt - intrcnt; 568 569 printf("interrupt total\n"); 570 while (--nintr >= 0) { 571 if (*curintr) 572 printf("%-12s %20lu\n", curname, *curintr); 573 curname += strlen(curname) + 1; 574 inttotal += *curintr++; 575 } 576 printf("Total %20ju\n", (uintmax_t)inttotal); 577 578 #ifdef KDB 579 kdb_backtrace(); 580 kdb_enter("watchdog timeout"); 581 #else 582 panic("watchdog timeout"); 583 #endif /* KDB */ 584 } 585 586 #endif /* SW_WATCHDOG */ 587