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 * From: @(#)kern_clock.c 8.5 (Berkeley) 1/21/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_callout_profiling.h" 41 #if defined(__arm__) 42 #include "opt_timer.h" 43 #endif 44 #include "opt_rss.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/bus.h> 49 #include <sys/callout.h> 50 #include <sys/file.h> 51 #include <sys/interrupt.h> 52 #include <sys/kernel.h> 53 #include <sys/ktr.h> 54 #include <sys/lock.h> 55 #include <sys/malloc.h> 56 #include <sys/mutex.h> 57 #include <sys/proc.h> 58 #include <sys/sdt.h> 59 #include <sys/sleepqueue.h> 60 #include <sys/sysctl.h> 61 #include <sys/smp.h> 62 63 #ifdef SMP 64 #include <machine/cpu.h> 65 #endif 66 67 #ifndef NO_EVENTTIMERS 68 DPCPU_DECLARE(sbintime_t, hardclocktime); 69 #endif 70 71 SDT_PROVIDER_DEFINE(callout_execute); 72 SDT_PROBE_DEFINE1(callout_execute, kernel, , callout__start, 73 "struct callout *"); 74 SDT_PROBE_DEFINE1(callout_execute, kernel, , callout__end, 75 "struct callout *"); 76 77 #ifdef CALLOUT_PROFILING 78 static int avg_depth; 79 SYSCTL_INT(_debug, OID_AUTO, to_avg_depth, CTLFLAG_RD, &avg_depth, 0, 80 "Average number of items examined per softclock call. Units = 1/1000"); 81 static int avg_gcalls; 82 SYSCTL_INT(_debug, OID_AUTO, to_avg_gcalls, CTLFLAG_RD, &avg_gcalls, 0, 83 "Average number of Giant callouts made per softclock call. Units = 1/1000"); 84 static int avg_lockcalls; 85 SYSCTL_INT(_debug, OID_AUTO, to_avg_lockcalls, CTLFLAG_RD, &avg_lockcalls, 0, 86 "Average number of lock callouts made per softclock call. Units = 1/1000"); 87 static int avg_mpcalls; 88 SYSCTL_INT(_debug, OID_AUTO, to_avg_mpcalls, CTLFLAG_RD, &avg_mpcalls, 0, 89 "Average number of MP callouts made per softclock call. Units = 1/1000"); 90 static int avg_depth_dir; 91 SYSCTL_INT(_debug, OID_AUTO, to_avg_depth_dir, CTLFLAG_RD, &avg_depth_dir, 0, 92 "Average number of direct callouts examined per callout_process call. " 93 "Units = 1/1000"); 94 static int avg_lockcalls_dir; 95 SYSCTL_INT(_debug, OID_AUTO, to_avg_lockcalls_dir, CTLFLAG_RD, 96 &avg_lockcalls_dir, 0, "Average number of lock direct callouts made per " 97 "callout_process call. Units = 1/1000"); 98 static int avg_mpcalls_dir; 99 SYSCTL_INT(_debug, OID_AUTO, to_avg_mpcalls_dir, CTLFLAG_RD, &avg_mpcalls_dir, 100 0, "Average number of MP direct callouts made per callout_process call. " 101 "Units = 1/1000"); 102 #endif 103 104 static int ncallout; 105 SYSCTL_INT(_kern, OID_AUTO, ncallout, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &ncallout, 0, 106 "Number of entries in callwheel and size of timeout() preallocation"); 107 108 #ifdef RSS 109 static int pin_default_swi = 1; 110 static int pin_pcpu_swi = 1; 111 #else 112 static int pin_default_swi = 0; 113 static int pin_pcpu_swi = 0; 114 #endif 115 116 SYSCTL_INT(_kern, OID_AUTO, pin_default_swi, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &pin_default_swi, 117 0, "Pin the default (non-per-cpu) swi (shared with PCPU 0 swi)"); 118 SYSCTL_INT(_kern, OID_AUTO, pin_pcpu_swi, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &pin_pcpu_swi, 119 0, "Pin the per-CPU swis (except PCPU 0, which is also default"); 120 121 /* 122 * TODO: 123 * allocate more timeout table slots when table overflows. 124 */ 125 u_int callwheelsize, callwheelmask; 126 127 /* 128 * The callout cpu exec entities represent informations necessary for 129 * describing the state of callouts currently running on the CPU and the ones 130 * necessary for migrating callouts to the new callout cpu. In particular, 131 * the first entry of the array cc_exec_entity holds informations for callout 132 * running in SWI thread context, while the second one holds informations 133 * for callout running directly from hardware interrupt context. 134 * The cached informations are very important for deferring migration when 135 * the migrating callout is already running. 136 */ 137 struct cc_exec { 138 struct callout *cc_next; 139 struct callout *cc_curr; 140 #ifdef SMP 141 void (*ce_migration_func)(void *); 142 void *ce_migration_arg; 143 int ce_migration_cpu; 144 sbintime_t ce_migration_time; 145 sbintime_t ce_migration_prec; 146 #endif 147 bool cc_cancel; 148 bool cc_waiting; 149 }; 150 151 /* 152 * There is one struct callout_cpu per cpu, holding all relevant 153 * state for the callout processing thread on the individual CPU. 154 */ 155 struct callout_cpu { 156 struct mtx_padalign cc_lock; 157 struct cc_exec cc_exec_entity[2]; 158 struct callout *cc_callout; 159 struct callout_list *cc_callwheel; 160 struct callout_tailq cc_expireq; 161 struct callout_slist cc_callfree; 162 sbintime_t cc_firstevent; 163 sbintime_t cc_lastscan; 164 void *cc_cookie; 165 u_int cc_bucket; 166 }; 167 168 #define cc_exec_curr cc_exec_entity[0].cc_curr 169 #define cc_exec_next cc_exec_entity[0].cc_next 170 #define cc_exec_cancel cc_exec_entity[0].cc_cancel 171 #define cc_exec_waiting cc_exec_entity[0].cc_waiting 172 #define cc_exec_curr_dir cc_exec_entity[1].cc_curr 173 #define cc_exec_next_dir cc_exec_entity[1].cc_next 174 #define cc_exec_cancel_dir cc_exec_entity[1].cc_cancel 175 #define cc_exec_waiting_dir cc_exec_entity[1].cc_waiting 176 177 #ifdef SMP 178 #define cc_migration_func cc_exec_entity[0].ce_migration_func 179 #define cc_migration_arg cc_exec_entity[0].ce_migration_arg 180 #define cc_migration_cpu cc_exec_entity[0].ce_migration_cpu 181 #define cc_migration_time cc_exec_entity[0].ce_migration_time 182 #define cc_migration_prec cc_exec_entity[0].ce_migration_prec 183 #define cc_migration_func_dir cc_exec_entity[1].ce_migration_func 184 #define cc_migration_arg_dir cc_exec_entity[1].ce_migration_arg 185 #define cc_migration_cpu_dir cc_exec_entity[1].ce_migration_cpu 186 #define cc_migration_time_dir cc_exec_entity[1].ce_migration_time 187 #define cc_migration_prec_dir cc_exec_entity[1].ce_migration_prec 188 189 struct callout_cpu cc_cpu[MAXCPU]; 190 #define CPUBLOCK MAXCPU 191 #define CC_CPU(cpu) (&cc_cpu[(cpu)]) 192 #define CC_SELF() CC_CPU(PCPU_GET(cpuid)) 193 #else 194 struct callout_cpu cc_cpu; 195 #define CC_CPU(cpu) &cc_cpu 196 #define CC_SELF() &cc_cpu 197 #endif 198 #define CC_LOCK(cc) mtx_lock_spin(&(cc)->cc_lock) 199 #define CC_UNLOCK(cc) mtx_unlock_spin(&(cc)->cc_lock) 200 #define CC_LOCK_ASSERT(cc) mtx_assert(&(cc)->cc_lock, MA_OWNED) 201 202 static int timeout_cpu; 203 204 static void callout_cpu_init(struct callout_cpu *cc); 205 static void softclock_call_cc(struct callout *c, struct callout_cpu *cc, 206 #ifdef CALLOUT_PROFILING 207 int *mpcalls, int *lockcalls, int *gcalls, 208 #endif 209 int direct); 210 211 static MALLOC_DEFINE(M_CALLOUT, "callout", "Callout datastructures"); 212 213 /** 214 * Locked by cc_lock: 215 * cc_curr - If a callout is in progress, it is cc_curr. 216 * If cc_curr is non-NULL, threads waiting in 217 * callout_drain() will be woken up as soon as the 218 * relevant callout completes. 219 * cc_cancel - Changing to 1 with both callout_lock and cc_lock held 220 * guarantees that the current callout will not run. 221 * The softclock() function sets this to 0 before it 222 * drops callout_lock to acquire c_lock, and it calls 223 * the handler only if curr_cancelled is still 0 after 224 * cc_lock is successfully acquired. 225 * cc_waiting - If a thread is waiting in callout_drain(), then 226 * callout_wait is nonzero. Set only when 227 * cc_curr is non-NULL. 228 */ 229 230 /* 231 * Resets the execution entity tied to a specific callout cpu. 232 */ 233 static void 234 cc_cce_cleanup(struct callout_cpu *cc, int direct) 235 { 236 237 cc->cc_exec_entity[direct].cc_curr = NULL; 238 cc->cc_exec_entity[direct].cc_next = NULL; 239 cc->cc_exec_entity[direct].cc_cancel = false; 240 cc->cc_exec_entity[direct].cc_waiting = false; 241 #ifdef SMP 242 cc->cc_exec_entity[direct].ce_migration_cpu = CPUBLOCK; 243 cc->cc_exec_entity[direct].ce_migration_time = 0; 244 cc->cc_exec_entity[direct].ce_migration_prec = 0; 245 cc->cc_exec_entity[direct].ce_migration_func = NULL; 246 cc->cc_exec_entity[direct].ce_migration_arg = NULL; 247 #endif 248 } 249 250 /* 251 * Checks if migration is requested by a specific callout cpu. 252 */ 253 static int 254 cc_cce_migrating(struct callout_cpu *cc, int direct) 255 { 256 257 #ifdef SMP 258 return (cc->cc_exec_entity[direct].ce_migration_cpu != CPUBLOCK); 259 #else 260 return (0); 261 #endif 262 } 263 264 /* 265 * Kernel low level callwheel initialization 266 * called on cpu0 during kernel startup. 267 */ 268 static void 269 callout_callwheel_init(void *dummy) 270 { 271 struct callout_cpu *cc; 272 273 /* 274 * Calculate the size of the callout wheel and the preallocated 275 * timeout() structures. 276 * XXX: Clip callout to result of previous function of maxusers 277 * maximum 384. This is still huge, but acceptable. 278 */ 279 ncallout = imin(16 + maxproc + maxfiles, 18508); 280 TUNABLE_INT_FETCH("kern.ncallout", &ncallout); 281 282 /* 283 * Calculate callout wheel size, should be next power of two higher 284 * than 'ncallout'. 285 */ 286 callwheelsize = 1 << fls(ncallout); 287 callwheelmask = callwheelsize - 1; 288 289 /* 290 * Fetch whether we're pinning the swi's or not. 291 */ 292 TUNABLE_INT_FETCH("kern.pin_default_swi", &pin_default_swi); 293 TUNABLE_INT_FETCH("kern.pin_pcpu_swi", &pin_pcpu_swi); 294 295 /* 296 * Only cpu0 handles timeout(9) and receives a preallocation. 297 * 298 * XXX: Once all timeout(9) consumers are converted this can 299 * be removed. 300 */ 301 timeout_cpu = PCPU_GET(cpuid); 302 cc = CC_CPU(timeout_cpu); 303 cc->cc_callout = malloc(ncallout * sizeof(struct callout), 304 M_CALLOUT, M_WAITOK); 305 callout_cpu_init(cc); 306 } 307 SYSINIT(callwheel_init, SI_SUB_CPU, SI_ORDER_ANY, callout_callwheel_init, NULL); 308 309 /* 310 * Initialize the per-cpu callout structures. 311 */ 312 static void 313 callout_cpu_init(struct callout_cpu *cc) 314 { 315 struct callout *c; 316 int i; 317 318 mtx_init(&cc->cc_lock, "callout", NULL, MTX_SPIN | MTX_RECURSE); 319 SLIST_INIT(&cc->cc_callfree); 320 cc->cc_callwheel = malloc(sizeof(struct callout_list) * callwheelsize, 321 M_CALLOUT, M_WAITOK); 322 for (i = 0; i < callwheelsize; i++) 323 LIST_INIT(&cc->cc_callwheel[i]); 324 TAILQ_INIT(&cc->cc_expireq); 325 cc->cc_firstevent = SBT_MAX; 326 for (i = 0; i < 2; i++) 327 cc_cce_cleanup(cc, i); 328 if (cc->cc_callout == NULL) /* Only cpu0 handles timeout(9) */ 329 return; 330 for (i = 0; i < ncallout; i++) { 331 c = &cc->cc_callout[i]; 332 callout_init(c, 0); 333 c->c_flags = CALLOUT_LOCAL_ALLOC; 334 SLIST_INSERT_HEAD(&cc->cc_callfree, c, c_links.sle); 335 } 336 } 337 338 #ifdef SMP 339 /* 340 * Switches the cpu tied to a specific callout. 341 * The function expects a locked incoming callout cpu and returns with 342 * locked outcoming callout cpu. 343 */ 344 static struct callout_cpu * 345 callout_cpu_switch(struct callout *c, struct callout_cpu *cc, int new_cpu) 346 { 347 struct callout_cpu *new_cc; 348 349 MPASS(c != NULL && cc != NULL); 350 CC_LOCK_ASSERT(cc); 351 352 /* 353 * Avoid interrupts and preemption firing after the callout cpu 354 * is blocked in order to avoid deadlocks as the new thread 355 * may be willing to acquire the callout cpu lock. 356 */ 357 c->c_cpu = CPUBLOCK; 358 spinlock_enter(); 359 CC_UNLOCK(cc); 360 new_cc = CC_CPU(new_cpu); 361 CC_LOCK(new_cc); 362 spinlock_exit(); 363 c->c_cpu = new_cpu; 364 return (new_cc); 365 } 366 #endif 367 368 /* 369 * Start standard softclock thread. 370 */ 371 static void 372 start_softclock(void *dummy) 373 { 374 struct callout_cpu *cc; 375 char name[MAXCOMLEN]; 376 #ifdef SMP 377 int cpu; 378 struct intr_event *ie; 379 #endif 380 381 cc = CC_CPU(timeout_cpu); 382 snprintf(name, sizeof(name), "clock (%d)", timeout_cpu); 383 if (swi_add(&clk_intr_event, name, softclock, cc, SWI_CLOCK, 384 INTR_MPSAFE, &cc->cc_cookie)) 385 panic("died while creating standard software ithreads"); 386 if (pin_default_swi && 387 (intr_event_bind(clk_intr_event, timeout_cpu) != 0)) { 388 printf("%s: timeout clock couldn't be pinned to cpu %d\n", 389 __func__, 390 timeout_cpu); 391 } 392 393 #ifdef SMP 394 CPU_FOREACH(cpu) { 395 if (cpu == timeout_cpu) 396 continue; 397 cc = CC_CPU(cpu); 398 cc->cc_callout = NULL; /* Only cpu0 handles timeout(9). */ 399 callout_cpu_init(cc); 400 snprintf(name, sizeof(name), "clock (%d)", cpu); 401 ie = NULL; 402 if (swi_add(&ie, name, softclock, cc, SWI_CLOCK, 403 INTR_MPSAFE, &cc->cc_cookie)) 404 panic("died while creating standard software ithreads"); 405 if (pin_pcpu_swi && (intr_event_bind(ie, cpu) != 0)) { 406 printf("%s: per-cpu clock couldn't be pinned to " 407 "cpu %d\n", 408 __func__, 409 cpu); 410 } 411 } 412 #endif 413 } 414 SYSINIT(start_softclock, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softclock, NULL); 415 416 #define CC_HASH_SHIFT 8 417 418 static inline u_int 419 callout_hash(sbintime_t sbt) 420 { 421 422 return (sbt >> (32 - CC_HASH_SHIFT)); 423 } 424 425 static inline u_int 426 callout_get_bucket(sbintime_t sbt) 427 { 428 429 return (callout_hash(sbt) & callwheelmask); 430 } 431 432 void 433 callout_process(sbintime_t now) 434 { 435 struct callout *tmp, *tmpn; 436 struct callout_cpu *cc; 437 struct callout_list *sc; 438 sbintime_t first, last, max, tmp_max; 439 uint32_t lookahead; 440 u_int firstb, lastb, nowb; 441 #ifdef CALLOUT_PROFILING 442 int depth_dir = 0, mpcalls_dir = 0, lockcalls_dir = 0; 443 #endif 444 445 cc = CC_SELF(); 446 mtx_lock_spin_flags(&cc->cc_lock, MTX_QUIET); 447 448 /* Compute the buckets of the last scan and present times. */ 449 firstb = callout_hash(cc->cc_lastscan); 450 cc->cc_lastscan = now; 451 nowb = callout_hash(now); 452 453 /* Compute the last bucket and minimum time of the bucket after it. */ 454 if (nowb == firstb) 455 lookahead = (SBT_1S / 16); 456 else if (nowb - firstb == 1) 457 lookahead = (SBT_1S / 8); 458 else 459 lookahead = (SBT_1S / 2); 460 first = last = now; 461 first += (lookahead / 2); 462 last += lookahead; 463 last &= (0xffffffffffffffffLLU << (32 - CC_HASH_SHIFT)); 464 lastb = callout_hash(last) - 1; 465 max = last; 466 467 /* 468 * Check if we wrapped around the entire wheel from the last scan. 469 * In case, we need to scan entirely the wheel for pending callouts. 470 */ 471 if (lastb - firstb >= callwheelsize) { 472 lastb = firstb + callwheelsize - 1; 473 if (nowb - firstb >= callwheelsize) 474 nowb = lastb; 475 } 476 477 /* Iterate callwheel from firstb to nowb and then up to lastb. */ 478 do { 479 sc = &cc->cc_callwheel[firstb & callwheelmask]; 480 tmp = LIST_FIRST(sc); 481 while (tmp != NULL) { 482 /* Run the callout if present time within allowed. */ 483 if (tmp->c_time <= now) { 484 /* 485 * Consumer told us the callout may be run 486 * directly from hardware interrupt context. 487 */ 488 if (tmp->c_flags & CALLOUT_DIRECT) { 489 #ifdef CALLOUT_PROFILING 490 ++depth_dir; 491 #endif 492 cc->cc_exec_next_dir = 493 LIST_NEXT(tmp, c_links.le); 494 cc->cc_bucket = firstb & callwheelmask; 495 LIST_REMOVE(tmp, c_links.le); 496 softclock_call_cc(tmp, cc, 497 #ifdef CALLOUT_PROFILING 498 &mpcalls_dir, &lockcalls_dir, NULL, 499 #endif 500 1); 501 tmp = cc->cc_exec_next_dir; 502 } else { 503 tmpn = LIST_NEXT(tmp, c_links.le); 504 LIST_REMOVE(tmp, c_links.le); 505 TAILQ_INSERT_TAIL(&cc->cc_expireq, 506 tmp, c_links.tqe); 507 tmp->c_flags |= CALLOUT_PROCESSED; 508 tmp = tmpn; 509 } 510 continue; 511 } 512 /* Skip events from distant future. */ 513 if (tmp->c_time >= max) 514 goto next; 515 /* 516 * Event minimal time is bigger than present maximal 517 * time, so it cannot be aggregated. 518 */ 519 if (tmp->c_time > last) { 520 lastb = nowb; 521 goto next; 522 } 523 /* Update first and last time, respecting this event. */ 524 if (tmp->c_time < first) 525 first = tmp->c_time; 526 tmp_max = tmp->c_time + tmp->c_precision; 527 if (tmp_max < last) 528 last = tmp_max; 529 next: 530 tmp = LIST_NEXT(tmp, c_links.le); 531 } 532 /* Proceed with the next bucket. */ 533 firstb++; 534 /* 535 * Stop if we looked after present time and found 536 * some event we can't execute at now. 537 * Stop if we looked far enough into the future. 538 */ 539 } while (((int)(firstb - lastb)) <= 0); 540 cc->cc_firstevent = last; 541 #ifndef NO_EVENTTIMERS 542 cpu_new_callout(curcpu, last, first); 543 #endif 544 #ifdef CALLOUT_PROFILING 545 avg_depth_dir += (depth_dir * 1000 - avg_depth_dir) >> 8; 546 avg_mpcalls_dir += (mpcalls_dir * 1000 - avg_mpcalls_dir) >> 8; 547 avg_lockcalls_dir += (lockcalls_dir * 1000 - avg_lockcalls_dir) >> 8; 548 #endif 549 mtx_unlock_spin_flags(&cc->cc_lock, MTX_QUIET); 550 /* 551 * swi_sched acquires the thread lock, so we don't want to call it 552 * with cc_lock held; incorrect locking order. 553 */ 554 if (!TAILQ_EMPTY(&cc->cc_expireq)) 555 swi_sched(cc->cc_cookie, 0); 556 } 557 558 static struct callout_cpu * 559 callout_lock(struct callout *c) 560 { 561 struct callout_cpu *cc; 562 int cpu; 563 564 for (;;) { 565 cpu = c->c_cpu; 566 #ifdef SMP 567 if (cpu == CPUBLOCK) { 568 while (c->c_cpu == CPUBLOCK) 569 cpu_spinwait(); 570 continue; 571 } 572 #endif 573 cc = CC_CPU(cpu); 574 CC_LOCK(cc); 575 if (cpu == c->c_cpu) 576 break; 577 CC_UNLOCK(cc); 578 } 579 return (cc); 580 } 581 582 static void 583 callout_cc_add(struct callout *c, struct callout_cpu *cc, 584 sbintime_t sbt, sbintime_t precision, void (*func)(void *), 585 void *arg, int cpu, int flags) 586 { 587 int bucket; 588 589 CC_LOCK_ASSERT(cc); 590 if (sbt < cc->cc_lastscan) 591 sbt = cc->cc_lastscan; 592 c->c_arg = arg; 593 c->c_flags |= (CALLOUT_ACTIVE | CALLOUT_PENDING); 594 if (flags & C_DIRECT_EXEC) 595 c->c_flags |= CALLOUT_DIRECT; 596 c->c_flags &= ~CALLOUT_PROCESSED; 597 c->c_func = func; 598 c->c_time = sbt; 599 c->c_precision = precision; 600 bucket = callout_get_bucket(c->c_time); 601 CTR3(KTR_CALLOUT, "precision set for %p: %d.%08x", 602 c, (int)(c->c_precision >> 32), 603 (u_int)(c->c_precision & 0xffffffff)); 604 LIST_INSERT_HEAD(&cc->cc_callwheel[bucket], c, c_links.le); 605 if (cc->cc_bucket == bucket) 606 cc->cc_exec_next_dir = c; 607 #ifndef NO_EVENTTIMERS 608 /* 609 * Inform the eventtimers(4) subsystem there's a new callout 610 * that has been inserted, but only if really required. 611 */ 612 if (SBT_MAX - c->c_time < c->c_precision) 613 c->c_precision = SBT_MAX - c->c_time; 614 sbt = c->c_time + c->c_precision; 615 if (sbt < cc->cc_firstevent) { 616 cc->cc_firstevent = sbt; 617 cpu_new_callout(cpu, sbt, c->c_time); 618 } 619 #endif 620 } 621 622 static void 623 callout_cc_del(struct callout *c, struct callout_cpu *cc) 624 { 625 626 if ((c->c_flags & CALLOUT_LOCAL_ALLOC) == 0) 627 return; 628 c->c_func = NULL; 629 SLIST_INSERT_HEAD(&cc->cc_callfree, c, c_links.sle); 630 } 631 632 static void 633 softclock_call_cc(struct callout *c, struct callout_cpu *cc, 634 #ifdef CALLOUT_PROFILING 635 int *mpcalls, int *lockcalls, int *gcalls, 636 #endif 637 int direct) 638 { 639 struct rm_priotracker tracker; 640 void (*c_func)(void *); 641 void *c_arg; 642 struct lock_class *class; 643 struct lock_object *c_lock; 644 uintptr_t lock_status; 645 int c_flags; 646 #ifdef SMP 647 struct callout_cpu *new_cc; 648 void (*new_func)(void *); 649 void *new_arg; 650 int flags, new_cpu; 651 sbintime_t new_prec, new_time; 652 #endif 653 #if defined(DIAGNOSTIC) || defined(CALLOUT_PROFILING) 654 sbintime_t sbt1, sbt2; 655 struct timespec ts2; 656 static sbintime_t maxdt = 2 * SBT_1MS; /* 2 msec */ 657 static timeout_t *lastfunc; 658 #endif 659 660 KASSERT((c->c_flags & (CALLOUT_PENDING | CALLOUT_ACTIVE)) == 661 (CALLOUT_PENDING | CALLOUT_ACTIVE), 662 ("softclock_call_cc: pend|act %p %x", c, c->c_flags)); 663 class = (c->c_lock != NULL) ? LOCK_CLASS(c->c_lock) : NULL; 664 lock_status = 0; 665 if (c->c_flags & CALLOUT_SHAREDLOCK) { 666 if (class == &lock_class_rm) 667 lock_status = (uintptr_t)&tracker; 668 else 669 lock_status = 1; 670 } 671 c_lock = c->c_lock; 672 c_func = c->c_func; 673 c_arg = c->c_arg; 674 c_flags = c->c_flags; 675 if (c->c_flags & CALLOUT_LOCAL_ALLOC) 676 c->c_flags = CALLOUT_LOCAL_ALLOC; 677 else 678 c->c_flags &= ~CALLOUT_PENDING; 679 cc->cc_exec_entity[direct].cc_curr = c; 680 cc->cc_exec_entity[direct].cc_cancel = false; 681 CC_UNLOCK(cc); 682 if (c_lock != NULL) { 683 class->lc_lock(c_lock, lock_status); 684 /* 685 * The callout may have been cancelled 686 * while we switched locks. 687 */ 688 if (cc->cc_exec_entity[direct].cc_cancel) { 689 class->lc_unlock(c_lock); 690 goto skip; 691 } 692 /* The callout cannot be stopped now. */ 693 cc->cc_exec_entity[direct].cc_cancel = true; 694 if (c_lock == &Giant.lock_object) { 695 #ifdef CALLOUT_PROFILING 696 (*gcalls)++; 697 #endif 698 CTR3(KTR_CALLOUT, "callout giant %p func %p arg %p", 699 c, c_func, c_arg); 700 } else { 701 #ifdef CALLOUT_PROFILING 702 (*lockcalls)++; 703 #endif 704 CTR3(KTR_CALLOUT, "callout lock %p func %p arg %p", 705 c, c_func, c_arg); 706 } 707 } else { 708 #ifdef CALLOUT_PROFILING 709 (*mpcalls)++; 710 #endif 711 CTR3(KTR_CALLOUT, "callout %p func %p arg %p", 712 c, c_func, c_arg); 713 } 714 #if defined(DIAGNOSTIC) || defined(CALLOUT_PROFILING) 715 sbt1 = sbinuptime(); 716 #endif 717 THREAD_NO_SLEEPING(); 718 SDT_PROBE(callout_execute, kernel, , callout__start, c, 0, 0, 0, 0); 719 c_func(c_arg); 720 SDT_PROBE(callout_execute, kernel, , callout__end, c, 0, 0, 0, 0); 721 THREAD_SLEEPING_OK(); 722 #if defined(DIAGNOSTIC) || defined(CALLOUT_PROFILING) 723 sbt2 = sbinuptime(); 724 sbt2 -= sbt1; 725 if (sbt2 > maxdt) { 726 if (lastfunc != c_func || sbt2 > maxdt * 2) { 727 ts2 = sbttots(sbt2); 728 printf( 729 "Expensive timeout(9) function: %p(%p) %jd.%09ld s\n", 730 c_func, c_arg, (intmax_t)ts2.tv_sec, ts2.tv_nsec); 731 } 732 maxdt = sbt2; 733 lastfunc = c_func; 734 } 735 #endif 736 CTR1(KTR_CALLOUT, "callout %p finished", c); 737 if ((c_flags & CALLOUT_RETURNUNLOCKED) == 0) 738 class->lc_unlock(c_lock); 739 skip: 740 CC_LOCK(cc); 741 KASSERT(cc->cc_exec_entity[direct].cc_curr == c, ("mishandled cc_curr")); 742 cc->cc_exec_entity[direct].cc_curr = NULL; 743 if (cc->cc_exec_entity[direct].cc_waiting) { 744 /* 745 * There is someone waiting for the 746 * callout to complete. 747 * If the callout was scheduled for 748 * migration just cancel it. 749 */ 750 if (cc_cce_migrating(cc, direct)) { 751 cc_cce_cleanup(cc, direct); 752 753 /* 754 * It should be assert here that the callout is not 755 * destroyed but that is not easy. 756 */ 757 c->c_flags &= ~CALLOUT_DFRMIGRATION; 758 } 759 cc->cc_exec_entity[direct].cc_waiting = false; 760 CC_UNLOCK(cc); 761 wakeup(&cc->cc_exec_entity[direct].cc_waiting); 762 CC_LOCK(cc); 763 } else if (cc_cce_migrating(cc, direct)) { 764 KASSERT((c_flags & CALLOUT_LOCAL_ALLOC) == 0, 765 ("Migrating legacy callout %p", c)); 766 #ifdef SMP 767 /* 768 * If the callout was scheduled for 769 * migration just perform it now. 770 */ 771 new_cpu = cc->cc_exec_entity[direct].ce_migration_cpu; 772 new_time = cc->cc_exec_entity[direct].ce_migration_time; 773 new_prec = cc->cc_exec_entity[direct].ce_migration_prec; 774 new_func = cc->cc_exec_entity[direct].ce_migration_func; 775 new_arg = cc->cc_exec_entity[direct].ce_migration_arg; 776 cc_cce_cleanup(cc, direct); 777 778 /* 779 * It should be assert here that the callout is not destroyed 780 * but that is not easy. 781 * 782 * As first thing, handle deferred callout stops. 783 */ 784 if ((c->c_flags & CALLOUT_DFRMIGRATION) == 0) { 785 CTR3(KTR_CALLOUT, 786 "deferred cancelled %p func %p arg %p", 787 c, new_func, new_arg); 788 callout_cc_del(c, cc); 789 return; 790 } 791 c->c_flags &= ~CALLOUT_DFRMIGRATION; 792 793 new_cc = callout_cpu_switch(c, cc, new_cpu); 794 flags = (direct) ? C_DIRECT_EXEC : 0; 795 callout_cc_add(c, new_cc, new_time, new_prec, new_func, 796 new_arg, new_cpu, flags); 797 CC_UNLOCK(new_cc); 798 CC_LOCK(cc); 799 #else 800 panic("migration should not happen"); 801 #endif 802 } 803 /* 804 * If the current callout is locally allocated (from 805 * timeout(9)) then put it on the freelist. 806 * 807 * Note: we need to check the cached copy of c_flags because 808 * if it was not local, then it's not safe to deref the 809 * callout pointer. 810 */ 811 KASSERT((c_flags & CALLOUT_LOCAL_ALLOC) == 0 || 812 c->c_flags == CALLOUT_LOCAL_ALLOC, 813 ("corrupted callout")); 814 if (c_flags & CALLOUT_LOCAL_ALLOC) 815 callout_cc_del(c, cc); 816 } 817 818 /* 819 * The callout mechanism is based on the work of Adam M. Costello and 820 * George Varghese, published in a technical report entitled "Redesigning 821 * the BSD Callout and Timer Facilities" and modified slightly for inclusion 822 * in FreeBSD by Justin T. Gibbs. The original work on the data structures 823 * used in this implementation was published by G. Varghese and T. Lauck in 824 * the paper "Hashed and Hierarchical Timing Wheels: Data Structures for 825 * the Efficient Implementation of a Timer Facility" in the Proceedings of 826 * the 11th ACM Annual Symposium on Operating Systems Principles, 827 * Austin, Texas Nov 1987. 828 */ 829 830 /* 831 * Software (low priority) clock interrupt. 832 * Run periodic events from timeout queue. 833 */ 834 void 835 softclock(void *arg) 836 { 837 struct callout_cpu *cc; 838 struct callout *c; 839 #ifdef CALLOUT_PROFILING 840 int depth = 0, gcalls = 0, lockcalls = 0, mpcalls = 0; 841 #endif 842 843 cc = (struct callout_cpu *)arg; 844 CC_LOCK(cc); 845 while ((c = TAILQ_FIRST(&cc->cc_expireq)) != NULL) { 846 TAILQ_REMOVE(&cc->cc_expireq, c, c_links.tqe); 847 softclock_call_cc(c, cc, 848 #ifdef CALLOUT_PROFILING 849 &mpcalls, &lockcalls, &gcalls, 850 #endif 851 0); 852 #ifdef CALLOUT_PROFILING 853 ++depth; 854 #endif 855 } 856 #ifdef CALLOUT_PROFILING 857 avg_depth += (depth * 1000 - avg_depth) >> 8; 858 avg_mpcalls += (mpcalls * 1000 - avg_mpcalls) >> 8; 859 avg_lockcalls += (lockcalls * 1000 - avg_lockcalls) >> 8; 860 avg_gcalls += (gcalls * 1000 - avg_gcalls) >> 8; 861 #endif 862 CC_UNLOCK(cc); 863 } 864 865 /* 866 * timeout -- 867 * Execute a function after a specified length of time. 868 * 869 * untimeout -- 870 * Cancel previous timeout function call. 871 * 872 * callout_handle_init -- 873 * Initialize a handle so that using it with untimeout is benign. 874 * 875 * See AT&T BCI Driver Reference Manual for specification. This 876 * implementation differs from that one in that although an 877 * identification value is returned from timeout, the original 878 * arguments to timeout as well as the identifier are used to 879 * identify entries for untimeout. 880 */ 881 struct callout_handle 882 timeout(timeout_t *ftn, void *arg, int to_ticks) 883 { 884 struct callout_cpu *cc; 885 struct callout *new; 886 struct callout_handle handle; 887 888 cc = CC_CPU(timeout_cpu); 889 CC_LOCK(cc); 890 /* Fill in the next free callout structure. */ 891 new = SLIST_FIRST(&cc->cc_callfree); 892 if (new == NULL) 893 /* XXX Attempt to malloc first */ 894 panic("timeout table full"); 895 SLIST_REMOVE_HEAD(&cc->cc_callfree, c_links.sle); 896 callout_reset(new, to_ticks, ftn, arg); 897 handle.callout = new; 898 CC_UNLOCK(cc); 899 900 return (handle); 901 } 902 903 void 904 untimeout(timeout_t *ftn, void *arg, struct callout_handle handle) 905 { 906 struct callout_cpu *cc; 907 908 /* 909 * Check for a handle that was initialized 910 * by callout_handle_init, but never used 911 * for a real timeout. 912 */ 913 if (handle.callout == NULL) 914 return; 915 916 cc = callout_lock(handle.callout); 917 if (handle.callout->c_func == ftn && handle.callout->c_arg == arg) 918 callout_stop(handle.callout); 919 CC_UNLOCK(cc); 920 } 921 922 void 923 callout_handle_init(struct callout_handle *handle) 924 { 925 handle->callout = NULL; 926 } 927 928 /* 929 * New interface; clients allocate their own callout structures. 930 * 931 * callout_reset() - establish or change a timeout 932 * callout_stop() - disestablish a timeout 933 * callout_init() - initialize a callout structure so that it can 934 * safely be passed to callout_reset() and callout_stop() 935 * 936 * <sys/callout.h> defines three convenience macros: 937 * 938 * callout_active() - returns truth if callout has not been stopped, 939 * drained, or deactivated since the last time the callout was 940 * reset. 941 * callout_pending() - returns truth if callout is still waiting for timeout 942 * callout_deactivate() - marks the callout as having been serviced 943 */ 944 int 945 callout_reset_sbt_on(struct callout *c, sbintime_t sbt, sbintime_t precision, 946 void (*ftn)(void *), void *arg, int cpu, int flags) 947 { 948 sbintime_t to_sbt, pr; 949 struct callout_cpu *cc; 950 int cancelled, direct; 951 952 cancelled = 0; 953 if (flags & C_ABSOLUTE) { 954 to_sbt = sbt; 955 } else { 956 if ((flags & C_HARDCLOCK) && (sbt < tick_sbt)) 957 sbt = tick_sbt; 958 if ((flags & C_HARDCLOCK) || 959 #ifdef NO_EVENTTIMERS 960 sbt >= sbt_timethreshold) { 961 to_sbt = getsbinuptime(); 962 963 /* Add safety belt for the case of hz > 1000. */ 964 to_sbt += tc_tick_sbt - tick_sbt; 965 #else 966 sbt >= sbt_tickthreshold) { 967 /* 968 * Obtain the time of the last hardclock() call on 969 * this CPU directly from the kern_clocksource.c. 970 * This value is per-CPU, but it is equal for all 971 * active ones. 972 */ 973 #ifdef __LP64__ 974 to_sbt = DPCPU_GET(hardclocktime); 975 #else 976 spinlock_enter(); 977 to_sbt = DPCPU_GET(hardclocktime); 978 spinlock_exit(); 979 #endif 980 #endif 981 if ((flags & C_HARDCLOCK) == 0) 982 to_sbt += tick_sbt; 983 } else 984 to_sbt = sbinuptime(); 985 if (SBT_MAX - to_sbt < sbt) 986 to_sbt = SBT_MAX; 987 else 988 to_sbt += sbt; 989 pr = ((C_PRELGET(flags) < 0) ? sbt >> tc_precexp : 990 sbt >> C_PRELGET(flags)); 991 if (pr > precision) 992 precision = pr; 993 } 994 /* 995 * Don't allow migration of pre-allocated callouts lest they 996 * become unbalanced. 997 */ 998 if (c->c_flags & CALLOUT_LOCAL_ALLOC) 999 cpu = c->c_cpu; 1000 direct = (c->c_flags & CALLOUT_DIRECT) != 0; 1001 KASSERT(!direct || c->c_lock == NULL, 1002 ("%s: direct callout %p has lock", __func__, c)); 1003 cc = callout_lock(c); 1004 if (cc->cc_exec_entity[direct].cc_curr == c) { 1005 /* 1006 * We're being asked to reschedule a callout which is 1007 * currently in progress. If there is a lock then we 1008 * can cancel the callout if it has not really started. 1009 */ 1010 if (c->c_lock != NULL && !cc->cc_exec_entity[direct].cc_cancel) 1011 cancelled = cc->cc_exec_entity[direct].cc_cancel = true; 1012 if (cc->cc_exec_entity[direct].cc_waiting) { 1013 /* 1014 * Someone has called callout_drain to kill this 1015 * callout. Don't reschedule. 1016 */ 1017 CTR4(KTR_CALLOUT, "%s %p func %p arg %p", 1018 cancelled ? "cancelled" : "failed to cancel", 1019 c, c->c_func, c->c_arg); 1020 CC_UNLOCK(cc); 1021 return (cancelled); 1022 } 1023 } 1024 if (c->c_flags & CALLOUT_PENDING) { 1025 if ((c->c_flags & CALLOUT_PROCESSED) == 0) { 1026 if (cc->cc_exec_next_dir == c) 1027 cc->cc_exec_next_dir = LIST_NEXT(c, c_links.le); 1028 LIST_REMOVE(c, c_links.le); 1029 } else 1030 TAILQ_REMOVE(&cc->cc_expireq, c, c_links.tqe); 1031 cancelled = 1; 1032 c->c_flags &= ~(CALLOUT_ACTIVE | CALLOUT_PENDING); 1033 } 1034 1035 #ifdef SMP 1036 /* 1037 * If the callout must migrate try to perform it immediately. 1038 * If the callout is currently running, just defer the migration 1039 * to a more appropriate moment. 1040 */ 1041 if (c->c_cpu != cpu) { 1042 if (cc->cc_exec_entity[direct].cc_curr == c) { 1043 cc->cc_exec_entity[direct].ce_migration_cpu = cpu; 1044 cc->cc_exec_entity[direct].ce_migration_time 1045 = to_sbt; 1046 cc->cc_exec_entity[direct].ce_migration_prec 1047 = precision; 1048 cc->cc_exec_entity[direct].ce_migration_func = ftn; 1049 cc->cc_exec_entity[direct].ce_migration_arg = arg; 1050 c->c_flags |= CALLOUT_DFRMIGRATION; 1051 CTR6(KTR_CALLOUT, 1052 "migration of %p func %p arg %p in %d.%08x to %u deferred", 1053 c, c->c_func, c->c_arg, (int)(to_sbt >> 32), 1054 (u_int)(to_sbt & 0xffffffff), cpu); 1055 CC_UNLOCK(cc); 1056 return (cancelled); 1057 } 1058 cc = callout_cpu_switch(c, cc, cpu); 1059 } 1060 #endif 1061 1062 callout_cc_add(c, cc, to_sbt, precision, ftn, arg, cpu, flags); 1063 CTR6(KTR_CALLOUT, "%sscheduled %p func %p arg %p in %d.%08x", 1064 cancelled ? "re" : "", c, c->c_func, c->c_arg, (int)(to_sbt >> 32), 1065 (u_int)(to_sbt & 0xffffffff)); 1066 CC_UNLOCK(cc); 1067 1068 return (cancelled); 1069 } 1070 1071 /* 1072 * Common idioms that can be optimized in the future. 1073 */ 1074 int 1075 callout_schedule_on(struct callout *c, int to_ticks, int cpu) 1076 { 1077 return callout_reset_on(c, to_ticks, c->c_func, c->c_arg, cpu); 1078 } 1079 1080 int 1081 callout_schedule(struct callout *c, int to_ticks) 1082 { 1083 return callout_reset_on(c, to_ticks, c->c_func, c->c_arg, c->c_cpu); 1084 } 1085 1086 int 1087 _callout_stop_safe(struct callout *c, int safe) 1088 { 1089 struct callout_cpu *cc, *old_cc; 1090 struct lock_class *class; 1091 int direct, sq_locked, use_lock; 1092 1093 /* 1094 * Some old subsystems don't hold Giant while running a callout_stop(), 1095 * so just discard this check for the moment. 1096 */ 1097 if (!safe && c->c_lock != NULL) { 1098 if (c->c_lock == &Giant.lock_object) 1099 use_lock = mtx_owned(&Giant); 1100 else { 1101 use_lock = 1; 1102 class = LOCK_CLASS(c->c_lock); 1103 class->lc_assert(c->c_lock, LA_XLOCKED); 1104 } 1105 } else 1106 use_lock = 0; 1107 direct = (c->c_flags & CALLOUT_DIRECT) != 0; 1108 sq_locked = 0; 1109 old_cc = NULL; 1110 again: 1111 cc = callout_lock(c); 1112 1113 /* 1114 * If the callout was migrating while the callout cpu lock was 1115 * dropped, just drop the sleepqueue lock and check the states 1116 * again. 1117 */ 1118 if (sq_locked != 0 && cc != old_cc) { 1119 #ifdef SMP 1120 CC_UNLOCK(cc); 1121 sleepq_release(&old_cc->cc_exec_entity[direct].cc_waiting); 1122 sq_locked = 0; 1123 old_cc = NULL; 1124 goto again; 1125 #else 1126 panic("migration should not happen"); 1127 #endif 1128 } 1129 1130 /* 1131 * If the callout isn't pending, it's not on the queue, so 1132 * don't attempt to remove it from the queue. We can try to 1133 * stop it by other means however. 1134 */ 1135 if (!(c->c_flags & CALLOUT_PENDING)) { 1136 c->c_flags &= ~CALLOUT_ACTIVE; 1137 1138 /* 1139 * If it wasn't on the queue and it isn't the current 1140 * callout, then we can't stop it, so just bail. 1141 */ 1142 if (cc->cc_exec_entity[direct].cc_curr != c) { 1143 CTR3(KTR_CALLOUT, "failed to stop %p func %p arg %p", 1144 c, c->c_func, c->c_arg); 1145 CC_UNLOCK(cc); 1146 if (sq_locked) 1147 sleepq_release( 1148 &cc->cc_exec_entity[direct].cc_waiting); 1149 return (0); 1150 } 1151 1152 if (safe) { 1153 /* 1154 * The current callout is running (or just 1155 * about to run) and blocking is allowed, so 1156 * just wait for the current invocation to 1157 * finish. 1158 */ 1159 while (cc->cc_exec_entity[direct].cc_curr == c) { 1160 /* 1161 * Use direct calls to sleepqueue interface 1162 * instead of cv/msleep in order to avoid 1163 * a LOR between cc_lock and sleepqueue 1164 * chain spinlocks. This piece of code 1165 * emulates a msleep_spin() call actually. 1166 * 1167 * If we already have the sleepqueue chain 1168 * locked, then we can safely block. If we 1169 * don't already have it locked, however, 1170 * we have to drop the cc_lock to lock 1171 * it. This opens several races, so we 1172 * restart at the beginning once we have 1173 * both locks. If nothing has changed, then 1174 * we will end up back here with sq_locked 1175 * set. 1176 */ 1177 if (!sq_locked) { 1178 CC_UNLOCK(cc); 1179 sleepq_lock( 1180 &cc->cc_exec_entity[direct].cc_waiting); 1181 sq_locked = 1; 1182 old_cc = cc; 1183 goto again; 1184 } 1185 1186 /* 1187 * Migration could be cancelled here, but 1188 * as long as it is still not sure when it 1189 * will be packed up, just let softclock() 1190 * take care of it. 1191 */ 1192 cc->cc_exec_entity[direct].cc_waiting = true; 1193 DROP_GIANT(); 1194 CC_UNLOCK(cc); 1195 sleepq_add( 1196 &cc->cc_exec_entity[direct].cc_waiting, 1197 &cc->cc_lock.lock_object, "codrain", 1198 SLEEPQ_SLEEP, 0); 1199 sleepq_wait( 1200 &cc->cc_exec_entity[direct].cc_waiting, 1201 0); 1202 sq_locked = 0; 1203 old_cc = NULL; 1204 1205 /* Reacquire locks previously released. */ 1206 PICKUP_GIANT(); 1207 CC_LOCK(cc); 1208 } 1209 } else if (use_lock && 1210 !cc->cc_exec_entity[direct].cc_cancel) { 1211 /* 1212 * The current callout is waiting for its 1213 * lock which we hold. Cancel the callout 1214 * and return. After our caller drops the 1215 * lock, the callout will be skipped in 1216 * softclock(). 1217 */ 1218 cc->cc_exec_entity[direct].cc_cancel = true; 1219 CTR3(KTR_CALLOUT, "cancelled %p func %p arg %p", 1220 c, c->c_func, c->c_arg); 1221 KASSERT(!cc_cce_migrating(cc, direct), 1222 ("callout wrongly scheduled for migration")); 1223 CC_UNLOCK(cc); 1224 KASSERT(!sq_locked, ("sleepqueue chain locked")); 1225 return (1); 1226 } else if ((c->c_flags & CALLOUT_DFRMIGRATION) != 0) { 1227 c->c_flags &= ~CALLOUT_DFRMIGRATION; 1228 CTR3(KTR_CALLOUT, "postponing stop %p func %p arg %p", 1229 c, c->c_func, c->c_arg); 1230 CC_UNLOCK(cc); 1231 return (1); 1232 } 1233 CTR3(KTR_CALLOUT, "failed to stop %p func %p arg %p", 1234 c, c->c_func, c->c_arg); 1235 CC_UNLOCK(cc); 1236 KASSERT(!sq_locked, ("sleepqueue chain still locked")); 1237 return (0); 1238 } 1239 if (sq_locked) 1240 sleepq_release(&cc->cc_exec_entity[direct].cc_waiting); 1241 1242 c->c_flags &= ~(CALLOUT_ACTIVE | CALLOUT_PENDING); 1243 1244 CTR3(KTR_CALLOUT, "cancelled %p func %p arg %p", 1245 c, c->c_func, c->c_arg); 1246 if ((c->c_flags & CALLOUT_PROCESSED) == 0) { 1247 if (cc->cc_exec_next_dir == c) 1248 cc->cc_exec_next_dir = LIST_NEXT(c, c_links.le); 1249 LIST_REMOVE(c, c_links.le); 1250 } else 1251 TAILQ_REMOVE(&cc->cc_expireq, c, c_links.tqe); 1252 callout_cc_del(c, cc); 1253 1254 CC_UNLOCK(cc); 1255 return (1); 1256 } 1257 1258 void 1259 callout_init(struct callout *c, int mpsafe) 1260 { 1261 bzero(c, sizeof *c); 1262 if (mpsafe) { 1263 c->c_lock = NULL; 1264 c->c_flags = CALLOUT_RETURNUNLOCKED; 1265 } else { 1266 c->c_lock = &Giant.lock_object; 1267 c->c_flags = 0; 1268 } 1269 c->c_cpu = timeout_cpu; 1270 } 1271 1272 void 1273 _callout_init_lock(struct callout *c, struct lock_object *lock, int flags) 1274 { 1275 bzero(c, sizeof *c); 1276 c->c_lock = lock; 1277 KASSERT((flags & ~(CALLOUT_RETURNUNLOCKED | CALLOUT_SHAREDLOCK)) == 0, 1278 ("callout_init_lock: bad flags %d", flags)); 1279 KASSERT(lock != NULL || (flags & CALLOUT_RETURNUNLOCKED) == 0, 1280 ("callout_init_lock: CALLOUT_RETURNUNLOCKED with no lock")); 1281 KASSERT(lock == NULL || !(LOCK_CLASS(lock)->lc_flags & 1282 (LC_SPINLOCK | LC_SLEEPABLE)), ("%s: invalid lock class", 1283 __func__)); 1284 c->c_flags = flags & (CALLOUT_RETURNUNLOCKED | CALLOUT_SHAREDLOCK); 1285 c->c_cpu = timeout_cpu; 1286 } 1287 1288 #ifdef APM_FIXUP_CALLTODO 1289 /* 1290 * Adjust the kernel calltodo timeout list. This routine is used after 1291 * an APM resume to recalculate the calltodo timer list values with the 1292 * number of hz's we have been sleeping. The next hardclock() will detect 1293 * that there are fired timers and run softclock() to execute them. 1294 * 1295 * Please note, I have not done an exhaustive analysis of what code this 1296 * might break. I am motivated to have my select()'s and alarm()'s that 1297 * have expired during suspend firing upon resume so that the applications 1298 * which set the timer can do the maintanence the timer was for as close 1299 * as possible to the originally intended time. Testing this code for a 1300 * week showed that resuming from a suspend resulted in 22 to 25 timers 1301 * firing, which seemed independant on whether the suspend was 2 hours or 1302 * 2 days. Your milage may vary. - Ken Key <key@cs.utk.edu> 1303 */ 1304 void 1305 adjust_timeout_calltodo(struct timeval *time_change) 1306 { 1307 register struct callout *p; 1308 unsigned long delta_ticks; 1309 1310 /* 1311 * How many ticks were we asleep? 1312 * (stolen from tvtohz()). 1313 */ 1314 1315 /* Don't do anything */ 1316 if (time_change->tv_sec < 0) 1317 return; 1318 else if (time_change->tv_sec <= LONG_MAX / 1000000) 1319 delta_ticks = (time_change->tv_sec * 1000000 + 1320 time_change->tv_usec + (tick - 1)) / tick + 1; 1321 else if (time_change->tv_sec <= LONG_MAX / hz) 1322 delta_ticks = time_change->tv_sec * hz + 1323 (time_change->tv_usec + (tick - 1)) / tick + 1; 1324 else 1325 delta_ticks = LONG_MAX; 1326 1327 if (delta_ticks > INT_MAX) 1328 delta_ticks = INT_MAX; 1329 1330 /* 1331 * Now rip through the timer calltodo list looking for timers 1332 * to expire. 1333 */ 1334 1335 /* don't collide with softclock() */ 1336 CC_LOCK(cc); 1337 for (p = calltodo.c_next; p != NULL; p = p->c_next) { 1338 p->c_time -= delta_ticks; 1339 1340 /* Break if the timer had more time on it than delta_ticks */ 1341 if (p->c_time > 0) 1342 break; 1343 1344 /* take back the ticks the timer didn't use (p->c_time <= 0) */ 1345 delta_ticks = -p->c_time; 1346 } 1347 CC_UNLOCK(cc); 1348 1349 return; 1350 } 1351 #endif /* APM_FIXUP_CALLTODO */ 1352 1353 static int 1354 flssbt(sbintime_t sbt) 1355 { 1356 1357 sbt += (uint64_t)sbt >> 1; 1358 if (sizeof(long) >= sizeof(sbintime_t)) 1359 return (flsl(sbt)); 1360 if (sbt >= SBT_1S) 1361 return (flsl(((uint64_t)sbt) >> 32) + 32); 1362 return (flsl(sbt)); 1363 } 1364 1365 /* 1366 * Dump immediate statistic snapshot of the scheduled callouts. 1367 */ 1368 static int 1369 sysctl_kern_callout_stat(SYSCTL_HANDLER_ARGS) 1370 { 1371 struct callout *tmp; 1372 struct callout_cpu *cc; 1373 struct callout_list *sc; 1374 sbintime_t maxpr, maxt, medpr, medt, now, spr, st, t; 1375 int ct[64], cpr[64], ccpbk[32]; 1376 int error, val, i, count, tcum, pcum, maxc, c, medc; 1377 #ifdef SMP 1378 int cpu; 1379 #endif 1380 1381 val = 0; 1382 error = sysctl_handle_int(oidp, &val, 0, req); 1383 if (error != 0 || req->newptr == NULL) 1384 return (error); 1385 count = maxc = 0; 1386 st = spr = maxt = maxpr = 0; 1387 bzero(ccpbk, sizeof(ccpbk)); 1388 bzero(ct, sizeof(ct)); 1389 bzero(cpr, sizeof(cpr)); 1390 now = sbinuptime(); 1391 #ifdef SMP 1392 CPU_FOREACH(cpu) { 1393 cc = CC_CPU(cpu); 1394 #else 1395 cc = CC_CPU(timeout_cpu); 1396 #endif 1397 CC_LOCK(cc); 1398 for (i = 0; i < callwheelsize; i++) { 1399 sc = &cc->cc_callwheel[i]; 1400 c = 0; 1401 LIST_FOREACH(tmp, sc, c_links.le) { 1402 c++; 1403 t = tmp->c_time - now; 1404 if (t < 0) 1405 t = 0; 1406 st += t / SBT_1US; 1407 spr += tmp->c_precision / SBT_1US; 1408 if (t > maxt) 1409 maxt = t; 1410 if (tmp->c_precision > maxpr) 1411 maxpr = tmp->c_precision; 1412 ct[flssbt(t)]++; 1413 cpr[flssbt(tmp->c_precision)]++; 1414 } 1415 if (c > maxc) 1416 maxc = c; 1417 ccpbk[fls(c + c / 2)]++; 1418 count += c; 1419 } 1420 CC_UNLOCK(cc); 1421 #ifdef SMP 1422 } 1423 #endif 1424 1425 for (i = 0, tcum = 0; i < 64 && tcum < count / 2; i++) 1426 tcum += ct[i]; 1427 medt = (i >= 2) ? (((sbintime_t)1) << (i - 2)) : 0; 1428 for (i = 0, pcum = 0; i < 64 && pcum < count / 2; i++) 1429 pcum += cpr[i]; 1430 medpr = (i >= 2) ? (((sbintime_t)1) << (i - 2)) : 0; 1431 for (i = 0, c = 0; i < 32 && c < count / 2; i++) 1432 c += ccpbk[i]; 1433 medc = (i >= 2) ? (1 << (i - 2)) : 0; 1434 1435 printf("Scheduled callouts statistic snapshot:\n"); 1436 printf(" Callouts: %6d Buckets: %6d*%-3d Bucket size: 0.%06ds\n", 1437 count, callwheelsize, mp_ncpus, 1000000 >> CC_HASH_SHIFT); 1438 printf(" C/Bk: med %5d avg %6d.%06jd max %6d\n", 1439 medc, 1440 count / callwheelsize / mp_ncpus, 1441 (uint64_t)count * 1000000 / callwheelsize / mp_ncpus % 1000000, 1442 maxc); 1443 printf(" Time: med %5jd.%06jds avg %6jd.%06jds max %6jd.%06jds\n", 1444 medt / SBT_1S, (medt & 0xffffffff) * 1000000 >> 32, 1445 (st / count) / 1000000, (st / count) % 1000000, 1446 maxt / SBT_1S, (maxt & 0xffffffff) * 1000000 >> 32); 1447 printf(" Prec: med %5jd.%06jds avg %6jd.%06jds max %6jd.%06jds\n", 1448 medpr / SBT_1S, (medpr & 0xffffffff) * 1000000 >> 32, 1449 (spr / count) / 1000000, (spr / count) % 1000000, 1450 maxpr / SBT_1S, (maxpr & 0xffffffff) * 1000000 >> 32); 1451 printf(" Distribution: \tbuckets\t time\t tcum\t" 1452 " prec\t pcum\n"); 1453 for (i = 0, tcum = pcum = 0; i < 64; i++) { 1454 if (ct[i] == 0 && cpr[i] == 0) 1455 continue; 1456 t = (i != 0) ? (((sbintime_t)1) << (i - 1)) : 0; 1457 tcum += ct[i]; 1458 pcum += cpr[i]; 1459 printf(" %10jd.%06jds\t 2**%d\t%7d\t%7d\t%7d\t%7d\n", 1460 t / SBT_1S, (t & 0xffffffff) * 1000000 >> 32, 1461 i - 1 - (32 - CC_HASH_SHIFT), 1462 ct[i], tcum, cpr[i], pcum); 1463 } 1464 return (error); 1465 } 1466 SYSCTL_PROC(_kern, OID_AUTO, callout_stat, 1467 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 1468 0, 0, sysctl_kern_callout_stat, "I", 1469 "Dump immediate statistic snapshot of the scheduled callouts"); 1470