1 /* $NetBSD: kern_timeout.c,v 1.30 2007/12/05 07:06:53 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 2003, 2006, 2007 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe, and by Andrew Doran. 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Copyright (c) 2001 Thomas Nordin <nordin@openbsd.org> 41 * Copyright (c) 2000-2001 Artur Grabowski <art@openbsd.org> 42 * All rights reserved. 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 48 * 1. Redistributions of source code must retain the above copyright 49 * notice, this list of conditions and the following disclaimer. 50 * 2. Redistributions in binary form must reproduce the above copyright 51 * notice, this list of conditions and the following disclaimer in the 52 * documentation and/or other materials provided with the distribution. 53 * 3. The name of the author may not be used to endorse or promote products 54 * derived from this software without specific prior written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 57 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY 58 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 59 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 60 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 61 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 62 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 63 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 64 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 65 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 66 */ 67 68 #include <sys/cdefs.h> 69 __KERNEL_RCSID(0, "$NetBSD: kern_timeout.c,v 1.30 2007/12/05 07:06:53 ad Exp $"); 70 71 /* 72 * Timeouts are kept in a hierarchical timing wheel. The c_time is the 73 * value of the global variable "hardclock_ticks" when the timeout should 74 * be called. There are four levels with 256 buckets each. See 'Scheme 7' 75 * in "Hashed and Hierarchical Timing Wheels: Efficient Data Structures 76 * for Implementing a Timer Facility" by George Varghese and Tony Lauck. 77 * 78 * Some of the "math" in here is a bit tricky. We have to beware of 79 * wrapping ints. 80 * 81 * We use the fact that any element added to the queue must be added with 82 * a positive time. That means that any element `to' on the queue cannot 83 * be scheduled to timeout further in time than INT_MAX, but c->c_time can 84 * be positive or negative so comparing it with anything is dangerous. 85 * The only way we can use the c->c_time value in any predictable way is 86 * when we calculate how far in the future `to' will timeout - "c->c_time 87 * - hardclock_ticks". The result will always be positive for future 88 * timeouts and 0 or negative for due timeouts. 89 */ 90 91 #define _CALLOUT_PRIVATE 92 93 #include <sys/param.h> 94 #include <sys/systm.h> 95 #include <sys/kernel.h> 96 #include <sys/lock.h> 97 #include <sys/callout.h> 98 #include <sys/mutex.h> 99 #include <sys/proc.h> 100 #include <sys/sleepq.h> 101 #include <sys/syncobj.h> 102 #include <sys/evcnt.h> 103 #include <sys/intr.h> 104 105 #ifdef DDB 106 #include <machine/db_machdep.h> 107 #include <ddb/db_interface.h> 108 #include <ddb/db_access.h> 109 #include <ddb/db_sym.h> 110 #include <ddb/db_output.h> 111 #endif 112 113 #define BUCKETS 1024 114 #define WHEELSIZE 256 115 #define WHEELMASK 255 116 #define WHEELBITS 8 117 118 static struct callout_circq timeout_wheel[BUCKETS]; /* Queues of timeouts */ 119 static struct callout_circq timeout_todo; /* Worklist */ 120 121 #define MASKWHEEL(wheel, time) (((time) >> ((wheel)*WHEELBITS)) & WHEELMASK) 122 123 #define BUCKET(rel, abs) \ 124 (((rel) <= (1 << (2*WHEELBITS))) \ 125 ? ((rel) <= (1 << WHEELBITS)) \ 126 ? &timeout_wheel[MASKWHEEL(0, (abs))] \ 127 : &timeout_wheel[MASKWHEEL(1, (abs)) + WHEELSIZE] \ 128 : ((rel) <= (1 << (3*WHEELBITS))) \ 129 ? &timeout_wheel[MASKWHEEL(2, (abs)) + 2*WHEELSIZE] \ 130 : &timeout_wheel[MASKWHEEL(3, (abs)) + 3*WHEELSIZE]) 131 132 #define MOVEBUCKET(wheel, time) \ 133 CIRCQ_APPEND(&timeout_todo, \ 134 &timeout_wheel[MASKWHEEL((wheel), (time)) + (wheel)*WHEELSIZE]) 135 136 /* 137 * Circular queue definitions. 138 */ 139 140 #define CIRCQ_INIT(list) \ 141 do { \ 142 (list)->cq_next_l = (list); \ 143 (list)->cq_prev_l = (list); \ 144 } while (/*CONSTCOND*/0) 145 146 #define CIRCQ_INSERT(elem, list) \ 147 do { \ 148 (elem)->cq_prev_e = (list)->cq_prev_e; \ 149 (elem)->cq_next_l = (list); \ 150 (list)->cq_prev_l->cq_next_l = (elem); \ 151 (list)->cq_prev_l = (elem); \ 152 } while (/*CONSTCOND*/0) 153 154 #define CIRCQ_APPEND(fst, snd) \ 155 do { \ 156 if (!CIRCQ_EMPTY(snd)) { \ 157 (fst)->cq_prev_l->cq_next_l = (snd)->cq_next_l; \ 158 (snd)->cq_next_l->cq_prev_l = (fst)->cq_prev_l; \ 159 (snd)->cq_prev_l->cq_next_l = (fst); \ 160 (fst)->cq_prev_l = (snd)->cq_prev_l; \ 161 CIRCQ_INIT(snd); \ 162 } \ 163 } while (/*CONSTCOND*/0) 164 165 #define CIRCQ_REMOVE(elem) \ 166 do { \ 167 (elem)->cq_next_l->cq_prev_e = (elem)->cq_prev_e; \ 168 (elem)->cq_prev_l->cq_next_e = (elem)->cq_next_e; \ 169 } while (/*CONSTCOND*/0) 170 171 #define CIRCQ_FIRST(list) ((list)->cq_next_e) 172 #define CIRCQ_NEXT(elem) ((elem)->cq_next_e) 173 #define CIRCQ_LAST(elem,list) ((elem)->cq_next_l == (list)) 174 #define CIRCQ_EMPTY(list) ((list)->cq_next_l == (list)) 175 176 static void callout_softclock(void *); 177 178 /* 179 * All wheels are locked with the same lock (which must also block out 180 * all interrupts). Eventually this should become per-CPU. 181 */ 182 kmutex_t callout_lock; 183 sleepq_t callout_sleepq; 184 void *callout_si; 185 186 static struct evcnt callout_ev_late; 187 static struct evcnt callout_ev_block; 188 189 /* 190 * callout_barrier: 191 * 192 * If the callout is already running, wait until it completes. 193 * XXX This should do priority inheritance. 194 */ 195 static void 196 callout_barrier(callout_impl_t *c) 197 { 198 extern syncobj_t sleep_syncobj; 199 struct cpu_info *ci; 200 struct lwp *l; 201 202 l = curlwp; 203 204 if ((c->c_flags & CALLOUT_MPSAFE) == 0) { 205 /* 206 * Note: we must be called with the kernel lock held, 207 * as we use it to synchronize with callout_softclock(). 208 */ 209 ci = c->c_oncpu; 210 ci->ci_data.cpu_callout_cancel = c; 211 return; 212 } 213 214 while ((ci = c->c_oncpu) != NULL && ci->ci_data.cpu_callout == c) { 215 KASSERT(l->l_wchan == NULL); 216 217 ci->ci_data.cpu_callout_nwait++; 218 callout_ev_block.ev_count++; 219 220 l->l_kpriority = true; 221 sleepq_enter(&callout_sleepq, l); 222 sleepq_enqueue(&callout_sleepq, ci, "callout", &sleep_syncobj); 223 sleepq_block(0, false); 224 mutex_spin_enter(&callout_lock); 225 } 226 } 227 228 /* 229 * callout_running: 230 * 231 * Return non-zero if callout 'c' is currently executing. 232 */ 233 static inline bool 234 callout_running(callout_impl_t *c) 235 { 236 struct cpu_info *ci; 237 238 if ((ci = c->c_oncpu) == NULL) 239 return false; 240 if (ci->ci_data.cpu_callout != c) 241 return false; 242 if (c->c_onlwp == curlwp) 243 return false; 244 return true; 245 } 246 247 /* 248 * callout_startup: 249 * 250 * Initialize the callout facility, called at system startup time. 251 */ 252 void 253 callout_startup(void) 254 { 255 int b; 256 257 KASSERT(sizeof(callout_impl_t) <= sizeof(callout_t)); 258 259 CIRCQ_INIT(&timeout_todo); 260 for (b = 0; b < BUCKETS; b++) 261 CIRCQ_INIT(&timeout_wheel[b]); 262 263 mutex_init(&callout_lock, MUTEX_DEFAULT, IPL_SCHED); 264 sleepq_init(&callout_sleepq, &callout_lock); 265 266 evcnt_attach_dynamic(&callout_ev_late, EVCNT_TYPE_MISC, 267 NULL, "callout", "late"); 268 evcnt_attach_dynamic(&callout_ev_block, EVCNT_TYPE_MISC, 269 NULL, "callout", "block waiting"); 270 } 271 272 /* 273 * callout_startup2: 274 * 275 * Complete initialization once soft interrupts are available. 276 */ 277 void 278 callout_startup2(void) 279 { 280 281 callout_si = softint_establish(SOFTINT_CLOCK | SOFTINT_MPSAFE, 282 callout_softclock, NULL); 283 if (callout_si == NULL) 284 panic("callout_startup2: unable to register softclock intr"); 285 } 286 287 /* 288 * callout_init: 289 * 290 * Initialize a callout structure. 291 */ 292 void 293 callout_init(callout_t *cs, u_int flags) 294 { 295 callout_impl_t *c = (callout_impl_t *)cs; 296 297 KASSERT((flags & ~CALLOUT_FLAGMASK) == 0); 298 299 memset(c, 0, sizeof(*c)); 300 c->c_flags = flags; 301 c->c_magic = CALLOUT_MAGIC; 302 } 303 304 /* 305 * callout_destroy: 306 * 307 * Destroy a callout structure. The callout must be stopped. 308 */ 309 void 310 callout_destroy(callout_t *cs) 311 { 312 callout_impl_t *c = (callout_impl_t *)cs; 313 314 /* 315 * It's not necessary to lock in order to see the correct value 316 * of c->c_flags. If the callout could potentially have been 317 * running, the current thread should have stopped it. 318 */ 319 KASSERT((c->c_flags & CALLOUT_PENDING) == 0); 320 if (c->c_oncpu != NULL) { 321 KASSERT( 322 ((struct cpu_info *)c->c_oncpu)->ci_data.cpu_callout != c); 323 } 324 KASSERT(c->c_magic == CALLOUT_MAGIC); 325 326 c->c_magic = 0; 327 } 328 329 /* 330 * callout_schedule_locked: 331 * 332 * Schedule a callout to run. The function and argument must 333 * already be set in the callout structure. Must be called with 334 * callout_lock. 335 */ 336 static void 337 callout_schedule_locked(callout_impl_t *c, int to_ticks) 338 { 339 int old_time; 340 341 KASSERT(to_ticks >= 0); 342 KASSERT(c->c_func != NULL); 343 344 /* Initialize the time here, it won't change. */ 345 old_time = c->c_time; 346 c->c_time = to_ticks + hardclock_ticks; 347 c->c_flags &= ~CALLOUT_FIRED; 348 349 /* 350 * If this timeout is already scheduled and now is moved 351 * earlier, reschedule it now. Otherwise leave it in place 352 * and let it be rescheduled later. 353 */ 354 if ((c->c_flags & CALLOUT_PENDING) != 0) { 355 if (c->c_time - old_time < 0) { 356 CIRCQ_REMOVE(&c->c_list); 357 CIRCQ_INSERT(&c->c_list, &timeout_todo); 358 } 359 } else { 360 c->c_flags |= CALLOUT_PENDING; 361 CIRCQ_INSERT(&c->c_list, &timeout_todo); 362 } 363 } 364 365 /* 366 * callout_reset: 367 * 368 * Reset a callout structure with a new function and argument, and 369 * schedule it to run. 370 */ 371 void 372 callout_reset(callout_t *cs, int to_ticks, void (*func)(void *), void *arg) 373 { 374 callout_impl_t *c = (callout_impl_t *)cs; 375 376 KASSERT(c->c_magic == CALLOUT_MAGIC); 377 378 mutex_spin_enter(&callout_lock); 379 380 c->c_func = func; 381 c->c_arg = arg; 382 383 callout_schedule_locked(c, to_ticks); 384 385 mutex_spin_exit(&callout_lock); 386 } 387 388 /* 389 * callout_schedule: 390 * 391 * Schedule a callout to run. The function and argument must 392 * already be set in the callout structure. 393 */ 394 void 395 callout_schedule(callout_t *cs, int to_ticks) 396 { 397 callout_impl_t *c = (callout_impl_t *)cs; 398 399 KASSERT(c->c_magic == CALLOUT_MAGIC); 400 401 mutex_spin_enter(&callout_lock); 402 callout_schedule_locked(c, to_ticks); 403 mutex_spin_exit(&callout_lock); 404 } 405 406 /* 407 * callout_stop: 408 * 409 * Cancel a pending callout. 410 */ 411 bool 412 callout_stop(callout_t *cs) 413 { 414 callout_impl_t *c = (callout_impl_t *)cs; 415 bool expired; 416 417 KASSERT(c->c_magic == CALLOUT_MAGIC); 418 419 mutex_spin_enter(&callout_lock); 420 421 if (callout_running(c)) 422 callout_barrier(c); 423 424 if ((c->c_flags & CALLOUT_PENDING) != 0) 425 CIRCQ_REMOVE(&c->c_list); 426 427 expired = ((c->c_flags & CALLOUT_FIRED) != 0); 428 c->c_flags &= ~(CALLOUT_PENDING|CALLOUT_FIRED); 429 430 mutex_spin_exit(&callout_lock); 431 432 return expired; 433 } 434 435 void 436 callout_setfunc(callout_t *cs, void (*func)(void *), void *arg) 437 { 438 callout_impl_t *c = (callout_impl_t *)cs; 439 440 KASSERT(c->c_magic == CALLOUT_MAGIC); 441 442 mutex_spin_enter(&callout_lock); 443 c->c_func = func; 444 c->c_arg = arg; 445 mutex_spin_exit(&callout_lock); 446 } 447 448 bool 449 callout_expired(callout_t *cs) 450 { 451 callout_impl_t *c = (callout_impl_t *)cs; 452 bool rv; 453 454 KASSERT(c->c_magic == CALLOUT_MAGIC); 455 456 mutex_spin_enter(&callout_lock); 457 rv = ((c->c_flags & CALLOUT_FIRED) != 0); 458 mutex_spin_exit(&callout_lock); 459 460 return rv; 461 } 462 463 bool 464 callout_active(callout_t *cs) 465 { 466 callout_impl_t *c = (callout_impl_t *)cs; 467 bool rv; 468 469 KASSERT(c->c_magic == CALLOUT_MAGIC); 470 471 mutex_spin_enter(&callout_lock); 472 rv = ((c->c_flags & (CALLOUT_PENDING|CALLOUT_FIRED)) != 0); 473 mutex_spin_exit(&callout_lock); 474 475 return rv; 476 } 477 478 bool 479 callout_pending(callout_t *cs) 480 { 481 callout_impl_t *c = (callout_impl_t *)cs; 482 bool rv; 483 484 KASSERT(c->c_magic == CALLOUT_MAGIC); 485 486 mutex_spin_enter(&callout_lock); 487 rv = ((c->c_flags & CALLOUT_PENDING) != 0); 488 mutex_spin_exit(&callout_lock); 489 490 return rv; 491 } 492 493 bool 494 callout_invoking(callout_t *cs) 495 { 496 callout_impl_t *c = (callout_impl_t *)cs; 497 bool rv; 498 499 KASSERT(c->c_magic == CALLOUT_MAGIC); 500 501 mutex_spin_enter(&callout_lock); 502 rv = ((c->c_flags & CALLOUT_INVOKING) != 0); 503 mutex_spin_exit(&callout_lock); 504 505 return rv; 506 } 507 508 void 509 callout_ack(callout_t *cs) 510 { 511 callout_impl_t *c = (callout_impl_t *)cs; 512 513 KASSERT(c->c_magic == CALLOUT_MAGIC); 514 515 mutex_spin_enter(&callout_lock); 516 c->c_flags &= ~CALLOUT_INVOKING; 517 mutex_spin_exit(&callout_lock); 518 } 519 520 /* 521 * This is called from hardclock() once every tick. 522 * We schedule callout_softclock() if there is work 523 * to be done. 524 */ 525 void 526 callout_hardclock(void) 527 { 528 int needsoftclock; 529 530 mutex_spin_enter(&callout_lock); 531 532 MOVEBUCKET(0, hardclock_ticks); 533 if (MASKWHEEL(0, hardclock_ticks) == 0) { 534 MOVEBUCKET(1, hardclock_ticks); 535 if (MASKWHEEL(1, hardclock_ticks) == 0) { 536 MOVEBUCKET(2, hardclock_ticks); 537 if (MASKWHEEL(2, hardclock_ticks) == 0) 538 MOVEBUCKET(3, hardclock_ticks); 539 } 540 } 541 542 needsoftclock = !CIRCQ_EMPTY(&timeout_todo); 543 mutex_spin_exit(&callout_lock); 544 545 if (needsoftclock) 546 softint_schedule(callout_si); 547 } 548 549 /* ARGSUSED */ 550 static void 551 callout_softclock(void *v) 552 { 553 callout_impl_t *c; 554 struct cpu_info *ci; 555 void (*func)(void *); 556 void *arg; 557 u_int mpsafe, count; 558 lwp_t *l; 559 560 l = curlwp; 561 ci = l->l_cpu; 562 563 mutex_spin_enter(&callout_lock); 564 565 while (!CIRCQ_EMPTY(&timeout_todo)) { 566 c = CIRCQ_FIRST(&timeout_todo); 567 KASSERT(c->c_magic == CALLOUT_MAGIC); 568 KASSERT(c->c_func != NULL); 569 KASSERT((c->c_flags & CALLOUT_PENDING) != 0); 570 KASSERT((c->c_flags & CALLOUT_FIRED) == 0); 571 CIRCQ_REMOVE(&c->c_list); 572 573 /* If due run it, otherwise insert it into the right bucket. */ 574 if (c->c_time - hardclock_ticks > 0) { 575 CIRCQ_INSERT(&c->c_list, 576 BUCKET((c->c_time - hardclock_ticks), c->c_time)); 577 } else { 578 if (c->c_time - hardclock_ticks < 0) 579 callout_ev_late.ev_count++; 580 581 c->c_flags ^= (CALLOUT_PENDING | CALLOUT_FIRED); 582 mpsafe = (c->c_flags & CALLOUT_MPSAFE); 583 func = c->c_func; 584 arg = c->c_arg; 585 c->c_oncpu = ci; 586 c->c_onlwp = l; 587 588 mutex_spin_exit(&callout_lock); 589 if (!mpsafe) { 590 KERNEL_LOCK(1, curlwp); 591 if (ci->ci_data.cpu_callout_cancel != c) 592 (*func)(arg); 593 KERNEL_UNLOCK_ONE(curlwp); 594 } else 595 (*func)(arg); 596 mutex_spin_enter(&callout_lock); 597 598 /* 599 * We can't touch 'c' here because it might be 600 * freed already. If LWPs waiting for callout 601 * to complete, awaken them. 602 */ 603 ci->ci_data.cpu_callout_cancel = NULL; 604 ci->ci_data.cpu_callout = NULL; 605 if ((count = ci->ci_data.cpu_callout_nwait) != 0) { 606 ci->ci_data.cpu_callout_nwait = 0; 607 /* sleepq_wake() drops the lock. */ 608 sleepq_wake(&callout_sleepq, ci, count); 609 mutex_spin_enter(&callout_lock); 610 } 611 } 612 } 613 614 mutex_spin_exit(&callout_lock); 615 } 616 617 #ifdef DDB 618 static void 619 db_show_callout_bucket(struct callout_circq *bucket) 620 { 621 callout_impl_t *c; 622 db_expr_t offset; 623 const char *name; 624 static char question[] = "?"; 625 626 if (CIRCQ_EMPTY(bucket)) 627 return; 628 629 for (c = CIRCQ_FIRST(bucket); /*nothing*/; c = CIRCQ_NEXT(&c->c_list)) { 630 db_find_sym_and_offset((db_addr_t)(intptr_t)c->c_func, &name, 631 &offset); 632 name = name ? name : question; 633 #ifdef _LP64 634 #define POINTER_WIDTH "%16lx" 635 #else 636 #define POINTER_WIDTH "%8lx" 637 #endif 638 db_printf("%9d %2d/%-4d " POINTER_WIDTH " %s\n", 639 c->c_time - hardclock_ticks, 640 (int)((bucket - timeout_wheel) / WHEELSIZE), 641 (int)(bucket - timeout_wheel), (u_long) c->c_arg, name); 642 643 if (CIRCQ_LAST(&c->c_list, bucket)) 644 break; 645 } 646 } 647 648 void 649 db_show_callout(db_expr_t addr, bool haddr, db_expr_t count, const char *modif) 650 { 651 int b; 652 653 db_printf("hardclock_ticks now: %d\n", hardclock_ticks); 654 #ifdef _LP64 655 db_printf(" ticks wheel arg func\n"); 656 #else 657 db_printf(" ticks wheel arg func\n"); 658 #endif 659 660 /* 661 * Don't lock the callwheel; all the other CPUs are paused 662 * anyhow, and we might be called in a circumstance where 663 * some other CPU was paused while holding the lock. 664 */ 665 666 db_show_callout_bucket(&timeout_todo); 667 for (b = 0; b < BUCKETS; b++) 668 db_show_callout_bucket(&timeout_wheel[b]); 669 } 670 #endif /* DDB */ 671