1 /*- 2 * Copyright (c) 1982, 1986, 1990, 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 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include "opt_hwpmc_hooks.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/kernel.h> 43 #include <sys/ktr.h> 44 #include <sys/lock.h> 45 #include <sys/kthread.h> 46 #include <sys/mutex.h> 47 #include <sys/proc.h> 48 #include <sys/resourcevar.h> 49 #include <sys/sched.h> 50 #include <sys/smp.h> 51 #include <sys/sysctl.h> 52 #include <sys/sx.h> 53 #include <sys/turnstile.h> 54 #include <sys/umtx.h> 55 #include <machine/pcb.h> 56 #include <machine/smp.h> 57 58 #ifdef HWPMC_HOOKS 59 #include <sys/pmckern.h> 60 #endif 61 62 /* 63 * INVERSE_ESTCPU_WEIGHT is only suitable for statclock() frequencies in 64 * the range 100-256 Hz (approximately). 65 */ 66 #define ESTCPULIM(e) \ 67 min((e), INVERSE_ESTCPU_WEIGHT * (NICE_WEIGHT * (PRIO_MAX - PRIO_MIN) - \ 68 RQ_PPQ) + INVERSE_ESTCPU_WEIGHT - 1) 69 #ifdef SMP 70 #define INVERSE_ESTCPU_WEIGHT (8 * smp_cpus) 71 #else 72 #define INVERSE_ESTCPU_WEIGHT 8 /* 1 / (priorities per estcpu level). */ 73 #endif 74 #define NICE_WEIGHT 1 /* Priorities per nice level. */ 75 76 /* 77 * The schedulable entity that runs a context. 78 * This is an extension to the thread structure and is tailored to 79 * the requirements of this scheduler 80 */ 81 struct td_sched { 82 TAILQ_ENTRY(td_sched) ts_procq; /* (j/z) Run queue. */ 83 struct thread *ts_thread; /* (*) Active associated thread. */ 84 fixpt_t ts_pctcpu; /* (j) %cpu during p_swtime. */ 85 u_char ts_rqindex; /* (j) Run queue index. */ 86 int ts_cpticks; /* (j) Ticks of cpu time. */ 87 struct runq *ts_runq; /* runq the thread is currently on */ 88 }; 89 90 /* flags kept in td_flags */ 91 #define TDF_DIDRUN TDF_SCHED0 /* thread actually ran. */ 92 #define TDF_EXIT TDF_SCHED1 /* thread is being killed. */ 93 #define TDF_BOUND TDF_SCHED2 94 95 #define ts_flags ts_thread->td_flags 96 #define TSF_DIDRUN TDF_DIDRUN /* thread actually ran. */ 97 #define TSF_EXIT TDF_EXIT /* thread is being killed. */ 98 #define TSF_BOUND TDF_BOUND /* stuck to one CPU */ 99 100 #define SKE_RUNQ_PCPU(ts) \ 101 ((ts)->ts_runq != 0 && (ts)->ts_runq != &runq) 102 103 static struct td_sched td_sched0; 104 105 static int sched_tdcnt; /* Total runnable threads in the system. */ 106 static int sched_quantum; /* Roundrobin scheduling quantum in ticks. */ 107 #define SCHED_QUANTUM (hz / 10) /* Default sched quantum */ 108 109 static struct callout roundrobin_callout; 110 111 static void setup_runqs(void); 112 static void roundrobin(void *arg); 113 static void schedcpu(void); 114 static void schedcpu_thread(void); 115 static void sched_priority(struct thread *td, u_char prio); 116 static void sched_setup(void *dummy); 117 static void maybe_resched(struct thread *td); 118 static void updatepri(struct thread *td); 119 static void resetpriority(struct thread *td); 120 static void resetpriority_thread(struct thread *td); 121 #ifdef SMP 122 static int forward_wakeup(int cpunum); 123 #endif 124 125 static struct kproc_desc sched_kp = { 126 "schedcpu", 127 schedcpu_thread, 128 NULL 129 }; 130 SYSINIT(schedcpu, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, kproc_start, &sched_kp) 131 SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL) 132 133 /* 134 * Global run queue. 135 */ 136 static struct runq runq; 137 138 #ifdef SMP 139 /* 140 * Per-CPU run queues 141 */ 142 static struct runq runq_pcpu[MAXCPU]; 143 #endif 144 145 static void 146 setup_runqs(void) 147 { 148 #ifdef SMP 149 int i; 150 151 for (i = 0; i < MAXCPU; ++i) 152 runq_init(&runq_pcpu[i]); 153 #endif 154 155 runq_init(&runq); 156 } 157 158 static int 159 sysctl_kern_quantum(SYSCTL_HANDLER_ARGS) 160 { 161 int error, new_val; 162 163 new_val = sched_quantum * tick; 164 error = sysctl_handle_int(oidp, &new_val, 0, req); 165 if (error != 0 || req->newptr == NULL) 166 return (error); 167 if (new_val < tick) 168 return (EINVAL); 169 sched_quantum = new_val / tick; 170 hogticks = 2 * sched_quantum; 171 return (0); 172 } 173 174 SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RD, 0, "Scheduler"); 175 176 SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "4BSD", 0, 177 "Scheduler name"); 178 179 SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, CTLTYPE_INT | CTLFLAG_RW, 180 0, sizeof sched_quantum, sysctl_kern_quantum, "I", 181 "Roundrobin scheduling quantum in microseconds"); 182 183 #ifdef SMP 184 /* Enable forwarding of wakeups to all other cpus */ 185 SYSCTL_NODE(_kern_sched, OID_AUTO, ipiwakeup, CTLFLAG_RD, NULL, "Kernel SMP"); 186 187 static int forward_wakeup_enabled = 1; 188 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, enabled, CTLFLAG_RW, 189 &forward_wakeup_enabled, 0, 190 "Forwarding of wakeup to idle CPUs"); 191 192 static int forward_wakeups_requested = 0; 193 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, requested, CTLFLAG_RD, 194 &forward_wakeups_requested, 0, 195 "Requests for Forwarding of wakeup to idle CPUs"); 196 197 static int forward_wakeups_delivered = 0; 198 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, delivered, CTLFLAG_RD, 199 &forward_wakeups_delivered, 0, 200 "Completed Forwarding of wakeup to idle CPUs"); 201 202 static int forward_wakeup_use_mask = 1; 203 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, usemask, CTLFLAG_RW, 204 &forward_wakeup_use_mask, 0, 205 "Use the mask of idle cpus"); 206 207 static int forward_wakeup_use_loop = 0; 208 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, useloop, CTLFLAG_RW, 209 &forward_wakeup_use_loop, 0, 210 "Use a loop to find idle cpus"); 211 212 static int forward_wakeup_use_single = 0; 213 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, onecpu, CTLFLAG_RW, 214 &forward_wakeup_use_single, 0, 215 "Only signal one idle cpu"); 216 217 static int forward_wakeup_use_htt = 0; 218 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, htt2, CTLFLAG_RW, 219 &forward_wakeup_use_htt, 0, 220 "account for htt"); 221 222 #endif 223 #if 0 224 static int sched_followon = 0; 225 SYSCTL_INT(_kern_sched, OID_AUTO, followon, CTLFLAG_RW, 226 &sched_followon, 0, 227 "allow threads to share a quantum"); 228 #endif 229 230 static __inline void 231 sched_load_add(void) 232 { 233 sched_tdcnt++; 234 CTR1(KTR_SCHED, "global load: %d", sched_tdcnt); 235 } 236 237 static __inline void 238 sched_load_rem(void) 239 { 240 sched_tdcnt--; 241 CTR1(KTR_SCHED, "global load: %d", sched_tdcnt); 242 } 243 /* 244 * Arrange to reschedule if necessary, taking the priorities and 245 * schedulers into account. 246 */ 247 static void 248 maybe_resched(struct thread *td) 249 { 250 251 mtx_assert(&sched_lock, MA_OWNED); 252 if (td->td_priority < curthread->td_priority) 253 curthread->td_flags |= TDF_NEEDRESCHED; 254 } 255 256 /* 257 * Force switch among equal priority processes every 100ms. 258 * We don't actually need to force a context switch of the current process. 259 * The act of firing the event triggers a context switch to softclock() and 260 * then switching back out again which is equivalent to a preemption, thus 261 * no further work is needed on the local CPU. 262 */ 263 /* ARGSUSED */ 264 static void 265 roundrobin(void *arg) 266 { 267 268 #ifdef SMP 269 mtx_lock_spin(&sched_lock); 270 forward_roundrobin(); 271 mtx_unlock_spin(&sched_lock); 272 #endif 273 274 callout_reset(&roundrobin_callout, sched_quantum, roundrobin, NULL); 275 } 276 277 /* 278 * Constants for digital decay and forget: 279 * 90% of (td_estcpu) usage in 5 * loadav time 280 * 95% of (ts_pctcpu) usage in 60 seconds (load insensitive) 281 * Note that, as ps(1) mentions, this can let percentages 282 * total over 100% (I've seen 137.9% for 3 processes). 283 * 284 * Note that schedclock() updates td_estcpu and p_cpticks asynchronously. 285 * 286 * We wish to decay away 90% of td_estcpu in (5 * loadavg) seconds. 287 * That is, the system wants to compute a value of decay such 288 * that the following for loop: 289 * for (i = 0; i < (5 * loadavg); i++) 290 * td_estcpu *= decay; 291 * will compute 292 * td_estcpu *= 0.1; 293 * for all values of loadavg: 294 * 295 * Mathematically this loop can be expressed by saying: 296 * decay ** (5 * loadavg) ~= .1 297 * 298 * The system computes decay as: 299 * decay = (2 * loadavg) / (2 * loadavg + 1) 300 * 301 * We wish to prove that the system's computation of decay 302 * will always fulfill the equation: 303 * decay ** (5 * loadavg) ~= .1 304 * 305 * If we compute b as: 306 * b = 2 * loadavg 307 * then 308 * decay = b / (b + 1) 309 * 310 * We now need to prove two things: 311 * 1) Given factor ** (5 * loadavg) ~= .1, prove factor == b/(b+1) 312 * 2) Given b/(b+1) ** power ~= .1, prove power == (5 * loadavg) 313 * 314 * Facts: 315 * For x close to zero, exp(x) =~ 1 + x, since 316 * exp(x) = 0! + x**1/1! + x**2/2! + ... . 317 * therefore exp(-1/b) =~ 1 - (1/b) = (b-1)/b. 318 * For x close to zero, ln(1+x) =~ x, since 319 * ln(1+x) = x - x**2/2 + x**3/3 - ... -1 < x < 1 320 * therefore ln(b/(b+1)) = ln(1 - 1/(b+1)) =~ -1/(b+1). 321 * ln(.1) =~ -2.30 322 * 323 * Proof of (1): 324 * Solve (factor)**(power) =~ .1 given power (5*loadav): 325 * solving for factor, 326 * ln(factor) =~ (-2.30/5*loadav), or 327 * factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) = 328 * exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED 329 * 330 * Proof of (2): 331 * Solve (factor)**(power) =~ .1 given factor == (b/(b+1)): 332 * solving for power, 333 * power*ln(b/(b+1)) =~ -2.30, or 334 * power =~ 2.3 * (b + 1) = 4.6*loadav + 2.3 =~ 5*loadav. QED 335 * 336 * Actual power values for the implemented algorithm are as follows: 337 * loadav: 1 2 3 4 338 * power: 5.68 10.32 14.94 19.55 339 */ 340 341 /* calculations for digital decay to forget 90% of usage in 5*loadav sec */ 342 #define loadfactor(loadav) (2 * (loadav)) 343 #define decay_cpu(loadfac, cpu) (((loadfac) * (cpu)) / ((loadfac) + FSCALE)) 344 345 /* decay 95% of `ts_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */ 346 static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */ 347 SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, ""); 348 349 /* 350 * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the 351 * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below 352 * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT). 353 * 354 * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used: 355 * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits). 356 * 357 * If you don't want to bother with the faster/more-accurate formula, you 358 * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate 359 * (more general) method of calculating the %age of CPU used by a process. 360 */ 361 #define CCPU_SHIFT 11 362 363 /* 364 * Recompute process priorities, every hz ticks. 365 * MP-safe, called without the Giant mutex. 366 */ 367 /* ARGSUSED */ 368 static void 369 schedcpu(void) 370 { 371 register fixpt_t loadfac = loadfactor(averunnable.ldavg[0]); 372 struct thread *td; 373 struct proc *p; 374 struct td_sched *ts; 375 int awake, realstathz; 376 377 realstathz = stathz ? stathz : hz; 378 sx_slock(&allproc_lock); 379 FOREACH_PROC_IN_SYSTEM(p) { 380 /* 381 * Prevent state changes and protect run queue. 382 */ 383 mtx_lock_spin(&sched_lock); 384 /* 385 * Increment time in/out of memory. We ignore overflow; with 386 * 16-bit int's (remember them?) overflow takes 45 days. 387 */ 388 p->p_swtime++; 389 FOREACH_THREAD_IN_PROC(p, td) { 390 awake = 0; 391 ts = td->td_sched; 392 /* 393 * Increment sleep time (if sleeping). We 394 * ignore overflow, as above. 395 */ 396 /* 397 * The td_sched slptimes are not touched in wakeup 398 * because the thread may not HAVE everything in 399 * memory? XXX I think this is out of date. 400 */ 401 if (TD_ON_RUNQ(td)) { 402 awake = 1; 403 ts->ts_flags &= ~TSF_DIDRUN; 404 } else if (TD_IS_RUNNING(td)) { 405 awake = 1; 406 /* Do not clear TSF_DIDRUN */ 407 } else if (ts->ts_flags & TSF_DIDRUN) { 408 awake = 1; 409 ts->ts_flags &= ~TSF_DIDRUN; 410 } 411 412 /* 413 * ts_pctcpu is only for ps and ttyinfo(). 414 * Do it per td_sched, and add them up at the end? 415 * XXXKSE 416 */ 417 ts->ts_pctcpu = (ts->ts_pctcpu * ccpu) >> FSHIFT; 418 /* 419 * If the td_sched has been idle the entire second, 420 * stop recalculating its priority until 421 * it wakes up. 422 */ 423 if (ts->ts_cpticks != 0) { 424 #if (FSHIFT >= CCPU_SHIFT) 425 ts->ts_pctcpu += (realstathz == 100) 426 ? ((fixpt_t) ts->ts_cpticks) << 427 (FSHIFT - CCPU_SHIFT) : 428 100 * (((fixpt_t) ts->ts_cpticks) 429 << (FSHIFT - CCPU_SHIFT)) / realstathz; 430 #else 431 ts->ts_pctcpu += ((FSCALE - ccpu) * 432 (ts->ts_cpticks * 433 FSCALE / realstathz)) >> FSHIFT; 434 #endif 435 ts->ts_cpticks = 0; 436 } 437 /* 438 * If there are ANY running threads in this process, 439 * then don't count it as sleeping. 440 XXX this is broken 441 442 */ 443 if (awake) { 444 if (td->td_slptime > 1) { 445 /* 446 * In an ideal world, this should not 447 * happen, because whoever woke us 448 * up from the long sleep should have 449 * unwound the slptime and reset our 450 * priority before we run at the stale 451 * priority. Should KASSERT at some 452 * point when all the cases are fixed. 453 */ 454 updatepri(td); 455 } 456 td->td_slptime = 0; 457 } else 458 td->td_slptime++; 459 if (td->td_slptime > 1) 460 continue; 461 td->td_estcpu = decay_cpu(loadfac, td->td_estcpu); 462 resetpriority(td); 463 resetpriority_thread(td); 464 } /* end of thread loop */ 465 mtx_unlock_spin(&sched_lock); 466 } /* end of process loop */ 467 sx_sunlock(&allproc_lock); 468 } 469 470 /* 471 * Main loop for a kthread that executes schedcpu once a second. 472 */ 473 static void 474 schedcpu_thread(void) 475 { 476 477 for (;;) { 478 schedcpu(); 479 pause("-", hz); 480 } 481 } 482 483 /* 484 * Recalculate the priority of a process after it has slept for a while. 485 * For all load averages >= 1 and max td_estcpu of 255, sleeping for at 486 * least six times the loadfactor will decay td_estcpu to zero. 487 */ 488 static void 489 updatepri(struct thread *td) 490 { 491 register fixpt_t loadfac; 492 register unsigned int newcpu; 493 494 loadfac = loadfactor(averunnable.ldavg[0]); 495 if (td->td_slptime > 5 * loadfac) 496 td->td_estcpu = 0; 497 else { 498 newcpu = td->td_estcpu; 499 td->td_slptime--; /* was incremented in schedcpu() */ 500 while (newcpu && --td->td_slptime) 501 newcpu = decay_cpu(loadfac, newcpu); 502 td->td_estcpu = newcpu; 503 } 504 } 505 506 /* 507 * Compute the priority of a process when running in user mode. 508 * Arrange to reschedule if the resulting priority is better 509 * than that of the current process. 510 */ 511 static void 512 resetpriority(struct thread *td) 513 { 514 register unsigned int newpriority; 515 516 if (td->td_pri_class == PRI_TIMESHARE) { 517 newpriority = PUSER + td->td_estcpu / INVERSE_ESTCPU_WEIGHT + 518 NICE_WEIGHT * (td->td_proc->p_nice - PRIO_MIN); 519 newpriority = min(max(newpriority, PRI_MIN_TIMESHARE), 520 PRI_MAX_TIMESHARE); 521 sched_user_prio(td, newpriority); 522 } 523 } 524 525 /* 526 * Update the thread's priority when the associated process's user 527 * priority changes. 528 */ 529 static void 530 resetpriority_thread(struct thread *td) 531 { 532 533 /* Only change threads with a time sharing user priority. */ 534 if (td->td_priority < PRI_MIN_TIMESHARE || 535 td->td_priority > PRI_MAX_TIMESHARE) 536 return; 537 538 /* XXX the whole needresched thing is broken, but not silly. */ 539 maybe_resched(td); 540 541 sched_prio(td, td->td_user_pri); 542 } 543 544 /* ARGSUSED */ 545 static void 546 sched_setup(void *dummy) 547 { 548 setup_runqs(); 549 550 if (sched_quantum == 0) 551 sched_quantum = SCHED_QUANTUM; 552 hogticks = 2 * sched_quantum; 553 554 callout_init(&roundrobin_callout, CALLOUT_MPSAFE); 555 556 /* Kick off timeout driven events by calling first time. */ 557 roundrobin(NULL); 558 559 /* Account for thread0. */ 560 sched_load_add(); 561 } 562 563 /* External interfaces start here */ 564 /* 565 * Very early in the boot some setup of scheduler-specific 566 * parts of proc0 and of some scheduler resources needs to be done. 567 * Called from: 568 * proc0_init() 569 */ 570 void 571 schedinit(void) 572 { 573 /* 574 * Set up the scheduler specific parts of proc0. 575 */ 576 proc0.p_sched = NULL; /* XXX */ 577 thread0.td_sched = &td_sched0; 578 td_sched0.ts_thread = &thread0; 579 } 580 581 int 582 sched_runnable(void) 583 { 584 #ifdef SMP 585 return runq_check(&runq) + runq_check(&runq_pcpu[PCPU_GET(cpuid)]); 586 #else 587 return runq_check(&runq); 588 #endif 589 } 590 591 int 592 sched_rr_interval(void) 593 { 594 if (sched_quantum == 0) 595 sched_quantum = SCHED_QUANTUM; 596 return (sched_quantum); 597 } 598 599 /* 600 * We adjust the priority of the current process. The priority of 601 * a process gets worse as it accumulates CPU time. The cpu usage 602 * estimator (td_estcpu) is increased here. resetpriority() will 603 * compute a different priority each time td_estcpu increases by 604 * INVERSE_ESTCPU_WEIGHT 605 * (until MAXPRI is reached). The cpu usage estimator ramps up 606 * quite quickly when the process is running (linearly), and decays 607 * away exponentially, at a rate which is proportionally slower when 608 * the system is busy. The basic principle is that the system will 609 * 90% forget that the process used a lot of CPU time in 5 * loadav 610 * seconds. This causes the system to favor processes which haven't 611 * run much recently, and to round-robin among other processes. 612 */ 613 void 614 sched_clock(struct thread *td) 615 { 616 struct td_sched *ts; 617 618 mtx_assert(&sched_lock, MA_OWNED); 619 ts = td->td_sched; 620 621 ts->ts_cpticks++; 622 td->td_estcpu = ESTCPULIM(td->td_estcpu + 1); 623 if ((td->td_estcpu % INVERSE_ESTCPU_WEIGHT) == 0) { 624 resetpriority(td); 625 resetpriority_thread(td); 626 } 627 } 628 629 /* 630 * charge childs scheduling cpu usage to parent. 631 */ 632 void 633 sched_exit(struct proc *p, struct thread *td) 634 { 635 636 CTR3(KTR_SCHED, "sched_exit: %p(%s) prio %d", 637 td, td->td_proc->p_comm, td->td_priority); 638 639 sched_exit_thread(FIRST_THREAD_IN_PROC(p), td); 640 } 641 642 void 643 sched_exit_thread(struct thread *td, struct thread *child) 644 { 645 struct proc *childproc = child->td_proc; 646 647 CTR3(KTR_SCHED, "sched_exit_thread: %p(%s) prio %d", 648 child, childproc->p_comm, child->td_priority); 649 td->td_estcpu = ESTCPULIM(td->td_estcpu + child->td_estcpu); 650 childproc->p_estcpu = ESTCPULIM(childproc->p_estcpu + 651 child->td_estcpu); 652 if ((child->td_proc->p_flag & P_NOLOAD) == 0) 653 sched_load_rem(); 654 } 655 656 void 657 sched_fork(struct thread *td, struct thread *childtd) 658 { 659 sched_fork_thread(td, childtd); 660 } 661 662 void 663 sched_fork_thread(struct thread *td, struct thread *childtd) 664 { 665 childtd->td_estcpu = td->td_estcpu; 666 sched_newthread(childtd); 667 } 668 669 void 670 sched_nice(struct proc *p, int nice) 671 { 672 struct thread *td; 673 674 PROC_LOCK_ASSERT(p, MA_OWNED); 675 mtx_assert(&sched_lock, MA_OWNED); 676 p->p_nice = nice; 677 FOREACH_THREAD_IN_PROC(p, td) { 678 resetpriority(td); 679 resetpriority_thread(td); 680 } 681 } 682 683 void 684 sched_class(struct thread *td, int class) 685 { 686 mtx_assert(&sched_lock, MA_OWNED); 687 td->td_pri_class = class; 688 } 689 690 /* 691 * Adjust the priority of a thread. 692 */ 693 static void 694 sched_priority(struct thread *td, u_char prio) 695 { 696 CTR6(KTR_SCHED, "sched_prio: %p(%s) prio %d newprio %d by %p(%s)", 697 td, td->td_proc->p_comm, td->td_priority, prio, curthread, 698 curthread->td_proc->p_comm); 699 700 mtx_assert(&sched_lock, MA_OWNED); 701 if (td->td_priority == prio) 702 return; 703 td->td_priority = prio; 704 if (TD_ON_RUNQ(td) && 705 td->td_sched->ts_rqindex != (prio / RQ_PPQ)) { 706 sched_rem(td); 707 sched_add(td, SRQ_BORING); 708 } 709 } 710 711 /* 712 * Update a thread's priority when it is lent another thread's 713 * priority. 714 */ 715 void 716 sched_lend_prio(struct thread *td, u_char prio) 717 { 718 719 td->td_flags |= TDF_BORROWING; 720 sched_priority(td, prio); 721 } 722 723 /* 724 * Restore a thread's priority when priority propagation is 725 * over. The prio argument is the minimum priority the thread 726 * needs to have to satisfy other possible priority lending 727 * requests. If the thread's regulary priority is less 728 * important than prio the thread will keep a priority boost 729 * of prio. 730 */ 731 void 732 sched_unlend_prio(struct thread *td, u_char prio) 733 { 734 u_char base_pri; 735 736 if (td->td_base_pri >= PRI_MIN_TIMESHARE && 737 td->td_base_pri <= PRI_MAX_TIMESHARE) 738 base_pri = td->td_user_pri; 739 else 740 base_pri = td->td_base_pri; 741 if (prio >= base_pri) { 742 td->td_flags &= ~TDF_BORROWING; 743 sched_prio(td, base_pri); 744 } else 745 sched_lend_prio(td, prio); 746 } 747 748 void 749 sched_prio(struct thread *td, u_char prio) 750 { 751 u_char oldprio; 752 753 /* First, update the base priority. */ 754 td->td_base_pri = prio; 755 756 /* 757 * If the thread is borrowing another thread's priority, don't ever 758 * lower the priority. 759 */ 760 if (td->td_flags & TDF_BORROWING && td->td_priority < prio) 761 return; 762 763 /* Change the real priority. */ 764 oldprio = td->td_priority; 765 sched_priority(td, prio); 766 767 /* 768 * If the thread is on a turnstile, then let the turnstile update 769 * its state. 770 */ 771 if (TD_ON_LOCK(td) && oldprio != prio) 772 turnstile_adjust(td, oldprio); 773 } 774 775 void 776 sched_user_prio(struct thread *td, u_char prio) 777 { 778 u_char oldprio; 779 780 td->td_base_user_pri = prio; 781 if (td->td_flags & TDF_UBORROWING && td->td_user_pri <= prio) 782 return; 783 oldprio = td->td_user_pri; 784 td->td_user_pri = prio; 785 786 if (TD_ON_UPILOCK(td) && oldprio != prio) 787 umtx_pi_adjust(td, oldprio); 788 } 789 790 void 791 sched_lend_user_prio(struct thread *td, u_char prio) 792 { 793 u_char oldprio; 794 795 td->td_flags |= TDF_UBORROWING; 796 797 oldprio = td->td_user_pri; 798 td->td_user_pri = prio; 799 800 if (TD_ON_UPILOCK(td) && oldprio != prio) 801 umtx_pi_adjust(td, oldprio); 802 } 803 804 void 805 sched_unlend_user_prio(struct thread *td, u_char prio) 806 { 807 u_char base_pri; 808 809 base_pri = td->td_base_user_pri; 810 if (prio >= base_pri) { 811 td->td_flags &= ~TDF_UBORROWING; 812 sched_user_prio(td, base_pri); 813 } else 814 sched_lend_user_prio(td, prio); 815 } 816 817 void 818 sched_sleep(struct thread *td) 819 { 820 821 mtx_assert(&sched_lock, MA_OWNED); 822 td->td_slptime = 0; 823 } 824 825 void 826 sched_switch(struct thread *td, struct thread *newtd, int flags) 827 { 828 struct td_sched *ts; 829 struct proc *p; 830 831 ts = td->td_sched; 832 p = td->td_proc; 833 834 mtx_assert(&sched_lock, MA_OWNED); 835 836 if ((p->p_flag & P_NOLOAD) == 0) 837 sched_load_rem(); 838 #if 0 839 /* 840 * We are volunteering to switch out so we get to nominate 841 * a successor for the rest of our quantum 842 * First try another thread in our process 843 * 844 * this is too expensive to do without per process run queues 845 * so skip it for now. 846 * XXX keep this comment as a marker. 847 */ 848 if (sched_followon && 849 (p->p_flag & P_HADTHREADS) && 850 (flags & SW_VOL) && 851 newtd == NULL) 852 newtd = mumble(); 853 #endif 854 855 if (newtd) 856 newtd->td_flags |= (td->td_flags & TDF_NEEDRESCHED); 857 858 td->td_lastcpu = td->td_oncpu; 859 td->td_flags &= ~TDF_NEEDRESCHED; 860 td->td_owepreempt = 0; 861 td->td_oncpu = NOCPU; 862 /* 863 * At the last moment, if this thread is still marked RUNNING, 864 * then put it back on the run queue as it has not been suspended 865 * or stopped or any thing else similar. We never put the idle 866 * threads on the run queue, however. 867 */ 868 if (td->td_flags & TDF_IDLETD) { 869 TD_SET_CAN_RUN(td); 870 #ifdef SMP 871 idle_cpus_mask &= ~PCPU_GET(cpumask); 872 #endif 873 } else { 874 if (TD_IS_RUNNING(td)) { 875 /* Put us back on the run queue. */ 876 sched_add(td, (flags & SW_PREEMPT) ? 877 SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED : 878 SRQ_OURSELF|SRQ_YIELDING); 879 } 880 } 881 if (newtd) { 882 /* 883 * The thread we are about to run needs to be counted 884 * as if it had been added to the run queue and selected. 885 * It came from: 886 * * A preemption 887 * * An upcall 888 * * A followon 889 */ 890 KASSERT((newtd->td_inhibitors == 0), 891 ("trying to run inhibited thread")); 892 newtd->td_sched->ts_flags |= TSF_DIDRUN; 893 TD_SET_RUNNING(newtd); 894 if ((newtd->td_proc->p_flag & P_NOLOAD) == 0) 895 sched_load_add(); 896 } else { 897 newtd = choosethread(); 898 } 899 900 if (td != newtd) { 901 #ifdef HWPMC_HOOKS 902 if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 903 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT); 904 #endif 905 906 /* I feel sleepy */ 907 cpu_switch(td, newtd); 908 /* 909 * Where am I? What year is it? 910 * We are in the same thread that went to sleep above, 911 * but any amount of time may have passed. All out context 912 * will still be available as will local variables. 913 * PCPU values however may have changed as we may have 914 * changed CPU so don't trust cached values of them. 915 * New threads will go to fork_exit() instead of here 916 * so if you change things here you may need to change 917 * things there too. 918 * If the thread above was exiting it will never wake 919 * up again here, so either it has saved everything it 920 * needed to, or the thread_wait() or wait() will 921 * need to reap it. 922 */ 923 #ifdef HWPMC_HOOKS 924 if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 925 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN); 926 #endif 927 } 928 929 #ifdef SMP 930 if (td->td_flags & TDF_IDLETD) 931 idle_cpus_mask |= PCPU_GET(cpumask); 932 #endif 933 sched_lock.mtx_lock = (uintptr_t)td; 934 td->td_oncpu = PCPU_GET(cpuid); 935 } 936 937 void 938 sched_wakeup(struct thread *td) 939 { 940 mtx_assert(&sched_lock, MA_OWNED); 941 if (td->td_slptime > 1) { 942 updatepri(td); 943 resetpriority(td); 944 } 945 td->td_slptime = 0; 946 sched_add(td, SRQ_BORING); 947 } 948 949 #ifdef SMP 950 /* enable HTT_2 if you have a 2-way HTT cpu.*/ 951 static int 952 forward_wakeup(int cpunum) 953 { 954 cpumask_t map, me, dontuse; 955 cpumask_t map2; 956 struct pcpu *pc; 957 cpumask_t id, map3; 958 959 mtx_assert(&sched_lock, MA_OWNED); 960 961 CTR0(KTR_RUNQ, "forward_wakeup()"); 962 963 if ((!forward_wakeup_enabled) || 964 (forward_wakeup_use_mask == 0 && forward_wakeup_use_loop == 0)) 965 return (0); 966 if (!smp_started || cold || panicstr) 967 return (0); 968 969 forward_wakeups_requested++; 970 971 /* 972 * check the idle mask we received against what we calculated before 973 * in the old version. 974 */ 975 me = PCPU_GET(cpumask); 976 /* 977 * don't bother if we should be doing it ourself.. 978 */ 979 if ((me & idle_cpus_mask) && (cpunum == NOCPU || me == (1 << cpunum))) 980 return (0); 981 982 dontuse = me | stopped_cpus | hlt_cpus_mask; 983 map3 = 0; 984 if (forward_wakeup_use_loop) { 985 SLIST_FOREACH(pc, &cpuhead, pc_allcpu) { 986 id = pc->pc_cpumask; 987 if ( (id & dontuse) == 0 && 988 pc->pc_curthread == pc->pc_idlethread) { 989 map3 |= id; 990 } 991 } 992 } 993 994 if (forward_wakeup_use_mask) { 995 map = 0; 996 map = idle_cpus_mask & ~dontuse; 997 998 /* If they are both on, compare and use loop if different */ 999 if (forward_wakeup_use_loop) { 1000 if (map != map3) { 1001 printf("map (%02X) != map3 (%02X)\n", 1002 map, map3); 1003 map = map3; 1004 } 1005 } 1006 } else { 1007 map = map3; 1008 } 1009 /* If we only allow a specific CPU, then mask off all the others */ 1010 if (cpunum != NOCPU) { 1011 KASSERT((cpunum <= mp_maxcpus),("forward_wakeup: bad cpunum.")); 1012 map &= (1 << cpunum); 1013 } else { 1014 /* Try choose an idle die. */ 1015 if (forward_wakeup_use_htt) { 1016 map2 = (map & (map >> 1)) & 0x5555; 1017 if (map2) { 1018 map = map2; 1019 } 1020 } 1021 1022 /* set only one bit */ 1023 if (forward_wakeup_use_single) { 1024 map = map & ((~map) + 1); 1025 } 1026 } 1027 if (map) { 1028 forward_wakeups_delivered++; 1029 ipi_selected(map, IPI_AST); 1030 return (1); 1031 } 1032 if (cpunum == NOCPU) 1033 printf("forward_wakeup: Idle processor not found\n"); 1034 return (0); 1035 } 1036 #endif 1037 1038 #ifdef SMP 1039 static void kick_other_cpu(int pri,int cpuid); 1040 1041 static void 1042 kick_other_cpu(int pri,int cpuid) 1043 { 1044 struct pcpu * pcpu = pcpu_find(cpuid); 1045 int cpri = pcpu->pc_curthread->td_priority; 1046 1047 if (idle_cpus_mask & pcpu->pc_cpumask) { 1048 forward_wakeups_delivered++; 1049 ipi_selected(pcpu->pc_cpumask, IPI_AST); 1050 return; 1051 } 1052 1053 if (pri >= cpri) 1054 return; 1055 1056 #if defined(IPI_PREEMPTION) && defined(PREEMPTION) 1057 #if !defined(FULL_PREEMPTION) 1058 if (pri <= PRI_MAX_ITHD) 1059 #endif /* ! FULL_PREEMPTION */ 1060 { 1061 ipi_selected(pcpu->pc_cpumask, IPI_PREEMPT); 1062 return; 1063 } 1064 #endif /* defined(IPI_PREEMPTION) && defined(PREEMPTION) */ 1065 1066 pcpu->pc_curthread->td_flags |= TDF_NEEDRESCHED; 1067 ipi_selected( pcpu->pc_cpumask , IPI_AST); 1068 return; 1069 } 1070 #endif /* SMP */ 1071 1072 void 1073 sched_add(struct thread *td, int flags) 1074 #ifdef SMP 1075 { 1076 struct td_sched *ts; 1077 int forwarded = 0; 1078 int cpu; 1079 int single_cpu = 0; 1080 1081 ts = td->td_sched; 1082 mtx_assert(&sched_lock, MA_OWNED); 1083 KASSERT((td->td_inhibitors == 0), 1084 ("sched_add: trying to run inhibited thread")); 1085 KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)), 1086 ("sched_add: bad thread state")); 1087 KASSERT(td->td_proc->p_sflag & PS_INMEM, 1088 ("sched_add: process swapped out")); 1089 CTR5(KTR_SCHED, "sched_add: %p(%s) prio %d by %p(%s)", 1090 td, td->td_proc->p_comm, td->td_priority, curthread, 1091 curthread->td_proc->p_comm); 1092 TD_SET_RUNQ(td); 1093 1094 if (td->td_pinned != 0) { 1095 cpu = td->td_lastcpu; 1096 ts->ts_runq = &runq_pcpu[cpu]; 1097 single_cpu = 1; 1098 CTR3(KTR_RUNQ, 1099 "sched_add: Put td_sched:%p(td:%p) on cpu%d runq", ts, td, cpu); 1100 } else if ((ts)->ts_flags & TSF_BOUND) { 1101 /* Find CPU from bound runq */ 1102 KASSERT(SKE_RUNQ_PCPU(ts),("sched_add: bound td_sched not on cpu runq")); 1103 cpu = ts->ts_runq - &runq_pcpu[0]; 1104 single_cpu = 1; 1105 CTR3(KTR_RUNQ, 1106 "sched_add: Put td_sched:%p(td:%p) on cpu%d runq", ts, td, cpu); 1107 } else { 1108 CTR2(KTR_RUNQ, 1109 "sched_add: adding td_sched:%p (td:%p) to gbl runq", ts, td); 1110 cpu = NOCPU; 1111 ts->ts_runq = &runq; 1112 } 1113 1114 if (single_cpu && (cpu != PCPU_GET(cpuid))) { 1115 kick_other_cpu(td->td_priority,cpu); 1116 } else { 1117 1118 if (!single_cpu) { 1119 cpumask_t me = PCPU_GET(cpumask); 1120 int idle = idle_cpus_mask & me; 1121 1122 if (!idle && ((flags & SRQ_INTR) == 0) && 1123 (idle_cpus_mask & ~(hlt_cpus_mask | me))) 1124 forwarded = forward_wakeup(cpu); 1125 } 1126 1127 if (!forwarded) { 1128 if ((flags & SRQ_YIELDING) == 0 && maybe_preempt(td)) 1129 return; 1130 else 1131 maybe_resched(td); 1132 } 1133 } 1134 1135 if ((td->td_proc->p_flag & P_NOLOAD) == 0) 1136 sched_load_add(); 1137 runq_add(ts->ts_runq, ts, flags); 1138 } 1139 #else /* SMP */ 1140 { 1141 struct td_sched *ts; 1142 ts = td->td_sched; 1143 mtx_assert(&sched_lock, MA_OWNED); 1144 KASSERT((td->td_inhibitors == 0), 1145 ("sched_add: trying to run inhibited thread")); 1146 KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)), 1147 ("sched_add: bad thread state")); 1148 KASSERT(td->td_proc->p_sflag & PS_INMEM, 1149 ("sched_add: process swapped out")); 1150 CTR5(KTR_SCHED, "sched_add: %p(%s) prio %d by %p(%s)", 1151 td, td->td_proc->p_comm, td->td_priority, curthread, 1152 curthread->td_proc->p_comm); 1153 TD_SET_RUNQ(td); 1154 CTR2(KTR_RUNQ, "sched_add: adding td_sched:%p (td:%p) to runq", ts, td); 1155 ts->ts_runq = &runq; 1156 1157 /* 1158 * If we are yielding (on the way out anyhow) 1159 * or the thread being saved is US, 1160 * then don't try be smart about preemption 1161 * or kicking off another CPU 1162 * as it won't help and may hinder. 1163 * In the YIEDLING case, we are about to run whoever is 1164 * being put in the queue anyhow, and in the 1165 * OURSELF case, we are puting ourself on the run queue 1166 * which also only happens when we are about to yield. 1167 */ 1168 if((flags & SRQ_YIELDING) == 0) { 1169 if (maybe_preempt(td)) 1170 return; 1171 } 1172 if ((td->td_proc->p_flag & P_NOLOAD) == 0) 1173 sched_load_add(); 1174 runq_add(ts->ts_runq, ts, flags); 1175 maybe_resched(td); 1176 } 1177 #endif /* SMP */ 1178 1179 void 1180 sched_rem(struct thread *td) 1181 { 1182 struct td_sched *ts; 1183 1184 ts = td->td_sched; 1185 KASSERT(td->td_proc->p_sflag & PS_INMEM, 1186 ("sched_rem: process swapped out")); 1187 KASSERT(TD_ON_RUNQ(td), 1188 ("sched_rem: thread not on run queue")); 1189 mtx_assert(&sched_lock, MA_OWNED); 1190 CTR5(KTR_SCHED, "sched_rem: %p(%s) prio %d by %p(%s)", 1191 td, td->td_proc->p_comm, td->td_priority, curthread, 1192 curthread->td_proc->p_comm); 1193 1194 if ((td->td_proc->p_flag & P_NOLOAD) == 0) 1195 sched_load_rem(); 1196 runq_remove(ts->ts_runq, ts); 1197 TD_SET_CAN_RUN(td); 1198 } 1199 1200 /* 1201 * Select threads to run. 1202 * Notice that the running threads still consume a slot. 1203 */ 1204 struct thread * 1205 sched_choose(void) 1206 { 1207 struct td_sched *ts; 1208 struct runq *rq; 1209 1210 #ifdef SMP 1211 struct td_sched *kecpu; 1212 1213 rq = &runq; 1214 ts = runq_choose(&runq); 1215 kecpu = runq_choose(&runq_pcpu[PCPU_GET(cpuid)]); 1216 1217 if (ts == NULL || 1218 (kecpu != NULL && 1219 kecpu->ts_thread->td_priority < ts->ts_thread->td_priority)) { 1220 CTR2(KTR_RUNQ, "choosing td_sched %p from pcpu runq %d", kecpu, 1221 PCPU_GET(cpuid)); 1222 ts = kecpu; 1223 rq = &runq_pcpu[PCPU_GET(cpuid)]; 1224 } else { 1225 CTR1(KTR_RUNQ, "choosing td_sched %p from main runq", ts); 1226 } 1227 1228 #else 1229 rq = &runq; 1230 ts = runq_choose(&runq); 1231 #endif 1232 1233 if (ts) { 1234 runq_remove(rq, ts); 1235 ts->ts_flags |= TSF_DIDRUN; 1236 1237 KASSERT(ts->ts_thread->td_proc->p_sflag & PS_INMEM, 1238 ("sched_choose: process swapped out")); 1239 return (ts->ts_thread); 1240 } 1241 return (PCPU_GET(idlethread)); 1242 } 1243 1244 void 1245 sched_userret(struct thread *td) 1246 { 1247 /* 1248 * XXX we cheat slightly on the locking here to avoid locking in 1249 * the usual case. Setting td_priority here is essentially an 1250 * incomplete workaround for not setting it properly elsewhere. 1251 * Now that some interrupt handlers are threads, not setting it 1252 * properly elsewhere can clobber it in the window between setting 1253 * it here and returning to user mode, so don't waste time setting 1254 * it perfectly here. 1255 */ 1256 KASSERT((td->td_flags & TDF_BORROWING) == 0, 1257 ("thread with borrowed priority returning to userland")); 1258 if (td->td_priority != td->td_user_pri) { 1259 mtx_lock_spin(&sched_lock); 1260 td->td_priority = td->td_user_pri; 1261 td->td_base_pri = td->td_user_pri; 1262 mtx_unlock_spin(&sched_lock); 1263 } 1264 } 1265 1266 void 1267 sched_bind(struct thread *td, int cpu) 1268 { 1269 struct td_sched *ts; 1270 1271 mtx_assert(&sched_lock, MA_OWNED); 1272 KASSERT(TD_IS_RUNNING(td), 1273 ("sched_bind: cannot bind non-running thread")); 1274 1275 ts = td->td_sched; 1276 1277 ts->ts_flags |= TSF_BOUND; 1278 #ifdef SMP 1279 ts->ts_runq = &runq_pcpu[cpu]; 1280 if (PCPU_GET(cpuid) == cpu) 1281 return; 1282 1283 mi_switch(SW_VOL, NULL); 1284 #endif 1285 } 1286 1287 void 1288 sched_unbind(struct thread* td) 1289 { 1290 mtx_assert(&sched_lock, MA_OWNED); 1291 td->td_sched->ts_flags &= ~TSF_BOUND; 1292 } 1293 1294 int 1295 sched_is_bound(struct thread *td) 1296 { 1297 mtx_assert(&sched_lock, MA_OWNED); 1298 return (td->td_sched->ts_flags & TSF_BOUND); 1299 } 1300 1301 void 1302 sched_relinquish(struct thread *td) 1303 { 1304 mtx_lock_spin(&sched_lock); 1305 if (td->td_pri_class == PRI_TIMESHARE) 1306 sched_prio(td, PRI_MAX_TIMESHARE); 1307 mi_switch(SW_VOL, NULL); 1308 mtx_unlock_spin(&sched_lock); 1309 } 1310 1311 int 1312 sched_load(void) 1313 { 1314 return (sched_tdcnt); 1315 } 1316 1317 int 1318 sched_sizeof_proc(void) 1319 { 1320 return (sizeof(struct proc)); 1321 } 1322 1323 int 1324 sched_sizeof_thread(void) 1325 { 1326 return (sizeof(struct thread) + sizeof(struct td_sched)); 1327 } 1328 1329 fixpt_t 1330 sched_pctcpu(struct thread *td) 1331 { 1332 struct td_sched *ts; 1333 1334 ts = td->td_sched; 1335 return (ts->ts_pctcpu); 1336 } 1337 1338 void 1339 sched_tick(void) 1340 { 1341 } 1342 1343 /* 1344 * The actual idle process. 1345 */ 1346 void 1347 sched_idletd(void *dummy) 1348 { 1349 struct proc *p; 1350 struct thread *td; 1351 1352 td = curthread; 1353 p = td->td_proc; 1354 for (;;) { 1355 mtx_assert(&Giant, MA_NOTOWNED); 1356 1357 while (sched_runnable() == 0) 1358 cpu_idle(); 1359 1360 mtx_lock_spin(&sched_lock); 1361 mi_switch(SW_VOL, NULL); 1362 mtx_unlock_spin(&sched_lock); 1363 } 1364 } 1365 1366 #define KERN_SWITCH_INCLUDE 1 1367 #include "kern/kern_switch.c" 1368