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 #define kse td_sched 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/ktr.h> 46 #include <sys/lock.h> 47 #include <sys/kthread.h> 48 #include <sys/mutex.h> 49 #include <sys/proc.h> 50 #include <sys/resourcevar.h> 51 #include <sys/sched.h> 52 #include <sys/smp.h> 53 #include <sys/sysctl.h> 54 #include <sys/sx.h> 55 #include <sys/turnstile.h> 56 #include <machine/pcb.h> 57 #include <machine/smp.h> 58 59 #ifdef HWPMC_HOOKS 60 #include <sys/pmckern.h> 61 #endif 62 63 /* 64 * INVERSE_ESTCPU_WEIGHT is only suitable for statclock() frequencies in 65 * the range 100-256 Hz (approximately). 66 */ 67 #define ESTCPULIM(e) \ 68 min((e), INVERSE_ESTCPU_WEIGHT * (NICE_WEIGHT * (PRIO_MAX - PRIO_MIN) - \ 69 RQ_PPQ) + INVERSE_ESTCPU_WEIGHT - 1) 70 #ifdef SMP 71 #define INVERSE_ESTCPU_WEIGHT (8 * smp_cpus) 72 #else 73 #define INVERSE_ESTCPU_WEIGHT 8 /* 1 / (priorities per estcpu level). */ 74 #endif 75 #define NICE_WEIGHT 1 /* Priorities per nice level. */ 76 77 /* 78 * The schedulable entity that can be given a context to run. 79 * A process may have several of these. Probably one per processor 80 * but possibly a few more. In this universe they are grouped 81 * with a KSEG that contains the priority and niceness 82 * for the group. 83 */ 84 struct kse { 85 TAILQ_ENTRY(kse) ke_procq; /* (j/z) Run queue. */ 86 struct thread *ke_thread; /* (*) Active associated thread. */ 87 fixpt_t ke_pctcpu; /* (j) %cpu during p_swtime. */ 88 u_char ke_rqindex; /* (j) Run queue index. */ 89 enum { 90 KES_THREAD = 0x0, /* slaved to thread state */ 91 KES_ONRUNQ 92 } ke_state; /* (j) KSE status. */ 93 int ke_cpticks; /* (j) Ticks of cpu time. */ 94 struct runq *ke_runq; /* runq the kse is currently on */ 95 }; 96 97 #define ke_proc ke_thread->td_proc 98 #define ke_ksegrp ke_thread->td_ksegrp 99 100 #define td_kse td_sched 101 102 /* flags kept in td_flags */ 103 #define TDF_DIDRUN TDF_SCHED0 /* KSE actually ran. */ 104 #define TDF_EXIT TDF_SCHED1 /* KSE is being killed. */ 105 #define TDF_BOUND TDF_SCHED2 106 107 #define ke_flags ke_thread->td_flags 108 #define KEF_DIDRUN TDF_DIDRUN /* KSE actually ran. */ 109 #define KEF_EXIT TDF_EXIT /* KSE is being killed. */ 110 #define KEF_BOUND TDF_BOUND /* stuck to one CPU */ 111 112 #define SKE_RUNQ_PCPU(ke) \ 113 ((ke)->ke_runq != 0 && (ke)->ke_runq != &runq) 114 115 struct kg_sched { 116 struct thread *skg_last_assigned; /* (j) Last thread assigned to */ 117 /* the system scheduler. */ 118 int skg_avail_opennings; /* (j) Num KSEs requested in group. */ 119 int skg_concurrency; /* (j) Num KSEs requested in group. */ 120 }; 121 #define kg_last_assigned kg_sched->skg_last_assigned 122 #define kg_avail_opennings kg_sched->skg_avail_opennings 123 #define kg_concurrency kg_sched->skg_concurrency 124 125 #define SLOT_RELEASE(kg) \ 126 do { \ 127 kg->kg_avail_opennings++; \ 128 CTR3(KTR_RUNQ, "kg %p(%d) Slot released (->%d)", \ 129 kg, \ 130 kg->kg_concurrency, \ 131 kg->kg_avail_opennings); \ 132 /* KASSERT((kg->kg_avail_opennings <= kg->kg_concurrency), \ 133 ("slots out of whack"));*/ \ 134 } while (0) 135 136 #define SLOT_USE(kg) \ 137 do { \ 138 kg->kg_avail_opennings--; \ 139 CTR3(KTR_RUNQ, "kg %p(%d) Slot used (->%d)", \ 140 kg, \ 141 kg->kg_concurrency, \ 142 kg->kg_avail_opennings); \ 143 /* KASSERT((kg->kg_avail_opennings >= 0), \ 144 ("slots out of whack"));*/ \ 145 } while (0) 146 147 /* 148 * KSE_CAN_MIGRATE macro returns true if the kse can migrate between 149 * cpus. 150 */ 151 #define KSE_CAN_MIGRATE(ke) \ 152 ((ke)->ke_thread->td_pinned == 0 && ((ke)->ke_flags & KEF_BOUND) == 0) 153 154 static struct kse kse0; 155 static struct kg_sched kg_sched0; 156 157 static int sched_tdcnt; /* Total runnable threads in the system. */ 158 static int sched_quantum; /* Roundrobin scheduling quantum in ticks. */ 159 #define SCHED_QUANTUM (hz / 10) /* Default sched quantum */ 160 161 static struct callout roundrobin_callout; 162 163 static void slot_fill(struct ksegrp *kg); 164 static struct kse *sched_choose(void); /* XXX Should be thread * */ 165 166 static void setup_runqs(void); 167 static void roundrobin(void *arg); 168 static void schedcpu(void); 169 static void schedcpu_thread(void); 170 static void sched_priority(struct thread *td, u_char prio); 171 static void sched_setup(void *dummy); 172 static void maybe_resched(struct thread *td); 173 static void updatepri(struct ksegrp *kg); 174 static void resetpriority(struct ksegrp *kg); 175 static void resetpriority_thread(struct thread *td, struct ksegrp *kg); 176 #ifdef SMP 177 static int forward_wakeup(int cpunum); 178 #endif 179 180 static struct kproc_desc sched_kp = { 181 "schedcpu", 182 schedcpu_thread, 183 NULL 184 }; 185 SYSINIT(schedcpu, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, kproc_start, &sched_kp) 186 SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL) 187 188 /* 189 * Global run queue. 190 */ 191 static struct runq runq; 192 193 #ifdef SMP 194 /* 195 * Per-CPU run queues 196 */ 197 static struct runq runq_pcpu[MAXCPU]; 198 #endif 199 200 static void 201 setup_runqs(void) 202 { 203 #ifdef SMP 204 int i; 205 206 for (i = 0; i < MAXCPU; ++i) 207 runq_init(&runq_pcpu[i]); 208 #endif 209 210 runq_init(&runq); 211 } 212 213 static int 214 sysctl_kern_quantum(SYSCTL_HANDLER_ARGS) 215 { 216 int error, new_val; 217 218 new_val = sched_quantum * tick; 219 error = sysctl_handle_int(oidp, &new_val, 0, req); 220 if (error != 0 || req->newptr == NULL) 221 return (error); 222 if (new_val < tick) 223 return (EINVAL); 224 sched_quantum = new_val / tick; 225 hogticks = 2 * sched_quantum; 226 return (0); 227 } 228 229 SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RD, 0, "Scheduler"); 230 231 SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "4BSD", 0, 232 "Scheduler name"); 233 234 SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, CTLTYPE_INT | CTLFLAG_RW, 235 0, sizeof sched_quantum, sysctl_kern_quantum, "I", 236 "Roundrobin scheduling quantum in microseconds"); 237 238 #ifdef SMP 239 /* Enable forwarding of wakeups to all other cpus */ 240 SYSCTL_NODE(_kern_sched, OID_AUTO, ipiwakeup, CTLFLAG_RD, NULL, "Kernel SMP"); 241 242 static int forward_wakeup_enabled = 1; 243 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, enabled, CTLFLAG_RW, 244 &forward_wakeup_enabled, 0, 245 "Forwarding of wakeup to idle CPUs"); 246 247 static int forward_wakeups_requested = 0; 248 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, requested, CTLFLAG_RD, 249 &forward_wakeups_requested, 0, 250 "Requests for Forwarding of wakeup to idle CPUs"); 251 252 static int forward_wakeups_delivered = 0; 253 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, delivered, CTLFLAG_RD, 254 &forward_wakeups_delivered, 0, 255 "Completed Forwarding of wakeup to idle CPUs"); 256 257 static int forward_wakeup_use_mask = 1; 258 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, usemask, CTLFLAG_RW, 259 &forward_wakeup_use_mask, 0, 260 "Use the mask of idle cpus"); 261 262 static int forward_wakeup_use_loop = 0; 263 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, useloop, CTLFLAG_RW, 264 &forward_wakeup_use_loop, 0, 265 "Use a loop to find idle cpus"); 266 267 static int forward_wakeup_use_single = 0; 268 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, onecpu, CTLFLAG_RW, 269 &forward_wakeup_use_single, 0, 270 "Only signal one idle cpu"); 271 272 static int forward_wakeup_use_htt = 0; 273 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, htt2, CTLFLAG_RW, 274 &forward_wakeup_use_htt, 0, 275 "account for htt"); 276 277 #endif 278 static int sched_followon = 0; 279 SYSCTL_INT(_kern_sched, OID_AUTO, followon, CTLFLAG_RW, 280 &sched_followon, 0, 281 "allow threads to share a quantum"); 282 283 static int sched_pfollowons = 0; 284 SYSCTL_INT(_kern_sched, OID_AUTO, pfollowons, CTLFLAG_RD, 285 &sched_pfollowons, 0, 286 "number of followons done to a different ksegrp"); 287 288 static int sched_kgfollowons = 0; 289 SYSCTL_INT(_kern_sched, OID_AUTO, kgfollowons, CTLFLAG_RD, 290 &sched_kgfollowons, 0, 291 "number of followons done in a ksegrp"); 292 293 static __inline void 294 sched_load_add(void) 295 { 296 sched_tdcnt++; 297 CTR1(KTR_SCHED, "global load: %d", sched_tdcnt); 298 } 299 300 static __inline void 301 sched_load_rem(void) 302 { 303 sched_tdcnt--; 304 CTR1(KTR_SCHED, "global load: %d", sched_tdcnt); 305 } 306 /* 307 * Arrange to reschedule if necessary, taking the priorities and 308 * schedulers into account. 309 */ 310 static void 311 maybe_resched(struct thread *td) 312 { 313 314 mtx_assert(&sched_lock, MA_OWNED); 315 if (td->td_priority < curthread->td_priority) 316 curthread->td_flags |= TDF_NEEDRESCHED; 317 } 318 319 /* 320 * Force switch among equal priority processes every 100ms. 321 * We don't actually need to force a context switch of the current process. 322 * The act of firing the event triggers a context switch to softclock() and 323 * then switching back out again which is equivalent to a preemption, thus 324 * no further work is needed on the local CPU. 325 */ 326 /* ARGSUSED */ 327 static void 328 roundrobin(void *arg) 329 { 330 331 #ifdef SMP 332 mtx_lock_spin(&sched_lock); 333 forward_roundrobin(); 334 mtx_unlock_spin(&sched_lock); 335 #endif 336 337 callout_reset(&roundrobin_callout, sched_quantum, roundrobin, NULL); 338 } 339 340 /* 341 * Constants for digital decay and forget: 342 * 90% of (kg_estcpu) usage in 5 * loadav time 343 * 95% of (ke_pctcpu) usage in 60 seconds (load insensitive) 344 * Note that, as ps(1) mentions, this can let percentages 345 * total over 100% (I've seen 137.9% for 3 processes). 346 * 347 * Note that schedclock() updates kg_estcpu and p_cpticks asynchronously. 348 * 349 * We wish to decay away 90% of kg_estcpu in (5 * loadavg) seconds. 350 * That is, the system wants to compute a value of decay such 351 * that the following for loop: 352 * for (i = 0; i < (5 * loadavg); i++) 353 * kg_estcpu *= decay; 354 * will compute 355 * kg_estcpu *= 0.1; 356 * for all values of loadavg: 357 * 358 * Mathematically this loop can be expressed by saying: 359 * decay ** (5 * loadavg) ~= .1 360 * 361 * The system computes decay as: 362 * decay = (2 * loadavg) / (2 * loadavg + 1) 363 * 364 * We wish to prove that the system's computation of decay 365 * will always fulfill the equation: 366 * decay ** (5 * loadavg) ~= .1 367 * 368 * If we compute b as: 369 * b = 2 * loadavg 370 * then 371 * decay = b / (b + 1) 372 * 373 * We now need to prove two things: 374 * 1) Given factor ** (5 * loadavg) ~= .1, prove factor == b/(b+1) 375 * 2) Given b/(b+1) ** power ~= .1, prove power == (5 * loadavg) 376 * 377 * Facts: 378 * For x close to zero, exp(x) =~ 1 + x, since 379 * exp(x) = 0! + x**1/1! + x**2/2! + ... . 380 * therefore exp(-1/b) =~ 1 - (1/b) = (b-1)/b. 381 * For x close to zero, ln(1+x) =~ x, since 382 * ln(1+x) = x - x**2/2 + x**3/3 - ... -1 < x < 1 383 * therefore ln(b/(b+1)) = ln(1 - 1/(b+1)) =~ -1/(b+1). 384 * ln(.1) =~ -2.30 385 * 386 * Proof of (1): 387 * Solve (factor)**(power) =~ .1 given power (5*loadav): 388 * solving for factor, 389 * ln(factor) =~ (-2.30/5*loadav), or 390 * factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) = 391 * exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED 392 * 393 * Proof of (2): 394 * Solve (factor)**(power) =~ .1 given factor == (b/(b+1)): 395 * solving for power, 396 * power*ln(b/(b+1)) =~ -2.30, or 397 * power =~ 2.3 * (b + 1) = 4.6*loadav + 2.3 =~ 5*loadav. QED 398 * 399 * Actual power values for the implemented algorithm are as follows: 400 * loadav: 1 2 3 4 401 * power: 5.68 10.32 14.94 19.55 402 */ 403 404 /* calculations for digital decay to forget 90% of usage in 5*loadav sec */ 405 #define loadfactor(loadav) (2 * (loadav)) 406 #define decay_cpu(loadfac, cpu) (((loadfac) * (cpu)) / ((loadfac) + FSCALE)) 407 408 /* decay 95% of `ke_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */ 409 static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */ 410 SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, ""); 411 412 /* 413 * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the 414 * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below 415 * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT). 416 * 417 * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used: 418 * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits). 419 * 420 * If you don't want to bother with the faster/more-accurate formula, you 421 * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate 422 * (more general) method of calculating the %age of CPU used by a process. 423 */ 424 #define CCPU_SHIFT 11 425 426 /* 427 * Recompute process priorities, every hz ticks. 428 * MP-safe, called without the Giant mutex. 429 */ 430 /* ARGSUSED */ 431 static void 432 schedcpu(void) 433 { 434 register fixpt_t loadfac = loadfactor(averunnable.ldavg[0]); 435 struct thread *td; 436 struct proc *p; 437 struct kse *ke; 438 struct ksegrp *kg; 439 int awake, realstathz; 440 441 realstathz = stathz ? stathz : hz; 442 sx_slock(&allproc_lock); 443 FOREACH_PROC_IN_SYSTEM(p) { 444 /* 445 * Prevent state changes and protect run queue. 446 */ 447 mtx_lock_spin(&sched_lock); 448 /* 449 * Increment time in/out of memory. We ignore overflow; with 450 * 16-bit int's (remember them?) overflow takes 45 days. 451 */ 452 p->p_swtime++; 453 FOREACH_KSEGRP_IN_PROC(p, kg) { 454 awake = 0; 455 FOREACH_THREAD_IN_GROUP(kg, td) { 456 ke = td->td_kse; 457 /* 458 * Increment sleep time (if sleeping). We 459 * ignore overflow, as above. 460 */ 461 /* 462 * The kse slptimes are not touched in wakeup 463 * because the thread may not HAVE a KSE. 464 */ 465 if (ke->ke_state == KES_ONRUNQ) { 466 awake = 1; 467 ke->ke_flags &= ~KEF_DIDRUN; 468 } else if ((ke->ke_state == KES_THREAD) && 469 (TD_IS_RUNNING(td))) { 470 awake = 1; 471 /* Do not clear KEF_DIDRUN */ 472 } else if (ke->ke_flags & KEF_DIDRUN) { 473 awake = 1; 474 ke->ke_flags &= ~KEF_DIDRUN; 475 } 476 477 /* 478 * ke_pctcpu is only for ps and ttyinfo(). 479 * Do it per kse, and add them up at the end? 480 * XXXKSE 481 */ 482 ke->ke_pctcpu = (ke->ke_pctcpu * ccpu) >> 483 FSHIFT; 484 /* 485 * If the kse has been idle the entire second, 486 * stop recalculating its priority until 487 * it wakes up. 488 */ 489 if (ke->ke_cpticks == 0) 490 continue; 491 #if (FSHIFT >= CCPU_SHIFT) 492 ke->ke_pctcpu += (realstathz == 100) 493 ? ((fixpt_t) ke->ke_cpticks) << 494 (FSHIFT - CCPU_SHIFT) : 495 100 * (((fixpt_t) ke->ke_cpticks) 496 << (FSHIFT - CCPU_SHIFT)) / realstathz; 497 #else 498 ke->ke_pctcpu += ((FSCALE - ccpu) * 499 (ke->ke_cpticks * 500 FSCALE / realstathz)) >> FSHIFT; 501 #endif 502 ke->ke_cpticks = 0; 503 } /* end of kse loop */ 504 /* 505 * If there are ANY running threads in this KSEGRP, 506 * then don't count it as sleeping. 507 */ 508 if (awake) { 509 if (kg->kg_slptime > 1) { 510 /* 511 * In an ideal world, this should not 512 * happen, because whoever woke us 513 * up from the long sleep should have 514 * unwound the slptime and reset our 515 * priority before we run at the stale 516 * priority. Should KASSERT at some 517 * point when all the cases are fixed. 518 */ 519 updatepri(kg); 520 } 521 kg->kg_slptime = 0; 522 } else 523 kg->kg_slptime++; 524 if (kg->kg_slptime > 1) 525 continue; 526 kg->kg_estcpu = decay_cpu(loadfac, kg->kg_estcpu); 527 resetpriority(kg); 528 FOREACH_THREAD_IN_GROUP(kg, td) { 529 resetpriority_thread(td, kg); 530 } 531 } /* end of ksegrp loop */ 532 mtx_unlock_spin(&sched_lock); 533 } /* end of process loop */ 534 sx_sunlock(&allproc_lock); 535 } 536 537 /* 538 * Main loop for a kthread that executes schedcpu once a second. 539 */ 540 static void 541 schedcpu_thread(void) 542 { 543 int nowake; 544 545 for (;;) { 546 schedcpu(); 547 tsleep(&nowake, 0, "-", hz); 548 } 549 } 550 551 /* 552 * Recalculate the priority of a process after it has slept for a while. 553 * For all load averages >= 1 and max kg_estcpu of 255, sleeping for at 554 * least six times the loadfactor will decay kg_estcpu to zero. 555 */ 556 static void 557 updatepri(struct ksegrp *kg) 558 { 559 register fixpt_t loadfac; 560 register unsigned int newcpu; 561 562 loadfac = loadfactor(averunnable.ldavg[0]); 563 if (kg->kg_slptime > 5 * loadfac) 564 kg->kg_estcpu = 0; 565 else { 566 newcpu = kg->kg_estcpu; 567 kg->kg_slptime--; /* was incremented in schedcpu() */ 568 while (newcpu && --kg->kg_slptime) 569 newcpu = decay_cpu(loadfac, newcpu); 570 kg->kg_estcpu = newcpu; 571 } 572 } 573 574 /* 575 * Compute the priority of a process when running in user mode. 576 * Arrange to reschedule if the resulting priority is better 577 * than that of the current process. 578 */ 579 static void 580 resetpriority(struct ksegrp *kg) 581 { 582 register unsigned int newpriority; 583 584 if (kg->kg_pri_class == PRI_TIMESHARE) { 585 newpriority = PUSER + kg->kg_estcpu / INVERSE_ESTCPU_WEIGHT + 586 NICE_WEIGHT * (kg->kg_proc->p_nice - PRIO_MIN); 587 newpriority = min(max(newpriority, PRI_MIN_TIMESHARE), 588 PRI_MAX_TIMESHARE); 589 kg->kg_user_pri = newpriority; 590 } 591 } 592 593 /* 594 * Update the thread's priority when the associated ksegroup's user 595 * priority changes. 596 */ 597 static void 598 resetpriority_thread(struct thread *td, struct ksegrp *kg) 599 { 600 601 /* Only change threads with a time sharing user priority. */ 602 if (td->td_priority < PRI_MIN_TIMESHARE || 603 td->td_priority > PRI_MAX_TIMESHARE) 604 return; 605 606 /* XXX the whole needresched thing is broken, but not silly. */ 607 maybe_resched(td); 608 609 sched_prio(td, kg->kg_user_pri); 610 } 611 612 /* ARGSUSED */ 613 static void 614 sched_setup(void *dummy) 615 { 616 setup_runqs(); 617 618 if (sched_quantum == 0) 619 sched_quantum = SCHED_QUANTUM; 620 hogticks = 2 * sched_quantum; 621 622 callout_init(&roundrobin_callout, CALLOUT_MPSAFE); 623 624 /* Kick off timeout driven events by calling first time. */ 625 roundrobin(NULL); 626 627 /* Account for thread0. */ 628 sched_load_add(); 629 } 630 631 /* External interfaces start here */ 632 /* 633 * Very early in the boot some setup of scheduler-specific 634 * parts of proc0 and of some scheduler resources needs to be done. 635 * Called from: 636 * proc0_init() 637 */ 638 void 639 schedinit(void) 640 { 641 /* 642 * Set up the scheduler specific parts of proc0. 643 */ 644 proc0.p_sched = NULL; /* XXX */ 645 ksegrp0.kg_sched = &kg_sched0; 646 thread0.td_sched = &kse0; 647 kse0.ke_thread = &thread0; 648 kse0.ke_state = KES_THREAD; 649 kg_sched0.skg_concurrency = 1; 650 kg_sched0.skg_avail_opennings = 0; /* we are already running */ 651 } 652 653 int 654 sched_runnable(void) 655 { 656 #ifdef SMP 657 return runq_check(&runq) + runq_check(&runq_pcpu[PCPU_GET(cpuid)]); 658 #else 659 return runq_check(&runq); 660 #endif 661 } 662 663 int 664 sched_rr_interval(void) 665 { 666 if (sched_quantum == 0) 667 sched_quantum = SCHED_QUANTUM; 668 return (sched_quantum); 669 } 670 671 /* 672 * We adjust the priority of the current process. The priority of 673 * a process gets worse as it accumulates CPU time. The cpu usage 674 * estimator (kg_estcpu) is increased here. resetpriority() will 675 * compute a different priority each time kg_estcpu increases by 676 * INVERSE_ESTCPU_WEIGHT 677 * (until MAXPRI is reached). The cpu usage estimator ramps up 678 * quite quickly when the process is running (linearly), and decays 679 * away exponentially, at a rate which is proportionally slower when 680 * the system is busy. The basic principle is that the system will 681 * 90% forget that the process used a lot of CPU time in 5 * loadav 682 * seconds. This causes the system to favor processes which haven't 683 * run much recently, and to round-robin among other processes. 684 */ 685 void 686 sched_clock(struct thread *td) 687 { 688 struct ksegrp *kg; 689 struct kse *ke; 690 691 mtx_assert(&sched_lock, MA_OWNED); 692 kg = td->td_ksegrp; 693 ke = td->td_kse; 694 695 ke->ke_cpticks++; 696 kg->kg_estcpu = ESTCPULIM(kg->kg_estcpu + 1); 697 if ((kg->kg_estcpu % INVERSE_ESTCPU_WEIGHT) == 0) { 698 resetpriority(kg); 699 resetpriority_thread(td, kg); 700 } 701 } 702 703 /* 704 * charge childs scheduling cpu usage to parent. 705 * 706 * XXXKSE assume only one thread & kse & ksegrp keep estcpu in each ksegrp. 707 * Charge it to the ksegrp that did the wait since process estcpu is sum of 708 * all ksegrps, this is strictly as expected. Assume that the child process 709 * aggregated all the estcpu into the 'built-in' ksegrp. 710 */ 711 void 712 sched_exit(struct proc *p, struct thread *td) 713 { 714 sched_exit_ksegrp(FIRST_KSEGRP_IN_PROC(p), td); 715 sched_exit_thread(FIRST_THREAD_IN_PROC(p), td); 716 } 717 718 void 719 sched_exit_ksegrp(struct ksegrp *kg, struct thread *childtd) 720 { 721 722 mtx_assert(&sched_lock, MA_OWNED); 723 kg->kg_estcpu = ESTCPULIM(kg->kg_estcpu + childtd->td_ksegrp->kg_estcpu); 724 } 725 726 void 727 sched_exit_thread(struct thread *td, struct thread *child) 728 { 729 CTR3(KTR_SCHED, "sched_exit_thread: %p(%s) prio %d", 730 child, child->td_proc->p_comm, child->td_priority); 731 if ((child->td_proc->p_flag & P_NOLOAD) == 0) 732 sched_load_rem(); 733 } 734 735 void 736 sched_fork(struct thread *td, struct thread *childtd) 737 { 738 sched_fork_ksegrp(td, childtd->td_ksegrp); 739 sched_fork_thread(td, childtd); 740 } 741 742 void 743 sched_fork_ksegrp(struct thread *td, struct ksegrp *child) 744 { 745 mtx_assert(&sched_lock, MA_OWNED); 746 child->kg_estcpu = td->td_ksegrp->kg_estcpu; 747 } 748 749 void 750 sched_fork_thread(struct thread *td, struct thread *childtd) 751 { 752 sched_newthread(childtd); 753 } 754 755 void 756 sched_nice(struct proc *p, int nice) 757 { 758 struct ksegrp *kg; 759 struct thread *td; 760 761 PROC_LOCK_ASSERT(p, MA_OWNED); 762 mtx_assert(&sched_lock, MA_OWNED); 763 p->p_nice = nice; 764 FOREACH_KSEGRP_IN_PROC(p, kg) { 765 resetpriority(kg); 766 FOREACH_THREAD_IN_GROUP(kg, td) { 767 resetpriority_thread(td, kg); 768 } 769 } 770 } 771 772 void 773 sched_class(struct ksegrp *kg, int class) 774 { 775 mtx_assert(&sched_lock, MA_OWNED); 776 kg->kg_pri_class = class; 777 } 778 779 /* 780 * Adjust the priority of a thread. 781 * This may include moving the thread within the KSEGRP, 782 * changing the assignment of a kse to the thread, 783 * and moving a KSE in the system run queue. 784 */ 785 static void 786 sched_priority(struct thread *td, u_char prio) 787 { 788 CTR6(KTR_SCHED, "sched_prio: %p(%s) prio %d newprio %d by %p(%s)", 789 td, td->td_proc->p_comm, td->td_priority, prio, curthread, 790 curthread->td_proc->p_comm); 791 792 mtx_assert(&sched_lock, MA_OWNED); 793 if (td->td_priority == prio) 794 return; 795 if (TD_ON_RUNQ(td)) { 796 adjustrunqueue(td, prio); 797 } else { 798 td->td_priority = prio; 799 } 800 } 801 802 /* 803 * Update a thread's priority when it is lent another thread's 804 * priority. 805 */ 806 void 807 sched_lend_prio(struct thread *td, u_char prio) 808 { 809 810 td->td_flags |= TDF_BORROWING; 811 sched_priority(td, prio); 812 } 813 814 /* 815 * Restore a thread's priority when priority propagation is 816 * over. The prio argument is the minimum priority the thread 817 * needs to have to satisfy other possible priority lending 818 * requests. If the thread's regulary priority is less 819 * important than prio the thread will keep a priority boost 820 * of prio. 821 */ 822 void 823 sched_unlend_prio(struct thread *td, u_char prio) 824 { 825 u_char base_pri; 826 827 if (td->td_base_pri >= PRI_MIN_TIMESHARE && 828 td->td_base_pri <= PRI_MAX_TIMESHARE) 829 base_pri = td->td_ksegrp->kg_user_pri; 830 else 831 base_pri = td->td_base_pri; 832 if (prio >= base_pri) { 833 td->td_flags &= ~TDF_BORROWING; 834 sched_prio(td, base_pri); 835 } else 836 sched_lend_prio(td, prio); 837 } 838 839 void 840 sched_prio(struct thread *td, u_char prio) 841 { 842 u_char oldprio; 843 844 /* First, update the base priority. */ 845 td->td_base_pri = prio; 846 847 /* 848 * If the thread is borrowing another thread's priority, don't ever 849 * lower the priority. 850 */ 851 if (td->td_flags & TDF_BORROWING && td->td_priority < prio) 852 return; 853 854 /* Change the real priority. */ 855 oldprio = td->td_priority; 856 sched_priority(td, prio); 857 858 /* 859 * If the thread is on a turnstile, then let the turnstile update 860 * its state. 861 */ 862 if (TD_ON_LOCK(td) && oldprio != prio) 863 turnstile_adjust(td, oldprio); 864 } 865 866 void 867 sched_sleep(struct thread *td) 868 { 869 870 mtx_assert(&sched_lock, MA_OWNED); 871 td->td_ksegrp->kg_slptime = 0; 872 } 873 874 static void remrunqueue(struct thread *td); 875 876 void 877 sched_switch(struct thread *td, struct thread *newtd, int flags) 878 { 879 struct kse *ke; 880 struct ksegrp *kg; 881 struct proc *p; 882 883 ke = td->td_kse; 884 p = td->td_proc; 885 886 mtx_assert(&sched_lock, MA_OWNED); 887 888 if ((p->p_flag & P_NOLOAD) == 0) 889 sched_load_rem(); 890 /* 891 * We are volunteering to switch out so we get to nominate 892 * a successor for the rest of our quantum 893 * First try another thread in our ksegrp, and then look for 894 * other ksegrps in our process. 895 */ 896 if (sched_followon && 897 (p->p_flag & P_HADTHREADS) && 898 (flags & SW_VOL) && 899 newtd == NULL) { 900 /* lets schedule another thread from this process */ 901 kg = td->td_ksegrp; 902 if ((newtd = TAILQ_FIRST(&kg->kg_runq))) { 903 remrunqueue(newtd); 904 sched_kgfollowons++; 905 } else { 906 FOREACH_KSEGRP_IN_PROC(p, kg) { 907 if ((newtd = TAILQ_FIRST(&kg->kg_runq))) { 908 sched_pfollowons++; 909 remrunqueue(newtd); 910 break; 911 } 912 } 913 } 914 } 915 916 if (newtd) 917 newtd->td_flags |= (td->td_flags & TDF_NEEDRESCHED); 918 919 td->td_lastcpu = td->td_oncpu; 920 td->td_flags &= ~TDF_NEEDRESCHED; 921 td->td_owepreempt = 0; 922 td->td_oncpu = NOCPU; 923 /* 924 * At the last moment, if this thread is still marked RUNNING, 925 * then put it back on the run queue as it has not been suspended 926 * or stopped or any thing else similar. We never put the idle 927 * threads on the run queue, however. 928 */ 929 if (td == PCPU_GET(idlethread)) 930 TD_SET_CAN_RUN(td); 931 else { 932 SLOT_RELEASE(td->td_ksegrp); 933 if (TD_IS_RUNNING(td)) { 934 /* Put us back on the run queue (kse and all). */ 935 setrunqueue(td, (flags & SW_PREEMPT) ? 936 SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED : 937 SRQ_OURSELF|SRQ_YIELDING); 938 } else if (p->p_flag & P_HADTHREADS) { 939 /* 940 * We will not be on the run queue. So we must be 941 * sleeping or similar. As it's available, 942 * someone else can use the KSE if they need it. 943 * It's NOT available if we are about to need it 944 */ 945 if (newtd == NULL || newtd->td_ksegrp != td->td_ksegrp) 946 slot_fill(td->td_ksegrp); 947 } 948 } 949 if (newtd) { 950 /* 951 * The thread we are about to run needs to be counted 952 * as if it had been added to the run queue and selected. 953 * It came from: 954 * * A preemption 955 * * An upcall 956 * * A followon 957 */ 958 KASSERT((newtd->td_inhibitors == 0), 959 ("trying to run inhibitted thread")); 960 SLOT_USE(newtd->td_ksegrp); 961 newtd->td_kse->ke_flags |= KEF_DIDRUN; 962 TD_SET_RUNNING(newtd); 963 if ((newtd->td_proc->p_flag & P_NOLOAD) == 0) 964 sched_load_add(); 965 } else { 966 newtd = choosethread(); 967 } 968 969 if (td != newtd) { 970 #ifdef HWPMC_HOOKS 971 if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 972 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT); 973 #endif 974 cpu_switch(td, newtd); 975 #ifdef HWPMC_HOOKS 976 if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 977 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN); 978 #endif 979 } 980 981 sched_lock.mtx_lock = (uintptr_t)td; 982 td->td_oncpu = PCPU_GET(cpuid); 983 } 984 985 void 986 sched_wakeup(struct thread *td) 987 { 988 struct ksegrp *kg; 989 990 mtx_assert(&sched_lock, MA_OWNED); 991 kg = td->td_ksegrp; 992 if (kg->kg_slptime > 1) { 993 updatepri(kg); 994 resetpriority(kg); 995 } 996 kg->kg_slptime = 0; 997 setrunqueue(td, SRQ_BORING); 998 } 999 1000 #ifdef SMP 1001 /* enable HTT_2 if you have a 2-way HTT cpu.*/ 1002 static int 1003 forward_wakeup(int cpunum) 1004 { 1005 cpumask_t map, me, dontuse; 1006 cpumask_t map2; 1007 struct pcpu *pc; 1008 cpumask_t id, map3; 1009 1010 mtx_assert(&sched_lock, MA_OWNED); 1011 1012 CTR0(KTR_RUNQ, "forward_wakeup()"); 1013 1014 if ((!forward_wakeup_enabled) || 1015 (forward_wakeup_use_mask == 0 && forward_wakeup_use_loop == 0)) 1016 return (0); 1017 if (!smp_started || cold || panicstr) 1018 return (0); 1019 1020 forward_wakeups_requested++; 1021 1022 /* 1023 * check the idle mask we received against what we calculated before 1024 * in the old version. 1025 */ 1026 me = PCPU_GET(cpumask); 1027 /* 1028 * don't bother if we should be doing it ourself.. 1029 */ 1030 if ((me & idle_cpus_mask) && (cpunum == NOCPU || me == (1 << cpunum))) 1031 return (0); 1032 1033 dontuse = me | stopped_cpus | hlt_cpus_mask; 1034 map3 = 0; 1035 if (forward_wakeup_use_loop) { 1036 SLIST_FOREACH(pc, &cpuhead, pc_allcpu) { 1037 id = pc->pc_cpumask; 1038 if ( (id & dontuse) == 0 && 1039 pc->pc_curthread == pc->pc_idlethread) { 1040 map3 |= id; 1041 } 1042 } 1043 } 1044 1045 if (forward_wakeup_use_mask) { 1046 map = 0; 1047 map = idle_cpus_mask & ~dontuse; 1048 1049 /* If they are both on, compare and use loop if different */ 1050 if (forward_wakeup_use_loop) { 1051 if (map != map3) { 1052 printf("map (%02X) != map3 (%02X)\n", 1053 map, map3); 1054 map = map3; 1055 } 1056 } 1057 } else { 1058 map = map3; 1059 } 1060 /* If we only allow a specific CPU, then mask off all the others */ 1061 if (cpunum != NOCPU) { 1062 KASSERT((cpunum <= mp_maxcpus),("forward_wakeup: bad cpunum.")); 1063 map &= (1 << cpunum); 1064 } else { 1065 /* Try choose an idle die. */ 1066 if (forward_wakeup_use_htt) { 1067 map2 = (map & (map >> 1)) & 0x5555; 1068 if (map2) { 1069 map = map2; 1070 } 1071 } 1072 1073 /* set only one bit */ 1074 if (forward_wakeup_use_single) { 1075 map = map & ((~map) + 1); 1076 } 1077 } 1078 if (map) { 1079 forward_wakeups_delivered++; 1080 ipi_selected(map, IPI_AST); 1081 return (1); 1082 } 1083 if (cpunum == NOCPU) 1084 printf("forward_wakeup: Idle processor not found\n"); 1085 return (0); 1086 } 1087 #endif 1088 1089 #ifdef SMP 1090 static void kick_other_cpu(int pri,int cpuid); 1091 1092 static void 1093 kick_other_cpu(int pri,int cpuid) 1094 { 1095 struct pcpu * pcpu = pcpu_find(cpuid); 1096 int cpri = pcpu->pc_curthread->td_priority; 1097 1098 if (idle_cpus_mask & pcpu->pc_cpumask) { 1099 forward_wakeups_delivered++; 1100 ipi_selected(pcpu->pc_cpumask, IPI_AST); 1101 return; 1102 } 1103 1104 if (pri >= cpri) 1105 return; 1106 1107 #if defined(IPI_PREEMPTION) && defined(PREEMPTION) 1108 #if !defined(FULL_PREEMPTION) 1109 if (pri <= PRI_MAX_ITHD) 1110 #endif /* ! FULL_PREEMPTION */ 1111 { 1112 ipi_selected(pcpu->pc_cpumask, IPI_PREEMPT); 1113 return; 1114 } 1115 #endif /* defined(IPI_PREEMPTION) && defined(PREEMPTION) */ 1116 1117 pcpu->pc_curthread->td_flags |= TDF_NEEDRESCHED; 1118 ipi_selected( pcpu->pc_cpumask , IPI_AST); 1119 return; 1120 } 1121 #endif /* SMP */ 1122 1123 void 1124 sched_add(struct thread *td, int flags) 1125 #ifdef SMP 1126 { 1127 struct kse *ke; 1128 int forwarded = 0; 1129 int cpu; 1130 int single_cpu = 0; 1131 1132 ke = td->td_kse; 1133 mtx_assert(&sched_lock, MA_OWNED); 1134 KASSERT(ke->ke_state != KES_ONRUNQ, 1135 ("sched_add: kse %p (%s) already in run queue", ke, 1136 ke->ke_proc->p_comm)); 1137 KASSERT(ke->ke_proc->p_sflag & PS_INMEM, 1138 ("sched_add: process swapped out")); 1139 CTR5(KTR_SCHED, "sched_add: %p(%s) prio %d by %p(%s)", 1140 td, td->td_proc->p_comm, td->td_priority, curthread, 1141 curthread->td_proc->p_comm); 1142 1143 1144 if (td->td_pinned != 0) { 1145 cpu = td->td_lastcpu; 1146 ke->ke_runq = &runq_pcpu[cpu]; 1147 single_cpu = 1; 1148 CTR3(KTR_RUNQ, 1149 "sched_add: Put kse:%p(td:%p) on cpu%d runq", ke, td, cpu); 1150 } else if ((ke)->ke_flags & KEF_BOUND) { 1151 /* Find CPU from bound runq */ 1152 KASSERT(SKE_RUNQ_PCPU(ke),("sched_add: bound kse not on cpu runq")); 1153 cpu = ke->ke_runq - &runq_pcpu[0]; 1154 single_cpu = 1; 1155 CTR3(KTR_RUNQ, 1156 "sched_add: Put kse:%p(td:%p) on cpu%d runq", ke, td, cpu); 1157 } else { 1158 CTR2(KTR_RUNQ, 1159 "sched_add: adding kse:%p (td:%p) to gbl runq", ke, td); 1160 cpu = NOCPU; 1161 ke->ke_runq = &runq; 1162 } 1163 1164 if (single_cpu && (cpu != PCPU_GET(cpuid))) { 1165 kick_other_cpu(td->td_priority,cpu); 1166 } else { 1167 1168 if (!single_cpu) { 1169 cpumask_t me = PCPU_GET(cpumask); 1170 int idle = idle_cpus_mask & me; 1171 1172 if (!idle && ((flags & SRQ_INTR) == 0) && 1173 (idle_cpus_mask & ~(hlt_cpus_mask | me))) 1174 forwarded = forward_wakeup(cpu); 1175 } 1176 1177 if (!forwarded) { 1178 if ((flags & SRQ_YIELDING) == 0 && maybe_preempt(td)) 1179 return; 1180 else 1181 maybe_resched(td); 1182 } 1183 } 1184 1185 if ((td->td_proc->p_flag & P_NOLOAD) == 0) 1186 sched_load_add(); 1187 SLOT_USE(td->td_ksegrp); 1188 runq_add(ke->ke_runq, ke, flags); 1189 ke->ke_state = KES_ONRUNQ; 1190 } 1191 #else /* SMP */ 1192 { 1193 struct kse *ke; 1194 ke = td->td_kse; 1195 mtx_assert(&sched_lock, MA_OWNED); 1196 KASSERT(ke->ke_state != KES_ONRUNQ, 1197 ("sched_add: kse %p (%s) already in run queue", ke, 1198 ke->ke_proc->p_comm)); 1199 KASSERT(ke->ke_proc->p_sflag & PS_INMEM, 1200 ("sched_add: process swapped out")); 1201 CTR5(KTR_SCHED, "sched_add: %p(%s) prio %d by %p(%s)", 1202 td, td->td_proc->p_comm, td->td_priority, curthread, 1203 curthread->td_proc->p_comm); 1204 CTR2(KTR_RUNQ, "sched_add: adding kse:%p (td:%p) to runq", ke, td); 1205 ke->ke_runq = &runq; 1206 1207 /* 1208 * If we are yielding (on the way out anyhow) 1209 * or the thread being saved is US, 1210 * then don't try be smart about preemption 1211 * or kicking off another CPU 1212 * as it won't help and may hinder. 1213 * In the YIEDLING case, we are about to run whoever is 1214 * being put in the queue anyhow, and in the 1215 * OURSELF case, we are puting ourself on the run queue 1216 * which also only happens when we are about to yield. 1217 */ 1218 if((flags & SRQ_YIELDING) == 0) { 1219 if (maybe_preempt(td)) 1220 return; 1221 } 1222 if ((td->td_proc->p_flag & P_NOLOAD) == 0) 1223 sched_load_add(); 1224 SLOT_USE(td->td_ksegrp); 1225 runq_add(ke->ke_runq, ke, flags); 1226 ke->ke_state = KES_ONRUNQ; 1227 maybe_resched(td); 1228 } 1229 #endif /* SMP */ 1230 1231 void 1232 sched_rem(struct thread *td) 1233 { 1234 struct kse *ke; 1235 1236 ke = td->td_kse; 1237 KASSERT(ke->ke_proc->p_sflag & PS_INMEM, 1238 ("sched_rem: process swapped out")); 1239 KASSERT((ke->ke_state == KES_ONRUNQ), 1240 ("sched_rem: KSE not on run queue")); 1241 mtx_assert(&sched_lock, MA_OWNED); 1242 CTR5(KTR_SCHED, "sched_rem: %p(%s) prio %d by %p(%s)", 1243 td, td->td_proc->p_comm, td->td_priority, curthread, 1244 curthread->td_proc->p_comm); 1245 1246 if ((td->td_proc->p_flag & P_NOLOAD) == 0) 1247 sched_load_rem(); 1248 SLOT_RELEASE(td->td_ksegrp); 1249 runq_remove(ke->ke_runq, ke); 1250 1251 ke->ke_state = KES_THREAD; 1252 } 1253 1254 /* 1255 * Select threads to run. 1256 * Notice that the running threads still consume a slot. 1257 */ 1258 struct kse * 1259 sched_choose(void) 1260 { 1261 struct kse *ke; 1262 struct runq *rq; 1263 1264 #ifdef SMP 1265 struct kse *kecpu; 1266 1267 rq = &runq; 1268 ke = runq_choose(&runq); 1269 kecpu = runq_choose(&runq_pcpu[PCPU_GET(cpuid)]); 1270 1271 if (ke == NULL || 1272 (kecpu != NULL && 1273 kecpu->ke_thread->td_priority < ke->ke_thread->td_priority)) { 1274 CTR2(KTR_RUNQ, "choosing kse %p from pcpu runq %d", kecpu, 1275 PCPU_GET(cpuid)); 1276 ke = kecpu; 1277 rq = &runq_pcpu[PCPU_GET(cpuid)]; 1278 } else { 1279 CTR1(KTR_RUNQ, "choosing kse %p from main runq", ke); 1280 } 1281 1282 #else 1283 rq = &runq; 1284 ke = runq_choose(&runq); 1285 #endif 1286 1287 if (ke != NULL) { 1288 runq_remove(rq, ke); 1289 ke->ke_state = KES_THREAD; 1290 1291 KASSERT(ke->ke_proc->p_sflag & PS_INMEM, 1292 ("sched_choose: process swapped out")); 1293 } 1294 return (ke); 1295 } 1296 1297 void 1298 sched_userret(struct thread *td) 1299 { 1300 struct ksegrp *kg; 1301 /* 1302 * XXX we cheat slightly on the locking here to avoid locking in 1303 * the usual case. Setting td_priority here is essentially an 1304 * incomplete workaround for not setting it properly elsewhere. 1305 * Now that some interrupt handlers are threads, not setting it 1306 * properly elsewhere can clobber it in the window between setting 1307 * it here and returning to user mode, so don't waste time setting 1308 * it perfectly here. 1309 */ 1310 KASSERT((td->td_flags & TDF_BORROWING) == 0, 1311 ("thread with borrowed priority returning to userland")); 1312 kg = td->td_ksegrp; 1313 if (td->td_priority != kg->kg_user_pri) { 1314 mtx_lock_spin(&sched_lock); 1315 td->td_priority = kg->kg_user_pri; 1316 td->td_base_pri = kg->kg_user_pri; 1317 mtx_unlock_spin(&sched_lock); 1318 } 1319 } 1320 1321 void 1322 sched_bind(struct thread *td, int cpu) 1323 { 1324 struct kse *ke; 1325 1326 mtx_assert(&sched_lock, MA_OWNED); 1327 KASSERT(TD_IS_RUNNING(td), 1328 ("sched_bind: cannot bind non-running thread")); 1329 1330 ke = td->td_kse; 1331 1332 ke->ke_flags |= KEF_BOUND; 1333 #ifdef SMP 1334 ke->ke_runq = &runq_pcpu[cpu]; 1335 if (PCPU_GET(cpuid) == cpu) 1336 return; 1337 1338 ke->ke_state = KES_THREAD; 1339 1340 mi_switch(SW_VOL, NULL); 1341 #endif 1342 } 1343 1344 void 1345 sched_unbind(struct thread* td) 1346 { 1347 mtx_assert(&sched_lock, MA_OWNED); 1348 td->td_kse->ke_flags &= ~KEF_BOUND; 1349 } 1350 1351 int 1352 sched_is_bound(struct thread *td) 1353 { 1354 mtx_assert(&sched_lock, MA_OWNED); 1355 return (td->td_kse->ke_flags & KEF_BOUND); 1356 } 1357 1358 void 1359 sched_relinquish(struct thread *td) 1360 { 1361 struct ksegrp *kg; 1362 1363 kg = td->td_ksegrp; 1364 mtx_lock_spin(&sched_lock); 1365 if (kg->kg_pri_class == PRI_TIMESHARE) 1366 sched_prio(td, PRI_MAX_TIMESHARE); 1367 mi_switch(SW_VOL, NULL); 1368 mtx_unlock_spin(&sched_lock); 1369 } 1370 1371 int 1372 sched_load(void) 1373 { 1374 return (sched_tdcnt); 1375 } 1376 1377 int 1378 sched_sizeof_ksegrp(void) 1379 { 1380 return (sizeof(struct ksegrp) + sizeof(struct kg_sched)); 1381 } 1382 1383 int 1384 sched_sizeof_proc(void) 1385 { 1386 return (sizeof(struct proc)); 1387 } 1388 1389 int 1390 sched_sizeof_thread(void) 1391 { 1392 return (sizeof(struct thread) + sizeof(struct kse)); 1393 } 1394 1395 fixpt_t 1396 sched_pctcpu(struct thread *td) 1397 { 1398 struct kse *ke; 1399 1400 ke = td->td_kse; 1401 return (ke->ke_pctcpu); 1402 } 1403 1404 void 1405 sched_tick(void) 1406 { 1407 } 1408 #define KERN_SWITCH_INCLUDE 1 1409 #include "kern/kern_switch.c" 1410