1 /*- 2 * Copyright (c) 2002-2007, Jeffrey Roberson <jeff@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_hwpmc_hooks.h" 31 #include "opt_sched.h" 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kdb.h> 36 #include <sys/kernel.h> 37 #include <sys/ktr.h> 38 #include <sys/lock.h> 39 #include <sys/mutex.h> 40 #include <sys/proc.h> 41 #include <sys/resource.h> 42 #include <sys/resourcevar.h> 43 #include <sys/sched.h> 44 #include <sys/smp.h> 45 #include <sys/sx.h> 46 #include <sys/sysctl.h> 47 #include <sys/sysproto.h> 48 #include <sys/turnstile.h> 49 #include <sys/umtx.h> 50 #include <sys/vmmeter.h> 51 #ifdef KTRACE 52 #include <sys/uio.h> 53 #include <sys/ktrace.h> 54 #endif 55 56 #ifdef HWPMC_HOOKS 57 #include <sys/pmckern.h> 58 #endif 59 60 #include <machine/cpu.h> 61 #include <machine/smp.h> 62 63 #ifndef PREEMPTION 64 #error "SCHED_ULE requires options PREEMPTION" 65 #endif 66 67 /* 68 * TODO: 69 * Pick idle from affinity group or self group first. 70 * Implement pick_score. 71 */ 72 73 #define KTR_ULE 0x0 /* Enable for pickpri debugging. */ 74 75 /* 76 * Thread scheduler specific section. 77 */ 78 struct td_sched { 79 TAILQ_ENTRY(td_sched) ts_procq; /* (j/z) Run queue. */ 80 int ts_flags; /* (j) TSF_* flags. */ 81 struct thread *ts_thread; /* (*) Active associated thread. */ 82 u_char ts_rqindex; /* (j) Run queue index. */ 83 int ts_slptime; 84 int ts_slice; 85 struct runq *ts_runq; 86 u_char ts_cpu; /* CPU that we have affinity for. */ 87 /* The following variables are only used for pctcpu calculation */ 88 int ts_ltick; /* Last tick that we were running on */ 89 int ts_ftick; /* First tick that we were running on */ 90 int ts_ticks; /* Tick count */ 91 #ifdef SMP 92 int ts_rltick; /* Real last tick, for affinity. */ 93 #endif 94 95 /* originally from kg_sched */ 96 u_int skg_slptime; /* Number of ticks we vol. slept */ 97 u_int skg_runtime; /* Number of ticks we were running */ 98 }; 99 /* flags kept in ts_flags */ 100 #define TSF_BOUND 0x0001 /* Thread can not migrate. */ 101 #define TSF_XFERABLE 0x0002 /* Thread was added as transferable. */ 102 103 static struct td_sched td_sched0; 104 105 /* 106 * Cpu percentage computation macros and defines. 107 * 108 * SCHED_TICK_SECS: Number of seconds to average the cpu usage across. 109 * SCHED_TICK_TARG: Number of hz ticks to average the cpu usage across. 110 * SCHED_TICK_MAX: Maximum number of ticks before scaling back. 111 * SCHED_TICK_SHIFT: Shift factor to avoid rounding away results. 112 * SCHED_TICK_HZ: Compute the number of hz ticks for a given ticks count. 113 * SCHED_TICK_TOTAL: Gives the amount of time we've been recording ticks. 114 */ 115 #define SCHED_TICK_SECS 10 116 #define SCHED_TICK_TARG (hz * SCHED_TICK_SECS) 117 #define SCHED_TICK_MAX (SCHED_TICK_TARG + hz) 118 #define SCHED_TICK_SHIFT 10 119 #define SCHED_TICK_HZ(ts) ((ts)->ts_ticks >> SCHED_TICK_SHIFT) 120 #define SCHED_TICK_TOTAL(ts) (max((ts)->ts_ltick - (ts)->ts_ftick, hz)) 121 122 /* 123 * These macros determine priorities for non-interactive threads. They are 124 * assigned a priority based on their recent cpu utilization as expressed 125 * by the ratio of ticks to the tick total. NHALF priorities at the start 126 * and end of the MIN to MAX timeshare range are only reachable with negative 127 * or positive nice respectively. 128 * 129 * PRI_RANGE: Priority range for utilization dependent priorities. 130 * PRI_NRESV: Number of nice values. 131 * PRI_TICKS: Compute a priority in PRI_RANGE from the ticks count and total. 132 * PRI_NICE: Determines the part of the priority inherited from nice. 133 */ 134 #define SCHED_PRI_NRESV (PRIO_MAX - PRIO_MIN) 135 #define SCHED_PRI_NHALF (SCHED_PRI_NRESV / 2) 136 #define SCHED_PRI_MIN (PRI_MIN_TIMESHARE + SCHED_PRI_NHALF) 137 #define SCHED_PRI_MAX (PRI_MAX_TIMESHARE - SCHED_PRI_NHALF) 138 #define SCHED_PRI_RANGE (SCHED_PRI_MAX - SCHED_PRI_MIN + 1) 139 #define SCHED_PRI_TICKS(ts) \ 140 (SCHED_TICK_HZ((ts)) / \ 141 (roundup(SCHED_TICK_TOTAL((ts)), SCHED_PRI_RANGE) / SCHED_PRI_RANGE)) 142 #define SCHED_PRI_NICE(nice) (nice) 143 144 /* 145 * These determine the interactivity of a process. Interactivity differs from 146 * cpu utilization in that it expresses the voluntary time slept vs time ran 147 * while cpu utilization includes all time not running. This more accurately 148 * models the intent of the thread. 149 * 150 * SLP_RUN_MAX: Maximum amount of sleep time + run time we'll accumulate 151 * before throttling back. 152 * SLP_RUN_FORK: Maximum slp+run time to inherit at fork time. 153 * INTERACT_MAX: Maximum interactivity value. Smaller is better. 154 * INTERACT_THRESH: Threshhold for placement on the current runq. 155 */ 156 #define SCHED_SLP_RUN_MAX ((hz * 5) << SCHED_TICK_SHIFT) 157 #define SCHED_SLP_RUN_FORK ((hz / 2) << SCHED_TICK_SHIFT) 158 #define SCHED_INTERACT_MAX (100) 159 #define SCHED_INTERACT_HALF (SCHED_INTERACT_MAX / 2) 160 #define SCHED_INTERACT_THRESH (30) 161 162 /* 163 * tickincr: Converts a stathz tick into a hz domain scaled by 164 * the shift factor. Without the shift the error rate 165 * due to rounding would be unacceptably high. 166 * realstathz: stathz is sometimes 0 and run off of hz. 167 * sched_slice: Runtime of each thread before rescheduling. 168 */ 169 static int sched_interact = SCHED_INTERACT_THRESH; 170 static int realstathz; 171 static int tickincr; 172 static int sched_slice; 173 174 /* 175 * tdq - per processor runqs and statistics. 176 */ 177 struct tdq { 178 struct runq tdq_idle; /* Queue of IDLE threads. */ 179 struct runq tdq_timeshare; /* timeshare run queue. */ 180 struct runq tdq_realtime; /* real-time run queue. */ 181 u_char tdq_idx; /* Current insert index. */ 182 u_char tdq_ridx; /* Current removal index. */ 183 short tdq_flags; /* Thread queue flags */ 184 int tdq_load; /* Aggregate load. */ 185 #ifdef SMP 186 int tdq_transferable; 187 LIST_ENTRY(tdq) tdq_siblings; /* Next in tdq group. */ 188 struct tdq_group *tdq_group; /* Our processor group. */ 189 #else 190 int tdq_sysload; /* For loadavg, !ITHD load. */ 191 #endif 192 }; 193 194 #define TDQF_BUSY 0x0001 /* Queue is marked as busy */ 195 196 #ifdef SMP 197 /* 198 * tdq groups are groups of processors which can cheaply share threads. When 199 * one processor in the group goes idle it will check the runqs of the other 200 * processors in its group prior to halting and waiting for an interrupt. 201 * These groups are suitable for SMT (Symetric Multi-Threading) and not NUMA. 202 * In a numa environment we'd want an idle bitmap per group and a two tiered 203 * load balancer. 204 */ 205 struct tdq_group { 206 int tdg_cpus; /* Count of CPUs in this tdq group. */ 207 cpumask_t tdg_cpumask; /* Mask of cpus in this group. */ 208 cpumask_t tdg_idlemask; /* Idle cpus in this group. */ 209 cpumask_t tdg_mask; /* Bit mask for first cpu. */ 210 int tdg_load; /* Total load of this group. */ 211 int tdg_transferable; /* Transferable load of this group. */ 212 LIST_HEAD(, tdq) tdg_members; /* Linked list of all members. */ 213 }; 214 215 #define SCHED_AFFINITY_DEFAULT (hz / 100) 216 #define SCHED_AFFINITY(ts) ((ts)->ts_rltick > ticks - affinity) 217 218 /* 219 * Run-time tunables. 220 */ 221 static int rebalance = 0; 222 static int pick_pri = 1; 223 static int affinity; 224 static int tryself = 1; 225 static int tryselfidle = 1; 226 static int ipi_ast = 0; 227 static int ipi_preempt = 1; 228 static int ipi_thresh = PRI_MIN_KERN; 229 static int steal_htt = 1; 230 static int steal_busy = 1; 231 static int busy_thresh = 4; 232 233 /* 234 * One thread queue per processor. 235 */ 236 static volatile cpumask_t tdq_idle; 237 static volatile cpumask_t tdq_busy; 238 static int tdg_maxid; 239 static struct tdq tdq_cpu[MAXCPU]; 240 static struct tdq_group tdq_groups[MAXCPU]; 241 static int bal_tick; 242 static int gbal_tick; 243 static int balance_groups; 244 245 #define TDQ_SELF() (&tdq_cpu[PCPU_GET(cpuid)]) 246 #define TDQ_CPU(x) (&tdq_cpu[(x)]) 247 #define TDQ_ID(x) ((x) - tdq_cpu) 248 #define TDQ_GROUP(x) (&tdq_groups[(x)]) 249 #else /* !SMP */ 250 static struct tdq tdq_cpu; 251 252 #define TDQ_SELF() (&tdq_cpu) 253 #define TDQ_CPU(x) (&tdq_cpu) 254 #endif 255 256 static void sched_priority(struct thread *); 257 static void sched_thread_priority(struct thread *, u_char); 258 static int sched_interact_score(struct thread *); 259 static void sched_interact_update(struct thread *); 260 static void sched_interact_fork(struct thread *); 261 static void sched_pctcpu_update(struct td_sched *); 262 static inline void sched_pin_td(struct thread *td); 263 static inline void sched_unpin_td(struct thread *td); 264 265 /* Operations on per processor queues */ 266 static struct td_sched * tdq_choose(struct tdq *); 267 static void tdq_setup(struct tdq *); 268 static void tdq_load_add(struct tdq *, struct td_sched *); 269 static void tdq_load_rem(struct tdq *, struct td_sched *); 270 static __inline void tdq_runq_add(struct tdq *, struct td_sched *, int); 271 static __inline void tdq_runq_rem(struct tdq *, struct td_sched *); 272 void tdq_print(int cpu); 273 static void runq_print(struct runq *rq); 274 #ifdef SMP 275 static int tdq_pickidle(struct tdq *, struct td_sched *); 276 static int tdq_pickpri(struct tdq *, struct td_sched *, int); 277 static struct td_sched *runq_steal(struct runq *); 278 static void sched_balance(void); 279 static void sched_balance_groups(void); 280 static void sched_balance_group(struct tdq_group *); 281 static void sched_balance_pair(struct tdq *, struct tdq *); 282 static void sched_smp_tick(struct thread *); 283 static void tdq_move(struct tdq *, int); 284 static int tdq_idled(struct tdq *); 285 static void tdq_notify(struct td_sched *); 286 static struct td_sched *tdq_steal(struct tdq *, int); 287 288 #define THREAD_CAN_MIGRATE(td) ((td)->td_pinned == 0) 289 #endif 290 291 static void sched_setup(void *dummy); 292 SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL) 293 294 static void sched_initticks(void *dummy); 295 SYSINIT(sched_initticks, SI_SUB_CLOCKS, SI_ORDER_THIRD, sched_initticks, NULL) 296 297 static inline void 298 sched_pin_td(struct thread *td) 299 { 300 td->td_pinned++; 301 } 302 303 static inline void 304 sched_unpin_td(struct thread *td) 305 { 306 td->td_pinned--; 307 } 308 309 static void 310 runq_print(struct runq *rq) 311 { 312 struct rqhead *rqh; 313 struct td_sched *ts; 314 int pri; 315 int j; 316 int i; 317 318 for (i = 0; i < RQB_LEN; i++) { 319 printf("\t\trunq bits %d 0x%zx\n", 320 i, rq->rq_status.rqb_bits[i]); 321 for (j = 0; j < RQB_BPW; j++) 322 if (rq->rq_status.rqb_bits[i] & (1ul << j)) { 323 pri = j + (i << RQB_L2BPW); 324 rqh = &rq->rq_queues[pri]; 325 TAILQ_FOREACH(ts, rqh, ts_procq) { 326 printf("\t\t\ttd %p(%s) priority %d rqindex %d pri %d\n", 327 ts->ts_thread, ts->ts_thread->td_proc->p_comm, ts->ts_thread->td_priority, ts->ts_rqindex, pri); 328 } 329 } 330 } 331 } 332 333 void 334 tdq_print(int cpu) 335 { 336 struct tdq *tdq; 337 338 tdq = TDQ_CPU(cpu); 339 340 printf("tdq:\n"); 341 printf("\tload: %d\n", tdq->tdq_load); 342 printf("\ttimeshare idx: %d\n", tdq->tdq_idx); 343 printf("\ttimeshare ridx: %d\n", tdq->tdq_ridx); 344 printf("\trealtime runq:\n"); 345 runq_print(&tdq->tdq_realtime); 346 printf("\ttimeshare runq:\n"); 347 runq_print(&tdq->tdq_timeshare); 348 printf("\tidle runq:\n"); 349 runq_print(&tdq->tdq_idle); 350 #ifdef SMP 351 printf("\tload transferable: %d\n", tdq->tdq_transferable); 352 #endif 353 } 354 355 static __inline void 356 tdq_runq_add(struct tdq *tdq, struct td_sched *ts, int flags) 357 { 358 #ifdef SMP 359 if (THREAD_CAN_MIGRATE(ts->ts_thread)) { 360 tdq->tdq_transferable++; 361 tdq->tdq_group->tdg_transferable++; 362 ts->ts_flags |= TSF_XFERABLE; 363 if (tdq->tdq_transferable >= busy_thresh && 364 (tdq->tdq_flags & TDQF_BUSY) == 0) { 365 tdq->tdq_flags |= TDQF_BUSY; 366 atomic_set_int(&tdq_busy, 1 << TDQ_ID(tdq)); 367 } 368 } 369 #endif 370 if (ts->ts_runq == &tdq->tdq_timeshare) { 371 u_char pri; 372 373 pri = ts->ts_thread->td_priority; 374 KASSERT(pri <= PRI_MAX_TIMESHARE && pri >= PRI_MIN_TIMESHARE, 375 ("Invalid priority %d on timeshare runq", pri)); 376 /* 377 * This queue contains only priorities between MIN and MAX 378 * realtime. Use the whole queue to represent these values. 379 */ 380 #define TS_RQ_PPQ (((PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE) + 1) / RQ_NQS) 381 if ((flags & SRQ_BORROWING) == 0) { 382 pri = (pri - PRI_MIN_TIMESHARE) / TS_RQ_PPQ; 383 pri = (pri + tdq->tdq_idx) % RQ_NQS; 384 /* 385 * This effectively shortens the queue by one so we 386 * can have a one slot difference between idx and 387 * ridx while we wait for threads to drain. 388 */ 389 if (tdq->tdq_ridx != tdq->tdq_idx && 390 pri == tdq->tdq_ridx) 391 pri = (pri - 1) % RQ_NQS; 392 } else 393 pri = tdq->tdq_ridx; 394 runq_add_pri(ts->ts_runq, ts, pri, flags); 395 } else 396 runq_add(ts->ts_runq, ts, flags); 397 } 398 399 static __inline void 400 tdq_runq_rem(struct tdq *tdq, struct td_sched *ts) 401 { 402 #ifdef SMP 403 if (ts->ts_flags & TSF_XFERABLE) { 404 tdq->tdq_transferable--; 405 tdq->tdq_group->tdg_transferable--; 406 ts->ts_flags &= ~TSF_XFERABLE; 407 if (tdq->tdq_transferable < busy_thresh && 408 (tdq->tdq_flags & TDQF_BUSY)) { 409 atomic_clear_int(&tdq_busy, 1 << TDQ_ID(tdq)); 410 tdq->tdq_flags &= ~TDQF_BUSY; 411 } 412 } 413 #endif 414 if (ts->ts_runq == &tdq->tdq_timeshare) { 415 if (tdq->tdq_idx != tdq->tdq_ridx) 416 runq_remove_idx(ts->ts_runq, ts, &tdq->tdq_ridx); 417 else 418 runq_remove_idx(ts->ts_runq, ts, NULL); 419 /* 420 * For timeshare threads we update the priority here so 421 * the priority reflects the time we've been sleeping. 422 */ 423 ts->ts_ltick = ticks; 424 sched_pctcpu_update(ts); 425 sched_priority(ts->ts_thread); 426 } else 427 runq_remove(ts->ts_runq, ts); 428 } 429 430 static void 431 tdq_load_add(struct tdq *tdq, struct td_sched *ts) 432 { 433 int class; 434 mtx_assert(&sched_lock, MA_OWNED); 435 class = PRI_BASE(ts->ts_thread->td_pri_class); 436 tdq->tdq_load++; 437 CTR1(KTR_SCHED, "load: %d", tdq->tdq_load); 438 if (class != PRI_ITHD && 439 (ts->ts_thread->td_proc->p_flag & P_NOLOAD) == 0) 440 #ifdef SMP 441 tdq->tdq_group->tdg_load++; 442 #else 443 tdq->tdq_sysload++; 444 #endif 445 } 446 447 static void 448 tdq_load_rem(struct tdq *tdq, struct td_sched *ts) 449 { 450 int class; 451 mtx_assert(&sched_lock, MA_OWNED); 452 class = PRI_BASE(ts->ts_thread->td_pri_class); 453 if (class != PRI_ITHD && 454 (ts->ts_thread->td_proc->p_flag & P_NOLOAD) == 0) 455 #ifdef SMP 456 tdq->tdq_group->tdg_load--; 457 #else 458 tdq->tdq_sysload--; 459 #endif 460 tdq->tdq_load--; 461 CTR1(KTR_SCHED, "load: %d", tdq->tdq_load); 462 ts->ts_runq = NULL; 463 } 464 465 #ifdef SMP 466 static void 467 sched_smp_tick(struct thread *td) 468 { 469 struct tdq *tdq; 470 471 tdq = TDQ_SELF(); 472 if (rebalance) { 473 if (ticks >= bal_tick) 474 sched_balance(); 475 if (ticks >= gbal_tick && balance_groups) 476 sched_balance_groups(); 477 } 478 td->td_sched->ts_rltick = ticks; 479 } 480 481 /* 482 * sched_balance is a simple CPU load balancing algorithm. It operates by 483 * finding the least loaded and most loaded cpu and equalizing their load 484 * by migrating some processes. 485 * 486 * Dealing only with two CPUs at a time has two advantages. Firstly, most 487 * installations will only have 2 cpus. Secondly, load balancing too much at 488 * once can have an unpleasant effect on the system. The scheduler rarely has 489 * enough information to make perfect decisions. So this algorithm chooses 490 * algorithm simplicity and more gradual effects on load in larger systems. 491 * 492 * It could be improved by considering the priorities and slices assigned to 493 * each task prior to balancing them. There are many pathological cases with 494 * any approach and so the semi random algorithm below may work as well as any. 495 * 496 */ 497 static void 498 sched_balance(void) 499 { 500 struct tdq_group *high; 501 struct tdq_group *low; 502 struct tdq_group *tdg; 503 int cnt; 504 int i; 505 506 bal_tick = ticks + (random() % (hz * 2)); 507 if (smp_started == 0) 508 return; 509 low = high = NULL; 510 i = random() % (tdg_maxid + 1); 511 for (cnt = 0; cnt <= tdg_maxid; cnt++) { 512 tdg = TDQ_GROUP(i); 513 /* 514 * Find the CPU with the highest load that has some 515 * threads to transfer. 516 */ 517 if ((high == NULL || tdg->tdg_load > high->tdg_load) 518 && tdg->tdg_transferable) 519 high = tdg; 520 if (low == NULL || tdg->tdg_load < low->tdg_load) 521 low = tdg; 522 if (++i > tdg_maxid) 523 i = 0; 524 } 525 if (low != NULL && high != NULL && high != low) 526 sched_balance_pair(LIST_FIRST(&high->tdg_members), 527 LIST_FIRST(&low->tdg_members)); 528 } 529 530 static void 531 sched_balance_groups(void) 532 { 533 int i; 534 535 gbal_tick = ticks + (random() % (hz * 2)); 536 mtx_assert(&sched_lock, MA_OWNED); 537 if (smp_started) 538 for (i = 0; i <= tdg_maxid; i++) 539 sched_balance_group(TDQ_GROUP(i)); 540 } 541 542 static void 543 sched_balance_group(struct tdq_group *tdg) 544 { 545 struct tdq *tdq; 546 struct tdq *high; 547 struct tdq *low; 548 int load; 549 550 if (tdg->tdg_transferable == 0) 551 return; 552 low = NULL; 553 high = NULL; 554 LIST_FOREACH(tdq, &tdg->tdg_members, tdq_siblings) { 555 load = tdq->tdq_load; 556 if (high == NULL || load > high->tdq_load) 557 high = tdq; 558 if (low == NULL || load < low->tdq_load) 559 low = tdq; 560 } 561 if (high != NULL && low != NULL && high != low) 562 sched_balance_pair(high, low); 563 } 564 565 static void 566 sched_balance_pair(struct tdq *high, struct tdq *low) 567 { 568 int transferable; 569 int high_load; 570 int low_load; 571 int move; 572 int diff; 573 int i; 574 575 /* 576 * If we're transfering within a group we have to use this specific 577 * tdq's transferable count, otherwise we can steal from other members 578 * of the group. 579 */ 580 if (high->tdq_group == low->tdq_group) { 581 transferable = high->tdq_transferable; 582 high_load = high->tdq_load; 583 low_load = low->tdq_load; 584 } else { 585 transferable = high->tdq_group->tdg_transferable; 586 high_load = high->tdq_group->tdg_load; 587 low_load = low->tdq_group->tdg_load; 588 } 589 if (transferable == 0) 590 return; 591 /* 592 * Determine what the imbalance is and then adjust that to how many 593 * threads we actually have to give up (transferable). 594 */ 595 diff = high_load - low_load; 596 move = diff / 2; 597 if (diff & 0x1) 598 move++; 599 move = min(move, transferable); 600 for (i = 0; i < move; i++) 601 tdq_move(high, TDQ_ID(low)); 602 return; 603 } 604 605 static void 606 tdq_move(struct tdq *from, int cpu) 607 { 608 struct tdq *tdq; 609 struct tdq *to; 610 struct td_sched *ts; 611 612 tdq = from; 613 to = TDQ_CPU(cpu); 614 ts = tdq_steal(tdq, 1); 615 if (ts == NULL) { 616 struct tdq_group *tdg; 617 618 tdg = tdq->tdq_group; 619 LIST_FOREACH(tdq, &tdg->tdg_members, tdq_siblings) { 620 if (tdq == from || tdq->tdq_transferable == 0) 621 continue; 622 ts = tdq_steal(tdq, 1); 623 break; 624 } 625 if (ts == NULL) 626 panic("tdq_move: No threads available with a " 627 "transferable count of %d\n", 628 tdg->tdg_transferable); 629 } 630 if (tdq == to) 631 return; 632 sched_rem(ts->ts_thread); 633 ts->ts_cpu = cpu; 634 sched_pin_td(ts->ts_thread); 635 sched_add(ts->ts_thread, SRQ_YIELDING); 636 sched_unpin_td(ts->ts_thread); 637 } 638 639 static int 640 tdq_idled(struct tdq *tdq) 641 { 642 struct tdq_group *tdg; 643 struct tdq *steal; 644 struct td_sched *ts; 645 646 tdg = tdq->tdq_group; 647 /* 648 * If we're in a cpu group, try and steal threads from another cpu in 649 * the group before idling. 650 */ 651 if (steal_htt && tdg->tdg_cpus > 1 && tdg->tdg_transferable) { 652 LIST_FOREACH(steal, &tdg->tdg_members, tdq_siblings) { 653 if (steal == tdq || steal->tdq_transferable == 0) 654 continue; 655 ts = tdq_steal(steal, 0); 656 if (ts) 657 goto steal; 658 } 659 } 660 if (steal_busy) { 661 while (tdq_busy) { 662 int cpu; 663 664 cpu = ffs(tdq_busy); 665 if (cpu == 0) 666 break; 667 cpu--; 668 steal = TDQ_CPU(cpu); 669 if (steal->tdq_transferable == 0) 670 continue; 671 ts = tdq_steal(steal, 1); 672 if (ts == NULL) 673 continue; 674 CTR5(KTR_ULE, 675 "tdq_idled: stealing td %p(%s) pri %d from %d busy 0x%X", 676 ts->ts_thread, ts->ts_thread->td_proc->p_comm, 677 ts->ts_thread->td_priority, cpu, tdq_busy); 678 goto steal; 679 } 680 } 681 /* 682 * We only set the idled bit when all of the cpus in the group are 683 * idle. Otherwise we could get into a situation where a thread bounces 684 * back and forth between two idle cores on seperate physical CPUs. 685 */ 686 tdg->tdg_idlemask |= PCPU_GET(cpumask); 687 if (tdg->tdg_idlemask == tdg->tdg_cpumask) 688 atomic_set_int(&tdq_idle, tdg->tdg_mask); 689 return (1); 690 steal: 691 sched_rem(ts->ts_thread); 692 ts->ts_cpu = PCPU_GET(cpuid); 693 sched_pin_td(ts->ts_thread); 694 sched_add(ts->ts_thread, SRQ_YIELDING); 695 sched_unpin_td(ts->ts_thread); 696 697 return (0); 698 } 699 700 static void 701 tdq_notify(struct td_sched *ts) 702 { 703 struct thread *ctd; 704 struct pcpu *pcpu; 705 int cpri; 706 int pri; 707 int cpu; 708 709 cpu = ts->ts_cpu; 710 pri = ts->ts_thread->td_priority; 711 pcpu = pcpu_find(cpu); 712 ctd = pcpu->pc_curthread; 713 cpri = ctd->td_priority; 714 715 /* 716 * If our priority is not better than the current priority there is 717 * nothing to do. 718 */ 719 if (pri > cpri) 720 return; 721 /* 722 * Always IPI idle. 723 */ 724 if (cpri > PRI_MIN_IDLE) 725 goto sendipi; 726 /* 727 * If we're realtime or better and there is timeshare or worse running 728 * send an IPI. 729 */ 730 if (pri < PRI_MAX_REALTIME && cpri > PRI_MAX_REALTIME) 731 goto sendipi; 732 /* 733 * Otherwise only IPI if we exceed the threshold. 734 */ 735 if (pri > ipi_thresh) 736 return; 737 sendipi: 738 ctd->td_flags |= TDF_NEEDRESCHED; 739 if (cpri < PRI_MIN_IDLE) { 740 if (ipi_ast) 741 ipi_selected(1 << cpu, IPI_AST); 742 else if (ipi_preempt) 743 ipi_selected(1 << cpu, IPI_PREEMPT); 744 } else 745 ipi_selected(1 << cpu, IPI_PREEMPT); 746 } 747 748 static struct td_sched * 749 runq_steal(struct runq *rq) 750 { 751 struct rqhead *rqh; 752 struct rqbits *rqb; 753 struct td_sched *ts; 754 int word; 755 int bit; 756 757 mtx_assert(&sched_lock, MA_OWNED); 758 rqb = &rq->rq_status; 759 for (word = 0; word < RQB_LEN; word++) { 760 if (rqb->rqb_bits[word] == 0) 761 continue; 762 for (bit = 0; bit < RQB_BPW; bit++) { 763 if ((rqb->rqb_bits[word] & (1ul << bit)) == 0) 764 continue; 765 rqh = &rq->rq_queues[bit + (word << RQB_L2BPW)]; 766 TAILQ_FOREACH(ts, rqh, ts_procq) { 767 if (THREAD_CAN_MIGRATE(ts->ts_thread)) 768 return (ts); 769 } 770 } 771 } 772 return (NULL); 773 } 774 775 static struct td_sched * 776 tdq_steal(struct tdq *tdq, int stealidle) 777 { 778 struct td_sched *ts; 779 780 /* 781 * Steal from next first to try to get a non-interactive task that 782 * may not have run for a while. 783 * XXX Need to effect steal order for timeshare threads. 784 */ 785 if ((ts = runq_steal(&tdq->tdq_realtime)) != NULL) 786 return (ts); 787 if ((ts = runq_steal(&tdq->tdq_timeshare)) != NULL) 788 return (ts); 789 if (stealidle) 790 return (runq_steal(&tdq->tdq_idle)); 791 return (NULL); 792 } 793 794 int 795 tdq_pickidle(struct tdq *tdq, struct td_sched *ts) 796 { 797 struct tdq_group *tdg; 798 int self; 799 int cpu; 800 801 self = PCPU_GET(cpuid); 802 if (smp_started == 0) 803 return (self); 804 /* 805 * If the current CPU has idled, just run it here. 806 */ 807 if ((tdq->tdq_group->tdg_idlemask & PCPU_GET(cpumask)) != 0) 808 return (self); 809 /* 810 * Try the last group we ran on. 811 */ 812 tdg = TDQ_CPU(ts->ts_cpu)->tdq_group; 813 cpu = ffs(tdg->tdg_idlemask); 814 if (cpu) 815 return (cpu - 1); 816 /* 817 * Search for an idle group. 818 */ 819 cpu = ffs(tdq_idle); 820 if (cpu) 821 return (cpu - 1); 822 /* 823 * XXX If there are no idle groups, check for an idle core. 824 */ 825 /* 826 * No idle CPUs? 827 */ 828 return (self); 829 } 830 831 static int 832 tdq_pickpri(struct tdq *tdq, struct td_sched *ts, int flags) 833 { 834 struct pcpu *pcpu; 835 int lowpri; 836 int lowcpu; 837 int lowload; 838 int load; 839 int self; 840 int pri; 841 int cpu; 842 843 self = PCPU_GET(cpuid); 844 if (smp_started == 0) 845 return (self); 846 847 pri = ts->ts_thread->td_priority; 848 /* 849 * Regardless of affinity, if the last cpu is idle send it there. 850 */ 851 pcpu = pcpu_find(ts->ts_cpu); 852 if (pcpu->pc_curthread->td_priority > PRI_MIN_IDLE) { 853 CTR5(KTR_ULE, 854 "ts_cpu %d idle, ltick %d ticks %d pri %d curthread %d", 855 ts->ts_cpu, ts->ts_rltick, ticks, pri, 856 pcpu->pc_curthread->td_priority); 857 return (ts->ts_cpu); 858 } 859 /* 860 * If we have affinity, try to place it on the cpu we last ran on. 861 */ 862 if (SCHED_AFFINITY(ts) && pcpu->pc_curthread->td_priority > pri) { 863 CTR5(KTR_ULE, 864 "affinity for %d, ltick %d ticks %d pri %d curthread %d", 865 ts->ts_cpu, ts->ts_rltick, ticks, pri, 866 pcpu->pc_curthread->td_priority); 867 return (ts->ts_cpu); 868 } 869 /* 870 * Try ourself first; If we're running something lower priority this 871 * may have some locality with the waking thread and execute faster 872 * here. 873 */ 874 if (tryself) { 875 /* 876 * If we're being awoken by an interrupt thread or the waker 877 * is going right to sleep run here as well. 878 */ 879 if ((TDQ_SELF()->tdq_load == 1) && (flags & SRQ_YIELDING || 880 curthread->td_pri_class == PRI_ITHD)) { 881 CTR2(KTR_ULE, "tryself load %d flags %d", 882 TDQ_SELF()->tdq_load, flags); 883 return (self); 884 } 885 } 886 /* 887 * Look for an idle group. 888 */ 889 CTR1(KTR_ULE, "tdq_idle %X", tdq_idle); 890 cpu = ffs(tdq_idle); 891 if (cpu) 892 return (cpu - 1); 893 if (tryselfidle && pri < curthread->td_priority) { 894 CTR1(KTR_ULE, "tryself %d", 895 curthread->td_priority); 896 return (self); 897 } 898 /* 899 * Now search for the cpu running the lowest priority thread with 900 * the least load. 901 */ 902 lowload = 0; 903 lowpri = lowcpu = 0; 904 for (cpu = 0; cpu <= mp_maxid; cpu++) { 905 if (CPU_ABSENT(cpu)) 906 continue; 907 pcpu = pcpu_find(cpu); 908 pri = pcpu->pc_curthread->td_priority; 909 CTR4(KTR_ULE, 910 "cpu %d pri %d lowcpu %d lowpri %d", 911 cpu, pri, lowcpu, lowpri); 912 if (pri < lowpri) 913 continue; 914 load = TDQ_CPU(cpu)->tdq_load; 915 if (lowpri && lowpri == pri && load > lowload) 916 continue; 917 lowpri = pri; 918 lowcpu = cpu; 919 lowload = load; 920 } 921 922 return (lowcpu); 923 } 924 925 #endif /* SMP */ 926 927 /* 928 * Pick the highest priority task we have and return it. 929 */ 930 931 static struct td_sched * 932 tdq_choose(struct tdq *tdq) 933 { 934 struct td_sched *ts; 935 936 mtx_assert(&sched_lock, MA_OWNED); 937 938 ts = runq_choose(&tdq->tdq_realtime); 939 if (ts != NULL) { 940 KASSERT(ts->ts_thread->td_priority <= PRI_MAX_REALTIME, 941 ("tdq_choose: Invalid priority on realtime queue %d", 942 ts->ts_thread->td_priority)); 943 return (ts); 944 } 945 ts = runq_choose_from(&tdq->tdq_timeshare, tdq->tdq_ridx); 946 if (ts != NULL) { 947 KASSERT(ts->ts_thread->td_priority <= PRI_MAX_TIMESHARE && 948 ts->ts_thread->td_priority >= PRI_MIN_TIMESHARE, 949 ("tdq_choose: Invalid priority on timeshare queue %d", 950 ts->ts_thread->td_priority)); 951 return (ts); 952 } 953 954 ts = runq_choose(&tdq->tdq_idle); 955 if (ts != NULL) { 956 KASSERT(ts->ts_thread->td_priority >= PRI_MIN_IDLE, 957 ("tdq_choose: Invalid priority on idle queue %d", 958 ts->ts_thread->td_priority)); 959 return (ts); 960 } 961 962 return (NULL); 963 } 964 965 static void 966 tdq_setup(struct tdq *tdq) 967 { 968 runq_init(&tdq->tdq_realtime); 969 runq_init(&tdq->tdq_timeshare); 970 runq_init(&tdq->tdq_idle); 971 tdq->tdq_load = 0; 972 } 973 974 static void 975 sched_setup(void *dummy) 976 { 977 #ifdef SMP 978 int i; 979 #endif 980 981 /* 982 * To avoid divide-by-zero, we set realstathz a dummy value 983 * in case which sched_clock() called before sched_initticks(). 984 */ 985 realstathz = hz; 986 sched_slice = (realstathz/10); /* ~100ms */ 987 tickincr = 1 << SCHED_TICK_SHIFT; 988 989 #ifdef SMP 990 balance_groups = 0; 991 /* 992 * Initialize the tdqs. 993 */ 994 for (i = 0; i < MAXCPU; i++) { 995 struct tdq *tdq; 996 997 tdq = &tdq_cpu[i]; 998 tdq_setup(&tdq_cpu[i]); 999 } 1000 if (1) { 1001 struct tdq_group *tdg; 1002 struct tdq *tdq; 1003 int cpus; 1004 1005 for (cpus = 0, i = 0; i < MAXCPU; i++) { 1006 if (CPU_ABSENT(i)) 1007 continue; 1008 tdq = &tdq_cpu[i]; 1009 tdg = &tdq_groups[cpus]; 1010 /* 1011 * Setup a tdq group with one member. 1012 */ 1013 tdq->tdq_transferable = 0; 1014 tdq->tdq_group = tdg; 1015 tdg->tdg_cpus = 1; 1016 tdg->tdg_idlemask = 0; 1017 tdg->tdg_cpumask = tdg->tdg_mask = 1 << i; 1018 tdg->tdg_load = 0; 1019 tdg->tdg_transferable = 0; 1020 LIST_INIT(&tdg->tdg_members); 1021 LIST_INSERT_HEAD(&tdg->tdg_members, tdq, tdq_siblings); 1022 cpus++; 1023 } 1024 tdg_maxid = cpus - 1; 1025 } else { 1026 struct tdq_group *tdg; 1027 struct cpu_group *cg; 1028 int j; 1029 1030 for (i = 0; i < smp_topology->ct_count; i++) { 1031 cg = &smp_topology->ct_group[i]; 1032 tdg = &tdq_groups[i]; 1033 /* 1034 * Initialize the group. 1035 */ 1036 tdg->tdg_idlemask = 0; 1037 tdg->tdg_load = 0; 1038 tdg->tdg_transferable = 0; 1039 tdg->tdg_cpus = cg->cg_count; 1040 tdg->tdg_cpumask = cg->cg_mask; 1041 LIST_INIT(&tdg->tdg_members); 1042 /* 1043 * Find all of the group members and add them. 1044 */ 1045 for (j = 0; j < MAXCPU; j++) { 1046 if ((cg->cg_mask & (1 << j)) != 0) { 1047 if (tdg->tdg_mask == 0) 1048 tdg->tdg_mask = 1 << j; 1049 tdq_cpu[j].tdq_transferable = 0; 1050 tdq_cpu[j].tdq_group = tdg; 1051 LIST_INSERT_HEAD(&tdg->tdg_members, 1052 &tdq_cpu[j], tdq_siblings); 1053 } 1054 } 1055 if (tdg->tdg_cpus > 1) 1056 balance_groups = 1; 1057 } 1058 tdg_maxid = smp_topology->ct_count - 1; 1059 } 1060 /* 1061 * Stagger the group and global load balancer so they do not 1062 * interfere with each other. 1063 */ 1064 bal_tick = ticks + hz; 1065 if (balance_groups) 1066 gbal_tick = ticks + (hz / 2); 1067 #else 1068 tdq_setup(TDQ_SELF()); 1069 #endif 1070 mtx_lock_spin(&sched_lock); 1071 tdq_load_add(TDQ_SELF(), &td_sched0); 1072 mtx_unlock_spin(&sched_lock); 1073 } 1074 1075 /* ARGSUSED */ 1076 static void 1077 sched_initticks(void *dummy) 1078 { 1079 mtx_lock_spin(&sched_lock); 1080 realstathz = stathz ? stathz : hz; 1081 sched_slice = (realstathz/10); /* ~100ms */ 1082 1083 /* 1084 * tickincr is shifted out by 10 to avoid rounding errors due to 1085 * hz not being evenly divisible by stathz on all platforms. 1086 */ 1087 tickincr = (hz << SCHED_TICK_SHIFT) / realstathz; 1088 /* 1089 * This does not work for values of stathz that are more than 1090 * 1 << SCHED_TICK_SHIFT * hz. In practice this does not happen. 1091 */ 1092 if (tickincr == 0) 1093 tickincr = 1; 1094 #ifdef SMP 1095 affinity = SCHED_AFFINITY_DEFAULT; 1096 #endif 1097 mtx_unlock_spin(&sched_lock); 1098 } 1099 1100 1101 /* 1102 * Scale the scheduling priority according to the "interactivity" of this 1103 * process. 1104 */ 1105 static void 1106 sched_priority(struct thread *td) 1107 { 1108 int score; 1109 int pri; 1110 1111 if (td->td_pri_class != PRI_TIMESHARE) 1112 return; 1113 /* 1114 * If the score is interactive we place the thread in the realtime 1115 * queue with a priority that is less than kernel and interrupt 1116 * priorities. These threads are not subject to nice restrictions. 1117 * 1118 * Scores greater than this are placed on the normal realtime queue 1119 * where the priority is partially decided by the most recent cpu 1120 * utilization and the rest is decided by nice value. 1121 */ 1122 score = sched_interact_score(td); 1123 if (score < sched_interact) { 1124 pri = PRI_MIN_REALTIME; 1125 pri += ((PRI_MAX_REALTIME - PRI_MIN_REALTIME) / sched_interact) 1126 * score; 1127 KASSERT(pri >= PRI_MIN_REALTIME && pri <= PRI_MAX_REALTIME, 1128 ("sched_priority: invalid interactive priority %d score %d", 1129 pri, score)); 1130 } else { 1131 pri = SCHED_PRI_MIN; 1132 if (td->td_sched->ts_ticks) 1133 pri += SCHED_PRI_TICKS(td->td_sched); 1134 pri += SCHED_PRI_NICE(td->td_proc->p_nice); 1135 if (!(pri >= PRI_MIN_TIMESHARE && pri <= PRI_MAX_TIMESHARE)) { 1136 static int once = 1; 1137 if (once) { 1138 printf("sched_priority: invalid priority %d", 1139 pri); 1140 printf("nice %d, ticks %d ftick %d ltick %d tick pri %d\n", 1141 td->td_proc->p_nice, 1142 td->td_sched->ts_ticks, 1143 td->td_sched->ts_ftick, 1144 td->td_sched->ts_ltick, 1145 SCHED_PRI_TICKS(td->td_sched)); 1146 once = 0; 1147 } 1148 pri = min(max(pri, PRI_MIN_TIMESHARE), 1149 PRI_MAX_TIMESHARE); 1150 } 1151 } 1152 sched_user_prio(td, pri); 1153 1154 return; 1155 } 1156 1157 /* 1158 * This routine enforces a maximum limit on the amount of scheduling history 1159 * kept. It is called after either the slptime or runtime is adjusted. 1160 */ 1161 static void 1162 sched_interact_update(struct thread *td) 1163 { 1164 struct td_sched *ts; 1165 u_int sum; 1166 1167 ts = td->td_sched; 1168 sum = ts->skg_runtime + ts->skg_slptime; 1169 if (sum < SCHED_SLP_RUN_MAX) 1170 return; 1171 /* 1172 * This only happens from two places: 1173 * 1) We have added an unusual amount of run time from fork_exit. 1174 * 2) We have added an unusual amount of sleep time from sched_sleep(). 1175 */ 1176 if (sum > SCHED_SLP_RUN_MAX * 2) { 1177 if (ts->skg_runtime > ts->skg_slptime) { 1178 ts->skg_runtime = SCHED_SLP_RUN_MAX; 1179 ts->skg_slptime = 1; 1180 } else { 1181 ts->skg_slptime = SCHED_SLP_RUN_MAX; 1182 ts->skg_runtime = 1; 1183 } 1184 return; 1185 } 1186 /* 1187 * If we have exceeded by more than 1/5th then the algorithm below 1188 * will not bring us back into range. Dividing by two here forces 1189 * us into the range of [4/5 * SCHED_INTERACT_MAX, SCHED_INTERACT_MAX] 1190 */ 1191 if (sum > (SCHED_SLP_RUN_MAX / 5) * 6) { 1192 ts->skg_runtime /= 2; 1193 ts->skg_slptime /= 2; 1194 return; 1195 } 1196 ts->skg_runtime = (ts->skg_runtime / 5) * 4; 1197 ts->skg_slptime = (ts->skg_slptime / 5) * 4; 1198 } 1199 1200 static void 1201 sched_interact_fork(struct thread *td) 1202 { 1203 int ratio; 1204 int sum; 1205 1206 sum = td->td_sched->skg_runtime + td->td_sched->skg_slptime; 1207 if (sum > SCHED_SLP_RUN_FORK) { 1208 ratio = sum / SCHED_SLP_RUN_FORK; 1209 td->td_sched->skg_runtime /= ratio; 1210 td->td_sched->skg_slptime /= ratio; 1211 } 1212 } 1213 1214 static int 1215 sched_interact_score(struct thread *td) 1216 { 1217 int div; 1218 1219 if (td->td_sched->skg_runtime > td->td_sched->skg_slptime) { 1220 div = max(1, td->td_sched->skg_runtime / SCHED_INTERACT_HALF); 1221 return (SCHED_INTERACT_HALF + 1222 (SCHED_INTERACT_HALF - (td->td_sched->skg_slptime / div))); 1223 } if (td->td_sched->skg_slptime > td->td_sched->skg_runtime) { 1224 div = max(1, td->td_sched->skg_slptime / SCHED_INTERACT_HALF); 1225 return (td->td_sched->skg_runtime / div); 1226 } 1227 1228 /* 1229 * This can happen if slptime and runtime are 0. 1230 */ 1231 return (0); 1232 1233 } 1234 1235 /* 1236 * Called from proc0_init() to bootstrap the scheduler. 1237 */ 1238 void 1239 schedinit(void) 1240 { 1241 1242 /* 1243 * Set up the scheduler specific parts of proc0. 1244 */ 1245 proc0.p_sched = NULL; /* XXX */ 1246 thread0.td_sched = &td_sched0; 1247 td_sched0.ts_ltick = ticks; 1248 td_sched0.ts_ftick = ticks; 1249 td_sched0.ts_thread = &thread0; 1250 } 1251 1252 /* 1253 * This is only somewhat accurate since given many processes of the same 1254 * priority they will switch when their slices run out, which will be 1255 * at most sched_slice stathz ticks. 1256 */ 1257 int 1258 sched_rr_interval(void) 1259 { 1260 1261 /* Convert sched_slice to hz */ 1262 return (hz/(realstathz/sched_slice)); 1263 } 1264 1265 static void 1266 sched_pctcpu_update(struct td_sched *ts) 1267 { 1268 1269 if (ts->ts_ticks == 0) 1270 return; 1271 if (ticks - (hz / 10) < ts->ts_ltick && 1272 SCHED_TICK_TOTAL(ts) < SCHED_TICK_MAX) 1273 return; 1274 /* 1275 * Adjust counters and watermark for pctcpu calc. 1276 */ 1277 if (ts->ts_ltick > ticks - SCHED_TICK_TARG) 1278 ts->ts_ticks = (ts->ts_ticks / (ticks - ts->ts_ftick)) * 1279 SCHED_TICK_TARG; 1280 else 1281 ts->ts_ticks = 0; 1282 ts->ts_ltick = ticks; 1283 ts->ts_ftick = ts->ts_ltick - SCHED_TICK_TARG; 1284 } 1285 1286 static void 1287 sched_thread_priority(struct thread *td, u_char prio) 1288 { 1289 struct td_sched *ts; 1290 1291 CTR6(KTR_SCHED, "sched_prio: %p(%s) prio %d newprio %d by %p(%s)", 1292 td, td->td_proc->p_comm, td->td_priority, prio, curthread, 1293 curthread->td_proc->p_comm); 1294 ts = td->td_sched; 1295 mtx_assert(&sched_lock, MA_OWNED); 1296 if (td->td_priority == prio) 1297 return; 1298 1299 if (TD_ON_RUNQ(td) && prio < td->td_priority) { 1300 /* 1301 * If the priority has been elevated due to priority 1302 * propagation, we may have to move ourselves to a new 1303 * queue. This could be optimized to not re-add in some 1304 * cases. 1305 */ 1306 sched_rem(td); 1307 td->td_priority = prio; 1308 sched_add(td, SRQ_BORROWING); 1309 } else 1310 td->td_priority = prio; 1311 } 1312 1313 /* 1314 * Update a thread's priority when it is lent another thread's 1315 * priority. 1316 */ 1317 void 1318 sched_lend_prio(struct thread *td, u_char prio) 1319 { 1320 1321 td->td_flags |= TDF_BORROWING; 1322 sched_thread_priority(td, prio); 1323 } 1324 1325 /* 1326 * Restore a thread's priority when priority propagation is 1327 * over. The prio argument is the minimum priority the thread 1328 * needs to have to satisfy other possible priority lending 1329 * requests. If the thread's regular priority is less 1330 * important than prio, the thread will keep a priority boost 1331 * of prio. 1332 */ 1333 void 1334 sched_unlend_prio(struct thread *td, u_char prio) 1335 { 1336 u_char base_pri; 1337 1338 if (td->td_base_pri >= PRI_MIN_TIMESHARE && 1339 td->td_base_pri <= PRI_MAX_TIMESHARE) 1340 base_pri = td->td_user_pri; 1341 else 1342 base_pri = td->td_base_pri; 1343 if (prio >= base_pri) { 1344 td->td_flags &= ~TDF_BORROWING; 1345 sched_thread_priority(td, base_pri); 1346 } else 1347 sched_lend_prio(td, prio); 1348 } 1349 1350 void 1351 sched_prio(struct thread *td, u_char prio) 1352 { 1353 u_char oldprio; 1354 1355 /* First, update the base priority. */ 1356 td->td_base_pri = prio; 1357 1358 /* 1359 * If the thread is borrowing another thread's priority, don't 1360 * ever lower the priority. 1361 */ 1362 if (td->td_flags & TDF_BORROWING && td->td_priority < prio) 1363 return; 1364 1365 /* Change the real priority. */ 1366 oldprio = td->td_priority; 1367 sched_thread_priority(td, prio); 1368 1369 /* 1370 * If the thread is on a turnstile, then let the turnstile update 1371 * its state. 1372 */ 1373 if (TD_ON_LOCK(td) && oldprio != prio) 1374 turnstile_adjust(td, oldprio); 1375 } 1376 1377 void 1378 sched_user_prio(struct thread *td, u_char prio) 1379 { 1380 u_char oldprio; 1381 1382 td->td_base_user_pri = prio; 1383 if (td->td_flags & TDF_UBORROWING && td->td_user_pri <= prio) 1384 return; 1385 oldprio = td->td_user_pri; 1386 td->td_user_pri = prio; 1387 1388 if (TD_ON_UPILOCK(td) && oldprio != prio) 1389 umtx_pi_adjust(td, oldprio); 1390 } 1391 1392 void 1393 sched_lend_user_prio(struct thread *td, u_char prio) 1394 { 1395 u_char oldprio; 1396 1397 td->td_flags |= TDF_UBORROWING; 1398 1399 oldprio = td->td_user_pri; 1400 td->td_user_pri = prio; 1401 1402 if (TD_ON_UPILOCK(td) && oldprio != prio) 1403 umtx_pi_adjust(td, oldprio); 1404 } 1405 1406 void 1407 sched_unlend_user_prio(struct thread *td, u_char prio) 1408 { 1409 u_char base_pri; 1410 1411 base_pri = td->td_base_user_pri; 1412 if (prio >= base_pri) { 1413 td->td_flags &= ~TDF_UBORROWING; 1414 sched_user_prio(td, base_pri); 1415 } else 1416 sched_lend_user_prio(td, prio); 1417 } 1418 1419 void 1420 sched_switch(struct thread *td, struct thread *newtd, int flags) 1421 { 1422 struct tdq *tdq; 1423 struct td_sched *ts; 1424 int preempt; 1425 1426 mtx_assert(&sched_lock, MA_OWNED); 1427 1428 preempt = flags & SW_PREEMPT; 1429 tdq = TDQ_SELF(); 1430 ts = td->td_sched; 1431 td->td_lastcpu = td->td_oncpu; 1432 td->td_oncpu = NOCPU; 1433 td->td_flags &= ~TDF_NEEDRESCHED; 1434 td->td_owepreempt = 0; 1435 /* 1436 * If the thread has been assigned it may be in the process of switching 1437 * to the new cpu. This is the case in sched_bind(). 1438 */ 1439 if (td == PCPU_GET(idlethread)) { 1440 TD_SET_CAN_RUN(td); 1441 } else { 1442 tdq_load_rem(tdq, ts); 1443 if (TD_IS_RUNNING(td)) { 1444 /* 1445 * Don't allow the thread to migrate 1446 * from a preemption. 1447 */ 1448 if (preempt) 1449 sched_pin_td(td); 1450 sched_add(td, preempt ? 1451 SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED : 1452 SRQ_OURSELF|SRQ_YIELDING); 1453 if (preempt) 1454 sched_unpin_td(td); 1455 } 1456 } 1457 if (newtd != NULL) { 1458 /* 1459 * If we bring in a thread account for it as if it had been 1460 * added to the run queue and then chosen. 1461 */ 1462 TD_SET_RUNNING(newtd); 1463 tdq_load_add(TDQ_SELF(), newtd->td_sched); 1464 } else 1465 newtd = choosethread(); 1466 if (td != newtd) { 1467 #ifdef HWPMC_HOOKS 1468 if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 1469 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT); 1470 #endif 1471 1472 cpu_switch(td, newtd); 1473 #ifdef HWPMC_HOOKS 1474 if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 1475 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN); 1476 #endif 1477 } 1478 sched_lock.mtx_lock = (uintptr_t)td; 1479 td->td_oncpu = PCPU_GET(cpuid); 1480 } 1481 1482 void 1483 sched_nice(struct proc *p, int nice) 1484 { 1485 struct thread *td; 1486 1487 PROC_LOCK_ASSERT(p, MA_OWNED); 1488 mtx_assert(&sched_lock, MA_OWNED); 1489 1490 p->p_nice = nice; 1491 FOREACH_THREAD_IN_PROC(p, td) { 1492 sched_priority(td); 1493 sched_prio(td, td->td_base_user_pri); 1494 } 1495 } 1496 1497 void 1498 sched_sleep(struct thread *td) 1499 { 1500 1501 mtx_assert(&sched_lock, MA_OWNED); 1502 1503 td->td_sched->ts_slptime = ticks; 1504 } 1505 1506 void 1507 sched_wakeup(struct thread *td) 1508 { 1509 struct td_sched *ts; 1510 int slptime; 1511 1512 mtx_assert(&sched_lock, MA_OWNED); 1513 ts = td->td_sched; 1514 /* 1515 * If we slept for more than a tick update our interactivity and 1516 * priority. 1517 */ 1518 slptime = ts->ts_slptime; 1519 ts->ts_slptime = 0; 1520 if (slptime && slptime != ticks) { 1521 u_int hzticks; 1522 1523 hzticks = (ticks - slptime) << SCHED_TICK_SHIFT; 1524 ts->skg_slptime += hzticks; 1525 sched_interact_update(td); 1526 sched_pctcpu_update(ts); 1527 sched_priority(td); 1528 } 1529 /* Reset the slice value after we sleep. */ 1530 ts->ts_slice = sched_slice; 1531 sched_add(td, SRQ_BORING); 1532 } 1533 1534 /* 1535 * Penalize the parent for creating a new child and initialize the child's 1536 * priority. 1537 */ 1538 void 1539 sched_fork(struct thread *td, struct thread *child) 1540 { 1541 mtx_assert(&sched_lock, MA_OWNED); 1542 sched_fork_thread(td, child); 1543 /* 1544 * Penalize the parent and child for forking. 1545 */ 1546 sched_interact_fork(child); 1547 sched_priority(child); 1548 td->td_sched->skg_runtime += tickincr; 1549 sched_interact_update(td); 1550 sched_priority(td); 1551 } 1552 1553 void 1554 sched_fork_thread(struct thread *td, struct thread *child) 1555 { 1556 struct td_sched *ts; 1557 struct td_sched *ts2; 1558 1559 /* 1560 * Initialize child. 1561 */ 1562 sched_newthread(child); 1563 ts = td->td_sched; 1564 ts2 = child->td_sched; 1565 ts2->ts_cpu = ts->ts_cpu; 1566 ts2->ts_runq = NULL; 1567 /* 1568 * Grab our parents cpu estimation information and priority. 1569 */ 1570 ts2->ts_ticks = ts->ts_ticks; 1571 ts2->ts_ltick = ts->ts_ltick; 1572 ts2->ts_ftick = ts->ts_ftick; 1573 child->td_user_pri = td->td_user_pri; 1574 child->td_base_user_pri = td->td_base_user_pri; 1575 /* 1576 * And update interactivity score. 1577 */ 1578 ts2->skg_slptime = ts->skg_slptime; 1579 ts2->skg_runtime = ts->skg_runtime; 1580 ts2->ts_slice = 1; /* Attempt to quickly learn interactivity. */ 1581 } 1582 1583 void 1584 sched_class(struct thread *td, int class) 1585 { 1586 1587 mtx_assert(&sched_lock, MA_OWNED); 1588 if (td->td_pri_class == class) 1589 return; 1590 1591 #ifdef SMP 1592 /* 1593 * On SMP if we're on the RUNQ we must adjust the transferable 1594 * count because could be changing to or from an interrupt 1595 * class. 1596 */ 1597 if (TD_ON_RUNQ(td)) { 1598 struct tdq *tdq; 1599 1600 tdq = TDQ_CPU(td->td_sched->ts_cpu); 1601 if (THREAD_CAN_MIGRATE(td)) { 1602 tdq->tdq_transferable--; 1603 tdq->tdq_group->tdg_transferable--; 1604 } 1605 td->td_pri_class = class; 1606 if (THREAD_CAN_MIGRATE(td)) { 1607 tdq->tdq_transferable++; 1608 tdq->tdq_group->tdg_transferable++; 1609 } 1610 } 1611 #endif 1612 td->td_pri_class = class; 1613 } 1614 1615 /* 1616 * Return some of the child's priority and interactivity to the parent. 1617 */ 1618 void 1619 sched_exit(struct proc *p, struct thread *child) 1620 { 1621 struct thread *td; 1622 1623 CTR3(KTR_SCHED, "sched_exit: %p(%s) prio %d", 1624 child, child->td_proc->p_comm, child->td_priority); 1625 1626 td = FIRST_THREAD_IN_PROC(p); 1627 sched_exit_thread(td, child); 1628 } 1629 1630 void 1631 sched_exit_thread(struct thread *td, struct thread *child) 1632 { 1633 1634 CTR3(KTR_SCHED, "sched_exit_thread: %p(%s) prio %d", 1635 child, child->td_proc->p_comm, child->td_priority); 1636 1637 tdq_load_rem(TDQ_CPU(child->td_sched->ts_cpu), child->td_sched); 1638 #ifdef KSE 1639 /* 1640 * KSE forks and exits so often that this penalty causes short-lived 1641 * threads to always be non-interactive. This causes mozilla to 1642 * crawl under load. 1643 */ 1644 if ((td->td_pflags & TDP_SA) && td->td_proc == child->td_proc) 1645 return; 1646 #endif 1647 /* 1648 * Give the child's runtime to the parent without returning the 1649 * sleep time as a penalty to the parent. This causes shells that 1650 * launch expensive things to mark their children as expensive. 1651 */ 1652 td->td_sched->skg_runtime += child->td_sched->skg_runtime; 1653 sched_interact_update(td); 1654 sched_priority(td); 1655 } 1656 1657 void 1658 sched_userret(struct thread *td) 1659 { 1660 /* 1661 * XXX we cheat slightly on the locking here to avoid locking in 1662 * the usual case. Setting td_priority here is essentially an 1663 * incomplete workaround for not setting it properly elsewhere. 1664 * Now that some interrupt handlers are threads, not setting it 1665 * properly elsewhere can clobber it in the window between setting 1666 * it here and returning to user mode, so don't waste time setting 1667 * it perfectly here. 1668 */ 1669 KASSERT((td->td_flags & TDF_BORROWING) == 0, 1670 ("thread with borrowed priority returning to userland")); 1671 if (td->td_priority != td->td_user_pri) { 1672 mtx_lock_spin(&sched_lock); 1673 td->td_priority = td->td_user_pri; 1674 td->td_base_pri = td->td_user_pri; 1675 mtx_unlock_spin(&sched_lock); 1676 } 1677 } 1678 1679 void 1680 sched_clock(struct thread *td) 1681 { 1682 struct tdq *tdq; 1683 struct td_sched *ts; 1684 1685 mtx_assert(&sched_lock, MA_OWNED); 1686 #ifdef SMP 1687 sched_smp_tick(td); 1688 #endif 1689 tdq = TDQ_SELF(); 1690 /* 1691 * Advance the insert index once for each tick to ensure that all 1692 * threads get a chance to run. 1693 */ 1694 if (tdq->tdq_idx == tdq->tdq_ridx) { 1695 tdq->tdq_idx = (tdq->tdq_idx + 1) % RQ_NQS; 1696 if (TAILQ_EMPTY(&tdq->tdq_timeshare.rq_queues[tdq->tdq_ridx])) 1697 tdq->tdq_ridx = tdq->tdq_idx; 1698 } 1699 ts = td->td_sched; 1700 /* 1701 * We only do slicing code for TIMESHARE threads. 1702 */ 1703 if (td->td_pri_class != PRI_TIMESHARE) 1704 return; 1705 /* 1706 * We used a tick; charge it to the thread so that we can compute our 1707 * interactivity. 1708 */ 1709 td->td_sched->skg_runtime += tickincr; 1710 sched_interact_update(td); 1711 /* 1712 * We used up one time slice. 1713 */ 1714 if (--ts->ts_slice > 0) 1715 return; 1716 /* 1717 * We're out of time, recompute priorities and requeue. 1718 */ 1719 sched_priority(td); 1720 td->td_flags |= TDF_NEEDRESCHED; 1721 } 1722 1723 int 1724 sched_runnable(void) 1725 { 1726 struct tdq *tdq; 1727 int load; 1728 1729 load = 1; 1730 1731 tdq = TDQ_SELF(); 1732 #ifdef SMP 1733 if (tdq_busy) 1734 goto out; 1735 #endif 1736 if ((curthread->td_flags & TDF_IDLETD) != 0) { 1737 if (tdq->tdq_load > 0) 1738 goto out; 1739 } else 1740 if (tdq->tdq_load - 1 > 0) 1741 goto out; 1742 load = 0; 1743 out: 1744 return (load); 1745 } 1746 1747 struct thread * 1748 sched_choose(void) 1749 { 1750 struct tdq *tdq; 1751 struct td_sched *ts; 1752 1753 mtx_assert(&sched_lock, MA_OWNED); 1754 tdq = TDQ_SELF(); 1755 #ifdef SMP 1756 restart: 1757 #endif 1758 ts = tdq_choose(tdq); 1759 if (ts) { 1760 #ifdef SMP 1761 if (ts->ts_thread->td_priority > PRI_MIN_IDLE) 1762 if (tdq_idled(tdq) == 0) 1763 goto restart; 1764 #endif 1765 tdq_runq_rem(tdq, ts); 1766 return (ts->ts_thread); 1767 } 1768 #ifdef SMP 1769 if (tdq_idled(tdq) == 0) 1770 goto restart; 1771 #endif 1772 return (PCPU_GET(idlethread)); 1773 } 1774 1775 static int 1776 sched_preempt(struct thread *td) 1777 { 1778 struct thread *ctd; 1779 int cpri; 1780 int pri; 1781 1782 ctd = curthread; 1783 pri = td->td_priority; 1784 cpri = ctd->td_priority; 1785 if (panicstr != NULL || pri >= cpri || cold || TD_IS_INHIBITED(ctd)) 1786 return (0); 1787 /* 1788 * Always preempt IDLE threads. Otherwise only if the preempting 1789 * thread is an ithread. 1790 */ 1791 if (pri > PRI_MAX_ITHD && cpri < PRI_MIN_IDLE) 1792 return (0); 1793 if (ctd->td_critnest > 1) { 1794 CTR1(KTR_PROC, "sched_preempt: in critical section %d", 1795 ctd->td_critnest); 1796 ctd->td_owepreempt = 1; 1797 return (0); 1798 } 1799 /* 1800 * Thread is runnable but not yet put on system run queue. 1801 */ 1802 MPASS(TD_ON_RUNQ(td)); 1803 TD_SET_RUNNING(td); 1804 CTR3(KTR_PROC, "preempting to thread %p (pid %d, %s)\n", td, 1805 td->td_proc->p_pid, td->td_proc->p_comm); 1806 mi_switch(SW_INVOL|SW_PREEMPT, td); 1807 return (1); 1808 } 1809 1810 void 1811 sched_add(struct thread *td, int flags) 1812 { 1813 struct tdq *tdq; 1814 struct td_sched *ts; 1815 int preemptive; 1816 int class; 1817 #ifdef SMP 1818 int cpuid; 1819 int cpumask; 1820 #endif 1821 ts = td->td_sched; 1822 1823 mtx_assert(&sched_lock, MA_OWNED); 1824 CTR5(KTR_SCHED, "sched_add: %p(%s) prio %d by %p(%s)", 1825 td, td->td_proc->p_comm, td->td_priority, curthread, 1826 curthread->td_proc->p_comm); 1827 KASSERT((td->td_inhibitors == 0), 1828 ("sched_add: trying to run inhibited thread")); 1829 KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)), 1830 ("sched_add: bad thread state")); 1831 KASSERT(td->td_proc->p_sflag & PS_INMEM, 1832 ("sched_add: process swapped out")); 1833 KASSERT(ts->ts_runq == NULL, 1834 ("sched_add: thread %p is still assigned to a run queue", td)); 1835 TD_SET_RUNQ(td); 1836 tdq = TDQ_SELF(); 1837 class = PRI_BASE(td->td_pri_class); 1838 preemptive = !(flags & SRQ_YIELDING); 1839 /* 1840 * Recalculate the priority before we select the target cpu or 1841 * run-queue. 1842 */ 1843 if (class == PRI_TIMESHARE) 1844 sched_priority(td); 1845 if (ts->ts_slice == 0) 1846 ts->ts_slice = sched_slice; 1847 #ifdef SMP 1848 cpuid = PCPU_GET(cpuid); 1849 /* 1850 * Pick the destination cpu and if it isn't ours transfer to the 1851 * target cpu. 1852 */ 1853 if (THREAD_CAN_MIGRATE(td)) { 1854 if (td->td_priority <= PRI_MAX_ITHD) { 1855 CTR2(KTR_ULE, "ithd %d < %d", 1856 td->td_priority, PRI_MAX_ITHD); 1857 ts->ts_cpu = cpuid; 1858 } 1859 if (pick_pri) 1860 ts->ts_cpu = tdq_pickpri(tdq, ts, flags); 1861 else 1862 ts->ts_cpu = tdq_pickidle(tdq, ts); 1863 } else 1864 CTR1(KTR_ULE, "pinned %d", td->td_pinned); 1865 if (ts->ts_cpu != cpuid) 1866 preemptive = 0; 1867 tdq = TDQ_CPU(ts->ts_cpu); 1868 cpumask = 1 << ts->ts_cpu; 1869 /* 1870 * If we had been idle, clear our bit in the group and potentially 1871 * the global bitmap. 1872 */ 1873 if ((class != PRI_IDLE && class != PRI_ITHD) && 1874 (tdq->tdq_group->tdg_idlemask & cpumask) != 0) { 1875 /* 1876 * Check to see if our group is unidling, and if so, remove it 1877 * from the global idle mask. 1878 */ 1879 if (tdq->tdq_group->tdg_idlemask == 1880 tdq->tdq_group->tdg_cpumask) 1881 atomic_clear_int(&tdq_idle, tdq->tdq_group->tdg_mask); 1882 /* 1883 * Now remove ourselves from the group specific idle mask. 1884 */ 1885 tdq->tdq_group->tdg_idlemask &= ~cpumask; 1886 } 1887 #endif 1888 /* 1889 * Pick the run queue based on priority. 1890 */ 1891 if (td->td_priority <= PRI_MAX_REALTIME) 1892 ts->ts_runq = &tdq->tdq_realtime; 1893 else if (td->td_priority <= PRI_MAX_TIMESHARE) 1894 ts->ts_runq = &tdq->tdq_timeshare; 1895 else 1896 ts->ts_runq = &tdq->tdq_idle; 1897 if (preemptive && sched_preempt(td)) 1898 return; 1899 tdq_runq_add(tdq, ts, flags); 1900 tdq_load_add(tdq, ts); 1901 #ifdef SMP 1902 if (ts->ts_cpu != cpuid) { 1903 tdq_notify(ts); 1904 return; 1905 } 1906 #endif 1907 if (td->td_priority < curthread->td_priority) 1908 curthread->td_flags |= TDF_NEEDRESCHED; 1909 } 1910 1911 void 1912 sched_rem(struct thread *td) 1913 { 1914 struct tdq *tdq; 1915 struct td_sched *ts; 1916 1917 CTR5(KTR_SCHED, "sched_rem: %p(%s) prio %d by %p(%s)", 1918 td, td->td_proc->p_comm, td->td_priority, curthread, 1919 curthread->td_proc->p_comm); 1920 mtx_assert(&sched_lock, MA_OWNED); 1921 ts = td->td_sched; 1922 KASSERT(TD_ON_RUNQ(td), 1923 ("sched_rem: thread not on run queue")); 1924 1925 tdq = TDQ_CPU(ts->ts_cpu); 1926 tdq_runq_rem(tdq, ts); 1927 tdq_load_rem(tdq, ts); 1928 TD_SET_CAN_RUN(td); 1929 } 1930 1931 fixpt_t 1932 sched_pctcpu(struct thread *td) 1933 { 1934 fixpt_t pctcpu; 1935 struct td_sched *ts; 1936 1937 pctcpu = 0; 1938 ts = td->td_sched; 1939 if (ts == NULL) 1940 return (0); 1941 1942 mtx_lock_spin(&sched_lock); 1943 if (ts->ts_ticks) { 1944 int rtick; 1945 1946 sched_pctcpu_update(ts); 1947 /* How many rtick per second ? */ 1948 rtick = min(SCHED_TICK_HZ(ts) / SCHED_TICK_SECS, hz); 1949 pctcpu = (FSCALE * ((FSCALE * rtick)/hz)) >> FSHIFT; 1950 } 1951 td->td_proc->p_swtime = ts->ts_ltick - ts->ts_ftick; 1952 mtx_unlock_spin(&sched_lock); 1953 1954 return (pctcpu); 1955 } 1956 1957 void 1958 sched_bind(struct thread *td, int cpu) 1959 { 1960 struct td_sched *ts; 1961 1962 mtx_assert(&sched_lock, MA_OWNED); 1963 ts = td->td_sched; 1964 if (ts->ts_flags & TSF_BOUND) 1965 sched_unbind(td); 1966 ts->ts_flags |= TSF_BOUND; 1967 #ifdef SMP 1968 sched_pin(); 1969 if (PCPU_GET(cpuid) == cpu) 1970 return; 1971 ts->ts_cpu = cpu; 1972 /* When we return from mi_switch we'll be on the correct cpu. */ 1973 mi_switch(SW_VOL, NULL); 1974 #endif 1975 } 1976 1977 void 1978 sched_unbind(struct thread *td) 1979 { 1980 struct td_sched *ts; 1981 1982 mtx_assert(&sched_lock, MA_OWNED); 1983 ts = td->td_sched; 1984 if ((ts->ts_flags & TSF_BOUND) == 0) 1985 return; 1986 ts->ts_flags &= ~TSF_BOUND; 1987 #ifdef SMP 1988 sched_unpin(); 1989 #endif 1990 } 1991 1992 int 1993 sched_is_bound(struct thread *td) 1994 { 1995 mtx_assert(&sched_lock, MA_OWNED); 1996 return (td->td_sched->ts_flags & TSF_BOUND); 1997 } 1998 1999 void 2000 sched_relinquish(struct thread *td) 2001 { 2002 mtx_lock_spin(&sched_lock); 2003 if (td->td_pri_class == PRI_TIMESHARE) 2004 sched_prio(td, PRI_MAX_TIMESHARE); 2005 mi_switch(SW_VOL, NULL); 2006 mtx_unlock_spin(&sched_lock); 2007 } 2008 2009 int 2010 sched_load(void) 2011 { 2012 #ifdef SMP 2013 int total; 2014 int i; 2015 2016 total = 0; 2017 for (i = 0; i <= tdg_maxid; i++) 2018 total += TDQ_GROUP(i)->tdg_load; 2019 return (total); 2020 #else 2021 return (TDQ_SELF()->tdq_sysload); 2022 #endif 2023 } 2024 2025 int 2026 sched_sizeof_proc(void) 2027 { 2028 return (sizeof(struct proc)); 2029 } 2030 2031 int 2032 sched_sizeof_thread(void) 2033 { 2034 return (sizeof(struct thread) + sizeof(struct td_sched)); 2035 } 2036 2037 void 2038 sched_tick(void) 2039 { 2040 struct td_sched *ts; 2041 2042 ts = curthread->td_sched; 2043 /* Adjust ticks for pctcpu */ 2044 ts->ts_ticks += 1 << SCHED_TICK_SHIFT; 2045 ts->ts_ltick = ticks; 2046 /* 2047 * Update if we've exceeded our desired tick threshhold by over one 2048 * second. 2049 */ 2050 if (ts->ts_ftick + SCHED_TICK_MAX < ts->ts_ltick) 2051 sched_pctcpu_update(ts); 2052 } 2053 2054 /* 2055 * The actual idle process. 2056 */ 2057 void 2058 sched_idletd(void *dummy) 2059 { 2060 struct proc *p; 2061 struct thread *td; 2062 2063 td = curthread; 2064 p = td->td_proc; 2065 mtx_assert(&Giant, MA_NOTOWNED); 2066 /* ULE Relies on preemption for idle interruption. */ 2067 for (;;) 2068 cpu_idle(); 2069 } 2070 2071 static SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW, 0, "Scheduler"); 2072 SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "ule", 0, 2073 "Scheduler name"); 2074 SYSCTL_INT(_kern_sched, OID_AUTO, slice, CTLFLAG_RW, &sched_slice, 0, ""); 2075 SYSCTL_INT(_kern_sched, OID_AUTO, interact, CTLFLAG_RW, &sched_interact, 0, ""); 2076 SYSCTL_INT(_kern_sched, OID_AUTO, tickincr, CTLFLAG_RD, &tickincr, 0, ""); 2077 SYSCTL_INT(_kern_sched, OID_AUTO, realstathz, CTLFLAG_RD, &realstathz, 0, ""); 2078 #ifdef SMP 2079 SYSCTL_INT(_kern_sched, OID_AUTO, pick_pri, CTLFLAG_RW, &pick_pri, 0, ""); 2080 SYSCTL_INT(_kern_sched, OID_AUTO, pick_pri_affinity, CTLFLAG_RW, 2081 &affinity, 0, ""); 2082 SYSCTL_INT(_kern_sched, OID_AUTO, pick_pri_tryself, CTLFLAG_RW, 2083 &tryself, 0, ""); 2084 SYSCTL_INT(_kern_sched, OID_AUTO, pick_pri_tryselfidle, CTLFLAG_RW, 2085 &tryselfidle, 0, ""); 2086 SYSCTL_INT(_kern_sched, OID_AUTO, balance, CTLFLAG_RW, &rebalance, 0, ""); 2087 SYSCTL_INT(_kern_sched, OID_AUTO, ipi_preempt, CTLFLAG_RW, &ipi_preempt, 0, ""); 2088 SYSCTL_INT(_kern_sched, OID_AUTO, ipi_ast, CTLFLAG_RW, &ipi_ast, 0, ""); 2089 SYSCTL_INT(_kern_sched, OID_AUTO, ipi_thresh, CTLFLAG_RW, &ipi_thresh, 0, ""); 2090 SYSCTL_INT(_kern_sched, OID_AUTO, steal_htt, CTLFLAG_RW, &steal_htt, 0, ""); 2091 SYSCTL_INT(_kern_sched, OID_AUTO, steal_busy, CTLFLAG_RW, &steal_busy, 0, ""); 2092 SYSCTL_INT(_kern_sched, OID_AUTO, busy_thresh, CTLFLAG_RW, &busy_thresh, 0, ""); 2093 #endif 2094 2095 /* ps compat */ 2096 static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */ 2097 SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, ""); 2098 2099 2100 #define KERN_SWITCH_INCLUDE 1 2101 #include "kern/kern_switch.c" 2102