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 /* 28 * This file implements the ULE scheduler. ULE supports independent CPU 29 * run queues and fine grain locking. It has superior interactive 30 * performance under load even on uni-processor systems. 31 * 32 * etymology: 33 * ULE is the last three letters in schedule. It owes its name to a 34 * generic user created for a scheduling system by Paul Mikesell at 35 * Isilon Systems and a general lack of creativity on the part of the author. 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include "opt_hwpmc_hooks.h" 42 #include "opt_sched.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kdb.h> 47 #include <sys/kernel.h> 48 #include <sys/ktr.h> 49 #include <sys/lock.h> 50 #include <sys/mutex.h> 51 #include <sys/proc.h> 52 #include <sys/resource.h> 53 #include <sys/resourcevar.h> 54 #include <sys/sched.h> 55 #include <sys/smp.h> 56 #include <sys/sx.h> 57 #include <sys/sysctl.h> 58 #include <sys/sysproto.h> 59 #include <sys/turnstile.h> 60 #include <sys/umtx.h> 61 #include <sys/vmmeter.h> 62 #include <sys/cpuset.h> 63 #ifdef KTRACE 64 #include <sys/uio.h> 65 #include <sys/ktrace.h> 66 #endif 67 68 #ifdef HWPMC_HOOKS 69 #include <sys/pmckern.h> 70 #endif 71 72 #include <machine/cpu.h> 73 #include <machine/smp.h> 74 75 #if defined(__sparc64__) || defined(__mips__) 76 #error "This architecture is not currently compatible with ULE" 77 #endif 78 79 #define KTR_ULE 0 80 81 /* 82 * Thread scheduler specific section. All fields are protected 83 * by the thread lock. 84 */ 85 struct td_sched { 86 struct runq *ts_runq; /* Run-queue we're queued on. */ 87 short ts_flags; /* TSF_* flags. */ 88 u_char ts_cpu; /* CPU that we have affinity for. */ 89 int ts_rltick; /* Real last tick, for affinity. */ 90 int ts_slice; /* Ticks of slice remaining. */ 91 u_int ts_slptime; /* Number of ticks we vol. slept */ 92 u_int ts_runtime; /* Number of ticks we were running */ 93 int ts_ltick; /* Last tick that we were running on */ 94 int ts_ftick; /* First tick that we were running on */ 95 int ts_ticks; /* Tick count */ 96 }; 97 /* flags kept in ts_flags */ 98 #define TSF_BOUND 0x0001 /* Thread can not migrate. */ 99 #define TSF_XFERABLE 0x0002 /* Thread was added as transferable. */ 100 101 static struct td_sched td_sched0; 102 103 #define THREAD_CAN_MIGRATE(td) ((td)->td_pinned == 0) 104 #define THREAD_CAN_SCHED(td, cpu) \ 105 CPU_ISSET((cpu), &(td)->td_cpuset->cs_mask) 106 107 /* 108 * Cpu percentage computation macros and defines. 109 * 110 * SCHED_TICK_SECS: Number of seconds to average the cpu usage across. 111 * SCHED_TICK_TARG: Number of hz ticks to average the cpu usage across. 112 * SCHED_TICK_MAX: Maximum number of ticks before scaling back. 113 * SCHED_TICK_SHIFT: Shift factor to avoid rounding away results. 114 * SCHED_TICK_HZ: Compute the number of hz ticks for a given ticks count. 115 * SCHED_TICK_TOTAL: Gives the amount of time we've been recording ticks. 116 */ 117 #define SCHED_TICK_SECS 10 118 #define SCHED_TICK_TARG (hz * SCHED_TICK_SECS) 119 #define SCHED_TICK_MAX (SCHED_TICK_TARG + hz) 120 #define SCHED_TICK_SHIFT 10 121 #define SCHED_TICK_HZ(ts) ((ts)->ts_ticks >> SCHED_TICK_SHIFT) 122 #define SCHED_TICK_TOTAL(ts) (max((ts)->ts_ltick - (ts)->ts_ftick, hz)) 123 124 /* 125 * These macros determine priorities for non-interactive threads. They are 126 * assigned a priority based on their recent cpu utilization as expressed 127 * by the ratio of ticks to the tick total. NHALF priorities at the start 128 * and end of the MIN to MAX timeshare range are only reachable with negative 129 * or positive nice respectively. 130 * 131 * PRI_RANGE: Priority range for utilization dependent priorities. 132 * PRI_NRESV: Number of nice values. 133 * PRI_TICKS: Compute a priority in PRI_RANGE from the ticks count and total. 134 * PRI_NICE: Determines the part of the priority inherited from nice. 135 */ 136 #define SCHED_PRI_NRESV (PRIO_MAX - PRIO_MIN) 137 #define SCHED_PRI_NHALF (SCHED_PRI_NRESV / 2) 138 #define SCHED_PRI_MIN (PRI_MIN_TIMESHARE + SCHED_PRI_NHALF) 139 #define SCHED_PRI_MAX (PRI_MAX_TIMESHARE - SCHED_PRI_NHALF) 140 #define SCHED_PRI_RANGE (SCHED_PRI_MAX - SCHED_PRI_MIN) 141 #define SCHED_PRI_TICKS(ts) \ 142 (SCHED_TICK_HZ((ts)) / \ 143 (roundup(SCHED_TICK_TOTAL((ts)), SCHED_PRI_RANGE) / SCHED_PRI_RANGE)) 144 #define SCHED_PRI_NICE(nice) (nice) 145 146 /* 147 * These determine the interactivity of a process. Interactivity differs from 148 * cpu utilization in that it expresses the voluntary time slept vs time ran 149 * while cpu utilization includes all time not running. This more accurately 150 * models the intent of the thread. 151 * 152 * SLP_RUN_MAX: Maximum amount of sleep time + run time we'll accumulate 153 * before throttling back. 154 * SLP_RUN_FORK: Maximum slp+run time to inherit at fork time. 155 * INTERACT_MAX: Maximum interactivity value. Smaller is better. 156 * INTERACT_THRESH: Threshhold for placement on the current runq. 157 */ 158 #define SCHED_SLP_RUN_MAX ((hz * 5) << SCHED_TICK_SHIFT) 159 #define SCHED_SLP_RUN_FORK ((hz / 2) << SCHED_TICK_SHIFT) 160 #define SCHED_INTERACT_MAX (100) 161 #define SCHED_INTERACT_HALF (SCHED_INTERACT_MAX / 2) 162 #define SCHED_INTERACT_THRESH (30) 163 164 /* 165 * tickincr: Converts a stathz tick into a hz domain scaled by 166 * the shift factor. Without the shift the error rate 167 * due to rounding would be unacceptably high. 168 * realstathz: stathz is sometimes 0 and run off of hz. 169 * sched_slice: Runtime of each thread before rescheduling. 170 * preempt_thresh: Priority threshold for preemption and remote IPIs. 171 */ 172 static int sched_interact = SCHED_INTERACT_THRESH; 173 static int realstathz; 174 static int tickincr; 175 static int sched_slice = 1; 176 #ifdef PREEMPTION 177 #ifdef FULL_PREEMPTION 178 static int preempt_thresh = PRI_MAX_IDLE; 179 #else 180 static int preempt_thresh = PRI_MIN_KERN; 181 #endif 182 #else 183 static int preempt_thresh = 0; 184 #endif 185 static int static_boost = PRI_MIN_TIMESHARE; 186 static int sched_idlespins = 10000; 187 static int sched_idlespinthresh = 4; 188 189 /* 190 * tdq - per processor runqs and statistics. All fields are protected by the 191 * tdq_lock. The load and lowpri may be accessed without to avoid excess 192 * locking in sched_pickcpu(); 193 */ 194 struct tdq { 195 /* Ordered to improve efficiency of cpu_search() and switch(). */ 196 struct mtx tdq_lock; /* run queue lock. */ 197 struct cpu_group *tdq_cg; /* Pointer to cpu topology. */ 198 volatile int tdq_load; /* Aggregate load. */ 199 int tdq_sysload; /* For loadavg, !ITHD load. */ 200 int tdq_transferable; /* Transferable thread count. */ 201 volatile int tdq_idlestate; /* State of the idle thread. */ 202 short tdq_switchcnt; /* Switches this tick. */ 203 short tdq_oldswitchcnt; /* Switches last tick. */ 204 u_char tdq_lowpri; /* Lowest priority thread. */ 205 u_char tdq_ipipending; /* IPI pending. */ 206 u_char tdq_idx; /* Current insert index. */ 207 u_char tdq_ridx; /* Current removal index. */ 208 struct runq tdq_realtime; /* real-time run queue. */ 209 struct runq tdq_timeshare; /* timeshare run queue. */ 210 struct runq tdq_idle; /* Queue of IDLE threads. */ 211 char tdq_name[sizeof("sched lock") + 6]; 212 } __aligned(64); 213 214 /* Idle thread states and config. */ 215 #define TDQ_RUNNING 1 216 #define TDQ_IDLE 2 217 218 #ifdef SMP 219 struct cpu_group *cpu_top; 220 221 #define SCHED_AFFINITY_DEFAULT (max(1, hz / 1000)) 222 #define SCHED_AFFINITY(ts, t) ((ts)->ts_rltick > ticks - ((t) * affinity)) 223 224 /* 225 * Run-time tunables. 226 */ 227 static int rebalance = 1; 228 static int balance_interval = 128; /* Default set in sched_initticks(). */ 229 static int affinity; 230 static int steal_htt = 1; 231 static int steal_idle = 1; 232 static int steal_thresh = 2; 233 234 /* 235 * One thread queue per processor. 236 */ 237 static struct tdq tdq_cpu[MAXCPU]; 238 static struct tdq *balance_tdq; 239 static int balance_ticks; 240 241 #define TDQ_SELF() (&tdq_cpu[PCPU_GET(cpuid)]) 242 #define TDQ_CPU(x) (&tdq_cpu[(x)]) 243 #define TDQ_ID(x) ((int)((x) - tdq_cpu)) 244 #else /* !SMP */ 245 static struct tdq tdq_cpu; 246 247 #define TDQ_ID(x) (0) 248 #define TDQ_SELF() (&tdq_cpu) 249 #define TDQ_CPU(x) (&tdq_cpu) 250 #endif 251 252 #define TDQ_LOCK_ASSERT(t, type) mtx_assert(TDQ_LOCKPTR((t)), (type)) 253 #define TDQ_LOCK(t) mtx_lock_spin(TDQ_LOCKPTR((t))) 254 #define TDQ_LOCK_FLAGS(t, f) mtx_lock_spin_flags(TDQ_LOCKPTR((t)), (f)) 255 #define TDQ_UNLOCK(t) mtx_unlock_spin(TDQ_LOCKPTR((t))) 256 #define TDQ_LOCKPTR(t) (&(t)->tdq_lock) 257 258 static void sched_priority(struct thread *); 259 static void sched_thread_priority(struct thread *, u_char); 260 static int sched_interact_score(struct thread *); 261 static void sched_interact_update(struct thread *); 262 static void sched_interact_fork(struct thread *); 263 static void sched_pctcpu_update(struct td_sched *); 264 265 /* Operations on per processor queues */ 266 static struct thread *tdq_choose(struct tdq *); 267 static void tdq_setup(struct tdq *); 268 static void tdq_load_add(struct tdq *, struct thread *); 269 static void tdq_load_rem(struct tdq *, struct thread *); 270 static __inline void tdq_runq_add(struct tdq *, struct thread *, int); 271 static __inline void tdq_runq_rem(struct tdq *, struct thread *); 272 static inline int sched_shouldpreempt(int, int, int); 273 void tdq_print(int cpu); 274 static void runq_print(struct runq *rq); 275 static void tdq_add(struct tdq *, struct thread *, int); 276 #ifdef SMP 277 static int tdq_move(struct tdq *, struct tdq *); 278 static int tdq_idled(struct tdq *); 279 static void tdq_notify(struct tdq *, struct thread *); 280 static struct thread *tdq_steal(struct tdq *, int); 281 static struct thread *runq_steal(struct runq *, int); 282 static int sched_pickcpu(struct thread *, int); 283 static void sched_balance(void); 284 static int sched_balance_pair(struct tdq *, struct tdq *); 285 static inline struct tdq *sched_setcpu(struct thread *, int, int); 286 static inline struct mtx *thread_block_switch(struct thread *); 287 static inline void thread_unblock_switch(struct thread *, struct mtx *); 288 static struct mtx *sched_switch_migrate(struct tdq *, struct thread *, int); 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, 296 NULL); 297 298 /* 299 * Print the threads waiting on a run-queue. 300 */ 301 static void 302 runq_print(struct runq *rq) 303 { 304 struct rqhead *rqh; 305 struct thread *td; 306 int pri; 307 int j; 308 int i; 309 310 for (i = 0; i < RQB_LEN; i++) { 311 printf("\t\trunq bits %d 0x%zx\n", 312 i, rq->rq_status.rqb_bits[i]); 313 for (j = 0; j < RQB_BPW; j++) 314 if (rq->rq_status.rqb_bits[i] & (1ul << j)) { 315 pri = j + (i << RQB_L2BPW); 316 rqh = &rq->rq_queues[pri]; 317 TAILQ_FOREACH(td, rqh, td_runq) { 318 printf("\t\t\ttd %p(%s) priority %d rqindex %d pri %d\n", 319 td, td->td_name, td->td_priority, 320 td->td_rqindex, pri); 321 } 322 } 323 } 324 } 325 326 /* 327 * Print the status of a per-cpu thread queue. Should be a ddb show cmd. 328 */ 329 void 330 tdq_print(int cpu) 331 { 332 struct tdq *tdq; 333 334 tdq = TDQ_CPU(cpu); 335 336 printf("tdq %d:\n", TDQ_ID(tdq)); 337 printf("\tlock %p\n", TDQ_LOCKPTR(tdq)); 338 printf("\tLock name: %s\n", tdq->tdq_name); 339 printf("\tload: %d\n", tdq->tdq_load); 340 printf("\tswitch cnt: %d\n", tdq->tdq_switchcnt); 341 printf("\told switch cnt: %d\n", tdq->tdq_oldswitchcnt); 342 printf("\tidle state: %d\n", tdq->tdq_idlestate); 343 printf("\ttimeshare idx: %d\n", tdq->tdq_idx); 344 printf("\ttimeshare ridx: %d\n", tdq->tdq_ridx); 345 printf("\tload transferable: %d\n", tdq->tdq_transferable); 346 printf("\tlowest priority: %d\n", tdq->tdq_lowpri); 347 printf("\trealtime runq:\n"); 348 runq_print(&tdq->tdq_realtime); 349 printf("\ttimeshare runq:\n"); 350 runq_print(&tdq->tdq_timeshare); 351 printf("\tidle runq:\n"); 352 runq_print(&tdq->tdq_idle); 353 } 354 355 static inline int 356 sched_shouldpreempt(int pri, int cpri, int remote) 357 { 358 /* 359 * If the new priority is not better than the current priority there is 360 * nothing to do. 361 */ 362 if (pri >= cpri) 363 return (0); 364 /* 365 * Always preempt idle. 366 */ 367 if (cpri >= PRI_MIN_IDLE) 368 return (1); 369 /* 370 * If preemption is disabled don't preempt others. 371 */ 372 if (preempt_thresh == 0) 373 return (0); 374 /* 375 * Preempt if we exceed the threshold. 376 */ 377 if (pri <= preempt_thresh) 378 return (1); 379 /* 380 * If we're realtime or better and there is timeshare or worse running 381 * preempt only remote processors. 382 */ 383 if (remote && pri <= PRI_MAX_REALTIME && cpri > PRI_MAX_REALTIME) 384 return (1); 385 return (0); 386 } 387 388 #define TS_RQ_PPQ (((PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE) + 1) / RQ_NQS) 389 /* 390 * Add a thread to the actual run-queue. Keeps transferable counts up to 391 * date with what is actually on the run-queue. Selects the correct 392 * queue position for timeshare threads. 393 */ 394 static __inline void 395 tdq_runq_add(struct tdq *tdq, struct thread *td, int flags) 396 { 397 struct td_sched *ts; 398 u_char pri; 399 400 TDQ_LOCK_ASSERT(tdq, MA_OWNED); 401 THREAD_LOCK_ASSERT(td, MA_OWNED); 402 403 pri = td->td_priority; 404 ts = td->td_sched; 405 TD_SET_RUNQ(td); 406 if (THREAD_CAN_MIGRATE(td)) { 407 tdq->tdq_transferable++; 408 ts->ts_flags |= TSF_XFERABLE; 409 } 410 if (pri <= PRI_MAX_REALTIME) { 411 ts->ts_runq = &tdq->tdq_realtime; 412 } else if (pri <= PRI_MAX_TIMESHARE) { 413 ts->ts_runq = &tdq->tdq_timeshare; 414 KASSERT(pri <= PRI_MAX_TIMESHARE && pri >= PRI_MIN_TIMESHARE, 415 ("Invalid priority %d on timeshare runq", pri)); 416 /* 417 * This queue contains only priorities between MIN and MAX 418 * realtime. Use the whole queue to represent these values. 419 */ 420 if ((flags & (SRQ_BORROWING|SRQ_PREEMPTED)) == 0) { 421 pri = (pri - PRI_MIN_TIMESHARE) / TS_RQ_PPQ; 422 pri = (pri + tdq->tdq_idx) % RQ_NQS; 423 /* 424 * This effectively shortens the queue by one so we 425 * can have a one slot difference between idx and 426 * ridx while we wait for threads to drain. 427 */ 428 if (tdq->tdq_ridx != tdq->tdq_idx && 429 pri == tdq->tdq_ridx) 430 pri = (unsigned char)(pri - 1) % RQ_NQS; 431 } else 432 pri = tdq->tdq_ridx; 433 runq_add_pri(ts->ts_runq, td, pri, flags); 434 return; 435 } else 436 ts->ts_runq = &tdq->tdq_idle; 437 runq_add(ts->ts_runq, td, flags); 438 } 439 440 /* 441 * Remove a thread from a run-queue. This typically happens when a thread 442 * is selected to run. Running threads are not on the queue and the 443 * transferable count does not reflect them. 444 */ 445 static __inline void 446 tdq_runq_rem(struct tdq *tdq, struct thread *td) 447 { 448 struct td_sched *ts; 449 450 ts = td->td_sched; 451 TDQ_LOCK_ASSERT(tdq, MA_OWNED); 452 KASSERT(ts->ts_runq != NULL, 453 ("tdq_runq_remove: thread %p null ts_runq", td)); 454 if (ts->ts_flags & TSF_XFERABLE) { 455 tdq->tdq_transferable--; 456 ts->ts_flags &= ~TSF_XFERABLE; 457 } 458 if (ts->ts_runq == &tdq->tdq_timeshare) { 459 if (tdq->tdq_idx != tdq->tdq_ridx) 460 runq_remove_idx(ts->ts_runq, td, &tdq->tdq_ridx); 461 else 462 runq_remove_idx(ts->ts_runq, td, NULL); 463 } else 464 runq_remove(ts->ts_runq, td); 465 } 466 467 /* 468 * Load is maintained for all threads RUNNING and ON_RUNQ. Add the load 469 * for this thread to the referenced thread queue. 470 */ 471 static void 472 tdq_load_add(struct tdq *tdq, struct thread *td) 473 { 474 475 TDQ_LOCK_ASSERT(tdq, MA_OWNED); 476 THREAD_LOCK_ASSERT(td, MA_OWNED); 477 478 tdq->tdq_load++; 479 if ((td->td_proc->p_flag & P_NOLOAD) == 0) 480 tdq->tdq_sysload++; 481 CTR2(KTR_SCHED, "cpu %d load: %d", TDQ_ID(tdq), tdq->tdq_load); 482 } 483 484 /* 485 * Remove the load from a thread that is transitioning to a sleep state or 486 * exiting. 487 */ 488 static void 489 tdq_load_rem(struct tdq *tdq, struct thread *td) 490 { 491 492 THREAD_LOCK_ASSERT(td, MA_OWNED); 493 TDQ_LOCK_ASSERT(tdq, MA_OWNED); 494 KASSERT(tdq->tdq_load != 0, 495 ("tdq_load_rem: Removing with 0 load on queue %d", TDQ_ID(tdq))); 496 497 tdq->tdq_load--; 498 if ((td->td_proc->p_flag & P_NOLOAD) == 0) 499 tdq->tdq_sysload--; 500 CTR1(KTR_SCHED, "load: %d", tdq->tdq_load); 501 } 502 503 /* 504 * Set lowpri to its exact value by searching the run-queue and 505 * evaluating curthread. curthread may be passed as an optimization. 506 */ 507 static void 508 tdq_setlowpri(struct tdq *tdq, struct thread *ctd) 509 { 510 struct thread *td; 511 512 TDQ_LOCK_ASSERT(tdq, MA_OWNED); 513 if (ctd == NULL) 514 ctd = pcpu_find(TDQ_ID(tdq))->pc_curthread; 515 td = tdq_choose(tdq); 516 if (td == NULL || td->td_priority > ctd->td_priority) 517 tdq->tdq_lowpri = ctd->td_priority; 518 else 519 tdq->tdq_lowpri = td->td_priority; 520 } 521 522 #ifdef SMP 523 struct cpu_search { 524 cpumask_t cs_mask; /* Mask of valid cpus. */ 525 u_int cs_load; 526 u_int cs_cpu; 527 int cs_limit; /* Min priority for low min load for high. */ 528 }; 529 530 #define CPU_SEARCH_LOWEST 0x1 531 #define CPU_SEARCH_HIGHEST 0x2 532 #define CPU_SEARCH_BOTH (CPU_SEARCH_LOWEST|CPU_SEARCH_HIGHEST) 533 534 #define CPUMASK_FOREACH(cpu, mask) \ 535 for ((cpu) = 0; (cpu) < sizeof((mask)) * 8; (cpu)++) \ 536 if ((mask) & 1 << (cpu)) 537 538 static __inline int cpu_search(struct cpu_group *cg, struct cpu_search *low, 539 struct cpu_search *high, const int match); 540 int cpu_search_lowest(struct cpu_group *cg, struct cpu_search *low); 541 int cpu_search_highest(struct cpu_group *cg, struct cpu_search *high); 542 int cpu_search_both(struct cpu_group *cg, struct cpu_search *low, 543 struct cpu_search *high); 544 545 /* 546 * This routine compares according to the match argument and should be 547 * reduced in actual instantiations via constant propagation and dead code 548 * elimination. 549 */ 550 static __inline int 551 cpu_compare(int cpu, struct cpu_search *low, struct cpu_search *high, 552 const int match) 553 { 554 struct tdq *tdq; 555 556 tdq = TDQ_CPU(cpu); 557 if (match & CPU_SEARCH_LOWEST) 558 if (low->cs_mask & (1 << cpu) && 559 tdq->tdq_load < low->cs_load && 560 tdq->tdq_lowpri > low->cs_limit) { 561 low->cs_cpu = cpu; 562 low->cs_load = tdq->tdq_load; 563 } 564 if (match & CPU_SEARCH_HIGHEST) 565 if (high->cs_mask & (1 << cpu) && 566 tdq->tdq_load >= high->cs_limit && 567 tdq->tdq_load > high->cs_load && 568 tdq->tdq_transferable) { 569 high->cs_cpu = cpu; 570 high->cs_load = tdq->tdq_load; 571 } 572 return (tdq->tdq_load); 573 } 574 575 /* 576 * Search the tree of cpu_groups for the lowest or highest loaded cpu 577 * according to the match argument. This routine actually compares the 578 * load on all paths through the tree and finds the least loaded cpu on 579 * the least loaded path, which may differ from the least loaded cpu in 580 * the system. This balances work among caches and busses. 581 * 582 * This inline is instantiated in three forms below using constants for the 583 * match argument. It is reduced to the minimum set for each case. It is 584 * also recursive to the depth of the tree. 585 */ 586 static __inline int 587 cpu_search(struct cpu_group *cg, struct cpu_search *low, 588 struct cpu_search *high, const int match) 589 { 590 int total; 591 592 total = 0; 593 if (cg->cg_children) { 594 struct cpu_search lgroup; 595 struct cpu_search hgroup; 596 struct cpu_group *child; 597 u_int lload; 598 int hload; 599 int load; 600 int i; 601 602 lload = -1; 603 hload = -1; 604 for (i = 0; i < cg->cg_children; i++) { 605 child = &cg->cg_child[i]; 606 if (match & CPU_SEARCH_LOWEST) { 607 lgroup = *low; 608 lgroup.cs_load = -1; 609 } 610 if (match & CPU_SEARCH_HIGHEST) { 611 hgroup = *high; 612 lgroup.cs_load = 0; 613 } 614 switch (match) { 615 case CPU_SEARCH_LOWEST: 616 load = cpu_search_lowest(child, &lgroup); 617 break; 618 case CPU_SEARCH_HIGHEST: 619 load = cpu_search_highest(child, &hgroup); 620 break; 621 case CPU_SEARCH_BOTH: 622 load = cpu_search_both(child, &lgroup, &hgroup); 623 break; 624 } 625 total += load; 626 if (match & CPU_SEARCH_LOWEST) 627 if (load < lload || low->cs_cpu == -1) { 628 *low = lgroup; 629 lload = load; 630 } 631 if (match & CPU_SEARCH_HIGHEST) 632 if (load > hload || high->cs_cpu == -1) { 633 hload = load; 634 *high = hgroup; 635 } 636 } 637 } else { 638 int cpu; 639 640 CPUMASK_FOREACH(cpu, cg->cg_mask) 641 total += cpu_compare(cpu, low, high, match); 642 } 643 return (total); 644 } 645 646 /* 647 * cpu_search instantiations must pass constants to maintain the inline 648 * optimization. 649 */ 650 int 651 cpu_search_lowest(struct cpu_group *cg, struct cpu_search *low) 652 { 653 return cpu_search(cg, low, NULL, CPU_SEARCH_LOWEST); 654 } 655 656 int 657 cpu_search_highest(struct cpu_group *cg, struct cpu_search *high) 658 { 659 return cpu_search(cg, NULL, high, CPU_SEARCH_HIGHEST); 660 } 661 662 int 663 cpu_search_both(struct cpu_group *cg, struct cpu_search *low, 664 struct cpu_search *high) 665 { 666 return cpu_search(cg, low, high, CPU_SEARCH_BOTH); 667 } 668 669 /* 670 * Find the cpu with the least load via the least loaded path that has a 671 * lowpri greater than pri pri. A pri of -1 indicates any priority is 672 * acceptable. 673 */ 674 static inline int 675 sched_lowest(struct cpu_group *cg, cpumask_t mask, int pri) 676 { 677 struct cpu_search low; 678 679 low.cs_cpu = -1; 680 low.cs_load = -1; 681 low.cs_mask = mask; 682 low.cs_limit = pri; 683 cpu_search_lowest(cg, &low); 684 return low.cs_cpu; 685 } 686 687 /* 688 * Find the cpu with the highest load via the highest loaded path. 689 */ 690 static inline int 691 sched_highest(struct cpu_group *cg, cpumask_t mask, int minload) 692 { 693 struct cpu_search high; 694 695 high.cs_cpu = -1; 696 high.cs_load = 0; 697 high.cs_mask = mask; 698 high.cs_limit = minload; 699 cpu_search_highest(cg, &high); 700 return high.cs_cpu; 701 } 702 703 /* 704 * Simultaneously find the highest and lowest loaded cpu reachable via 705 * cg. 706 */ 707 static inline void 708 sched_both(struct cpu_group *cg, cpumask_t mask, int *lowcpu, int *highcpu) 709 { 710 struct cpu_search high; 711 struct cpu_search low; 712 713 low.cs_cpu = -1; 714 low.cs_limit = -1; 715 low.cs_load = -1; 716 low.cs_mask = mask; 717 high.cs_load = 0; 718 high.cs_cpu = -1; 719 high.cs_limit = -1; 720 high.cs_mask = mask; 721 cpu_search_both(cg, &low, &high); 722 *lowcpu = low.cs_cpu; 723 *highcpu = high.cs_cpu; 724 return; 725 } 726 727 static void 728 sched_balance_group(struct cpu_group *cg) 729 { 730 cpumask_t mask; 731 int high; 732 int low; 733 int i; 734 735 mask = -1; 736 for (;;) { 737 sched_both(cg, mask, &low, &high); 738 if (low == high || low == -1 || high == -1) 739 break; 740 if (sched_balance_pair(TDQ_CPU(high), TDQ_CPU(low))) 741 break; 742 /* 743 * If we failed to move any threads determine which cpu 744 * to kick out of the set and try again. 745 */ 746 if (TDQ_CPU(high)->tdq_transferable == 0) 747 mask &= ~(1 << high); 748 else 749 mask &= ~(1 << low); 750 } 751 752 for (i = 0; i < cg->cg_children; i++) 753 sched_balance_group(&cg->cg_child[i]); 754 } 755 756 static void 757 sched_balance() 758 { 759 struct tdq *tdq; 760 761 /* 762 * Select a random time between .5 * balance_interval and 763 * 1.5 * balance_interval. 764 */ 765 balance_ticks = max(balance_interval / 2, 1); 766 balance_ticks += random() % balance_interval; 767 if (smp_started == 0 || rebalance == 0) 768 return; 769 tdq = TDQ_SELF(); 770 TDQ_UNLOCK(tdq); 771 sched_balance_group(cpu_top); 772 TDQ_LOCK(tdq); 773 } 774 775 /* 776 * Lock two thread queues using their address to maintain lock order. 777 */ 778 static void 779 tdq_lock_pair(struct tdq *one, struct tdq *two) 780 { 781 if (one < two) { 782 TDQ_LOCK(one); 783 TDQ_LOCK_FLAGS(two, MTX_DUPOK); 784 } else { 785 TDQ_LOCK(two); 786 TDQ_LOCK_FLAGS(one, MTX_DUPOK); 787 } 788 } 789 790 /* 791 * Unlock two thread queues. Order is not important here. 792 */ 793 static void 794 tdq_unlock_pair(struct tdq *one, struct tdq *two) 795 { 796 TDQ_UNLOCK(one); 797 TDQ_UNLOCK(two); 798 } 799 800 /* 801 * Transfer load between two imbalanced thread queues. 802 */ 803 static int 804 sched_balance_pair(struct tdq *high, struct tdq *low) 805 { 806 int transferable; 807 int high_load; 808 int low_load; 809 int moved; 810 int move; 811 int diff; 812 int i; 813 814 tdq_lock_pair(high, low); 815 transferable = high->tdq_transferable; 816 high_load = high->tdq_load; 817 low_load = low->tdq_load; 818 moved = 0; 819 /* 820 * Determine what the imbalance is and then adjust that to how many 821 * threads we actually have to give up (transferable). 822 */ 823 if (transferable != 0) { 824 diff = high_load - low_load; 825 move = diff / 2; 826 if (diff & 0x1) 827 move++; 828 move = min(move, transferable); 829 for (i = 0; i < move; i++) 830 moved += tdq_move(high, low); 831 /* 832 * IPI the target cpu to force it to reschedule with the new 833 * workload. 834 */ 835 ipi_selected(1 << TDQ_ID(low), IPI_PREEMPT); 836 } 837 tdq_unlock_pair(high, low); 838 return (moved); 839 } 840 841 /* 842 * Move a thread from one thread queue to another. 843 */ 844 static int 845 tdq_move(struct tdq *from, struct tdq *to) 846 { 847 struct td_sched *ts; 848 struct thread *td; 849 struct tdq *tdq; 850 int cpu; 851 852 TDQ_LOCK_ASSERT(from, MA_OWNED); 853 TDQ_LOCK_ASSERT(to, MA_OWNED); 854 855 tdq = from; 856 cpu = TDQ_ID(to); 857 td = tdq_steal(tdq, cpu); 858 if (td == NULL) 859 return (0); 860 ts = td->td_sched; 861 /* 862 * Although the run queue is locked the thread may be blocked. Lock 863 * it to clear this and acquire the run-queue lock. 864 */ 865 thread_lock(td); 866 /* Drop recursive lock on from acquired via thread_lock(). */ 867 TDQ_UNLOCK(from); 868 sched_rem(td); 869 ts->ts_cpu = cpu; 870 td->td_lock = TDQ_LOCKPTR(to); 871 tdq_add(to, td, SRQ_YIELDING); 872 return (1); 873 } 874 875 /* 876 * This tdq has idled. Try to steal a thread from another cpu and switch 877 * to it. 878 */ 879 static int 880 tdq_idled(struct tdq *tdq) 881 { 882 struct cpu_group *cg; 883 struct tdq *steal; 884 cpumask_t mask; 885 int thresh; 886 int cpu; 887 888 if (smp_started == 0 || steal_idle == 0) 889 return (1); 890 mask = -1; 891 mask &= ~PCPU_GET(cpumask); 892 /* We don't want to be preempted while we're iterating. */ 893 spinlock_enter(); 894 for (cg = tdq->tdq_cg; cg != NULL; ) { 895 if ((cg->cg_flags & (CG_FLAG_HTT | CG_FLAG_THREAD)) == 0) 896 thresh = steal_thresh; 897 else 898 thresh = 1; 899 cpu = sched_highest(cg, mask, thresh); 900 if (cpu == -1) { 901 cg = cg->cg_parent; 902 continue; 903 } 904 steal = TDQ_CPU(cpu); 905 mask &= ~(1 << cpu); 906 tdq_lock_pair(tdq, steal); 907 if (steal->tdq_load < thresh || steal->tdq_transferable == 0) { 908 tdq_unlock_pair(tdq, steal); 909 continue; 910 } 911 /* 912 * If a thread was added while interrupts were disabled don't 913 * steal one here. If we fail to acquire one due to affinity 914 * restrictions loop again with this cpu removed from the 915 * set. 916 */ 917 if (tdq->tdq_load == 0 && tdq_move(steal, tdq) == 0) { 918 tdq_unlock_pair(tdq, steal); 919 continue; 920 } 921 spinlock_exit(); 922 TDQ_UNLOCK(steal); 923 mi_switch(SW_VOL | SWT_IDLE, NULL); 924 thread_unlock(curthread); 925 926 return (0); 927 } 928 spinlock_exit(); 929 return (1); 930 } 931 932 /* 933 * Notify a remote cpu of new work. Sends an IPI if criteria are met. 934 */ 935 static void 936 tdq_notify(struct tdq *tdq, struct thread *td) 937 { 938 int cpri; 939 int pri; 940 int cpu; 941 942 if (tdq->tdq_ipipending) 943 return; 944 cpu = td->td_sched->ts_cpu; 945 pri = td->td_priority; 946 cpri = pcpu_find(cpu)->pc_curthread->td_priority; 947 if (!sched_shouldpreempt(pri, cpri, 1)) 948 return; 949 if (TD_IS_IDLETHREAD(td)) { 950 /* 951 * If the idle thread is still 'running' it's probably 952 * waiting on us to release the tdq spinlock already. No 953 * need to ipi. 954 */ 955 if (tdq->tdq_idlestate == TDQ_RUNNING) 956 return; 957 /* 958 * If the MD code has an idle wakeup routine try that before 959 * falling back to IPI. 960 */ 961 if (cpu_idle_wakeup(cpu)) 962 return; 963 } 964 tdq->tdq_ipipending = 1; 965 ipi_selected(1 << cpu, IPI_PREEMPT); 966 } 967 968 /* 969 * Steals load from a timeshare queue. Honors the rotating queue head 970 * index. 971 */ 972 static struct thread * 973 runq_steal_from(struct runq *rq, int cpu, u_char start) 974 { 975 struct rqbits *rqb; 976 struct rqhead *rqh; 977 struct thread *td; 978 int first; 979 int bit; 980 int pri; 981 int i; 982 983 rqb = &rq->rq_status; 984 bit = start & (RQB_BPW -1); 985 pri = 0; 986 first = 0; 987 again: 988 for (i = RQB_WORD(start); i < RQB_LEN; bit = 0, i++) { 989 if (rqb->rqb_bits[i] == 0) 990 continue; 991 if (bit != 0) { 992 for (pri = bit; pri < RQB_BPW; pri++) 993 if (rqb->rqb_bits[i] & (1ul << pri)) 994 break; 995 if (pri >= RQB_BPW) 996 continue; 997 } else 998 pri = RQB_FFS(rqb->rqb_bits[i]); 999 pri += (i << RQB_L2BPW); 1000 rqh = &rq->rq_queues[pri]; 1001 TAILQ_FOREACH(td, rqh, td_runq) { 1002 if (first && THREAD_CAN_MIGRATE(td) && 1003 THREAD_CAN_SCHED(td, cpu)) 1004 return (td); 1005 first = 1; 1006 } 1007 } 1008 if (start != 0) { 1009 start = 0; 1010 goto again; 1011 } 1012 1013 return (NULL); 1014 } 1015 1016 /* 1017 * Steals load from a standard linear queue. 1018 */ 1019 static struct thread * 1020 runq_steal(struct runq *rq, int cpu) 1021 { 1022 struct rqhead *rqh; 1023 struct rqbits *rqb; 1024 struct thread *td; 1025 int word; 1026 int bit; 1027 1028 rqb = &rq->rq_status; 1029 for (word = 0; word < RQB_LEN; word++) { 1030 if (rqb->rqb_bits[word] == 0) 1031 continue; 1032 for (bit = 0; bit < RQB_BPW; bit++) { 1033 if ((rqb->rqb_bits[word] & (1ul << bit)) == 0) 1034 continue; 1035 rqh = &rq->rq_queues[bit + (word << RQB_L2BPW)]; 1036 TAILQ_FOREACH(td, rqh, td_runq) 1037 if (THREAD_CAN_MIGRATE(td) && 1038 THREAD_CAN_SCHED(td, cpu)) 1039 return (td); 1040 } 1041 } 1042 return (NULL); 1043 } 1044 1045 /* 1046 * Attempt to steal a thread in priority order from a thread queue. 1047 */ 1048 static struct thread * 1049 tdq_steal(struct tdq *tdq, int cpu) 1050 { 1051 struct thread *td; 1052 1053 TDQ_LOCK_ASSERT(tdq, MA_OWNED); 1054 if ((td = runq_steal(&tdq->tdq_realtime, cpu)) != NULL) 1055 return (td); 1056 if ((td = runq_steal_from(&tdq->tdq_timeshare, 1057 cpu, tdq->tdq_ridx)) != NULL) 1058 return (td); 1059 return (runq_steal(&tdq->tdq_idle, cpu)); 1060 } 1061 1062 /* 1063 * Sets the thread lock and ts_cpu to match the requested cpu. Unlocks the 1064 * current lock and returns with the assigned queue locked. 1065 */ 1066 static inline struct tdq * 1067 sched_setcpu(struct thread *td, int cpu, int flags) 1068 { 1069 1070 struct tdq *tdq; 1071 1072 THREAD_LOCK_ASSERT(td, MA_OWNED); 1073 tdq = TDQ_CPU(cpu); 1074 td->td_sched->ts_cpu = cpu; 1075 /* 1076 * If the lock matches just return the queue. 1077 */ 1078 if (td->td_lock == TDQ_LOCKPTR(tdq)) 1079 return (tdq); 1080 #ifdef notyet 1081 /* 1082 * If the thread isn't running its lockptr is a 1083 * turnstile or a sleepqueue. We can just lock_set without 1084 * blocking. 1085 */ 1086 if (TD_CAN_RUN(td)) { 1087 TDQ_LOCK(tdq); 1088 thread_lock_set(td, TDQ_LOCKPTR(tdq)); 1089 return (tdq); 1090 } 1091 #endif 1092 /* 1093 * The hard case, migration, we need to block the thread first to 1094 * prevent order reversals with other cpus locks. 1095 */ 1096 thread_lock_block(td); 1097 TDQ_LOCK(tdq); 1098 thread_lock_unblock(td, TDQ_LOCKPTR(tdq)); 1099 return (tdq); 1100 } 1101 1102 SCHED_STAT_DEFINE(pickcpu_intrbind, "Soft interrupt binding"); 1103 SCHED_STAT_DEFINE(pickcpu_idle_affinity, "Picked idle cpu based on affinity"); 1104 SCHED_STAT_DEFINE(pickcpu_affinity, "Picked cpu based on affinity"); 1105 SCHED_STAT_DEFINE(pickcpu_lowest, "Selected lowest load"); 1106 SCHED_STAT_DEFINE(pickcpu_local, "Migrated to current cpu"); 1107 SCHED_STAT_DEFINE(pickcpu_migration, "Selection may have caused migration"); 1108 1109 static int 1110 sched_pickcpu(struct thread *td, int flags) 1111 { 1112 struct cpu_group *cg; 1113 struct td_sched *ts; 1114 struct tdq *tdq; 1115 cpumask_t mask; 1116 int self; 1117 int pri; 1118 int cpu; 1119 1120 self = PCPU_GET(cpuid); 1121 ts = td->td_sched; 1122 if (smp_started == 0) 1123 return (self); 1124 /* 1125 * Don't migrate a running thread from sched_switch(). 1126 */ 1127 if ((flags & SRQ_OURSELF) || !THREAD_CAN_MIGRATE(td)) 1128 return (ts->ts_cpu); 1129 /* 1130 * Prefer to run interrupt threads on the processors that generate 1131 * the interrupt. 1132 */ 1133 if (td->td_priority <= PRI_MAX_ITHD && THREAD_CAN_SCHED(td, self) && 1134 curthread->td_intr_nesting_level && ts->ts_cpu != self) { 1135 SCHED_STAT_INC(pickcpu_intrbind); 1136 ts->ts_cpu = self; 1137 } 1138 /* 1139 * If the thread can run on the last cpu and the affinity has not 1140 * expired or it is idle run it there. 1141 */ 1142 pri = td->td_priority; 1143 tdq = TDQ_CPU(ts->ts_cpu); 1144 if (THREAD_CAN_SCHED(td, ts->ts_cpu)) { 1145 if (tdq->tdq_lowpri > PRI_MIN_IDLE) { 1146 SCHED_STAT_INC(pickcpu_idle_affinity); 1147 return (ts->ts_cpu); 1148 } 1149 if (SCHED_AFFINITY(ts, CG_SHARE_L2) && tdq->tdq_lowpri > pri) { 1150 SCHED_STAT_INC(pickcpu_affinity); 1151 return (ts->ts_cpu); 1152 } 1153 } 1154 /* 1155 * Search for the highest level in the tree that still has affinity. 1156 */ 1157 cg = NULL; 1158 for (cg = tdq->tdq_cg; cg != NULL; cg = cg->cg_parent) 1159 if (SCHED_AFFINITY(ts, cg->cg_level)) 1160 break; 1161 cpu = -1; 1162 mask = td->td_cpuset->cs_mask.__bits[0]; 1163 if (cg) 1164 cpu = sched_lowest(cg, mask, pri); 1165 if (cpu == -1) 1166 cpu = sched_lowest(cpu_top, mask, -1); 1167 /* 1168 * Compare the lowest loaded cpu to current cpu. 1169 */ 1170 if (THREAD_CAN_SCHED(td, self) && TDQ_CPU(self)->tdq_lowpri > pri && 1171 TDQ_CPU(cpu)->tdq_lowpri < PRI_MIN_IDLE) { 1172 SCHED_STAT_INC(pickcpu_local); 1173 cpu = self; 1174 } else 1175 SCHED_STAT_INC(pickcpu_lowest); 1176 if (cpu != ts->ts_cpu) 1177 SCHED_STAT_INC(pickcpu_migration); 1178 KASSERT(cpu != -1, ("sched_pickcpu: Failed to find a cpu.")); 1179 return (cpu); 1180 } 1181 #endif 1182 1183 /* 1184 * Pick the highest priority task we have and return it. 1185 */ 1186 static struct thread * 1187 tdq_choose(struct tdq *tdq) 1188 { 1189 struct thread *td; 1190 1191 TDQ_LOCK_ASSERT(tdq, MA_OWNED); 1192 td = runq_choose(&tdq->tdq_realtime); 1193 if (td != NULL) 1194 return (td); 1195 td = runq_choose_from(&tdq->tdq_timeshare, tdq->tdq_ridx); 1196 if (td != NULL) { 1197 KASSERT(td->td_priority >= PRI_MIN_TIMESHARE, 1198 ("tdq_choose: Invalid priority on timeshare queue %d", 1199 td->td_priority)); 1200 return (td); 1201 } 1202 td = runq_choose(&tdq->tdq_idle); 1203 if (td != NULL) { 1204 KASSERT(td->td_priority >= PRI_MIN_IDLE, 1205 ("tdq_choose: Invalid priority on idle queue %d", 1206 td->td_priority)); 1207 return (td); 1208 } 1209 1210 return (NULL); 1211 } 1212 1213 /* 1214 * Initialize a thread queue. 1215 */ 1216 static void 1217 tdq_setup(struct tdq *tdq) 1218 { 1219 1220 if (bootverbose) 1221 printf("ULE: setup cpu %d\n", TDQ_ID(tdq)); 1222 runq_init(&tdq->tdq_realtime); 1223 runq_init(&tdq->tdq_timeshare); 1224 runq_init(&tdq->tdq_idle); 1225 snprintf(tdq->tdq_name, sizeof(tdq->tdq_name), 1226 "sched lock %d", (int)TDQ_ID(tdq)); 1227 mtx_init(&tdq->tdq_lock, tdq->tdq_name, "sched lock", 1228 MTX_SPIN | MTX_RECURSE); 1229 } 1230 1231 #ifdef SMP 1232 static void 1233 sched_setup_smp(void) 1234 { 1235 struct tdq *tdq; 1236 int i; 1237 1238 cpu_top = smp_topo(); 1239 for (i = 0; i < MAXCPU; i++) { 1240 if (CPU_ABSENT(i)) 1241 continue; 1242 tdq = TDQ_CPU(i); 1243 tdq_setup(tdq); 1244 tdq->tdq_cg = smp_topo_find(cpu_top, i); 1245 if (tdq->tdq_cg == NULL) 1246 panic("Can't find cpu group for %d\n", i); 1247 } 1248 balance_tdq = TDQ_SELF(); 1249 sched_balance(); 1250 } 1251 #endif 1252 1253 /* 1254 * Setup the thread queues and initialize the topology based on MD 1255 * information. 1256 */ 1257 static void 1258 sched_setup(void *dummy) 1259 { 1260 struct tdq *tdq; 1261 1262 tdq = TDQ_SELF(); 1263 #ifdef SMP 1264 sched_setup_smp(); 1265 #else 1266 tdq_setup(tdq); 1267 #endif 1268 /* 1269 * To avoid divide-by-zero, we set realstathz a dummy value 1270 * in case which sched_clock() called before sched_initticks(). 1271 */ 1272 realstathz = hz; 1273 sched_slice = (realstathz/10); /* ~100ms */ 1274 tickincr = 1 << SCHED_TICK_SHIFT; 1275 1276 /* Add thread0's load since it's running. */ 1277 TDQ_LOCK(tdq); 1278 thread0.td_lock = TDQ_LOCKPTR(TDQ_SELF()); 1279 tdq_load_add(tdq, &thread0); 1280 tdq->tdq_lowpri = thread0.td_priority; 1281 TDQ_UNLOCK(tdq); 1282 } 1283 1284 /* 1285 * This routine determines the tickincr after stathz and hz are setup. 1286 */ 1287 /* ARGSUSED */ 1288 static void 1289 sched_initticks(void *dummy) 1290 { 1291 int incr; 1292 1293 realstathz = stathz ? stathz : hz; 1294 sched_slice = (realstathz/10); /* ~100ms */ 1295 1296 /* 1297 * tickincr is shifted out by 10 to avoid rounding errors due to 1298 * hz not being evenly divisible by stathz on all platforms. 1299 */ 1300 incr = (hz << SCHED_TICK_SHIFT) / realstathz; 1301 /* 1302 * This does not work for values of stathz that are more than 1303 * 1 << SCHED_TICK_SHIFT * hz. In practice this does not happen. 1304 */ 1305 if (incr == 0) 1306 incr = 1; 1307 tickincr = incr; 1308 #ifdef SMP 1309 /* 1310 * Set the default balance interval now that we know 1311 * what realstathz is. 1312 */ 1313 balance_interval = realstathz; 1314 /* 1315 * Set steal thresh to log2(mp_ncpu) but no greater than 4. This 1316 * prevents excess thrashing on large machines and excess idle on 1317 * smaller machines. 1318 */ 1319 steal_thresh = min(ffs(mp_ncpus) - 1, 3); 1320 affinity = SCHED_AFFINITY_DEFAULT; 1321 #endif 1322 } 1323 1324 1325 /* 1326 * This is the core of the interactivity algorithm. Determines a score based 1327 * on past behavior. It is the ratio of sleep time to run time scaled to 1328 * a [0, 100] integer. This is the voluntary sleep time of a process, which 1329 * differs from the cpu usage because it does not account for time spent 1330 * waiting on a run-queue. Would be prettier if we had floating point. 1331 */ 1332 static int 1333 sched_interact_score(struct thread *td) 1334 { 1335 struct td_sched *ts; 1336 int div; 1337 1338 ts = td->td_sched; 1339 /* 1340 * The score is only needed if this is likely to be an interactive 1341 * task. Don't go through the expense of computing it if there's 1342 * no chance. 1343 */ 1344 if (sched_interact <= SCHED_INTERACT_HALF && 1345 ts->ts_runtime >= ts->ts_slptime) 1346 return (SCHED_INTERACT_HALF); 1347 1348 if (ts->ts_runtime > ts->ts_slptime) { 1349 div = max(1, ts->ts_runtime / SCHED_INTERACT_HALF); 1350 return (SCHED_INTERACT_HALF + 1351 (SCHED_INTERACT_HALF - (ts->ts_slptime / div))); 1352 } 1353 if (ts->ts_slptime > ts->ts_runtime) { 1354 div = max(1, ts->ts_slptime / SCHED_INTERACT_HALF); 1355 return (ts->ts_runtime / div); 1356 } 1357 /* runtime == slptime */ 1358 if (ts->ts_runtime) 1359 return (SCHED_INTERACT_HALF); 1360 1361 /* 1362 * This can happen if slptime and runtime are 0. 1363 */ 1364 return (0); 1365 1366 } 1367 1368 /* 1369 * Scale the scheduling priority according to the "interactivity" of this 1370 * process. 1371 */ 1372 static void 1373 sched_priority(struct thread *td) 1374 { 1375 int score; 1376 int pri; 1377 1378 if (td->td_pri_class != PRI_TIMESHARE) 1379 return; 1380 /* 1381 * If the score is interactive we place the thread in the realtime 1382 * queue with a priority that is less than kernel and interrupt 1383 * priorities. These threads are not subject to nice restrictions. 1384 * 1385 * Scores greater than this are placed on the normal timeshare queue 1386 * where the priority is partially decided by the most recent cpu 1387 * utilization and the rest is decided by nice value. 1388 * 1389 * The nice value of the process has a linear effect on the calculated 1390 * score. Negative nice values make it easier for a thread to be 1391 * considered interactive. 1392 */ 1393 score = imax(0, sched_interact_score(td) - td->td_proc->p_nice); 1394 if (score < sched_interact) { 1395 pri = PRI_MIN_REALTIME; 1396 pri += ((PRI_MAX_REALTIME - PRI_MIN_REALTIME) / sched_interact) 1397 * score; 1398 KASSERT(pri >= PRI_MIN_REALTIME && pri <= PRI_MAX_REALTIME, 1399 ("sched_priority: invalid interactive priority %d score %d", 1400 pri, score)); 1401 } else { 1402 pri = SCHED_PRI_MIN; 1403 if (td->td_sched->ts_ticks) 1404 pri += SCHED_PRI_TICKS(td->td_sched); 1405 pri += SCHED_PRI_NICE(td->td_proc->p_nice); 1406 KASSERT(pri >= PRI_MIN_TIMESHARE && pri <= PRI_MAX_TIMESHARE, 1407 ("sched_priority: invalid priority %d: nice %d, " 1408 "ticks %d ftick %d ltick %d tick pri %d", 1409 pri, td->td_proc->p_nice, td->td_sched->ts_ticks, 1410 td->td_sched->ts_ftick, td->td_sched->ts_ltick, 1411 SCHED_PRI_TICKS(td->td_sched))); 1412 } 1413 sched_user_prio(td, pri); 1414 1415 return; 1416 } 1417 1418 /* 1419 * This routine enforces a maximum limit on the amount of scheduling history 1420 * kept. It is called after either the slptime or runtime is adjusted. This 1421 * function is ugly due to integer math. 1422 */ 1423 static void 1424 sched_interact_update(struct thread *td) 1425 { 1426 struct td_sched *ts; 1427 u_int sum; 1428 1429 ts = td->td_sched; 1430 sum = ts->ts_runtime + ts->ts_slptime; 1431 if (sum < SCHED_SLP_RUN_MAX) 1432 return; 1433 /* 1434 * This only happens from two places: 1435 * 1) We have added an unusual amount of run time from fork_exit. 1436 * 2) We have added an unusual amount of sleep time from sched_sleep(). 1437 */ 1438 if (sum > SCHED_SLP_RUN_MAX * 2) { 1439 if (ts->ts_runtime > ts->ts_slptime) { 1440 ts->ts_runtime = SCHED_SLP_RUN_MAX; 1441 ts->ts_slptime = 1; 1442 } else { 1443 ts->ts_slptime = SCHED_SLP_RUN_MAX; 1444 ts->ts_runtime = 1; 1445 } 1446 return; 1447 } 1448 /* 1449 * If we have exceeded by more than 1/5th then the algorithm below 1450 * will not bring us back into range. Dividing by two here forces 1451 * us into the range of [4/5 * SCHED_INTERACT_MAX, SCHED_INTERACT_MAX] 1452 */ 1453 if (sum > (SCHED_SLP_RUN_MAX / 5) * 6) { 1454 ts->ts_runtime /= 2; 1455 ts->ts_slptime /= 2; 1456 return; 1457 } 1458 ts->ts_runtime = (ts->ts_runtime / 5) * 4; 1459 ts->ts_slptime = (ts->ts_slptime / 5) * 4; 1460 } 1461 1462 /* 1463 * Scale back the interactivity history when a child thread is created. The 1464 * history is inherited from the parent but the thread may behave totally 1465 * differently. For example, a shell spawning a compiler process. We want 1466 * to learn that the compiler is behaving badly very quickly. 1467 */ 1468 static void 1469 sched_interact_fork(struct thread *td) 1470 { 1471 int ratio; 1472 int sum; 1473 1474 sum = td->td_sched->ts_runtime + td->td_sched->ts_slptime; 1475 if (sum > SCHED_SLP_RUN_FORK) { 1476 ratio = sum / SCHED_SLP_RUN_FORK; 1477 td->td_sched->ts_runtime /= ratio; 1478 td->td_sched->ts_slptime /= ratio; 1479 } 1480 } 1481 1482 /* 1483 * Called from proc0_init() to setup the scheduler fields. 1484 */ 1485 void 1486 schedinit(void) 1487 { 1488 1489 /* 1490 * Set up the scheduler specific parts of proc0. 1491 */ 1492 proc0.p_sched = NULL; /* XXX */ 1493 thread0.td_sched = &td_sched0; 1494 td_sched0.ts_ltick = ticks; 1495 td_sched0.ts_ftick = ticks; 1496 td_sched0.ts_slice = sched_slice; 1497 } 1498 1499 /* 1500 * This is only somewhat accurate since given many processes of the same 1501 * priority they will switch when their slices run out, which will be 1502 * at most sched_slice stathz ticks. 1503 */ 1504 int 1505 sched_rr_interval(void) 1506 { 1507 1508 /* Convert sched_slice to hz */ 1509 return (hz/(realstathz/sched_slice)); 1510 } 1511 1512 /* 1513 * Update the percent cpu tracking information when it is requested or 1514 * the total history exceeds the maximum. We keep a sliding history of 1515 * tick counts that slowly decays. This is less precise than the 4BSD 1516 * mechanism since it happens with less regular and frequent events. 1517 */ 1518 static void 1519 sched_pctcpu_update(struct td_sched *ts) 1520 { 1521 1522 if (ts->ts_ticks == 0) 1523 return; 1524 if (ticks - (hz / 10) < ts->ts_ltick && 1525 SCHED_TICK_TOTAL(ts) < SCHED_TICK_MAX) 1526 return; 1527 /* 1528 * Adjust counters and watermark for pctcpu calc. 1529 */ 1530 if (ts->ts_ltick > ticks - SCHED_TICK_TARG) 1531 ts->ts_ticks = (ts->ts_ticks / (ticks - ts->ts_ftick)) * 1532 SCHED_TICK_TARG; 1533 else 1534 ts->ts_ticks = 0; 1535 ts->ts_ltick = ticks; 1536 ts->ts_ftick = ts->ts_ltick - SCHED_TICK_TARG; 1537 } 1538 1539 /* 1540 * Adjust the priority of a thread. Move it to the appropriate run-queue 1541 * if necessary. This is the back-end for several priority related 1542 * functions. 1543 */ 1544 static void 1545 sched_thread_priority(struct thread *td, u_char prio) 1546 { 1547 struct td_sched *ts; 1548 struct tdq *tdq; 1549 int oldpri; 1550 1551 CTR6(KTR_SCHED, "sched_prio: %p(%s) prio %d newprio %d by %p(%s)", 1552 td, td->td_name, td->td_priority, prio, curthread, 1553 curthread->td_name); 1554 ts = td->td_sched; 1555 THREAD_LOCK_ASSERT(td, MA_OWNED); 1556 if (td->td_priority == prio) 1557 return; 1558 /* 1559 * If the priority has been elevated due to priority 1560 * propagation, we may have to move ourselves to a new 1561 * queue. This could be optimized to not re-add in some 1562 * cases. 1563 */ 1564 if (TD_ON_RUNQ(td) && prio < td->td_priority) { 1565 sched_rem(td); 1566 td->td_priority = prio; 1567 sched_add(td, SRQ_BORROWING); 1568 return; 1569 } 1570 /* 1571 * If the thread is currently running we may have to adjust the lowpri 1572 * information so other cpus are aware of our current priority. 1573 */ 1574 if (TD_IS_RUNNING(td)) { 1575 tdq = TDQ_CPU(ts->ts_cpu); 1576 oldpri = td->td_priority; 1577 td->td_priority = prio; 1578 if (prio < tdq->tdq_lowpri) 1579 tdq->tdq_lowpri = prio; 1580 else if (tdq->tdq_lowpri == oldpri) 1581 tdq_setlowpri(tdq, td); 1582 return; 1583 } 1584 td->td_priority = prio; 1585 } 1586 1587 /* 1588 * Update a thread's priority when it is lent another thread's 1589 * priority. 1590 */ 1591 void 1592 sched_lend_prio(struct thread *td, u_char prio) 1593 { 1594 1595 td->td_flags |= TDF_BORROWING; 1596 sched_thread_priority(td, prio); 1597 } 1598 1599 /* 1600 * Restore a thread's priority when priority propagation is 1601 * over. The prio argument is the minimum priority the thread 1602 * needs to have to satisfy other possible priority lending 1603 * requests. If the thread's regular priority is less 1604 * important than prio, the thread will keep a priority boost 1605 * of prio. 1606 */ 1607 void 1608 sched_unlend_prio(struct thread *td, u_char prio) 1609 { 1610 u_char base_pri; 1611 1612 if (td->td_base_pri >= PRI_MIN_TIMESHARE && 1613 td->td_base_pri <= PRI_MAX_TIMESHARE) 1614 base_pri = td->td_user_pri; 1615 else 1616 base_pri = td->td_base_pri; 1617 if (prio >= base_pri) { 1618 td->td_flags &= ~TDF_BORROWING; 1619 sched_thread_priority(td, base_pri); 1620 } else 1621 sched_lend_prio(td, prio); 1622 } 1623 1624 /* 1625 * Standard entry for setting the priority to an absolute value. 1626 */ 1627 void 1628 sched_prio(struct thread *td, u_char prio) 1629 { 1630 u_char oldprio; 1631 1632 /* First, update the base priority. */ 1633 td->td_base_pri = prio; 1634 1635 /* 1636 * If the thread is borrowing another thread's priority, don't 1637 * ever lower the priority. 1638 */ 1639 if (td->td_flags & TDF_BORROWING && td->td_priority < prio) 1640 return; 1641 1642 /* Change the real priority. */ 1643 oldprio = td->td_priority; 1644 sched_thread_priority(td, prio); 1645 1646 /* 1647 * If the thread is on a turnstile, then let the turnstile update 1648 * its state. 1649 */ 1650 if (TD_ON_LOCK(td) && oldprio != prio) 1651 turnstile_adjust(td, oldprio); 1652 } 1653 1654 /* 1655 * Set the base user priority, does not effect current running priority. 1656 */ 1657 void 1658 sched_user_prio(struct thread *td, u_char prio) 1659 { 1660 u_char oldprio; 1661 1662 td->td_base_user_pri = prio; 1663 if (td->td_flags & TDF_UBORROWING && td->td_user_pri <= prio) 1664 return; 1665 oldprio = td->td_user_pri; 1666 td->td_user_pri = prio; 1667 } 1668 1669 void 1670 sched_lend_user_prio(struct thread *td, u_char prio) 1671 { 1672 u_char oldprio; 1673 1674 THREAD_LOCK_ASSERT(td, MA_OWNED); 1675 td->td_flags |= TDF_UBORROWING; 1676 oldprio = td->td_user_pri; 1677 td->td_user_pri = prio; 1678 } 1679 1680 void 1681 sched_unlend_user_prio(struct thread *td, u_char prio) 1682 { 1683 u_char base_pri; 1684 1685 THREAD_LOCK_ASSERT(td, MA_OWNED); 1686 base_pri = td->td_base_user_pri; 1687 if (prio >= base_pri) { 1688 td->td_flags &= ~TDF_UBORROWING; 1689 sched_user_prio(td, base_pri); 1690 } else { 1691 sched_lend_user_prio(td, prio); 1692 } 1693 } 1694 1695 /* 1696 * Block a thread for switching. Similar to thread_block() but does not 1697 * bump the spin count. 1698 */ 1699 static inline struct mtx * 1700 thread_block_switch(struct thread *td) 1701 { 1702 struct mtx *lock; 1703 1704 THREAD_LOCK_ASSERT(td, MA_OWNED); 1705 lock = td->td_lock; 1706 td->td_lock = &blocked_lock; 1707 mtx_unlock_spin(lock); 1708 1709 return (lock); 1710 } 1711 1712 /* 1713 * Handle migration from sched_switch(). This happens only for 1714 * cpu binding. 1715 */ 1716 static struct mtx * 1717 sched_switch_migrate(struct tdq *tdq, struct thread *td, int flags) 1718 { 1719 struct tdq *tdn; 1720 1721 tdn = TDQ_CPU(td->td_sched->ts_cpu); 1722 #ifdef SMP 1723 tdq_load_rem(tdq, td); 1724 /* 1725 * Do the lock dance required to avoid LOR. We grab an extra 1726 * spinlock nesting to prevent preemption while we're 1727 * not holding either run-queue lock. 1728 */ 1729 spinlock_enter(); 1730 thread_block_switch(td); /* This releases the lock on tdq. */ 1731 TDQ_LOCK(tdn); 1732 tdq_add(tdn, td, flags); 1733 tdq_notify(tdn, td); 1734 /* 1735 * After we unlock tdn the new cpu still can't switch into this 1736 * thread until we've unblocked it in cpu_switch(). The lock 1737 * pointers may match in the case of HTT cores. Don't unlock here 1738 * or we can deadlock when the other CPU runs the IPI handler. 1739 */ 1740 if (TDQ_LOCKPTR(tdn) != TDQ_LOCKPTR(tdq)) { 1741 TDQ_UNLOCK(tdn); 1742 TDQ_LOCK(tdq); 1743 } 1744 spinlock_exit(); 1745 #endif 1746 return (TDQ_LOCKPTR(tdn)); 1747 } 1748 1749 /* 1750 * Release a thread that was blocked with thread_block_switch(). 1751 */ 1752 static inline void 1753 thread_unblock_switch(struct thread *td, struct mtx *mtx) 1754 { 1755 atomic_store_rel_ptr((volatile uintptr_t *)&td->td_lock, 1756 (uintptr_t)mtx); 1757 } 1758 1759 /* 1760 * Switch threads. This function has to handle threads coming in while 1761 * blocked for some reason, running, or idle. It also must deal with 1762 * migrating a thread from one queue to another as running threads may 1763 * be assigned elsewhere via binding. 1764 */ 1765 void 1766 sched_switch(struct thread *td, struct thread *newtd, int flags) 1767 { 1768 struct tdq *tdq; 1769 struct td_sched *ts; 1770 struct mtx *mtx; 1771 int srqflag; 1772 int cpuid; 1773 1774 THREAD_LOCK_ASSERT(td, MA_OWNED); 1775 KASSERT(newtd == NULL, ("sched_switch: Unsupported newtd argument")); 1776 1777 cpuid = PCPU_GET(cpuid); 1778 tdq = TDQ_CPU(cpuid); 1779 ts = td->td_sched; 1780 mtx = td->td_lock; 1781 ts->ts_rltick = ticks; 1782 td->td_lastcpu = td->td_oncpu; 1783 td->td_oncpu = NOCPU; 1784 td->td_flags &= ~TDF_NEEDRESCHED; 1785 td->td_owepreempt = 0; 1786 tdq->tdq_switchcnt++; 1787 /* 1788 * The lock pointer in an idle thread should never change. Reset it 1789 * to CAN_RUN as well. 1790 */ 1791 if (TD_IS_IDLETHREAD(td)) { 1792 MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 1793 TD_SET_CAN_RUN(td); 1794 } else if (TD_IS_RUNNING(td)) { 1795 MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 1796 srqflag = (flags & SW_PREEMPT) ? 1797 SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED : 1798 SRQ_OURSELF|SRQ_YIELDING; 1799 if (ts->ts_cpu == cpuid) 1800 tdq_runq_add(tdq, td, srqflag); 1801 else 1802 mtx = sched_switch_migrate(tdq, td, srqflag); 1803 } else { 1804 /* This thread must be going to sleep. */ 1805 TDQ_LOCK(tdq); 1806 mtx = thread_block_switch(td); 1807 tdq_load_rem(tdq, td); 1808 } 1809 /* 1810 * We enter here with the thread blocked and assigned to the 1811 * appropriate cpu run-queue or sleep-queue and with the current 1812 * thread-queue locked. 1813 */ 1814 TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED); 1815 newtd = choosethread(); 1816 /* 1817 * Call the MD code to switch contexts if necessary. 1818 */ 1819 if (td != newtd) { 1820 #ifdef HWPMC_HOOKS 1821 if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 1822 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT); 1823 #endif 1824 lock_profile_release_lock(&TDQ_LOCKPTR(tdq)->lock_object); 1825 TDQ_LOCKPTR(tdq)->mtx_lock = (uintptr_t)newtd; 1826 cpu_switch(td, newtd, mtx); 1827 /* 1828 * We may return from cpu_switch on a different cpu. However, 1829 * we always return with td_lock pointing to the current cpu's 1830 * run queue lock. 1831 */ 1832 cpuid = PCPU_GET(cpuid); 1833 tdq = TDQ_CPU(cpuid); 1834 lock_profile_obtain_lock_success( 1835 &TDQ_LOCKPTR(tdq)->lock_object, 0, 0, __FILE__, __LINE__); 1836 #ifdef HWPMC_HOOKS 1837 if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 1838 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN); 1839 #endif 1840 } else 1841 thread_unblock_switch(td, mtx); 1842 /* 1843 * Assert that all went well and return. 1844 */ 1845 TDQ_LOCK_ASSERT(tdq, MA_OWNED|MA_NOTRECURSED); 1846 MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 1847 td->td_oncpu = cpuid; 1848 } 1849 1850 /* 1851 * Adjust thread priorities as a result of a nice request. 1852 */ 1853 void 1854 sched_nice(struct proc *p, int nice) 1855 { 1856 struct thread *td; 1857 1858 PROC_LOCK_ASSERT(p, MA_OWNED); 1859 1860 p->p_nice = nice; 1861 FOREACH_THREAD_IN_PROC(p, td) { 1862 thread_lock(td); 1863 sched_priority(td); 1864 sched_prio(td, td->td_base_user_pri); 1865 thread_unlock(td); 1866 } 1867 } 1868 1869 /* 1870 * Record the sleep time for the interactivity scorer. 1871 */ 1872 void 1873 sched_sleep(struct thread *td, int prio) 1874 { 1875 1876 THREAD_LOCK_ASSERT(td, MA_OWNED); 1877 1878 td->td_slptick = ticks; 1879 if (TD_IS_SUSPENDED(td) || prio <= PSOCK) 1880 td->td_flags |= TDF_CANSWAP; 1881 if (static_boost == 1 && prio) 1882 sched_prio(td, prio); 1883 else if (static_boost && td->td_priority > static_boost) 1884 sched_prio(td, static_boost); 1885 } 1886 1887 /* 1888 * Schedule a thread to resume execution and record how long it voluntarily 1889 * slept. We also update the pctcpu, interactivity, and priority. 1890 */ 1891 void 1892 sched_wakeup(struct thread *td) 1893 { 1894 struct td_sched *ts; 1895 int slptick; 1896 1897 THREAD_LOCK_ASSERT(td, MA_OWNED); 1898 ts = td->td_sched; 1899 td->td_flags &= ~TDF_CANSWAP; 1900 /* 1901 * If we slept for more than a tick update our interactivity and 1902 * priority. 1903 */ 1904 slptick = td->td_slptick; 1905 td->td_slptick = 0; 1906 if (slptick && slptick != ticks) { 1907 u_int hzticks; 1908 1909 hzticks = (ticks - slptick) << SCHED_TICK_SHIFT; 1910 ts->ts_slptime += hzticks; 1911 sched_interact_update(td); 1912 sched_pctcpu_update(ts); 1913 } 1914 /* Reset the slice value after we sleep. */ 1915 ts->ts_slice = sched_slice; 1916 sched_add(td, SRQ_BORING); 1917 } 1918 1919 /* 1920 * Penalize the parent for creating a new child and initialize the child's 1921 * priority. 1922 */ 1923 void 1924 sched_fork(struct thread *td, struct thread *child) 1925 { 1926 THREAD_LOCK_ASSERT(td, MA_OWNED); 1927 sched_fork_thread(td, child); 1928 /* 1929 * Penalize the parent and child for forking. 1930 */ 1931 sched_interact_fork(child); 1932 sched_priority(child); 1933 td->td_sched->ts_runtime += tickincr; 1934 sched_interact_update(td); 1935 sched_priority(td); 1936 } 1937 1938 /* 1939 * Fork a new thread, may be within the same process. 1940 */ 1941 void 1942 sched_fork_thread(struct thread *td, struct thread *child) 1943 { 1944 struct td_sched *ts; 1945 struct td_sched *ts2; 1946 1947 THREAD_LOCK_ASSERT(td, MA_OWNED); 1948 /* 1949 * Initialize child. 1950 */ 1951 ts = td->td_sched; 1952 ts2 = child->td_sched; 1953 child->td_lock = TDQ_LOCKPTR(TDQ_SELF()); 1954 child->td_cpuset = cpuset_ref(td->td_cpuset); 1955 ts2->ts_cpu = ts->ts_cpu; 1956 ts2->ts_flags = 0; 1957 /* 1958 * Grab our parents cpu estimation information and priority. 1959 */ 1960 ts2->ts_ticks = ts->ts_ticks; 1961 ts2->ts_ltick = ts->ts_ltick; 1962 ts2->ts_ftick = ts->ts_ftick; 1963 child->td_user_pri = td->td_user_pri; 1964 child->td_base_user_pri = td->td_base_user_pri; 1965 /* 1966 * And update interactivity score. 1967 */ 1968 ts2->ts_slptime = ts->ts_slptime; 1969 ts2->ts_runtime = ts->ts_runtime; 1970 ts2->ts_slice = 1; /* Attempt to quickly learn interactivity. */ 1971 } 1972 1973 /* 1974 * Adjust the priority class of a thread. 1975 */ 1976 void 1977 sched_class(struct thread *td, int class) 1978 { 1979 1980 THREAD_LOCK_ASSERT(td, MA_OWNED); 1981 if (td->td_pri_class == class) 1982 return; 1983 td->td_pri_class = class; 1984 } 1985 1986 /* 1987 * Return some of the child's priority and interactivity to the parent. 1988 */ 1989 void 1990 sched_exit(struct proc *p, struct thread *child) 1991 { 1992 struct thread *td; 1993 1994 CTR3(KTR_SCHED, "sched_exit: %p(%s) prio %d", 1995 child, child->td_name, child->td_priority); 1996 1997 PROC_LOCK_ASSERT(p, MA_OWNED); 1998 td = FIRST_THREAD_IN_PROC(p); 1999 sched_exit_thread(td, child); 2000 } 2001 2002 /* 2003 * Penalize another thread for the time spent on this one. This helps to 2004 * worsen the priority and interactivity of processes which schedule batch 2005 * jobs such as make. This has little effect on the make process itself but 2006 * causes new processes spawned by it to receive worse scores immediately. 2007 */ 2008 void 2009 sched_exit_thread(struct thread *td, struct thread *child) 2010 { 2011 2012 CTR3(KTR_SCHED, "sched_exit_thread: %p(%s) prio %d", 2013 child, child->td_name, child->td_priority); 2014 2015 /* 2016 * Give the child's runtime to the parent without returning the 2017 * sleep time as a penalty to the parent. This causes shells that 2018 * launch expensive things to mark their children as expensive. 2019 */ 2020 thread_lock(td); 2021 td->td_sched->ts_runtime += child->td_sched->ts_runtime; 2022 sched_interact_update(td); 2023 sched_priority(td); 2024 thread_unlock(td); 2025 } 2026 2027 void 2028 sched_preempt(struct thread *td) 2029 { 2030 struct tdq *tdq; 2031 2032 thread_lock(td); 2033 tdq = TDQ_SELF(); 2034 TDQ_LOCK_ASSERT(tdq, MA_OWNED); 2035 tdq->tdq_ipipending = 0; 2036 if (td->td_priority > tdq->tdq_lowpri) { 2037 int flags; 2038 2039 flags = SW_INVOL | SW_PREEMPT; 2040 if (td->td_critnest > 1) 2041 td->td_owepreempt = 1; 2042 else if (TD_IS_IDLETHREAD(td)) 2043 mi_switch(flags | SWT_REMOTEWAKEIDLE, NULL); 2044 else 2045 mi_switch(flags | SWT_REMOTEPREEMPT, NULL); 2046 } 2047 thread_unlock(td); 2048 } 2049 2050 /* 2051 * Fix priorities on return to user-space. Priorities may be elevated due 2052 * to static priorities in msleep() or similar. 2053 */ 2054 void 2055 sched_userret(struct thread *td) 2056 { 2057 /* 2058 * XXX we cheat slightly on the locking here to avoid locking in 2059 * the usual case. Setting td_priority here is essentially an 2060 * incomplete workaround for not setting it properly elsewhere. 2061 * Now that some interrupt handlers are threads, not setting it 2062 * properly elsewhere can clobber it in the window between setting 2063 * it here and returning to user mode, so don't waste time setting 2064 * it perfectly here. 2065 */ 2066 KASSERT((td->td_flags & TDF_BORROWING) == 0, 2067 ("thread with borrowed priority returning to userland")); 2068 if (td->td_priority != td->td_user_pri) { 2069 thread_lock(td); 2070 td->td_priority = td->td_user_pri; 2071 td->td_base_pri = td->td_user_pri; 2072 tdq_setlowpri(TDQ_SELF(), td); 2073 thread_unlock(td); 2074 } 2075 } 2076 2077 /* 2078 * Handle a stathz tick. This is really only relevant for timeshare 2079 * threads. 2080 */ 2081 void 2082 sched_clock(struct thread *td) 2083 { 2084 struct tdq *tdq; 2085 struct td_sched *ts; 2086 2087 THREAD_LOCK_ASSERT(td, MA_OWNED); 2088 tdq = TDQ_SELF(); 2089 #ifdef SMP 2090 /* 2091 * We run the long term load balancer infrequently on the first cpu. 2092 */ 2093 if (balance_tdq == tdq) { 2094 if (balance_ticks && --balance_ticks == 0) 2095 sched_balance(); 2096 } 2097 #endif 2098 /* 2099 * Save the old switch count so we have a record of the last ticks 2100 * activity. Initialize the new switch count based on our load. 2101 * If there is some activity seed it to reflect that. 2102 */ 2103 tdq->tdq_oldswitchcnt = tdq->tdq_switchcnt; 2104 tdq->tdq_switchcnt = tdq->tdq_load; 2105 /* 2106 * Advance the insert index once for each tick to ensure that all 2107 * threads get a chance to run. 2108 */ 2109 if (tdq->tdq_idx == tdq->tdq_ridx) { 2110 tdq->tdq_idx = (tdq->tdq_idx + 1) % RQ_NQS; 2111 if (TAILQ_EMPTY(&tdq->tdq_timeshare.rq_queues[tdq->tdq_ridx])) 2112 tdq->tdq_ridx = tdq->tdq_idx; 2113 } 2114 ts = td->td_sched; 2115 if (td->td_pri_class & PRI_FIFO_BIT) 2116 return; 2117 if (td->td_pri_class == PRI_TIMESHARE) { 2118 /* 2119 * We used a tick; charge it to the thread so 2120 * that we can compute our interactivity. 2121 */ 2122 td->td_sched->ts_runtime += tickincr; 2123 sched_interact_update(td); 2124 sched_priority(td); 2125 } 2126 /* 2127 * We used up one time slice. 2128 */ 2129 if (--ts->ts_slice > 0) 2130 return; 2131 /* 2132 * We're out of time, force a requeue at userret(). 2133 */ 2134 ts->ts_slice = sched_slice; 2135 td->td_flags |= TDF_NEEDRESCHED; 2136 } 2137 2138 /* 2139 * Called once per hz tick. Used for cpu utilization information. This 2140 * is easier than trying to scale based on stathz. 2141 */ 2142 void 2143 sched_tick(void) 2144 { 2145 struct td_sched *ts; 2146 2147 ts = curthread->td_sched; 2148 /* Adjust ticks for pctcpu */ 2149 ts->ts_ticks += 1 << SCHED_TICK_SHIFT; 2150 ts->ts_ltick = ticks; 2151 /* 2152 * Update if we've exceeded our desired tick threshhold by over one 2153 * second. 2154 */ 2155 if (ts->ts_ftick + SCHED_TICK_MAX < ts->ts_ltick) 2156 sched_pctcpu_update(ts); 2157 } 2158 2159 /* 2160 * Return whether the current CPU has runnable tasks. Used for in-kernel 2161 * cooperative idle threads. 2162 */ 2163 int 2164 sched_runnable(void) 2165 { 2166 struct tdq *tdq; 2167 int load; 2168 2169 load = 1; 2170 2171 tdq = TDQ_SELF(); 2172 if ((curthread->td_flags & TDF_IDLETD) != 0) { 2173 if (tdq->tdq_load > 0) 2174 goto out; 2175 } else 2176 if (tdq->tdq_load - 1 > 0) 2177 goto out; 2178 load = 0; 2179 out: 2180 return (load); 2181 } 2182 2183 /* 2184 * Choose the highest priority thread to run. The thread is removed from 2185 * the run-queue while running however the load remains. For SMP we set 2186 * the tdq in the global idle bitmask if it idles here. 2187 */ 2188 struct thread * 2189 sched_choose(void) 2190 { 2191 struct thread *td; 2192 struct tdq *tdq; 2193 2194 tdq = TDQ_SELF(); 2195 TDQ_LOCK_ASSERT(tdq, MA_OWNED); 2196 td = tdq_choose(tdq); 2197 if (td) { 2198 td->td_sched->ts_ltick = ticks; 2199 tdq_runq_rem(tdq, td); 2200 tdq->tdq_lowpri = td->td_priority; 2201 return (td); 2202 } 2203 tdq->tdq_lowpri = PRI_MAX_IDLE; 2204 return (PCPU_GET(idlethread)); 2205 } 2206 2207 /* 2208 * Set owepreempt if necessary. Preemption never happens directly in ULE, 2209 * we always request it once we exit a critical section. 2210 */ 2211 static inline void 2212 sched_setpreempt(struct thread *td) 2213 { 2214 struct thread *ctd; 2215 int cpri; 2216 int pri; 2217 2218 THREAD_LOCK_ASSERT(curthread, MA_OWNED); 2219 2220 ctd = curthread; 2221 pri = td->td_priority; 2222 cpri = ctd->td_priority; 2223 if (pri < cpri) 2224 ctd->td_flags |= TDF_NEEDRESCHED; 2225 if (panicstr != NULL || pri >= cpri || cold || TD_IS_INHIBITED(ctd)) 2226 return; 2227 if (!sched_shouldpreempt(pri, cpri, 0)) 2228 return; 2229 ctd->td_owepreempt = 1; 2230 } 2231 2232 /* 2233 * Add a thread to a thread queue. Select the appropriate runq and add the 2234 * thread to it. This is the internal function called when the tdq is 2235 * predetermined. 2236 */ 2237 void 2238 tdq_add(struct tdq *tdq, struct thread *td, int flags) 2239 { 2240 2241 TDQ_LOCK_ASSERT(tdq, MA_OWNED); 2242 KASSERT((td->td_inhibitors == 0), 2243 ("sched_add: trying to run inhibited thread")); 2244 KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)), 2245 ("sched_add: bad thread state")); 2246 KASSERT(td->td_flags & TDF_INMEM, 2247 ("sched_add: thread swapped out")); 2248 2249 if (td->td_priority < tdq->tdq_lowpri) 2250 tdq->tdq_lowpri = td->td_priority; 2251 tdq_runq_add(tdq, td, flags); 2252 tdq_load_add(tdq, td); 2253 } 2254 2255 /* 2256 * Select the target thread queue and add a thread to it. Request 2257 * preemption or IPI a remote processor if required. 2258 */ 2259 void 2260 sched_add(struct thread *td, int flags) 2261 { 2262 struct tdq *tdq; 2263 #ifdef SMP 2264 int cpu; 2265 #endif 2266 CTR5(KTR_SCHED, "sched_add: %p(%s) prio %d by %p(%s)", 2267 td, td->td_name, td->td_priority, curthread, 2268 curthread->td_name); 2269 THREAD_LOCK_ASSERT(td, MA_OWNED); 2270 /* 2271 * Recalculate the priority before we select the target cpu or 2272 * run-queue. 2273 */ 2274 if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) 2275 sched_priority(td); 2276 #ifdef SMP 2277 /* 2278 * Pick the destination cpu and if it isn't ours transfer to the 2279 * target cpu. 2280 */ 2281 cpu = sched_pickcpu(td, flags); 2282 tdq = sched_setcpu(td, cpu, flags); 2283 tdq_add(tdq, td, flags); 2284 if (cpu != PCPU_GET(cpuid)) { 2285 tdq_notify(tdq, td); 2286 return; 2287 } 2288 #else 2289 tdq = TDQ_SELF(); 2290 TDQ_LOCK(tdq); 2291 /* 2292 * Now that the thread is moving to the run-queue, set the lock 2293 * to the scheduler's lock. 2294 */ 2295 thread_lock_set(td, TDQ_LOCKPTR(tdq)); 2296 tdq_add(tdq, td, flags); 2297 #endif 2298 if (!(flags & SRQ_YIELDING)) 2299 sched_setpreempt(td); 2300 } 2301 2302 /* 2303 * Remove a thread from a run-queue without running it. This is used 2304 * when we're stealing a thread from a remote queue. Otherwise all threads 2305 * exit by calling sched_exit_thread() and sched_throw() themselves. 2306 */ 2307 void 2308 sched_rem(struct thread *td) 2309 { 2310 struct tdq *tdq; 2311 2312 CTR5(KTR_SCHED, "sched_rem: %p(%s) prio %d by %p(%s)", 2313 td, td->td_name, td->td_priority, curthread, 2314 curthread->td_name); 2315 tdq = TDQ_CPU(td->td_sched->ts_cpu); 2316 TDQ_LOCK_ASSERT(tdq, MA_OWNED); 2317 MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 2318 KASSERT(TD_ON_RUNQ(td), 2319 ("sched_rem: thread not on run queue")); 2320 tdq_runq_rem(tdq, td); 2321 tdq_load_rem(tdq, td); 2322 TD_SET_CAN_RUN(td); 2323 if (td->td_priority == tdq->tdq_lowpri) 2324 tdq_setlowpri(tdq, NULL); 2325 } 2326 2327 /* 2328 * Fetch cpu utilization information. Updates on demand. 2329 */ 2330 fixpt_t 2331 sched_pctcpu(struct thread *td) 2332 { 2333 fixpt_t pctcpu; 2334 struct td_sched *ts; 2335 2336 pctcpu = 0; 2337 ts = td->td_sched; 2338 if (ts == NULL) 2339 return (0); 2340 2341 thread_lock(td); 2342 if (ts->ts_ticks) { 2343 int rtick; 2344 2345 sched_pctcpu_update(ts); 2346 /* How many rtick per second ? */ 2347 rtick = min(SCHED_TICK_HZ(ts) / SCHED_TICK_SECS, hz); 2348 pctcpu = (FSCALE * ((FSCALE * rtick)/hz)) >> FSHIFT; 2349 } 2350 thread_unlock(td); 2351 2352 return (pctcpu); 2353 } 2354 2355 /* 2356 * Enforce affinity settings for a thread. Called after adjustments to 2357 * cpumask. 2358 */ 2359 void 2360 sched_affinity(struct thread *td) 2361 { 2362 #ifdef SMP 2363 struct td_sched *ts; 2364 int cpu; 2365 2366 THREAD_LOCK_ASSERT(td, MA_OWNED); 2367 ts = td->td_sched; 2368 if (THREAD_CAN_SCHED(td, ts->ts_cpu)) 2369 return; 2370 if (!TD_IS_RUNNING(td)) 2371 return; 2372 td->td_flags |= TDF_NEEDRESCHED; 2373 if (!THREAD_CAN_MIGRATE(td)) 2374 return; 2375 /* 2376 * Assign the new cpu and force a switch before returning to 2377 * userspace. If the target thread is not running locally send 2378 * an ipi to force the issue. 2379 */ 2380 cpu = ts->ts_cpu; 2381 ts->ts_cpu = sched_pickcpu(td, 0); 2382 if (cpu != PCPU_GET(cpuid)) 2383 ipi_selected(1 << cpu, IPI_PREEMPT); 2384 #endif 2385 } 2386 2387 /* 2388 * Bind a thread to a target cpu. 2389 */ 2390 void 2391 sched_bind(struct thread *td, int cpu) 2392 { 2393 struct td_sched *ts; 2394 2395 THREAD_LOCK_ASSERT(td, MA_OWNED|MA_NOTRECURSED); 2396 ts = td->td_sched; 2397 if (ts->ts_flags & TSF_BOUND) 2398 sched_unbind(td); 2399 ts->ts_flags |= TSF_BOUND; 2400 sched_pin(); 2401 if (PCPU_GET(cpuid) == cpu) 2402 return; 2403 ts->ts_cpu = cpu; 2404 /* When we return from mi_switch we'll be on the correct cpu. */ 2405 mi_switch(SW_VOL, NULL); 2406 } 2407 2408 /* 2409 * Release a bound thread. 2410 */ 2411 void 2412 sched_unbind(struct thread *td) 2413 { 2414 struct td_sched *ts; 2415 2416 THREAD_LOCK_ASSERT(td, MA_OWNED); 2417 ts = td->td_sched; 2418 if ((ts->ts_flags & TSF_BOUND) == 0) 2419 return; 2420 ts->ts_flags &= ~TSF_BOUND; 2421 sched_unpin(); 2422 } 2423 2424 int 2425 sched_is_bound(struct thread *td) 2426 { 2427 THREAD_LOCK_ASSERT(td, MA_OWNED); 2428 return (td->td_sched->ts_flags & TSF_BOUND); 2429 } 2430 2431 /* 2432 * Basic yield call. 2433 */ 2434 void 2435 sched_relinquish(struct thread *td) 2436 { 2437 thread_lock(td); 2438 mi_switch(SW_VOL | SWT_RELINQUISH, NULL); 2439 thread_unlock(td); 2440 } 2441 2442 /* 2443 * Return the total system load. 2444 */ 2445 int 2446 sched_load(void) 2447 { 2448 #ifdef SMP 2449 int total; 2450 int i; 2451 2452 total = 0; 2453 for (i = 0; i <= mp_maxid; i++) 2454 total += TDQ_CPU(i)->tdq_sysload; 2455 return (total); 2456 #else 2457 return (TDQ_SELF()->tdq_sysload); 2458 #endif 2459 } 2460 2461 int 2462 sched_sizeof_proc(void) 2463 { 2464 return (sizeof(struct proc)); 2465 } 2466 2467 int 2468 sched_sizeof_thread(void) 2469 { 2470 return (sizeof(struct thread) + sizeof(struct td_sched)); 2471 } 2472 2473 /* 2474 * The actual idle process. 2475 */ 2476 void 2477 sched_idletd(void *dummy) 2478 { 2479 struct thread *td; 2480 struct tdq *tdq; 2481 int switchcnt; 2482 int i; 2483 2484 td = curthread; 2485 tdq = TDQ_SELF(); 2486 mtx_assert(&Giant, MA_NOTOWNED); 2487 /* ULE relies on preemption for idle interruption. */ 2488 for (;;) { 2489 tdq->tdq_idlestate = TDQ_RUNNING; 2490 #ifdef SMP 2491 if (tdq_idled(tdq) == 0) 2492 continue; 2493 #endif 2494 switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 2495 /* 2496 * If we're switching very frequently, spin while checking 2497 * for load rather than entering a low power state that 2498 * requires an IPI. 2499 */ 2500 if (switchcnt > sched_idlespinthresh) { 2501 for (i = 0; i < sched_idlespins; i++) { 2502 if (tdq->tdq_load) 2503 break; 2504 cpu_spinwait(); 2505 } 2506 } 2507 /* 2508 * We must set our state to IDLE before checking 2509 * tdq_load for the last time to avoid a race with 2510 * tdq_notify(). 2511 */ 2512 if (tdq->tdq_load == 0) { 2513 switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 2514 tdq->tdq_idlestate = TDQ_IDLE; 2515 if (tdq->tdq_load == 0) 2516 cpu_idle(switchcnt > 1); 2517 } 2518 if (tdq->tdq_load) { 2519 thread_lock(td); 2520 mi_switch(SW_VOL | SWT_IDLE, NULL); 2521 thread_unlock(td); 2522 } 2523 } 2524 } 2525 2526 /* 2527 * A CPU is entering for the first time or a thread is exiting. 2528 */ 2529 void 2530 sched_throw(struct thread *td) 2531 { 2532 struct thread *newtd; 2533 struct tdq *tdq; 2534 2535 tdq = TDQ_SELF(); 2536 if (td == NULL) { 2537 /* Correct spinlock nesting and acquire the correct lock. */ 2538 TDQ_LOCK(tdq); 2539 spinlock_exit(); 2540 } else { 2541 MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 2542 tdq_load_rem(tdq, td); 2543 lock_profile_release_lock(&TDQ_LOCKPTR(tdq)->lock_object); 2544 } 2545 KASSERT(curthread->td_md.md_spinlock_count == 1, ("invalid count")); 2546 newtd = choosethread(); 2547 TDQ_LOCKPTR(tdq)->mtx_lock = (uintptr_t)newtd; 2548 PCPU_SET(switchtime, cpu_ticks()); 2549 PCPU_SET(switchticks, ticks); 2550 cpu_throw(td, newtd); /* doesn't return */ 2551 } 2552 2553 /* 2554 * This is called from fork_exit(). Just acquire the correct locks and 2555 * let fork do the rest of the work. 2556 */ 2557 void 2558 sched_fork_exit(struct thread *td) 2559 { 2560 struct td_sched *ts; 2561 struct tdq *tdq; 2562 int cpuid; 2563 2564 /* 2565 * Finish setting up thread glue so that it begins execution in a 2566 * non-nested critical section with the scheduler lock held. 2567 */ 2568 cpuid = PCPU_GET(cpuid); 2569 tdq = TDQ_CPU(cpuid); 2570 ts = td->td_sched; 2571 if (TD_IS_IDLETHREAD(td)) 2572 td->td_lock = TDQ_LOCKPTR(tdq); 2573 MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 2574 td->td_oncpu = cpuid; 2575 TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED); 2576 lock_profile_obtain_lock_success( 2577 &TDQ_LOCKPTR(tdq)->lock_object, 0, 0, __FILE__, __LINE__); 2578 } 2579 2580 SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW, 0, "Scheduler"); 2581 SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "ULE", 0, 2582 "Scheduler name"); 2583 SYSCTL_INT(_kern_sched, OID_AUTO, slice, CTLFLAG_RW, &sched_slice, 0, 2584 "Slice size for timeshare threads"); 2585 SYSCTL_INT(_kern_sched, OID_AUTO, interact, CTLFLAG_RW, &sched_interact, 0, 2586 "Interactivity score threshold"); 2587 SYSCTL_INT(_kern_sched, OID_AUTO, preempt_thresh, CTLFLAG_RW, &preempt_thresh, 2588 0,"Min priority for preemption, lower priorities have greater precedence"); 2589 SYSCTL_INT(_kern_sched, OID_AUTO, static_boost, CTLFLAG_RW, &static_boost, 2590 0,"Controls whether static kernel priorities are assigned to sleeping threads."); 2591 SYSCTL_INT(_kern_sched, OID_AUTO, idlespins, CTLFLAG_RW, &sched_idlespins, 2592 0,"Number of times idle will spin waiting for new work."); 2593 SYSCTL_INT(_kern_sched, OID_AUTO, idlespinthresh, CTLFLAG_RW, &sched_idlespinthresh, 2594 0,"Threshold before we will permit idle spinning."); 2595 #ifdef SMP 2596 SYSCTL_INT(_kern_sched, OID_AUTO, affinity, CTLFLAG_RW, &affinity, 0, 2597 "Number of hz ticks to keep thread affinity for"); 2598 SYSCTL_INT(_kern_sched, OID_AUTO, balance, CTLFLAG_RW, &rebalance, 0, 2599 "Enables the long-term load balancer"); 2600 SYSCTL_INT(_kern_sched, OID_AUTO, balance_interval, CTLFLAG_RW, 2601 &balance_interval, 0, 2602 "Average frequency in stathz ticks to run the long-term balancer"); 2603 SYSCTL_INT(_kern_sched, OID_AUTO, steal_htt, CTLFLAG_RW, &steal_htt, 0, 2604 "Steals work from another hyper-threaded core on idle"); 2605 SYSCTL_INT(_kern_sched, OID_AUTO, steal_idle, CTLFLAG_RW, &steal_idle, 0, 2606 "Attempts to steal work from other cores before idling"); 2607 SYSCTL_INT(_kern_sched, OID_AUTO, steal_thresh, CTLFLAG_RW, &steal_thresh, 0, 2608 "Minimum load on remote cpu before we'll steal"); 2609 #endif 2610 2611 /* ps compat. All cpu percentages from ULE are weighted. */ 2612 static int ccpu = 0; 2613 SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, ""); 2614