FreeBSD kernel kern code
sched_ule.c
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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: head/sys/kern/sched_ule.c 279999 2015-03-14 18:42:30Z ian $");
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/limits.h>
50 #include <sys/lock.h>
51 #include <sys/mutex.h>
52 #include <sys/proc.h>
53 #include <sys/resource.h>
54 #include <sys/resourcevar.h>
55 #include <sys/sched.h>
56 #include <sys/sdt.h>
57 #include <sys/smp.h>
58 #include <sys/sx.h>
59 #include <sys/sysctl.h>
60 #include <sys/sysproto.h>
61 #include <sys/turnstile.h>
62 #include <sys/umtx.h>
63 #include <sys/vmmeter.h>
64 #include <sys/cpuset.h>
65 #include <sys/sbuf.h>
66 
67 #ifdef HWPMC_HOOKS
68 #include <sys/pmckern.h>
69 #endif
70 
71 #ifdef KDTRACE_HOOKS
72 #include <sys/dtrace_bsd.h>
73 int dtrace_vtime_active;
74 dtrace_vtime_switch_func_t dtrace_vtime_switch_func;
75 #endif
76 
77 #include <machine/cpu.h>
78 #include <machine/smp.h>
79 
80 #define KTR_ULE 0
81 
82 #define TS_NAME_LEN (MAXCOMLEN + sizeof(" td ") + sizeof(__XSTRING(UINT_MAX)))
83 #define TDQ_NAME_LEN (sizeof("sched lock ") + sizeof(__XSTRING(MAXCPU)))
84 #define TDQ_LOADNAME_LEN (sizeof("CPU ") + sizeof(__XSTRING(MAXCPU)) - 1 + sizeof(" load"))
85 
86 /*
87  * Thread scheduler specific section. All fields are protected
88  * by the thread lock.
89  */
90 struct td_sched {
91  struct runq *ts_runq; /* Run-queue we're queued on. */
92  short ts_flags; /* TSF_* flags. */
93  int ts_cpu; /* CPU that we have affinity for. */
94  int ts_rltick; /* Real last tick, for affinity. */
95  int ts_slice; /* Ticks of slice remaining. */
96  u_int ts_slptime; /* Number of ticks we vol. slept */
97  u_int ts_runtime; /* Number of ticks we were running */
98  int ts_ltick; /* Last tick that we were running on */
99  int ts_ftick; /* First tick that we were running on */
100  int ts_ticks; /* Tick count */
101 #ifdef KTR
102  char ts_name[TS_NAME_LEN];
103 #endif
104 };
105 /* flags kept in ts_flags */
106 #define TSF_BOUND 0x0001 /* Thread can not migrate. */
107 #define TSF_XFERABLE 0x0002 /* Thread was added as transferable. */
108 
109 static struct td_sched td_sched0;
110 
111 #define THREAD_CAN_MIGRATE(td) ((td)->td_pinned == 0)
112 #define THREAD_CAN_SCHED(td, cpu) \
113  CPU_ISSET((cpu), &(td)->td_cpuset->cs_mask)
114 
115 /*
116  * Priority ranges used for interactive and non-interactive timeshare
117  * threads. The timeshare priorities are split up into four ranges.
118  * The first range handles interactive threads. The last three ranges
119  * (NHALF, x, and NHALF) handle non-interactive threads with the outer
120  * ranges supporting nice values.
121  */
122 #define PRI_TIMESHARE_RANGE (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE + 1)
123 #define PRI_INTERACT_RANGE ((PRI_TIMESHARE_RANGE - SCHED_PRI_NRESV) / 2)
124 #define PRI_BATCH_RANGE (PRI_TIMESHARE_RANGE - PRI_INTERACT_RANGE)
125 
126 #define PRI_MIN_INTERACT PRI_MIN_TIMESHARE
127 #define PRI_MAX_INTERACT (PRI_MIN_TIMESHARE + PRI_INTERACT_RANGE - 1)
128 #define PRI_MIN_BATCH (PRI_MIN_TIMESHARE + PRI_INTERACT_RANGE)
129 #define PRI_MAX_BATCH PRI_MAX_TIMESHARE
130 
131 /*
132  * Cpu percentage computation macros and defines.
133  *
134  * SCHED_TICK_SECS: Number of seconds to average the cpu usage across.
135  * SCHED_TICK_TARG: Number of hz ticks to average the cpu usage across.
136  * SCHED_TICK_MAX: Maximum number of ticks before scaling back.
137  * SCHED_TICK_SHIFT: Shift factor to avoid rounding away results.
138  * SCHED_TICK_HZ: Compute the number of hz ticks for a given ticks count.
139  * SCHED_TICK_TOTAL: Gives the amount of time we've been recording ticks.
140  */
141 #define SCHED_TICK_SECS 10
142 #define SCHED_TICK_TARG (hz * SCHED_TICK_SECS)
143 #define SCHED_TICK_MAX (SCHED_TICK_TARG + hz)
144 #define SCHED_TICK_SHIFT 10
145 #define SCHED_TICK_HZ(ts) ((ts)->ts_ticks >> SCHED_TICK_SHIFT)
146 #define SCHED_TICK_TOTAL(ts) (max((ts)->ts_ltick - (ts)->ts_ftick, hz))
147 
148 /*
149  * These macros determine priorities for non-interactive threads. They are
150  * assigned a priority based on their recent cpu utilization as expressed
151  * by the ratio of ticks to the tick total. NHALF priorities at the start
152  * and end of the MIN to MAX timeshare range are only reachable with negative
153  * or positive nice respectively.
154  *
155  * PRI_RANGE: Priority range for utilization dependent priorities.
156  * PRI_NRESV: Number of nice values.
157  * PRI_TICKS: Compute a priority in PRI_RANGE from the ticks count and total.
158  * PRI_NICE: Determines the part of the priority inherited from nice.
159  */
160 #define SCHED_PRI_NRESV (PRIO_MAX - PRIO_MIN)
161 #define SCHED_PRI_NHALF (SCHED_PRI_NRESV / 2)
162 #define SCHED_PRI_MIN (PRI_MIN_BATCH + SCHED_PRI_NHALF)
163 #define SCHED_PRI_MAX (PRI_MAX_BATCH - SCHED_PRI_NHALF)
164 #define SCHED_PRI_RANGE (SCHED_PRI_MAX - SCHED_PRI_MIN + 1)
165 #define SCHED_PRI_TICKS(ts) \
166  (SCHED_TICK_HZ((ts)) / \
167  (roundup(SCHED_TICK_TOTAL((ts)), SCHED_PRI_RANGE) / SCHED_PRI_RANGE))
168 #define SCHED_PRI_NICE(nice) (nice)
169 
170 /*
171  * These determine the interactivity of a process. Interactivity differs from
172  * cpu utilization in that it expresses the voluntary time slept vs time ran
173  * while cpu utilization includes all time not running. This more accurately
174  * models the intent of the thread.
175  *
176  * SLP_RUN_MAX: Maximum amount of sleep time + run time we'll accumulate
177  * before throttling back.
178  * SLP_RUN_FORK: Maximum slp+run time to inherit at fork time.
179  * INTERACT_MAX: Maximum interactivity value. Smaller is better.
180  * INTERACT_THRESH: Threshold for placement on the current runq.
181  */
182 #define SCHED_SLP_RUN_MAX ((hz * 5) << SCHED_TICK_SHIFT)
183 #define SCHED_SLP_RUN_FORK ((hz / 2) << SCHED_TICK_SHIFT)
184 #define SCHED_INTERACT_MAX (100)
185 #define SCHED_INTERACT_HALF (SCHED_INTERACT_MAX / 2)
186 #define SCHED_INTERACT_THRESH (30)
187 
188 /*
189  * These parameters determine the slice behavior for batch work.
190  */
191 #define SCHED_SLICE_DEFAULT_DIVISOR 10 /* ~94 ms, 12 stathz ticks. */
192 #define SCHED_SLICE_MIN_DIVISOR 6 /* DEFAULT/MIN = ~16 ms. */
193 
194 /* Flags kept in td_flags. */
195 #define TDF_SLICEEND TDF_SCHED2 /* Thread time slice is over. */
196 
197 /*
198  * tickincr: Converts a stathz tick into a hz domain scaled by
199  * the shift factor. Without the shift the error rate
200  * due to rounding would be unacceptably high.
201  * realstathz: stathz is sometimes 0 and run off of hz.
202  * sched_slice: Runtime of each thread before rescheduling.
203  * preempt_thresh: Priority threshold for preemption and remote IPIs.
204  */
206 static int tickincr = 8 << SCHED_TICK_SHIFT;
207 static int realstathz = 127; /* reset during boot. */
208 static int sched_slice = 10; /* reset during boot. */
209 static int sched_slice_min = 1; /* reset during boot. */
210 #ifdef PREEMPTION
211 #ifdef FULL_PREEMPTION
212 static int preempt_thresh = PRI_MAX_IDLE;
213 #else
214 static int preempt_thresh = PRI_MIN_KERN;
215 #endif
216 #else
217 static int preempt_thresh = 0;
218 #endif
220 static int sched_idlespins = 10000;
221 static int sched_idlespinthresh = -1;
222 
223 /*
224  * tdq - per processor runqs and statistics. All fields are protected by the
225  * tdq_lock. The load and lowpri may be accessed without to avoid excess
226  * locking in sched_pickcpu();
227  */
228 struct tdq {
229  /*
230  * Ordered to improve efficiency of cpu_search() and switch().
231  * tdq_lock is padded to avoid false sharing with tdq_load and
232  * tdq_cpu_idle.
233  */
234  struct mtx_padalign tdq_lock; /* run queue lock. */
235  struct cpu_group *tdq_cg; /* Pointer to cpu topology. */
236  volatile int tdq_load; /* Aggregate load. */
237  volatile int tdq_cpu_idle; /* cpu_idle() is active. */
238  int tdq_sysload; /* For loadavg, !ITHD load. */
239  int tdq_transferable; /* Transferable thread count. */
240  short tdq_switchcnt; /* Switches this tick. */
241  short tdq_oldswitchcnt; /* Switches last tick. */
242  u_char tdq_lowpri; /* Lowest priority thread. */
243  u_char tdq_ipipending; /* IPI pending. */
244  u_char tdq_idx; /* Current insert index. */
245  u_char tdq_ridx; /* Current removal index. */
246  struct runq tdq_realtime; /* real-time run queue. */
247  struct runq tdq_timeshare; /* timeshare run queue. */
248  struct runq tdq_idle; /* Queue of IDLE threads. */
250 #ifdef KTR
251  char tdq_loadname[TDQ_LOADNAME_LEN];
252 #endif
253 } __aligned(64);
254 
255 /* Idle thread states and config. */
256 #define TDQ_RUNNING 1
257 #define TDQ_IDLE 2
258 
259 #ifdef SMP
260 struct cpu_group *cpu_top; /* CPU topology */
261 
262 #define SCHED_AFFINITY_DEFAULT (max(1, hz / 1000))
263 #define SCHED_AFFINITY(ts, t) ((ts)->ts_rltick > ticks - ((t) * affinity))
264 
265 /*
266  * Run-time tunables.
267  */
268 static int rebalance = 1;
269 static int balance_interval = 128; /* Default set in sched_initticks(). */
270 static int affinity;
271 static int steal_idle = 1;
272 static int steal_thresh = 2;
273 
274 /*
275  * One thread queue per processor.
276  */
277 static struct tdq tdq_cpu[MAXCPU];
278 static struct tdq *balance_tdq;
279 static int balance_ticks;
280 static DPCPU_DEFINE(uint32_t, randomval);
281 
282 #define TDQ_SELF() (&tdq_cpu[PCPU_GET(cpuid)])
283 #define TDQ_CPU(x) (&tdq_cpu[(x)])
284 #define TDQ_ID(x) ((int)((x) - tdq_cpu))
285 #else /* !SMP */
286 static struct tdq tdq_cpu;
287 
288 #define TDQ_ID(x) (0)
289 #define TDQ_SELF() (&tdq_cpu)
290 #define TDQ_CPU(x) (&tdq_cpu)
291 #endif
292 
293 #define TDQ_LOCK_ASSERT(t, type) mtx_assert(TDQ_LOCKPTR((t)), (type))
294 #define TDQ_LOCK(t) mtx_lock_spin(TDQ_LOCKPTR((t)))
295 #define TDQ_LOCK_FLAGS(t, f) mtx_lock_spin_flags(TDQ_LOCKPTR((t)), (f))
296 #define TDQ_UNLOCK(t) mtx_unlock_spin(TDQ_LOCKPTR((t)))
297 #define TDQ_LOCKPTR(t) ((struct mtx *)(&(t)->tdq_lock))
298 
299 static void sched_priority(struct thread *);
300 static void sched_thread_priority(struct thread *, u_char);
301 static int sched_interact_score(struct thread *);
302 static void sched_interact_update(struct thread *);
303 static void sched_interact_fork(struct thread *);
304 static void sched_pctcpu_update(struct td_sched *, int);
305 
306 /* Operations on per processor queues */
307 static struct thread *tdq_choose(struct tdq *);
308 static void tdq_setup(struct tdq *);
309 static void tdq_load_add(struct tdq *, struct thread *);
310 static void tdq_load_rem(struct tdq *, struct thread *);
311 static __inline void tdq_runq_add(struct tdq *, struct thread *, int);
312 static __inline void tdq_runq_rem(struct tdq *, struct thread *);
313 static inline int sched_shouldpreempt(int, int, int);
314 void tdq_print(int cpu);
315 static void runq_print(struct runq *rq);
316 static void tdq_add(struct tdq *, struct thread *, int);
317 #ifdef SMP
318 static int tdq_move(struct tdq *, struct tdq *);
319 static int tdq_idled(struct tdq *);
320 static void tdq_notify(struct tdq *, struct thread *);
321 static struct thread *tdq_steal(struct tdq *, int);
322 static struct thread *runq_steal(struct runq *, int);
323 static int sched_pickcpu(struct thread *, int);
324 static void sched_balance(void);
325 static int sched_balance_pair(struct tdq *, struct tdq *);
326 static inline struct tdq *sched_setcpu(struct thread *, int, int);
327 static inline void thread_unblock_switch(struct thread *, struct mtx *);
328 static struct mtx *sched_switch_migrate(struct tdq *, struct thread *, int);
329 static int sysctl_kern_sched_topology_spec(SYSCTL_HANDLER_ARGS);
330 static int sysctl_kern_sched_topology_spec_internal(struct sbuf *sb,
331  struct cpu_group *cg, int indent);
332 #endif
333 
334 static void sched_setup(void *dummy);
335 SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL);
336 
337 static void sched_initticks(void *dummy);
338 SYSINIT(sched_initticks, SI_SUB_CLOCKS, SI_ORDER_THIRD, sched_initticks,
339  NULL);
340 
341 SDT_PROVIDER_DEFINE(sched);
342 
343 SDT_PROBE_DEFINE3(sched, , , change__pri, "struct thread *",
344  "struct proc *", "uint8_t");
345 SDT_PROBE_DEFINE3(sched, , , dequeue, "struct thread *",
346  "struct proc *", "void *");
347 SDT_PROBE_DEFINE4(sched, , , enqueue, "struct thread *",
348  "struct proc *", "void *", "int");
349 SDT_PROBE_DEFINE4(sched, , , lend__pri, "struct thread *",
350  "struct proc *", "uint8_t", "struct thread *");
351 SDT_PROBE_DEFINE2(sched, , , load__change, "int", "int");
352 SDT_PROBE_DEFINE2(sched, , , off__cpu, "struct thread *",
353  "struct proc *");
354 SDT_PROBE_DEFINE(sched, , , on__cpu);
355 SDT_PROBE_DEFINE(sched, , , remain__cpu);
356 SDT_PROBE_DEFINE2(sched, , , surrender, "struct thread *",
357  "struct proc *");
358 
359 #ifdef SMP
360 /*
361  * We need some randomness. Implement the classic Linear Congruential
362  * generator X_{n+1}=(aX_n+c) mod m. These values are optimized for
363  * m = 2^32, a = 69069 and c = 5. We only return the upper 16 bits
364  * of the random state (in the low bits of our answer) to return
365  * the maximum randomness.
366  */
367 static uint32_t
368 sched_random(void)
369 {
370  uint32_t *rndptr;
371 
372  rndptr = DPCPU_PTR(randomval);
373  *rndptr = *rndptr * 69069 + 5;
374 
375  return (*rndptr >> 16);
376 }
377 #endif
378 
379 /*
380  * Print the threads waiting on a run-queue.
381  */
382 static void
383 runq_print(struct runq *rq)
384 {
385  struct rqhead *rqh;
386  struct thread *td;
387  int pri;
388  int j;
389  int i;
390 
391  for (i = 0; i < RQB_LEN; i++) {
392  printf("\t\trunq bits %d 0x%zx\n",
393  i, rq->rq_status.rqb_bits[i]);
394  for (j = 0; j < RQB_BPW; j++)
395  if (rq->rq_status.rqb_bits[i] & (1ul << j)) {
396  pri = j + (i << RQB_L2BPW);
397  rqh = &rq->rq_queues[pri];
398  TAILQ_FOREACH(td, rqh, td_runq) {
399  printf("\t\t\ttd %p(%s) priority %d rqindex %d pri %d\n",
400  td, td->td_name, td->td_priority,
401  td->td_rqindex, pri);
402  }
403  }
404  }
405 }
406 
407 /*
408  * Print the status of a per-cpu thread queue. Should be a ddb show cmd.
409  */
410 void
411 tdq_print(int cpu)
412 {
413  struct tdq *tdq;
414 
415  tdq = TDQ_CPU(cpu);
416 
417  printf("tdq %d:\n", TDQ_ID(tdq));
418  printf("\tlock %p\n", TDQ_LOCKPTR(tdq));
419  printf("\tLock name: %s\n", tdq->tdq_name);
420  printf("\tload: %d\n", tdq->tdq_load);
421  printf("\tswitch cnt: %d\n", tdq->tdq_switchcnt);
422  printf("\told switch cnt: %d\n", tdq->tdq_oldswitchcnt);
423  printf("\ttimeshare idx: %d\n", tdq->tdq_idx);
424  printf("\ttimeshare ridx: %d\n", tdq->tdq_ridx);
425  printf("\tload transferable: %d\n", tdq->tdq_transferable);
426  printf("\tlowest priority: %d\n", tdq->tdq_lowpri);
427  printf("\trealtime runq:\n");
428  runq_print(&tdq->tdq_realtime);
429  printf("\ttimeshare runq:\n");
430  runq_print(&tdq->tdq_timeshare);
431  printf("\tidle runq:\n");
432  runq_print(&tdq->tdq_idle);
433 }
434 
435 static inline int
436 sched_shouldpreempt(int pri, int cpri, int remote)
437 {
438  /*
439  * If the new priority is not better than the current priority there is
440  * nothing to do.
441  */
442  if (pri >= cpri)
443  return (0);
444  /*
445  * Always preempt idle.
446  */
447  if (cpri >= PRI_MIN_IDLE)
448  return (1);
449  /*
450  * If preemption is disabled don't preempt others.
451  */
452  if (preempt_thresh == 0)
453  return (0);
454  /*
455  * Preempt if we exceed the threshold.
456  */
457  if (pri <= preempt_thresh)
458  return (1);
459  /*
460  * If we're interactive or better and there is non-interactive
461  * or worse running preempt only remote processors.
462  */
463  if (remote && pri <= PRI_MAX_INTERACT && cpri > PRI_MAX_INTERACT)
464  return (1);
465  return (0);
466 }
467 
468 /*
469  * Add a thread to the actual run-queue. Keeps transferable counts up to
470  * date with what is actually on the run-queue. Selects the correct
471  * queue position for timeshare threads.
472  */
473 static __inline void
474 tdq_runq_add(struct tdq *tdq, struct thread *td, int flags)
475 {
476  struct td_sched *ts;
477  u_char pri;
478 
479  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
480  THREAD_LOCK_ASSERT(td, MA_OWNED);
481 
482  pri = td->td_priority;
483  ts = td->td_sched;
484  TD_SET_RUNQ(td);
485  if (THREAD_CAN_MIGRATE(td)) {
486  tdq->tdq_transferable++;
487  ts->ts_flags |= TSF_XFERABLE;
488  }
489  if (pri < PRI_MIN_BATCH) {
490  ts->ts_runq = &tdq->tdq_realtime;
491  } else if (pri <= PRI_MAX_BATCH) {
492  ts->ts_runq = &tdq->tdq_timeshare;
493  KASSERT(pri <= PRI_MAX_BATCH && pri >= PRI_MIN_BATCH,
494  ("Invalid priority %d on timeshare runq", pri));
495  /*
496  * This queue contains only priorities between MIN and MAX
497  * realtime. Use the whole queue to represent these values.
498  */
499  if ((flags & (SRQ_BORROWING|SRQ_PREEMPTED)) == 0) {
500  pri = RQ_NQS * (pri - PRI_MIN_BATCH) / PRI_BATCH_RANGE;
501  pri = (pri + tdq->tdq_idx) % RQ_NQS;
502  /*
503  * This effectively shortens the queue by one so we
504  * can have a one slot difference between idx and
505  * ridx while we wait for threads to drain.
506  */
507  if (tdq->tdq_ridx != tdq->tdq_idx &&
508  pri == tdq->tdq_ridx)
509  pri = (unsigned char)(pri - 1) % RQ_NQS;
510  } else
511  pri = tdq->tdq_ridx;
512  runq_add_pri(ts->ts_runq, td, pri, flags);
513  return;
514  } else
515  ts->ts_runq = &tdq->tdq_idle;
516  runq_add(ts->ts_runq, td, flags);
517 }
518 
519 /*
520  * Remove a thread from a run-queue. This typically happens when a thread
521  * is selected to run. Running threads are not on the queue and the
522  * transferable count does not reflect them.
523  */
524 static __inline void
525 tdq_runq_rem(struct tdq *tdq, struct thread *td)
526 {
527  struct td_sched *ts;
528 
529  ts = td->td_sched;
530  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
531  KASSERT(ts->ts_runq != NULL,
532  ("tdq_runq_remove: thread %p null ts_runq", td));
533  if (ts->ts_flags & TSF_XFERABLE) {
534  tdq->tdq_transferable--;
535  ts->ts_flags &= ~TSF_XFERABLE;
536  }
537  if (ts->ts_runq == &tdq->tdq_timeshare) {
538  if (tdq->tdq_idx != tdq->tdq_ridx)
539  runq_remove_idx(ts->ts_runq, td, &tdq->tdq_ridx);
540  else
541  runq_remove_idx(ts->ts_runq, td, NULL);
542  } else
543  runq_remove(ts->ts_runq, td);
544 }
545 
546 /*
547  * Load is maintained for all threads RUNNING and ON_RUNQ. Add the load
548  * for this thread to the referenced thread queue.
549  */
550 static void
551 tdq_load_add(struct tdq *tdq, struct thread *td)
552 {
553 
554  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
555  THREAD_LOCK_ASSERT(td, MA_OWNED);
556 
557  tdq->tdq_load++;
558  if ((td->td_flags & TDF_NOLOAD) == 0)
559  tdq->tdq_sysload++;
560  KTR_COUNTER0(KTR_SCHED, "load", tdq->tdq_loadname, tdq->tdq_load);
561  SDT_PROBE2(sched, , , load__change, (int)TDQ_ID(tdq), tdq->tdq_load);
562 }
563 
564 /*
565  * Remove the load from a thread that is transitioning to a sleep state or
566  * exiting.
567  */
568 static void
569 tdq_load_rem(struct tdq *tdq, struct thread *td)
570 {
571 
572  THREAD_LOCK_ASSERT(td, MA_OWNED);
573  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
574  KASSERT(tdq->tdq_load != 0,
575  ("tdq_load_rem: Removing with 0 load on queue %d", TDQ_ID(tdq)));
576 
577  tdq->tdq_load--;
578  if ((td->td_flags & TDF_NOLOAD) == 0)
579  tdq->tdq_sysload--;
580  KTR_COUNTER0(KTR_SCHED, "load", tdq->tdq_loadname, tdq->tdq_load);
581  SDT_PROBE2(sched, , , load__change, (int)TDQ_ID(tdq), tdq->tdq_load);
582 }
583 
584 /*
585  * Bound timeshare latency by decreasing slice size as load increases. We
586  * consider the maximum latency as the sum of the threads waiting to run
587  * aside from curthread and target no more than sched_slice latency but
588  * no less than sched_slice_min runtime.
589  */
590 static inline int
591 tdq_slice(struct tdq *tdq)
592 {
593  int load;
594 
595  /*
596  * It is safe to use sys_load here because this is called from
597  * contexts where timeshare threads are running and so there
598  * cannot be higher priority load in the system.
599  */
600  load = tdq->tdq_sysload - 1;
601  if (load >= SCHED_SLICE_MIN_DIVISOR)
602  return (sched_slice_min);
603  if (load <= 1)
604  return (sched_slice);
605  return (sched_slice / load);
606 }
607 
608 /*
609  * Set lowpri to its exact value by searching the run-queue and
610  * evaluating curthread. curthread may be passed as an optimization.
611  */
612 static void
613 tdq_setlowpri(struct tdq *tdq, struct thread *ctd)
614 {
615  struct thread *td;
616 
617  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
618  if (ctd == NULL)
619  ctd = pcpu_find(TDQ_ID(tdq))->pc_curthread;
620  td = tdq_choose(tdq);
621  if (td == NULL || td->td_priority > ctd->td_priority)
622  tdq->tdq_lowpri = ctd->td_priority;
623  else
624  tdq->tdq_lowpri = td->td_priority;
625 }
626 
627 #ifdef SMP
628 struct cpu_search {
629  cpuset_t cs_mask;
630  u_int cs_prefer;
631  int cs_pri; /* Min priority for low. */
632  int cs_limit; /* Max load for low, min load for high. */
633  int cs_cpu;
634  int cs_load;
635 };
636 
637 #define CPU_SEARCH_LOWEST 0x1
638 #define CPU_SEARCH_HIGHEST 0x2
639 #define CPU_SEARCH_BOTH (CPU_SEARCH_LOWEST|CPU_SEARCH_HIGHEST)
640 
641 #define CPUSET_FOREACH(cpu, mask) \
642  for ((cpu) = 0; (cpu) <= mp_maxid; (cpu)++) \
643  if (CPU_ISSET(cpu, &mask))
644 
645 static __always_inline int cpu_search(const struct cpu_group *cg,
646  struct cpu_search *low, struct cpu_search *high, const int match);
647 int __noinline cpu_search_lowest(const struct cpu_group *cg,
648  struct cpu_search *low);
649 int __noinline cpu_search_highest(const struct cpu_group *cg,
650  struct cpu_search *high);
651 int __noinline cpu_search_both(const struct cpu_group *cg,
652  struct cpu_search *low, struct cpu_search *high);
653 
654 /*
655  * Search the tree of cpu_groups for the lowest or highest loaded cpu
656  * according to the match argument. This routine actually compares the
657  * load on all paths through the tree and finds the least loaded cpu on
658  * the least loaded path, which may differ from the least loaded cpu in
659  * the system. This balances work among caches and busses.
660  *
661  * This inline is instantiated in three forms below using constants for the
662  * match argument. It is reduced to the minimum set for each case. It is
663  * also recursive to the depth of the tree.
664  */
665 static __always_inline int
666 cpu_search(const struct cpu_group *cg, struct cpu_search *low,
667  struct cpu_search *high, const int match)
668 {
669  struct cpu_search lgroup;
670  struct cpu_search hgroup;
671  cpuset_t cpumask;
672  struct cpu_group *child;
673  struct tdq *tdq;
674  int cpu, i, hload, lload, load, total, rnd;
675 
676  total = 0;
677  cpumask = cg->cg_mask;
678  if (match & CPU_SEARCH_LOWEST) {
679  lload = INT_MAX;
680  lgroup = *low;
681  }
682  if (match & CPU_SEARCH_HIGHEST) {
683  hload = INT_MIN;
684  hgroup = *high;
685  }
686 
687  /* Iterate through the child CPU groups and then remaining CPUs. */
688  for (i = cg->cg_children, cpu = mp_maxid; ; ) {
689  if (i == 0) {
690 #ifdef HAVE_INLINE_FFSL
691  cpu = CPU_FFS(&cpumask) - 1;
692 #else
693  while (cpu >= 0 && !CPU_ISSET(cpu, &cpumask))
694  cpu--;
695 #endif
696  if (cpu < 0)
697  break;
698  child = NULL;
699  } else
700  child = &cg->cg_child[i - 1];
701 
702  if (match & CPU_SEARCH_LOWEST)
703  lgroup.cs_cpu = -1;
704  if (match & CPU_SEARCH_HIGHEST)
705  hgroup.cs_cpu = -1;
706  if (child) { /* Handle child CPU group. */
707  CPU_NAND(&cpumask, &child->cg_mask);
708  switch (match) {
709  case CPU_SEARCH_LOWEST:
710  load = cpu_search_lowest(child, &lgroup);
711  break;
712  case CPU_SEARCH_HIGHEST:
713  load = cpu_search_highest(child, &hgroup);
714  break;
715  case CPU_SEARCH_BOTH:
716  load = cpu_search_both(child, &lgroup, &hgroup);
717  break;
718  }
719  } else { /* Handle child CPU. */
720  CPU_CLR(cpu, &cpumask);
721  tdq = TDQ_CPU(cpu);
722  load = tdq->tdq_load * 256;
723  rnd = sched_random() % 32;
724  if (match & CPU_SEARCH_LOWEST) {
725  if (cpu == low->cs_prefer)
726  load -= 64;
727  /* If that CPU is allowed and get data. */
728  if (tdq->tdq_lowpri > lgroup.cs_pri &&
729  tdq->tdq_load <= lgroup.cs_limit &&
730  CPU_ISSET(cpu, &lgroup.cs_mask)) {
731  lgroup.cs_cpu = cpu;
732  lgroup.cs_load = load - rnd;
733  }
734  }
735  if (match & CPU_SEARCH_HIGHEST)
736  if (tdq->tdq_load >= hgroup.cs_limit &&
737  tdq->tdq_transferable &&
738  CPU_ISSET(cpu, &hgroup.cs_mask)) {
739  hgroup.cs_cpu = cpu;
740  hgroup.cs_load = load - rnd;
741  }
742  }
743  total += load;
744 
745  /* We have info about child item. Compare it. */
746  if (match & CPU_SEARCH_LOWEST) {
747  if (lgroup.cs_cpu >= 0 &&
748  (load < lload ||
749  (load == lload && lgroup.cs_load < low->cs_load))) {
750  lload = load;
751  low->cs_cpu = lgroup.cs_cpu;
752  low->cs_load = lgroup.cs_load;
753  }
754  }
755  if (match & CPU_SEARCH_HIGHEST)
756  if (hgroup.cs_cpu >= 0 &&
757  (load > hload ||
758  (load == hload && hgroup.cs_load > high->cs_load))) {
759  hload = load;
760  high->cs_cpu = hgroup.cs_cpu;
761  high->cs_load = hgroup.cs_load;
762  }
763  if (child) {
764  i--;
765  if (i == 0 && CPU_EMPTY(&cpumask))
766  break;
767  }
768 #ifndef HAVE_INLINE_FFSL
769  else
770  cpu--;
771 #endif
772  }
773  return (total);
774 }
775 
776 /*
777  * cpu_search instantiations must pass constants to maintain the inline
778  * optimization.
779  */
780 int
781 cpu_search_lowest(const struct cpu_group *cg, struct cpu_search *low)
782 {
783  return cpu_search(cg, low, NULL, CPU_SEARCH_LOWEST);
784 }
785 
786 int
787 cpu_search_highest(const struct cpu_group *cg, struct cpu_search *high)
788 {
789  return cpu_search(cg, NULL, high, CPU_SEARCH_HIGHEST);
790 }
791 
792 int
793 cpu_search_both(const struct cpu_group *cg, struct cpu_search *low,
794  struct cpu_search *high)
795 {
796  return cpu_search(cg, low, high, CPU_SEARCH_BOTH);
797 }
798 
799 /*
800  * Find the cpu with the least load via the least loaded path that has a
801  * lowpri greater than pri pri. A pri of -1 indicates any priority is
802  * acceptable.
803  */
804 static inline int
805 sched_lowest(const struct cpu_group *cg, cpuset_t mask, int pri, int maxload,
806  int prefer)
807 {
808  struct cpu_search low;
809 
810  low.cs_cpu = -1;
811  low.cs_prefer = prefer;
812  low.cs_mask = mask;
813  low.cs_pri = pri;
814  low.cs_limit = maxload;
815  cpu_search_lowest(cg, &low);
816  return low.cs_cpu;
817 }
818 
819 /*
820  * Find the cpu with the highest load via the highest loaded path.
821  */
822 static inline int
823 sched_highest(const struct cpu_group *cg, cpuset_t mask, int minload)
824 {
825  struct cpu_search high;
826 
827  high.cs_cpu = -1;
828  high.cs_mask = mask;
829  high.cs_limit = minload;
830  cpu_search_highest(cg, &high);
831  return high.cs_cpu;
832 }
833 
834 static void
835 sched_balance_group(struct cpu_group *cg)
836 {
837  cpuset_t hmask, lmask;
838  int high, low, anylow;
839 
840  CPU_FILL(&hmask);
841  for (;;) {
842  high = sched_highest(cg, hmask, 1);
843  /* Stop if there is no more CPU with transferrable threads. */
844  if (high == -1)
845  break;
846  CPU_CLR(high, &hmask);
847  CPU_COPY(&hmask, &lmask);
848  /* Stop if there is no more CPU left for low. */
849  if (CPU_EMPTY(&lmask))
850  break;
851  anylow = 1;
852 nextlow:
853  low = sched_lowest(cg, lmask, -1,
854  TDQ_CPU(high)->tdq_load - 1, high);
855  /* Stop if we looked well and found no less loaded CPU. */
856  if (anylow && low == -1)
857  break;
858  /* Go to next high if we found no less loaded CPU. */
859  if (low == -1)
860  continue;
861  /* Transfer thread from high to low. */
862  if (sched_balance_pair(TDQ_CPU(high), TDQ_CPU(low))) {
863  /* CPU that got thread can no longer be a donor. */
864  CPU_CLR(low, &hmask);
865  } else {
866  /*
867  * If failed, then there is no threads on high
868  * that can run on this low. Drop low from low
869  * mask and look for different one.
870  */
871  CPU_CLR(low, &lmask);
872  anylow = 0;
873  goto nextlow;
874  }
875  }
876 }
877 
878 static void
879 sched_balance(void)
880 {
881  struct tdq *tdq;
882 
883  if (smp_started == 0 || rebalance == 0)
884  return;
885 
886  balance_ticks = max(balance_interval / 2, 1) +
887  (sched_random() % balance_interval);
888  tdq = TDQ_SELF();
889  TDQ_UNLOCK(tdq);
890  sched_balance_group(cpu_top);
891  TDQ_LOCK(tdq);
892 }
893 
894 /*
895  * Lock two thread queues using their address to maintain lock order.
896  */
897 static void
898 tdq_lock_pair(struct tdq *one, struct tdq *two)
899 {
900  if (one < two) {
901  TDQ_LOCK(one);
902  TDQ_LOCK_FLAGS(two, MTX_DUPOK);
903  } else {
904  TDQ_LOCK(two);
905  TDQ_LOCK_FLAGS(one, MTX_DUPOK);
906  }
907 }
908 
909 /*
910  * Unlock two thread queues. Order is not important here.
911  */
912 static void
913 tdq_unlock_pair(struct tdq *one, struct tdq *two)
914 {
915  TDQ_UNLOCK(one);
916  TDQ_UNLOCK(two);
917 }
918 
919 /*
920  * Transfer load between two imbalanced thread queues.
921  */
922 static int
923 sched_balance_pair(struct tdq *high, struct tdq *low)
924 {
925  int moved;
926  int cpu;
927 
928  tdq_lock_pair(high, low);
929  moved = 0;
930  /*
931  * Determine what the imbalance is and then adjust that to how many
932  * threads we actually have to give up (transferable).
933  */
934  if (high->tdq_transferable != 0 && high->tdq_load > low->tdq_load &&
935  (moved = tdq_move(high, low)) > 0) {
936  /*
937  * In case the target isn't the current cpu IPI it to force a
938  * reschedule with the new workload.
939  */
940  cpu = TDQ_ID(low);
941  if (cpu != PCPU_GET(cpuid))
942  ipi_cpu(cpu, IPI_PREEMPT);
943  }
944  tdq_unlock_pair(high, low);
945  return (moved);
946 }
947 
948 /*
949  * Move a thread from one thread queue to another.
950  */
951 static int
952 tdq_move(struct tdq *from, struct tdq *to)
953 {
954  struct td_sched *ts;
955  struct thread *td;
956  struct tdq *tdq;
957  int cpu;
958 
959  TDQ_LOCK_ASSERT(from, MA_OWNED);
960  TDQ_LOCK_ASSERT(to, MA_OWNED);
961 
962  tdq = from;
963  cpu = TDQ_ID(to);
964  td = tdq_steal(tdq, cpu);
965  if (td == NULL)
966  return (0);
967  ts = td->td_sched;
968  /*
969  * Although the run queue is locked the thread may be blocked. Lock
970  * it to clear this and acquire the run-queue lock.
971  */
972  thread_lock(td);
973  /* Drop recursive lock on from acquired via thread_lock(). */
974  TDQ_UNLOCK(from);
975  sched_rem(td);
976  ts->ts_cpu = cpu;
977  td->td_lock = TDQ_LOCKPTR(to);
978  tdq_add(to, td, SRQ_YIELDING);
979  return (1);
980 }
981 
982 /*
983  * This tdq has idled. Try to steal a thread from another cpu and switch
984  * to it.
985  */
986 static int
987 tdq_idled(struct tdq *tdq)
988 {
989  struct cpu_group *cg;
990  struct tdq *steal;
991  cpuset_t mask;
992  int thresh;
993  int cpu;
994 
995  if (smp_started == 0 || steal_idle == 0)
996  return (1);
997  CPU_FILL(&mask);
998  CPU_CLR(PCPU_GET(cpuid), &mask);
999  /* We don't want to be preempted while we're iterating. */
1000  spinlock_enter();
1001  for (cg = tdq->tdq_cg; cg != NULL; ) {
1002  if ((cg->cg_flags & CG_FLAG_THREAD) == 0)
1003  thresh = steal_thresh;
1004  else
1005  thresh = 1;
1006  cpu = sched_highest(cg, mask, thresh);
1007  if (cpu == -1) {
1008  cg = cg->cg_parent;
1009  continue;
1010  }
1011  steal = TDQ_CPU(cpu);
1012  CPU_CLR(cpu, &mask);
1013  tdq_lock_pair(tdq, steal);
1014  if (steal->tdq_load < thresh || steal->tdq_transferable == 0) {
1015  tdq_unlock_pair(tdq, steal);
1016  continue;
1017  }
1018  /*
1019  * If a thread was added while interrupts were disabled don't
1020  * steal one here. If we fail to acquire one due to affinity
1021  * restrictions loop again with this cpu removed from the
1022  * set.
1023  */
1024  if (tdq->tdq_load == 0 && tdq_move(steal, tdq) == 0) {
1025  tdq_unlock_pair(tdq, steal);
1026  continue;
1027  }
1028  spinlock_exit();
1029  TDQ_UNLOCK(steal);
1030  mi_switch(SW_VOL | SWT_IDLE, NULL);
1031  thread_unlock(curthread);
1032 
1033  return (0);
1034  }
1035  spinlock_exit();
1036  return (1);
1037 }
1038 
1039 /*
1040  * Notify a remote cpu of new work. Sends an IPI if criteria are met.
1041  */
1042 static void
1043 tdq_notify(struct tdq *tdq, struct thread *td)
1044 {
1045  struct thread *ctd;
1046  int pri;
1047  int cpu;
1048 
1049  if (tdq->tdq_ipipending)
1050  return;
1051  cpu = td->td_sched->ts_cpu;
1052  pri = td->td_priority;
1053  ctd = pcpu_find(cpu)->pc_curthread;
1054  if (!sched_shouldpreempt(pri, ctd->td_priority, 1))
1055  return;
1056 
1057  /*
1058  * Make sure that our caller's earlier update to tdq_load is
1059  * globally visible before we read tdq_cpu_idle. Idle thread
1060  * accesses both of them without locks, and the order is important.
1061  */
1062  mb();
1063 
1064  if (TD_IS_IDLETHREAD(ctd)) {
1065  /*
1066  * If the MD code has an idle wakeup routine try that before
1067  * falling back to IPI.
1068  */
1069  if (!tdq->tdq_cpu_idle || cpu_idle_wakeup(cpu))
1070  return;
1071  }
1072  tdq->tdq_ipipending = 1;
1073  ipi_cpu(cpu, IPI_PREEMPT);
1074 }
1075 
1076 /*
1077  * Steals load from a timeshare queue. Honors the rotating queue head
1078  * index.
1079  */
1080 static struct thread *
1081 runq_steal_from(struct runq *rq, int cpu, u_char start)
1082 {
1083  struct rqbits *rqb;
1084  struct rqhead *rqh;
1085  struct thread *td, *first;
1086  int bit;
1087  int i;
1088 
1089  rqb = &rq->rq_status;
1090  bit = start & (RQB_BPW -1);
1091  first = NULL;
1092 again:
1093  for (i = RQB_WORD(start); i < RQB_LEN; bit = 0, i++) {
1094  if (rqb->rqb_bits[i] == 0)
1095  continue;
1096  if (bit == 0)
1097  bit = RQB_FFS(rqb->rqb_bits[i]);
1098  for (; bit < RQB_BPW; bit++) {
1099  if ((rqb->rqb_bits[i] & (1ul << bit)) == 0)
1100  continue;
1101  rqh = &rq->rq_queues[bit + (i << RQB_L2BPW)];
1102  TAILQ_FOREACH(td, rqh, td_runq) {
1103  if (first && THREAD_CAN_MIGRATE(td) &&
1104  THREAD_CAN_SCHED(td, cpu))
1105  return (td);
1106  first = td;
1107  }
1108  }
1109  }
1110  if (start != 0) {
1111  start = 0;
1112  goto again;
1113  }
1114 
1115  if (first && THREAD_CAN_MIGRATE(first) &&
1116  THREAD_CAN_SCHED(first, cpu))
1117  return (first);
1118  return (NULL);
1119 }
1120 
1121 /*
1122  * Steals load from a standard linear queue.
1123  */
1124 static struct thread *
1125 runq_steal(struct runq *rq, int cpu)
1126 {
1127  struct rqhead *rqh;
1128  struct rqbits *rqb;
1129  struct thread *td;
1130  int word;
1131  int bit;
1132 
1133  rqb = &rq->rq_status;
1134  for (word = 0; word < RQB_LEN; word++) {
1135  if (rqb->rqb_bits[word] == 0)
1136  continue;
1137  for (bit = 0; bit < RQB_BPW; bit++) {
1138  if ((rqb->rqb_bits[word] & (1ul << bit)) == 0)
1139  continue;
1140  rqh = &rq->rq_queues[bit + (word << RQB_L2BPW)];
1141  TAILQ_FOREACH(td, rqh, td_runq)
1142  if (THREAD_CAN_MIGRATE(td) &&
1143  THREAD_CAN_SCHED(td, cpu))
1144  return (td);
1145  }
1146  }
1147  return (NULL);
1148 }
1149 
1150 /*
1151  * Attempt to steal a thread in priority order from a thread queue.
1152  */
1153 static struct thread *
1154 tdq_steal(struct tdq *tdq, int cpu)
1155 {
1156  struct thread *td;
1157 
1158  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
1159  if ((td = runq_steal(&tdq->tdq_realtime, cpu)) != NULL)
1160  return (td);
1161  if ((td = runq_steal_from(&tdq->tdq_timeshare,
1162  cpu, tdq->tdq_ridx)) != NULL)
1163  return (td);
1164  return (runq_steal(&tdq->tdq_idle, cpu));
1165 }
1166 
1167 /*
1168  * Sets the thread lock and ts_cpu to match the requested cpu. Unlocks the
1169  * current lock and returns with the assigned queue locked.
1170  */
1171 static inline struct tdq *
1172 sched_setcpu(struct thread *td, int cpu, int flags)
1173 {
1174 
1175  struct tdq *tdq;
1176 
1177  THREAD_LOCK_ASSERT(td, MA_OWNED);
1178  tdq = TDQ_CPU(cpu);
1179  td->td_sched->ts_cpu = cpu;
1180  /*
1181  * If the lock matches just return the queue.
1182  */
1183  if (td->td_lock == TDQ_LOCKPTR(tdq))
1184  return (tdq);
1185 #ifdef notyet
1186  /*
1187  * If the thread isn't running its lockptr is a
1188  * turnstile or a sleepqueue. We can just lock_set without
1189  * blocking.
1190  */
1191  if (TD_CAN_RUN(td)) {
1192  TDQ_LOCK(tdq);
1193  thread_lock_set(td, TDQ_LOCKPTR(tdq));
1194  return (tdq);
1195  }
1196 #endif
1197  /*
1198  * The hard case, migration, we need to block the thread first to
1199  * prevent order reversals with other cpus locks.
1200  */
1201  spinlock_enter();
1202  thread_lock_block(td);
1203  TDQ_LOCK(tdq);
1204  thread_lock_unblock(td, TDQ_LOCKPTR(tdq));
1205  spinlock_exit();
1206  return (tdq);
1207 }
1208 
1209 SCHED_STAT_DEFINE(pickcpu_intrbind, "Soft interrupt binding");
1210 SCHED_STAT_DEFINE(pickcpu_idle_affinity, "Picked idle cpu based on affinity");
1211 SCHED_STAT_DEFINE(pickcpu_affinity, "Picked cpu based on affinity");
1212 SCHED_STAT_DEFINE(pickcpu_lowest, "Selected lowest load");
1213 SCHED_STAT_DEFINE(pickcpu_local, "Migrated to current cpu");
1214 SCHED_STAT_DEFINE(pickcpu_migration, "Selection may have caused migration");
1215 
1216 static int
1217 sched_pickcpu(struct thread *td, int flags)
1218 {
1219  struct cpu_group *cg, *ccg;
1220  struct td_sched *ts;
1221  struct tdq *tdq;
1222  cpuset_t mask;
1223  int cpu, pri, self;
1224 
1225  self = PCPU_GET(cpuid);
1226  ts = td->td_sched;
1227  if (smp_started == 0)
1228  return (self);
1229  /*
1230  * Don't migrate a running thread from sched_switch().
1231  */
1232  if ((flags & SRQ_OURSELF) || !THREAD_CAN_MIGRATE(td))
1233  return (ts->ts_cpu);
1234  /*
1235  * Prefer to run interrupt threads on the processors that generate
1236  * the interrupt.
1237  */
1238  pri = td->td_priority;
1239  if (td->td_priority <= PRI_MAX_ITHD && THREAD_CAN_SCHED(td, self) &&
1240  curthread->td_intr_nesting_level && ts->ts_cpu != self) {
1241  SCHED_STAT_INC(pickcpu_intrbind);
1242  ts->ts_cpu = self;
1243  if (TDQ_CPU(self)->tdq_lowpri > pri) {
1244  SCHED_STAT_INC(pickcpu_affinity);
1245  return (ts->ts_cpu);
1246  }
1247  }
1248  /*
1249  * If the thread can run on the last cpu and the affinity has not
1250  * expired or it is idle run it there.
1251  */
1252  tdq = TDQ_CPU(ts->ts_cpu);
1253  cg = tdq->tdq_cg;
1254  if (THREAD_CAN_SCHED(td, ts->ts_cpu) &&
1255  tdq->tdq_lowpri >= PRI_MIN_IDLE &&
1256  SCHED_AFFINITY(ts, CG_SHARE_L2)) {
1257  if (cg->cg_flags & CG_FLAG_THREAD) {
1258  CPUSET_FOREACH(cpu, cg->cg_mask) {
1259  if (TDQ_CPU(cpu)->tdq_lowpri < PRI_MIN_IDLE)
1260  break;
1261  }
1262  } else
1263  cpu = INT_MAX;
1264  if (cpu > mp_maxid) {
1265  SCHED_STAT_INC(pickcpu_idle_affinity);
1266  return (ts->ts_cpu);
1267  }
1268  }
1269  /*
1270  * Search for the last level cache CPU group in the tree.
1271  * Skip caches with expired affinity time and SMT groups.
1272  * Affinity to higher level caches will be handled less aggressively.
1273  */
1274  for (ccg = NULL; cg != NULL; cg = cg->cg_parent) {
1275  if (cg->cg_flags & CG_FLAG_THREAD)
1276  continue;
1277  if (!SCHED_AFFINITY(ts, cg->cg_level))
1278  continue;
1279  ccg = cg;
1280  }
1281  if (ccg != NULL)
1282  cg = ccg;
1283  cpu = -1;
1284  /* Search the group for the less loaded idle CPU we can run now. */
1285  mask = td->td_cpuset->cs_mask;
1286  if (cg != NULL && cg != cpu_top &&
1287  CPU_CMP(&cg->cg_mask, &cpu_top->cg_mask) != 0)
1288  cpu = sched_lowest(cg, mask, max(pri, PRI_MAX_TIMESHARE),
1289  INT_MAX, ts->ts_cpu);
1290  /* Search globally for the less loaded CPU we can run now. */
1291  if (cpu == -1)
1292  cpu = sched_lowest(cpu_top, mask, pri, INT_MAX, ts->ts_cpu);
1293  /* Search globally for the less loaded CPU. */
1294  if (cpu == -1)
1295  cpu = sched_lowest(cpu_top, mask, -1, INT_MAX, ts->ts_cpu);
1296  KASSERT(cpu != -1, ("sched_pickcpu: Failed to find a cpu."));
1297  /*
1298  * Compare the lowest loaded cpu to current cpu.
1299  */
1300  if (THREAD_CAN_SCHED(td, self) && TDQ_CPU(self)->tdq_lowpri > pri &&
1301  TDQ_CPU(cpu)->tdq_lowpri < PRI_MIN_IDLE &&
1302  TDQ_CPU(self)->tdq_load <= TDQ_CPU(cpu)->tdq_load + 1) {
1303  SCHED_STAT_INC(pickcpu_local);
1304  cpu = self;
1305  } else
1306  SCHED_STAT_INC(pickcpu_lowest);
1307  if (cpu != ts->ts_cpu)
1308  SCHED_STAT_INC(pickcpu_migration);
1309  return (cpu);
1310 }
1311 #endif
1312 
1313 /*
1314  * Pick the highest priority task we have and return it.
1315  */
1316 static struct thread *
1317 tdq_choose(struct tdq *tdq)
1318 {
1319  struct thread *td;
1320 
1321  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
1322  td = runq_choose(&tdq->tdq_realtime);
1323  if (td != NULL)
1324  return (td);
1325  td = runq_choose_from(&tdq->tdq_timeshare, tdq->tdq_ridx);
1326  if (td != NULL) {
1327  KASSERT(td->td_priority >= PRI_MIN_BATCH,
1328  ("tdq_choose: Invalid priority on timeshare queue %d",
1329  td->td_priority));
1330  return (td);
1331  }
1332  td = runq_choose(&tdq->tdq_idle);
1333  if (td != NULL) {
1334  KASSERT(td->td_priority >= PRI_MIN_IDLE,
1335  ("tdq_choose: Invalid priority on idle queue %d",
1336  td->td_priority));
1337  return (td);
1338  }
1339 
1340  return (NULL);
1341 }
1342 
1343 /*
1344  * Initialize a thread queue.
1345  */
1346 static void
1347 tdq_setup(struct tdq *tdq)
1348 {
1349 
1350  if (bootverbose)
1351  printf("ULE: setup cpu %d\n", TDQ_ID(tdq));
1352  runq_init(&tdq->tdq_realtime);
1353  runq_init(&tdq->tdq_timeshare);
1354  runq_init(&tdq->tdq_idle);
1355  snprintf(tdq->tdq_name, sizeof(tdq->tdq_name),
1356  "sched lock %d", (int)TDQ_ID(tdq));
1357  mtx_init(&tdq->tdq_lock, tdq->tdq_name, "sched lock",
1358  MTX_SPIN | MTX_RECURSE);
1359 #ifdef KTR
1360  snprintf(tdq->tdq_loadname, sizeof(tdq->tdq_loadname),
1361  "CPU %d load", (int)TDQ_ID(tdq));
1362 #endif
1363 }
1364 
1365 #ifdef SMP
1366 static void
1367 sched_setup_smp(void)
1368 {
1369  struct tdq *tdq;
1370  int i;
1371 
1372  cpu_top = smp_topo();
1373  CPU_FOREACH(i) {
1374  tdq = TDQ_CPU(i);
1375  tdq_setup(tdq);
1376  tdq->tdq_cg = smp_topo_find(cpu_top, i);
1377  if (tdq->tdq_cg == NULL)
1378  panic("Can't find cpu group for %d\n", i);
1379  }
1380  balance_tdq = TDQ_SELF();
1381  sched_balance();
1382 }
1383 #endif
1384 
1385 /*
1386  * Setup the thread queues and initialize the topology based on MD
1387  * information.
1388  */
1389 static void
1391 {
1392  struct tdq *tdq;
1393 
1394  tdq = TDQ_SELF();
1395 #ifdef SMP
1396  sched_setup_smp();
1397 #else
1398  tdq_setup(tdq);
1399 #endif
1400 
1401  /* Add thread0's load since it's running. */
1402  TDQ_LOCK(tdq);
1403  thread0.td_lock = TDQ_LOCKPTR(TDQ_SELF());
1404  tdq_load_add(tdq, &thread0);
1405  tdq->tdq_lowpri = thread0.td_priority;
1406  TDQ_UNLOCK(tdq);
1407 }
1408 
1409 /*
1410  * This routine determines time constants after stathz and hz are setup.
1411  */
1412 /* ARGSUSED */
1413 static void
1415 {
1416  int incr;
1417 
1418  realstathz = stathz ? stathz : hz;
1421  hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) /
1422  realstathz);
1423 
1424  /*
1425  * tickincr is shifted out by 10 to avoid rounding errors due to
1426  * hz not being evenly divisible by stathz on all platforms.
1427  */
1428  incr = (hz << SCHED_TICK_SHIFT) / realstathz;
1429  /*
1430  * This does not work for values of stathz that are more than
1431  * 1 << SCHED_TICK_SHIFT * hz. In practice this does not happen.
1432  */
1433  if (incr == 0)
1434  incr = 1;
1435  tickincr = incr;
1436 #ifdef SMP
1437  /*
1438  * Set the default balance interval now that we know
1439  * what realstathz is.
1440  */
1441  balance_interval = realstathz;
1442  affinity = SCHED_AFFINITY_DEFAULT;
1443 #endif
1444  if (sched_idlespinthresh < 0)
1445  sched_idlespinthresh = 2 * max(10000, 6 * hz) / realstathz;
1446 }
1447 
1448 
1449 /*
1450  * This is the core of the interactivity algorithm. Determines a score based
1451  * on past behavior. It is the ratio of sleep time to run time scaled to
1452  * a [0, 100] integer. This is the voluntary sleep time of a process, which
1453  * differs from the cpu usage because it does not account for time spent
1454  * waiting on a run-queue. Would be prettier if we had floating point.
1455  */
1456 static int
1457 sched_interact_score(struct thread *td)
1458 {
1459  struct td_sched *ts;
1460  int div;
1461 
1462  ts = td->td_sched;
1463  /*
1464  * The score is only needed if this is likely to be an interactive
1465  * task. Don't go through the expense of computing it if there's
1466  * no chance.
1467  */
1469  ts->ts_runtime >= ts->ts_slptime)
1470  return (SCHED_INTERACT_HALF);
1471 
1472  if (ts->ts_runtime > ts->ts_slptime) {
1473  div = max(1, ts->ts_runtime / SCHED_INTERACT_HALF);
1474  return (SCHED_INTERACT_HALF +
1475  (SCHED_INTERACT_HALF - (ts->ts_slptime / div)));
1476  }
1477  if (ts->ts_slptime > ts->ts_runtime) {
1478  div = max(1, ts->ts_slptime / SCHED_INTERACT_HALF);
1479  return (ts->ts_runtime / div);
1480  }
1481  /* runtime == slptime */
1482  if (ts->ts_runtime)
1483  return (SCHED_INTERACT_HALF);
1484 
1485  /*
1486  * This can happen if slptime and runtime are 0.
1487  */
1488  return (0);
1489 
1490 }
1491 
1492 /*
1493  * Scale the scheduling priority according to the "interactivity" of this
1494  * process.
1495  */
1496 static void
1497 sched_priority(struct thread *td)
1498 {
1499  int score;
1500  int pri;
1501 
1502  if (PRI_BASE(td->td_pri_class) != PRI_TIMESHARE)
1503  return;
1504  /*
1505  * If the score is interactive we place the thread in the realtime
1506  * queue with a priority that is less than kernel and interrupt
1507  * priorities. These threads are not subject to nice restrictions.
1508  *
1509  * Scores greater than this are placed on the normal timeshare queue
1510  * where the priority is partially decided by the most recent cpu
1511  * utilization and the rest is decided by nice value.
1512  *
1513  * The nice value of the process has a linear effect on the calculated
1514  * score. Negative nice values make it easier for a thread to be
1515  * considered interactive.
1516  */
1517  score = imax(0, sched_interact_score(td) + td->td_proc->p_nice);
1518  if (score < sched_interact) {
1519  pri = PRI_MIN_INTERACT;
1520  pri += ((PRI_MAX_INTERACT - PRI_MIN_INTERACT + 1) /
1521  sched_interact) * score;
1522  KASSERT(pri >= PRI_MIN_INTERACT && pri <= PRI_MAX_INTERACT,
1523  ("sched_priority: invalid interactive priority %d score %d",
1524  pri, score));
1525  } else {
1526  pri = SCHED_PRI_MIN;
1527  if (td->td_sched->ts_ticks)
1528  pri += min(SCHED_PRI_TICKS(td->td_sched),
1529  SCHED_PRI_RANGE - 1);
1530  pri += SCHED_PRI_NICE(td->td_proc->p_nice);
1531  KASSERT(pri >= PRI_MIN_BATCH && pri <= PRI_MAX_BATCH,
1532  ("sched_priority: invalid priority %d: nice %d, "
1533  "ticks %d ftick %d ltick %d tick pri %d",
1534  pri, td->td_proc->p_nice, td->td_sched->ts_ticks,
1535  td->td_sched->ts_ftick, td->td_sched->ts_ltick,
1536  SCHED_PRI_TICKS(td->td_sched)));
1537  }
1538  sched_user_prio(td, pri);
1539 
1540  return;
1541 }
1542 
1543 /*
1544  * This routine enforces a maximum limit on the amount of scheduling history
1545  * kept. It is called after either the slptime or runtime is adjusted. This
1546  * function is ugly due to integer math.
1547  */
1548 static void
1549 sched_interact_update(struct thread *td)
1550 {
1551  struct td_sched *ts;
1552  u_int sum;
1553 
1554  ts = td->td_sched;
1555  sum = ts->ts_runtime + ts->ts_slptime;
1556  if (sum < SCHED_SLP_RUN_MAX)
1557  return;
1558  /*
1559  * This only happens from two places:
1560  * 1) We have added an unusual amount of run time from fork_exit.
1561  * 2) We have added an unusual amount of sleep time from sched_sleep().
1562  */
1563  if (sum > SCHED_SLP_RUN_MAX * 2) {
1564  if (ts->ts_runtime > ts->ts_slptime) {
1566  ts->ts_slptime = 1;
1567  } else {
1569  ts->ts_runtime = 1;
1570  }
1571  return;
1572  }
1573  /*
1574  * If we have exceeded by more than 1/5th then the algorithm below
1575  * will not bring us back into range. Dividing by two here forces
1576  * us into the range of [4/5 * SCHED_INTERACT_MAX, SCHED_INTERACT_MAX]
1577  */
1578  if (sum > (SCHED_SLP_RUN_MAX / 5) * 6) {
1579  ts->ts_runtime /= 2;
1580  ts->ts_slptime /= 2;
1581  return;
1582  }
1583  ts->ts_runtime = (ts->ts_runtime / 5) * 4;
1584  ts->ts_slptime = (ts->ts_slptime / 5) * 4;
1585 }
1586 
1587 /*
1588  * Scale back the interactivity history when a child thread is created. The
1589  * history is inherited from the parent but the thread may behave totally
1590  * differently. For example, a shell spawning a compiler process. We want
1591  * to learn that the compiler is behaving badly very quickly.
1592  */
1593 static void
1594 sched_interact_fork(struct thread *td)
1595 {
1596  int ratio;
1597  int sum;
1598 
1599  sum = td->td_sched->ts_runtime + td->td_sched->ts_slptime;
1600  if (sum > SCHED_SLP_RUN_FORK) {
1601  ratio = sum / SCHED_SLP_RUN_FORK;
1602  td->td_sched->ts_runtime /= ratio;
1603  td->td_sched->ts_slptime /= ratio;
1604  }
1605 }
1606 
1607 /*
1608  * Called from proc0_init() to setup the scheduler fields.
1609  */
1610 void
1612 {
1613 
1614  /*
1615  * Set up the scheduler specific parts of proc0.
1616  */
1617  proc0.p_sched = NULL; /* XXX */
1618  thread0.td_sched = &td_sched0;
1621  td_sched0.ts_slice = 0;
1622 }
1623 
1624 /*
1625  * This is only somewhat accurate since given many processes of the same
1626  * priority they will switch when their slices run out, which will be
1627  * at most sched_slice stathz ticks.
1628  */
1629 int
1631 {
1632 
1633  /* Convert sched_slice from stathz to hz. */
1634  return (imax(1, (sched_slice * hz + realstathz / 2) / realstathz));
1635 }
1636 
1637 /*
1638  * Update the percent cpu tracking information when it is requested or
1639  * the total history exceeds the maximum. We keep a sliding history of
1640  * tick counts that slowly decays. This is less precise than the 4BSD
1641  * mechanism since it happens with less regular and frequent events.
1642  */
1643 static void
1644 sched_pctcpu_update(struct td_sched *ts, int run)
1645 {
1646  int t = ticks;
1647 
1648  if (t - ts->ts_ltick >= SCHED_TICK_TARG) {
1649  ts->ts_ticks = 0;
1650  ts->ts_ftick = t - SCHED_TICK_TARG;
1651  } else if (t - ts->ts_ftick >= SCHED_TICK_MAX) {
1652  ts->ts_ticks = (ts->ts_ticks / (ts->ts_ltick - ts->ts_ftick)) *
1653  (ts->ts_ltick - (t - SCHED_TICK_TARG));
1654  ts->ts_ftick = t - SCHED_TICK_TARG;
1655  }
1656  if (run)
1657  ts->ts_ticks += (t - ts->ts_ltick) << SCHED_TICK_SHIFT;
1658  ts->ts_ltick = t;
1659 }
1660 
1661 /*
1662  * Adjust the priority of a thread. Move it to the appropriate run-queue
1663  * if necessary. This is the back-end for several priority related
1664  * functions.
1665  */
1666 static void
1667 sched_thread_priority(struct thread *td, u_char prio)
1668 {
1669  struct td_sched *ts;
1670  struct tdq *tdq;
1671  int oldpri;
1672 
1673  KTR_POINT3(KTR_SCHED, "thread", sched_tdname(td), "prio",
1674  "prio:%d", td->td_priority, "new prio:%d", prio,
1675  KTR_ATTR_LINKED, sched_tdname(curthread));
1676  SDT_PROBE3(sched, , , change__pri, td, td->td_proc, prio);
1677  if (td != curthread && prio < td->td_priority) {
1678  KTR_POINT3(KTR_SCHED, "thread", sched_tdname(curthread),
1679  "lend prio", "prio:%d", td->td_priority, "new prio:%d",
1680  prio, KTR_ATTR_LINKED, sched_tdname(td));
1681  SDT_PROBE4(sched, , , lend__pri, td, td->td_proc, prio,
1682  curthread);
1683  }
1684  ts = td->td_sched;
1685  THREAD_LOCK_ASSERT(td, MA_OWNED);
1686  if (td->td_priority == prio)
1687  return;
1688  /*
1689  * If the priority has been elevated due to priority
1690  * propagation, we may have to move ourselves to a new
1691  * queue. This could be optimized to not re-add in some
1692  * cases.
1693  */
1694  if (TD_ON_RUNQ(td) && prio < td->td_priority) {
1695  sched_rem(td);
1696  td->td_priority = prio;
1697  sched_add(td, SRQ_BORROWING);
1698  return;
1699  }
1700  /*
1701  * If the thread is currently running we may have to adjust the lowpri
1702  * information so other cpus are aware of our current priority.
1703  */
1704  if (TD_IS_RUNNING(td)) {
1705  tdq = TDQ_CPU(ts->ts_cpu);
1706  oldpri = td->td_priority;
1707  td->td_priority = prio;
1708  if (prio < tdq->tdq_lowpri)
1709  tdq->tdq_lowpri = prio;
1710  else if (tdq->tdq_lowpri == oldpri)
1711  tdq_setlowpri(tdq, td);
1712  return;
1713  }
1714  td->td_priority = prio;
1715 }
1716 
1717 /*
1718  * Update a thread's priority when it is lent another thread's
1719  * priority.
1720  */
1721 void
1722 sched_lend_prio(struct thread *td, u_char prio)
1723 {
1724 
1725  td->td_flags |= TDF_BORROWING;
1726  sched_thread_priority(td, prio);
1727 }
1728 
1729 /*
1730  * Restore a thread's priority when priority propagation is
1731  * over. The prio argument is the minimum priority the thread
1732  * needs to have to satisfy other possible priority lending
1733  * requests. If the thread's regular priority is less
1734  * important than prio, the thread will keep a priority boost
1735  * of prio.
1736  */
1737 void
1738 sched_unlend_prio(struct thread *td, u_char prio)
1739 {
1740  u_char base_pri;
1741 
1742  if (td->td_base_pri >= PRI_MIN_TIMESHARE &&
1743  td->td_base_pri <= PRI_MAX_TIMESHARE)
1744  base_pri = td->td_user_pri;
1745  else
1746  base_pri = td->td_base_pri;
1747  if (prio >= base_pri) {
1748  td->td_flags &= ~TDF_BORROWING;
1749  sched_thread_priority(td, base_pri);
1750  } else
1751  sched_lend_prio(td, prio);
1752 }
1753 
1754 /*
1755  * Standard entry for setting the priority to an absolute value.
1756  */
1757 void
1758 sched_prio(struct thread *td, u_char prio)
1759 {
1760  u_char oldprio;
1761 
1762  /* First, update the base priority. */
1763  td->td_base_pri = prio;
1764 
1765  /*
1766  * If the thread is borrowing another thread's priority, don't
1767  * ever lower the priority.
1768  */
1769  if (td->td_flags & TDF_BORROWING && td->td_priority < prio)
1770  return;
1771 
1772  /* Change the real priority. */
1773  oldprio = td->td_priority;
1774  sched_thread_priority(td, prio);
1775 
1776  /*
1777  * If the thread is on a turnstile, then let the turnstile update
1778  * its state.
1779  */
1780  if (TD_ON_LOCK(td) && oldprio != prio)
1781  turnstile_adjust(td, oldprio);
1782 }
1783 
1784 /*
1785  * Set the base user priority, does not effect current running priority.
1786  */
1787 void
1788 sched_user_prio(struct thread *td, u_char prio)
1789 {
1790 
1791  td->td_base_user_pri = prio;
1792  if (td->td_lend_user_pri <= prio)
1793  return;
1794  td->td_user_pri = prio;
1795 }
1796 
1797 void
1798 sched_lend_user_prio(struct thread *td, u_char prio)
1799 {
1800 
1801  THREAD_LOCK_ASSERT(td, MA_OWNED);
1802  td->td_lend_user_pri = prio;
1803  td->td_user_pri = min(prio, td->td_base_user_pri);
1804  if (td->td_priority > td->td_user_pri)
1805  sched_prio(td, td->td_user_pri);
1806  else if (td->td_priority != td->td_user_pri)
1807  td->td_flags |= TDF_NEEDRESCHED;
1808 }
1809 
1810 /*
1811  * Handle migration from sched_switch(). This happens only for
1812  * cpu binding.
1813  */
1814 static struct mtx *
1815 sched_switch_migrate(struct tdq *tdq, struct thread *td, int flags)
1816 {
1817  struct tdq *tdn;
1818 
1819  tdn = TDQ_CPU(td->td_sched->ts_cpu);
1820 #ifdef SMP
1821  tdq_load_rem(tdq, td);
1822  /*
1823  * Do the lock dance required to avoid LOR. We grab an extra
1824  * spinlock nesting to prevent preemption while we're
1825  * not holding either run-queue lock.
1826  */
1827  spinlock_enter();
1828  thread_lock_block(td); /* This releases the lock on tdq. */
1829 
1830  /*
1831  * Acquire both run-queue locks before placing the thread on the new
1832  * run-queue to avoid deadlocks created by placing a thread with a
1833  * blocked lock on the run-queue of a remote processor. The deadlock
1834  * occurs when a third processor attempts to lock the two queues in
1835  * question while the target processor is spinning with its own
1836  * run-queue lock held while waiting for the blocked lock to clear.
1837  */
1838  tdq_lock_pair(tdn, tdq);
1839  tdq_add(tdn, td, flags);
1840  tdq_notify(tdn, td);
1841  TDQ_UNLOCK(tdn);
1842  spinlock_exit();
1843 #endif
1844  return (TDQ_LOCKPTR(tdn));
1845 }
1846 
1847 /*
1848  * Variadic version of thread_lock_unblock() that does not assume td_lock
1849  * is blocked.
1850  */
1851 static inline void
1852 thread_unblock_switch(struct thread *td, struct mtx *mtx)
1853 {
1854  atomic_store_rel_ptr((volatile uintptr_t *)&td->td_lock,
1855  (uintptr_t)mtx);
1856 }
1857 
1858 /*
1859  * Switch threads. This function has to handle threads coming in while
1860  * blocked for some reason, running, or idle. It also must deal with
1861  * migrating a thread from one queue to another as running threads may
1862  * be assigned elsewhere via binding.
1863  */
1864 void
1865 sched_switch(struct thread *td, struct thread *newtd, int flags)
1866 {
1867  struct tdq *tdq;
1868  struct td_sched *ts;
1869  struct mtx *mtx;
1870  int srqflag;
1871  int cpuid, preempted;
1872 
1873  THREAD_LOCK_ASSERT(td, MA_OWNED);
1874  KASSERT(newtd == NULL, ("sched_switch: Unsupported newtd argument"));
1875 
1876  cpuid = PCPU_GET(cpuid);
1877  tdq = TDQ_CPU(cpuid);
1878  ts = td->td_sched;
1879  mtx = td->td_lock;
1880  sched_pctcpu_update(ts, 1);
1881  ts->ts_rltick = ticks;
1882  td->td_lastcpu = td->td_oncpu;
1883  td->td_oncpu = NOCPU;
1884  preempted = !((td->td_flags & TDF_SLICEEND) ||
1885  (flags & SWT_RELINQUISH));
1886  td->td_flags &= ~(TDF_NEEDRESCHED | TDF_SLICEEND);
1887  td->td_owepreempt = 0;
1888  if (!TD_IS_IDLETHREAD(td))
1889  tdq->tdq_switchcnt++;
1890  /*
1891  * The lock pointer in an idle thread should never change. Reset it
1892  * to CAN_RUN as well.
1893  */
1894  if (TD_IS_IDLETHREAD(td)) {
1895  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
1896  TD_SET_CAN_RUN(td);
1897  } else if (TD_IS_RUNNING(td)) {
1898  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
1899  srqflag = preempted ?
1900  SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED :
1901  SRQ_OURSELF|SRQ_YIELDING;
1902 #ifdef SMP
1903  if (THREAD_CAN_MIGRATE(td) && !THREAD_CAN_SCHED(td, ts->ts_cpu))
1904  ts->ts_cpu = sched_pickcpu(td, 0);
1905 #endif
1906  if (ts->ts_cpu == cpuid)
1907  tdq_runq_add(tdq, td, srqflag);
1908  else {
1909  KASSERT(THREAD_CAN_MIGRATE(td) ||
1910  (ts->ts_flags & TSF_BOUND) != 0,
1911  ("Thread %p shouldn't migrate", td));
1912  mtx = sched_switch_migrate(tdq, td, srqflag);
1913  }
1914  } else {
1915  /* This thread must be going to sleep. */
1916  TDQ_LOCK(tdq);
1917  mtx = thread_lock_block(td);
1918  tdq_load_rem(tdq, td);
1919  }
1920  /*
1921  * We enter here with the thread blocked and assigned to the
1922  * appropriate cpu run-queue or sleep-queue and with the current
1923  * thread-queue locked.
1924  */
1925  TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED);
1926  newtd = choosethread();
1927  /*
1928  * Call the MD code to switch contexts if necessary.
1929  */
1930  if (td != newtd) {
1931 #ifdef HWPMC_HOOKS
1932  if (PMC_PROC_IS_USING_PMCS(td->td_proc))
1933  PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT);
1934 #endif
1935  SDT_PROBE2(sched, , , off__cpu, newtd, newtd->td_proc);
1936  lock_profile_release_lock(&TDQ_LOCKPTR(tdq)->lock_object);
1937  TDQ_LOCKPTR(tdq)->mtx_lock = (uintptr_t)newtd;
1938  sched_pctcpu_update(newtd->td_sched, 0);
1939 
1940 #ifdef KDTRACE_HOOKS
1941  /*
1942  * If DTrace has set the active vtime enum to anything
1943  * other than INACTIVE (0), then it should have set the
1944  * function to call.
1945  */
1946  if (dtrace_vtime_active)
1947  (*dtrace_vtime_switch_func)(newtd);
1948 #endif
1949 
1950  cpu_switch(td, newtd, mtx);
1951  /*
1952  * We may return from cpu_switch on a different cpu. However,
1953  * we always return with td_lock pointing to the current cpu's
1954  * run queue lock.
1955  */
1956  cpuid = PCPU_GET(cpuid);
1957  tdq = TDQ_CPU(cpuid);
1958  lock_profile_obtain_lock_success(
1959  &TDQ_LOCKPTR(tdq)->lock_object, 0, 0, __FILE__, __LINE__);
1960 
1961  SDT_PROBE0(sched, , , on__cpu);
1962 #ifdef HWPMC_HOOKS
1963  if (PMC_PROC_IS_USING_PMCS(td->td_proc))
1964  PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN);
1965 #endif
1966  } else {
1967  thread_unblock_switch(td, mtx);
1968  SDT_PROBE0(sched, , , remain__cpu);
1969  }
1970  /*
1971  * Assert that all went well and return.
1972  */
1973  TDQ_LOCK_ASSERT(tdq, MA_OWNED|MA_NOTRECURSED);
1974  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
1975  td->td_oncpu = cpuid;
1976 }
1977 
1978 /*
1979  * Adjust thread priorities as a result of a nice request.
1980  */
1981 void
1982 sched_nice(struct proc *p, int nice)
1983 {
1984  struct thread *td;
1985 
1986  PROC_LOCK_ASSERT(p, MA_OWNED);
1987 
1988  p->p_nice = nice;
1989  FOREACH_THREAD_IN_PROC(p, td) {
1990  thread_lock(td);
1991  sched_priority(td);
1992  sched_prio(td, td->td_base_user_pri);
1993  thread_unlock(td);
1994  }
1995 }
1996 
1997 /*
1998  * Record the sleep time for the interactivity scorer.
1999  */
2000 void
2001 sched_sleep(struct thread *td, int prio)
2002 {
2003 
2004  THREAD_LOCK_ASSERT(td, MA_OWNED);
2005 
2006  td->td_slptick = ticks;
2007  if (TD_IS_SUSPENDED(td) || prio >= PSOCK)
2008  td->td_flags |= TDF_CANSWAP;
2009  if (PRI_BASE(td->td_pri_class) != PRI_TIMESHARE)
2010  return;
2011  if (static_boost == 1 && prio)
2012  sched_prio(td, prio);
2013  else if (static_boost && td->td_priority > static_boost)
2014  sched_prio(td, static_boost);
2015 }
2016 
2017 /*
2018  * Schedule a thread to resume execution and record how long it voluntarily
2019  * slept. We also update the pctcpu, interactivity, and priority.
2020  */
2021 void
2022 sched_wakeup(struct thread *td)
2023 {
2024  struct td_sched *ts;
2025  int slptick;
2026 
2027  THREAD_LOCK_ASSERT(td, MA_OWNED);
2028  ts = td->td_sched;
2029  td->td_flags &= ~TDF_CANSWAP;
2030  /*
2031  * If we slept for more than a tick update our interactivity and
2032  * priority.
2033  */
2034  slptick = td->td_slptick;
2035  td->td_slptick = 0;
2036  if (slptick && slptick != ticks) {
2037  ts->ts_slptime += (ticks - slptick) << SCHED_TICK_SHIFT;
2039  sched_pctcpu_update(ts, 0);
2040  }
2041  /*
2042  * Reset the slice value since we slept and advanced the round-robin.
2043  */
2044  ts->ts_slice = 0;
2045  sched_add(td, SRQ_BORING);
2046 }
2047 
2048 /*
2049  * Penalize the parent for creating a new child and initialize the child's
2050  * priority.
2051  */
2052 void
2053 sched_fork(struct thread *td, struct thread *child)
2054 {
2055  THREAD_LOCK_ASSERT(td, MA_OWNED);
2056  sched_pctcpu_update(td->td_sched, 1);
2057  sched_fork_thread(td, child);
2058  /*
2059  * Penalize the parent and child for forking.
2060  */
2061  sched_interact_fork(child);
2062  sched_priority(child);
2063  td->td_sched->ts_runtime += tickincr;
2065  sched_priority(td);
2066 }
2067 
2068 /*
2069  * Fork a new thread, may be within the same process.
2070  */
2071 void
2072 sched_fork_thread(struct thread *td, struct thread *child)
2073 {
2074  struct td_sched *ts;
2075  struct td_sched *ts2;
2076  struct tdq *tdq;
2077 
2078  tdq = TDQ_SELF();
2079  THREAD_LOCK_ASSERT(td, MA_OWNED);
2080  /*
2081  * Initialize child.
2082  */
2083  ts = td->td_sched;
2084  ts2 = child->td_sched;
2085  child->td_lock = TDQ_LOCKPTR(tdq);
2086  child->td_cpuset = cpuset_ref(td->td_cpuset);
2087  ts2->ts_cpu = ts->ts_cpu;
2088  ts2->ts_flags = 0;
2089  /*
2090  * Grab our parents cpu estimation information.
2091  */
2092  ts2->ts_ticks = ts->ts_ticks;
2093  ts2->ts_ltick = ts->ts_ltick;
2094  ts2->ts_ftick = ts->ts_ftick;
2095  /*
2096  * Do not inherit any borrowed priority from the parent.
2097  */
2098  child->td_priority = child->td_base_pri;
2099  /*
2100  * And update interactivity score.
2101  */
2102  ts2->ts_slptime = ts->ts_slptime;
2103  ts2->ts_runtime = ts->ts_runtime;
2104  /* Attempt to quickly learn interactivity. */
2105  ts2->ts_slice = tdq_slice(tdq) - sched_slice_min;
2106 #ifdef KTR
2107  bzero(ts2->ts_name, sizeof(ts2->ts_name));
2108 #endif
2109 }
2110 
2111 /*
2112  * Adjust the priority class of a thread.
2113  */
2114 void
2115 sched_class(struct thread *td, int class)
2116 {
2117 
2118  THREAD_LOCK_ASSERT(td, MA_OWNED);
2119  if (td->td_pri_class == class)
2120  return;
2121  td->td_pri_class = class;
2122 }
2123 
2124 /*
2125  * Return some of the child's priority and interactivity to the parent.
2126  */
2127 void
2128 sched_exit(struct proc *p, struct thread *child)
2129 {
2130  struct thread *td;
2131 
2132  KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "proc exit",
2133  "prio:%d", child->td_priority);
2134  PROC_LOCK_ASSERT(p, MA_OWNED);
2135  td = FIRST_THREAD_IN_PROC(p);
2136  sched_exit_thread(td, child);
2137 }
2138 
2139 /*
2140  * Penalize another thread for the time spent on this one. This helps to
2141  * worsen the priority and interactivity of processes which schedule batch
2142  * jobs such as make. This has little effect on the make process itself but
2143  * causes new processes spawned by it to receive worse scores immediately.
2144  */
2145 void
2146 sched_exit_thread(struct thread *td, struct thread *child)
2147 {
2148 
2149  KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "thread exit",
2150  "prio:%d", child->td_priority);
2151  /*
2152  * Give the child's runtime to the parent without returning the
2153  * sleep time as a penalty to the parent. This causes shells that
2154  * launch expensive things to mark their children as expensive.
2155  */
2156  thread_lock(td);
2157  td->td_sched->ts_runtime += child->td_sched->ts_runtime;
2159  sched_priority(td);
2160  thread_unlock(td);
2161 }
2162 
2163 void
2164 sched_preempt(struct thread *td)
2165 {
2166  struct tdq *tdq;
2167 
2168  SDT_PROBE2(sched, , , surrender, td, td->td_proc);
2169 
2170  thread_lock(td);
2171  tdq = TDQ_SELF();
2172  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
2173  tdq->tdq_ipipending = 0;
2174  if (td->td_priority > tdq->tdq_lowpri) {
2175  int flags;
2176 
2177  flags = SW_INVOL | SW_PREEMPT;
2178  if (td->td_critnest > 1)
2179  td->td_owepreempt = 1;
2180  else if (TD_IS_IDLETHREAD(td))
2181  mi_switch(flags | SWT_REMOTEWAKEIDLE, NULL);
2182  else
2183  mi_switch(flags | SWT_REMOTEPREEMPT, NULL);
2184  }
2185  thread_unlock(td);
2186 }
2187 
2188 /*
2189  * Fix priorities on return to user-space. Priorities may be elevated due
2190  * to static priorities in msleep() or similar.
2191  */
2192 void
2193 sched_userret(struct thread *td)
2194 {
2195  /*
2196  * XXX we cheat slightly on the locking here to avoid locking in
2197  * the usual case. Setting td_priority here is essentially an
2198  * incomplete workaround for not setting it properly elsewhere.
2199  * Now that some interrupt handlers are threads, not setting it
2200  * properly elsewhere can clobber it in the window between setting
2201  * it here and returning to user mode, so don't waste time setting
2202  * it perfectly here.
2203  */
2204  KASSERT((td->td_flags & TDF_BORROWING) == 0,
2205  ("thread with borrowed priority returning to userland"));
2206  if (td->td_priority != td->td_user_pri) {
2207  thread_lock(td);
2208  td->td_priority = td->td_user_pri;
2209  td->td_base_pri = td->td_user_pri;
2210  tdq_setlowpri(TDQ_SELF(), td);
2211  thread_unlock(td);
2212  }
2213 }
2214 
2215 /*
2216  * Handle a stathz tick. This is really only relevant for timeshare
2217  * threads.
2218  */
2219 void
2220 sched_clock(struct thread *td)
2221 {
2222  struct tdq *tdq;
2223  struct td_sched *ts;
2224 
2225  THREAD_LOCK_ASSERT(td, MA_OWNED);
2226  tdq = TDQ_SELF();
2227 #ifdef SMP
2228  /*
2229  * We run the long term load balancer infrequently on the first cpu.
2230  */
2231  if (balance_tdq == tdq) {
2232  if (balance_ticks && --balance_ticks == 0)
2233  sched_balance();
2234  }
2235 #endif
2236  /*
2237  * Save the old switch count so we have a record of the last ticks
2238  * activity. Initialize the new switch count based on our load.
2239  * If there is some activity seed it to reflect that.
2240  */
2241  tdq->tdq_oldswitchcnt = tdq->tdq_switchcnt;
2242  tdq->tdq_switchcnt = tdq->tdq_load;
2243  /*
2244  * Advance the insert index once for each tick to ensure that all
2245  * threads get a chance to run.
2246  */
2247  if (tdq->tdq_idx == tdq->tdq_ridx) {
2248  tdq->tdq_idx = (tdq->tdq_idx + 1) % RQ_NQS;
2249  if (TAILQ_EMPTY(&tdq->tdq_timeshare.rq_queues[tdq->tdq_ridx]))
2250  tdq->tdq_ridx = tdq->tdq_idx;
2251  }
2252  ts = td->td_sched;
2253  sched_pctcpu_update(ts, 1);
2254  if (td->td_pri_class & PRI_FIFO_BIT)
2255  return;
2256  if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) {
2257  /*
2258  * We used a tick; charge it to the thread so
2259  * that we can compute our interactivity.
2260  */
2261  td->td_sched->ts_runtime += tickincr;
2263  sched_priority(td);
2264  }
2265 
2266  /*
2267  * Force a context switch if the current thread has used up a full
2268  * time slice (default is 100ms).
2269  */
2270  if (!TD_IS_IDLETHREAD(td) && ++ts->ts_slice >= tdq_slice(tdq)) {
2271  ts->ts_slice = 0;
2272  td->td_flags |= TDF_NEEDRESCHED | TDF_SLICEEND;
2273  }
2274 }
2275 
2276 /*
2277  * Called once per hz tick.
2278  */
2279 void
2280 sched_tick(int cnt)
2281 {
2282 
2283 }
2284 
2285 /*
2286  * Return whether the current CPU has runnable tasks. Used for in-kernel
2287  * cooperative idle threads.
2288  */
2289 int
2291 {
2292  struct tdq *tdq;
2293  int load;
2294 
2295  load = 1;
2296 
2297  tdq = TDQ_SELF();
2298  if ((curthread->td_flags & TDF_IDLETD) != 0) {
2299  if (tdq->tdq_load > 0)
2300  goto out;
2301  } else
2302  if (tdq->tdq_load - 1 > 0)
2303  goto out;
2304  load = 0;
2305 out:
2306  return (load);
2307 }
2308 
2309 /*
2310  * Choose the highest priority thread to run. The thread is removed from
2311  * the run-queue while running however the load remains. For SMP we set
2312  * the tdq in the global idle bitmask if it idles here.
2313  */
2314 struct thread *
2316 {
2317  struct thread *td;
2318  struct tdq *tdq;
2319 
2320  tdq = TDQ_SELF();
2321  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
2322  td = tdq_choose(tdq);
2323  if (td) {
2324  tdq_runq_rem(tdq, td);
2325  tdq->tdq_lowpri = td->td_priority;
2326  return (td);
2327  }
2328  tdq->tdq_lowpri = PRI_MAX_IDLE;
2329  return (PCPU_GET(idlethread));
2330 }
2331 
2332 /*
2333  * Set owepreempt if necessary. Preemption never happens directly in ULE,
2334  * we always request it once we exit a critical section.
2335  */
2336 static inline void
2337 sched_setpreempt(struct thread *td)
2338 {
2339  struct thread *ctd;
2340  int cpri;
2341  int pri;
2342 
2343  THREAD_LOCK_ASSERT(curthread, MA_OWNED);
2344 
2345  ctd = curthread;
2346  pri = td->td_priority;
2347  cpri = ctd->td_priority;
2348  if (pri < cpri)
2349  ctd->td_flags |= TDF_NEEDRESCHED;
2350  if (panicstr != NULL || pri >= cpri || cold || TD_IS_INHIBITED(ctd))
2351  return;
2352  if (!sched_shouldpreempt(pri, cpri, 0))
2353  return;
2354  ctd->td_owepreempt = 1;
2355 }
2356 
2357 /*
2358  * Add a thread to a thread queue. Select the appropriate runq and add the
2359  * thread to it. This is the internal function called when the tdq is
2360  * predetermined.
2361  */
2362 void
2363 tdq_add(struct tdq *tdq, struct thread *td, int flags)
2364 {
2365 
2366  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
2367  KASSERT((td->td_inhibitors == 0),
2368  ("sched_add: trying to run inhibited thread"));
2369  KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)),
2370  ("sched_add: bad thread state"));
2371  KASSERT(td->td_flags & TDF_INMEM,
2372  ("sched_add: thread swapped out"));
2373 
2374  if (td->td_priority < tdq->tdq_lowpri)
2375  tdq->tdq_lowpri = td->td_priority;
2376  tdq_runq_add(tdq, td, flags);
2377  tdq_load_add(tdq, td);
2378 }
2379 
2380 /*
2381  * Select the target thread queue and add a thread to it. Request
2382  * preemption or IPI a remote processor if required.
2383  */
2384 void
2385 sched_add(struct thread *td, int flags)
2386 {
2387  struct tdq *tdq;
2388 #ifdef SMP
2389  int cpu;
2390 #endif
2391 
2392  KTR_STATE2(KTR_SCHED, "thread", sched_tdname(td), "runq add",
2393  "prio:%d", td->td_priority, KTR_ATTR_LINKED,
2394  sched_tdname(curthread));
2395  KTR_POINT1(KTR_SCHED, "thread", sched_tdname(curthread), "wokeup",
2396  KTR_ATTR_LINKED, sched_tdname(td));
2397  SDT_PROBE4(sched, , , enqueue, td, td->td_proc, NULL,
2398  flags & SRQ_PREEMPTED);
2399  THREAD_LOCK_ASSERT(td, MA_OWNED);
2400  /*
2401  * Recalculate the priority before we select the target cpu or
2402  * run-queue.
2403  */
2404  if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE)
2405  sched_priority(td);
2406 #ifdef SMP
2407  /*
2408  * Pick the destination cpu and if it isn't ours transfer to the
2409  * target cpu.
2410  */
2411  cpu = sched_pickcpu(td, flags);
2412  tdq = sched_setcpu(td, cpu, flags);
2413  tdq_add(tdq, td, flags);
2414  if (cpu != PCPU_GET(cpuid)) {
2415  tdq_notify(tdq, td);
2416  return;
2417  }
2418 #else
2419  tdq = TDQ_SELF();
2420  TDQ_LOCK(tdq);
2421  /*
2422  * Now that the thread is moving to the run-queue, set the lock
2423  * to the scheduler's lock.
2424  */
2425  thread_lock_set(td, TDQ_LOCKPTR(tdq));
2426  tdq_add(tdq, td, flags);
2427 #endif
2428  if (!(flags & SRQ_YIELDING))
2429  sched_setpreempt(td);
2430 }
2431 
2432 /*
2433  * Remove a thread from a run-queue without running it. This is used
2434  * when we're stealing a thread from a remote queue. Otherwise all threads
2435  * exit by calling sched_exit_thread() and sched_throw() themselves.
2436  */
2437 void
2438 sched_rem(struct thread *td)
2439 {
2440  struct tdq *tdq;
2441 
2442  KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "runq rem",
2443  "prio:%d", td->td_priority);
2444  SDT_PROBE3(sched, , , dequeue, td, td->td_proc, NULL);
2445  tdq = TDQ_CPU(td->td_sched->ts_cpu);
2446  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
2447  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
2448  KASSERT(TD_ON_RUNQ(td),
2449  ("sched_rem: thread not on run queue"));
2450  tdq_runq_rem(tdq, td);
2451  tdq_load_rem(tdq, td);
2452  TD_SET_CAN_RUN(td);
2453  if (td->td_priority == tdq->tdq_lowpri)
2454  tdq_setlowpri(tdq, NULL);
2455 }
2456 
2457 /*
2458  * Fetch cpu utilization information. Updates on demand.
2459  */
2460 fixpt_t
2461 sched_pctcpu(struct thread *td)
2462 {
2463  fixpt_t pctcpu;
2464  struct td_sched *ts;
2465 
2466  pctcpu = 0;
2467  ts = td->td_sched;
2468  if (ts == NULL)
2469  return (0);
2470 
2471  THREAD_LOCK_ASSERT(td, MA_OWNED);
2472  sched_pctcpu_update(ts, TD_IS_RUNNING(td));
2473  if (ts->ts_ticks) {
2474  int rtick;
2475 
2476  /* How many rtick per second ? */
2477  rtick = min(SCHED_TICK_HZ(ts) / SCHED_TICK_SECS, hz);
2478  pctcpu = (FSCALE * ((FSCALE * rtick)/hz)) >> FSHIFT;
2479  }
2480 
2481  return (pctcpu);
2482 }
2483 
2484 /*
2485  * Enforce affinity settings for a thread. Called after adjustments to
2486  * cpumask.
2487  */
2488 void
2489 sched_affinity(struct thread *td)
2490 {
2491 #ifdef SMP
2492  struct td_sched *ts;
2493 
2494  THREAD_LOCK_ASSERT(td, MA_OWNED);
2495  ts = td->td_sched;
2496  if (THREAD_CAN_SCHED(td, ts->ts_cpu))
2497  return;
2498  if (TD_ON_RUNQ(td)) {
2499  sched_rem(td);
2500  sched_add(td, SRQ_BORING);
2501  return;
2502  }
2503  if (!TD_IS_RUNNING(td))
2504  return;
2505  /*
2506  * Force a switch before returning to userspace. If the
2507  * target thread is not running locally send an ipi to force
2508  * the issue.
2509  */
2510  td->td_flags |= TDF_NEEDRESCHED;
2511  if (td != curthread)
2512  ipi_cpu(ts->ts_cpu, IPI_PREEMPT);
2513 #endif
2514 }
2515 
2516 /*
2517  * Bind a thread to a target cpu.
2518  */
2519 void
2520 sched_bind(struct thread *td, int cpu)
2521 {
2522  struct td_sched *ts;
2523 
2524  THREAD_LOCK_ASSERT(td, MA_OWNED|MA_NOTRECURSED);
2525  KASSERT(td == curthread, ("sched_bind: can only bind curthread"));
2526  ts = td->td_sched;
2527  if (ts->ts_flags & TSF_BOUND)
2528  sched_unbind(td);
2529  KASSERT(THREAD_CAN_MIGRATE(td), ("%p must be migratable", td));
2530  ts->ts_flags |= TSF_BOUND;
2531  sched_pin();
2532  if (PCPU_GET(cpuid) == cpu)
2533  return;
2534  ts->ts_cpu = cpu;
2535  /* When we return from mi_switch we'll be on the correct cpu. */
2536  mi_switch(SW_VOL, NULL);
2537 }
2538 
2539 /*
2540  * Release a bound thread.
2541  */
2542 void
2543 sched_unbind(struct thread *td)
2544 {
2545  struct td_sched *ts;
2546 
2547  THREAD_LOCK_ASSERT(td, MA_OWNED);
2548  KASSERT(td == curthread, ("sched_unbind: can only bind curthread"));
2549  ts = td->td_sched;
2550  if ((ts->ts_flags & TSF_BOUND) == 0)
2551  return;
2552  ts->ts_flags &= ~TSF_BOUND;
2553  sched_unpin();
2554 }
2555 
2556 int
2557 sched_is_bound(struct thread *td)
2558 {
2559  THREAD_LOCK_ASSERT(td, MA_OWNED);
2560  return (td->td_sched->ts_flags & TSF_BOUND);
2561 }
2562 
2563 /*
2564  * Basic yield call.
2565  */
2566 void
2567 sched_relinquish(struct thread *td)
2568 {
2569  thread_lock(td);
2570  mi_switch(SW_VOL | SWT_RELINQUISH, NULL);
2571  thread_unlock(td);
2572 }
2573 
2574 /*
2575  * Return the total system load.
2576  */
2577 int
2579 {
2580 #ifdef SMP
2581  int total;
2582  int i;
2583 
2584  total = 0;
2585  CPU_FOREACH(i)
2586  total += TDQ_CPU(i)->tdq_sysload;
2587  return (total);
2588 #else
2589  return (TDQ_SELF()->tdq_sysload);
2590 #endif
2591 }
2592 
2593 int
2595 {
2596  return (sizeof(struct proc));
2597 }
2598 
2599 int
2601 {
2602  return (sizeof(struct thread) + sizeof(struct td_sched));
2603 }
2604 
2605 #ifdef SMP
2606 #define TDQ_IDLESPIN(tdq) \
2607  ((tdq)->tdq_cg != NULL && ((tdq)->tdq_cg->cg_flags & CG_FLAG_THREAD) == 0)
2608 #else
2609 #define TDQ_IDLESPIN(tdq) 1
2610 #endif
2611 
2612 /*
2613  * The actual idle process.
2614  */
2615 void
2617 {
2618  struct thread *td;
2619  struct tdq *tdq;
2620  int oldswitchcnt, switchcnt;
2621  int i;
2622 
2623  mtx_assert(&Giant, MA_NOTOWNED);
2624  td = curthread;
2625  tdq = TDQ_SELF();
2626  THREAD_NO_SLEEPING();
2627  oldswitchcnt = -1;
2628  for (;;) {
2629  if (tdq->tdq_load) {
2630  thread_lock(td);
2631  mi_switch(SW_VOL | SWT_IDLE, NULL);
2632  thread_unlock(td);
2633  }
2634  switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
2635 #ifdef SMP
2636  if (switchcnt != oldswitchcnt) {
2637  oldswitchcnt = switchcnt;
2638  if (tdq_idled(tdq) == 0)
2639  continue;
2640  }
2641  switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
2642 #else
2643  oldswitchcnt = switchcnt;
2644 #endif
2645  /*
2646  * If we're switching very frequently, spin while checking
2647  * for load rather than entering a low power state that
2648  * may require an IPI. However, don't do any busy
2649  * loops while on SMT machines as this simply steals
2650  * cycles from cores doing useful work.
2651  */
2652  if (TDQ_IDLESPIN(tdq) && switchcnt > sched_idlespinthresh) {
2653  for (i = 0; i < sched_idlespins; i++) {
2654  if (tdq->tdq_load)
2655  break;
2656  cpu_spinwait();
2657  }
2658  }
2659 
2660  /* If there was context switch during spin, restart it. */
2661  switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
2662  if (tdq->tdq_load != 0 || switchcnt != oldswitchcnt)
2663  continue;
2664 
2665  /* Run main MD idle handler. */
2666  tdq->tdq_cpu_idle = 1;
2667  /*
2668  * Make sure that tdq_cpu_idle update is globally visible
2669  * before cpu_idle() read tdq_load. The order is important
2670  * to avoid race with tdq_notify.
2671  */
2672  mb();
2673  cpu_idle(switchcnt * 4 > sched_idlespinthresh);
2674  tdq->tdq_cpu_idle = 0;
2675 
2676  /*
2677  * Account thread-less hardware interrupts and
2678  * other wakeup reasons equal to context switches.
2679  */
2680  switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
2681  if (switchcnt != oldswitchcnt)
2682  continue;
2683  tdq->tdq_switchcnt++;
2684  oldswitchcnt++;
2685  }
2686 }
2687 
2688 /*
2689  * A CPU is entering for the first time or a thread is exiting.
2690  */
2691 void
2692 sched_throw(struct thread *td)
2693 {
2694  struct thread *newtd;
2695  struct tdq *tdq;
2696 
2697  tdq = TDQ_SELF();
2698  if (td == NULL) {
2699  /* Correct spinlock nesting and acquire the correct lock. */
2700  TDQ_LOCK(tdq);
2701  spinlock_exit();
2702  PCPU_SET(switchtime, cpu_ticks());
2703  PCPU_SET(switchticks, ticks);
2704  } else {
2705  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
2706  tdq_load_rem(tdq, td);
2707  lock_profile_release_lock(&TDQ_LOCKPTR(tdq)->lock_object);
2708  }
2709  KASSERT(curthread->td_md.md_spinlock_count == 1, ("invalid count"));
2710  newtd = choosethread();
2711  TDQ_LOCKPTR(tdq)->mtx_lock = (uintptr_t)newtd;
2712  cpu_throw(td, newtd); /* doesn't return */
2713 }
2714 
2715 /*
2716  * This is called from fork_exit(). Just acquire the correct locks and
2717  * let fork do the rest of the work.
2718  */
2719 void
2720 sched_fork_exit(struct thread *td)
2721 {
2722  struct tdq *tdq;
2723  int cpuid;
2724 
2725  /*
2726  * Finish setting up thread glue so that it begins execution in a
2727  * non-nested critical section with the scheduler lock held.
2728  */
2729  cpuid = PCPU_GET(cpuid);
2730  tdq = TDQ_CPU(cpuid);
2731  if (TD_IS_IDLETHREAD(td))
2732  td->td_lock = TDQ_LOCKPTR(tdq);
2733  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
2734  td->td_oncpu = cpuid;
2735  TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED);
2736  lock_profile_obtain_lock_success(
2737  &TDQ_LOCKPTR(tdq)->lock_object, 0, 0, __FILE__, __LINE__);
2738 }
2739 
2740 /*
2741  * Create on first use to catch odd startup conditons.
2742  */
2743 char *
2744 sched_tdname(struct thread *td)
2745 {
2746 #ifdef KTR
2747  struct td_sched *ts;
2748 
2749  ts = td->td_sched;
2750  if (ts->ts_name[0] == '\0')
2751  snprintf(ts->ts_name, sizeof(ts->ts_name),
2752  "%s tid %d", td->td_name, td->td_tid);
2753  return (ts->ts_name);
2754 #else
2755  return (td->td_name);
2756 #endif
2757 }
2758 
2759 #ifdef KTR
2760 void
2761 sched_clear_tdname(struct thread *td)
2762 {
2763  struct td_sched *ts;
2764 
2765  ts = td->td_sched;
2766  ts->ts_name[0] = '\0';
2767 }
2768 #endif
2769 
2770 #ifdef SMP
2771 
2772 /*
2773  * Build the CPU topology dump string. Is recursively called to collect
2774  * the topology tree.
2775  */
2776 static int
2777 sysctl_kern_sched_topology_spec_internal(struct sbuf *sb, struct cpu_group *cg,
2778  int indent)
2779 {
2780  char cpusetbuf[CPUSETBUFSIZ];
2781  int i, first;
2782 
2783  sbuf_printf(sb, "%*s<group level=\"%d\" cache-level=\"%d\">\n", indent,
2784  "", 1 + indent / 2, cg->cg_level);
2785  sbuf_printf(sb, "%*s <cpu count=\"%d\" mask=\"%s\">", indent, "",
2786  cg->cg_count, cpusetobj_strprint(cpusetbuf, &cg->cg_mask));
2787  first = TRUE;
2788  for (i = 0; i < MAXCPU; i++) {
2789  if (CPU_ISSET(i, &cg->cg_mask)) {
2790  if (!first)
2791  sbuf_printf(sb, ", ");
2792  else
2793  first = FALSE;
2794  sbuf_printf(sb, "%d", i);
2795  }
2796  }
2797  sbuf_printf(sb, "</cpu>\n");
2798 
2799  if (cg->cg_flags != 0) {
2800  sbuf_printf(sb, "%*s <flags>", indent, "");
2801  if ((cg->cg_flags & CG_FLAG_HTT) != 0)
2802  sbuf_printf(sb, "<flag name=\"HTT\">HTT group</flag>");
2803  if ((cg->cg_flags & CG_FLAG_THREAD) != 0)
2804  sbuf_printf(sb, "<flag name=\"THREAD\">THREAD group</flag>");
2805  if ((cg->cg_flags & CG_FLAG_SMT) != 0)
2806  sbuf_printf(sb, "<flag name=\"SMT\">SMT group</flag>");
2807  sbuf_printf(sb, "</flags>\n");
2808  }
2809 
2810  if (cg->cg_children > 0) {
2811  sbuf_printf(sb, "%*s <children>\n", indent, "");
2812  for (i = 0; i < cg->cg_children; i++)
2813  sysctl_kern_sched_topology_spec_internal(sb,
2814  &cg->cg_child[i], indent+2);
2815  sbuf_printf(sb, "%*s </children>\n", indent, "");
2816  }
2817  sbuf_printf(sb, "%*s</group>\n", indent, "");
2818  return (0);
2819 }
2820 
2821 /*
2822  * Sysctl handler for retrieving topology dump. It's a wrapper for
2823  * the recursive sysctl_kern_smp_topology_spec_internal().
2824  */
2825 static int
2826 sysctl_kern_sched_topology_spec(SYSCTL_HANDLER_ARGS)
2827 {
2828  struct sbuf *topo;
2829  int err;
2830 
2831  KASSERT(cpu_top != NULL, ("cpu_top isn't initialized"));
2832 
2833  topo = sbuf_new_for_sysctl(NULL, NULL, 512, req);
2834  if (topo == NULL)
2835  return (ENOMEM);
2836 
2837  sbuf_printf(topo, "<groups>\n");
2838  err = sysctl_kern_sched_topology_spec_internal(topo, cpu_top, 1);
2839  sbuf_printf(topo, "</groups>\n");
2840 
2841  if (err == 0) {
2842  err = sbuf_finish(topo);
2843  }
2844  sbuf_delete(topo);
2845  return (err);
2846 }
2847 
2848 #endif
2849 
2850 static int
2851 sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
2852 {
2853  int error, new_val, period;
2854 
2855  period = 1000000 / realstathz;
2856  new_val = period * sched_slice;
2857  error = sysctl_handle_int(oidp, &new_val, 0, req);
2858  if (error != 0 || req->newptr == NULL)
2859  return (error);
2860  if (new_val <= 0)
2861  return (EINVAL);
2862  sched_slice = imax(1, (new_val + period / 2) / period);
2863  sched_slice_min = sched_slice / SCHED_SLICE_MIN_DIVISOR;
2864  hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) /
2865  realstathz);
2866  return (0);
2867 }
2868 
2869 SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW, 0, "Scheduler");
2870 SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "ULE", 0,
2871  "Scheduler name");
2872 SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, CTLTYPE_INT | CTLFLAG_RW,
2873  NULL, 0, sysctl_kern_quantum, "I",
2874  "Quantum for timeshare threads in microseconds");
2875 SYSCTL_INT(_kern_sched, OID_AUTO, slice, CTLFLAG_RW, &sched_slice, 0,
2876  "Quantum for timeshare threads in stathz ticks");
2877 SYSCTL_INT(_kern_sched, OID_AUTO, interact, CTLFLAG_RW, &sched_interact, 0,
2878  "Interactivity score threshold");
2879 SYSCTL_INT(_kern_sched, OID_AUTO, preempt_thresh, CTLFLAG_RW,
2880  &preempt_thresh, 0,
2881  "Maximal (lowest) priority for preemption");
2882 SYSCTL_INT(_kern_sched, OID_AUTO, static_boost, CTLFLAG_RW, &static_boost, 0,
2883  "Assign static kernel priorities to sleeping threads");
2884 SYSCTL_INT(_kern_sched, OID_AUTO, idlespins, CTLFLAG_RW, &sched_idlespins, 0,
2885  "Number of times idle thread will spin waiting for new work");
2886 SYSCTL_INT(_kern_sched, OID_AUTO, idlespinthresh, CTLFLAG_RW,
2888  "Threshold before we will permit idle thread spinning");
2889 #ifdef SMP
2890 SYSCTL_INT(_kern_sched, OID_AUTO, affinity, CTLFLAG_RW, &affinity, 0,
2891  "Number of hz ticks to keep thread affinity for");
2892 SYSCTL_INT(_kern_sched, OID_AUTO, balance, CTLFLAG_RW, &rebalance, 0,
2893  "Enables the long-term load balancer");
2894 SYSCTL_INT(_kern_sched, OID_AUTO, balance_interval, CTLFLAG_RW,
2895  &balance_interval, 0,
2896  "Average period in stathz ticks to run the long-term balancer");
2897 SYSCTL_INT(_kern_sched, OID_AUTO, steal_idle, CTLFLAG_RW, &steal_idle, 0,
2898  "Attempts to steal work from other cores before idling");
2899 SYSCTL_INT(_kern_sched, OID_AUTO, steal_thresh, CTLFLAG_RW, &steal_thresh, 0,
2900  "Minimum load on remote CPU before we'll steal");
2901 SYSCTL_PROC(_kern_sched, OID_AUTO, topology_spec, CTLTYPE_STRING |
2902  CTLFLAG_RD, NULL, 0, sysctl_kern_sched_topology_spec, "A",
2903  "XML dump of detected CPU topology");
2904 #endif
2905 
2906 /* ps compat. All cpu percentages from ULE are weighted. */
2907 static int ccpu = 0;
2908 SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
static struct tdq tdq_cpu
Definition: sched_ule.c:286
volatile int smp_started
Definition: subr_smp.c:72
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Definition: sched_ule.c:97
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Definition: sched_ule.c:1414
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Definition: sched_ule.c:100
#define TS_NAME_LEN
Definition: sched_ule.c:82
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Definition: sched_ule.c:293
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Definition: sched_ule.c:436
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Definition: sched_ule.c:1630
SDT_PROBE_DEFINE2(sched,,, load__change,"int","int")
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Definition: sched_ule.c:144
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Definition: sched_ule.c:290
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Definition: sched_ule.c:1611
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Definition: sched_ule.c:231
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Definition: sched_ule.c:237
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Definition: sched_ule.c:1722
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Definition: sched_ule.c:2315
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Definition: sched_ule.c:2115
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Definition: subr_prf.c:507
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Definition: clock_if.m:39
#define TDF_SLICEEND
Definition: sched_ule.c:195
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Definition: sched_ule.c:92
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Definition: sched_ule.c:2146
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Definition: sched_ule.c:2072
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Definition: init_main.c:115
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Definition: linker_if.m:86
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Definition: subr_smp.c:73
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Definition: sched_ule.c:96
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Definition: sched_ule.c:162
#define SCHED_PRI_RANGE
Definition: sched_ule.c:164
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Definition: sched_ule.c:1390
#define THREAD_CAN_SCHED(td, cpu)
Definition: sched_ule.c:112
static int sched_interact_score(struct thread *)
Definition: sched_ule.c:1457
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Definition: sched_ule.c:525
void sched_user_prio(struct thread *td, u_char prio)
Definition: sched_ule.c:1788
const char * panicstr
SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD,"ULE", 0,"Scheduler name")
static int sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
Definition: sched_ule.c:2851
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Definition: init_main.c:100
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Definition: sched_ule.c:241
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static void sched_interact_update(struct thread *)
Definition: sched_ule.c:1549
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Definition: kern_switch.c:154
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Definition: sched_ule.c:234
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Definition: sched_ule.c:243
struct tdq __aligned(64)
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Definition: sched_ule.c:128
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Definition: subr_pcpu.c:278
static int ccpu
Definition: sched_ule.c:2907
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Definition: sched_ule.c:1347
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Definition: sched_ule.c:2001
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Definition: sched_ule.c:107
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Definition: sched_ule.c:94
SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL)
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SDT_PROBE_DEFINE(sched,,, on__cpu)
u_char tdq_ridx
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Definition: sched_ule.c:220
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char tdq_name[TDQ_NAME_LEN]
Definition: sched_ule.c:249
#define SCHED_INTERACT_HALF
Definition: sched_ule.c:185
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Definition: sched_ule.c:2609
static int sched_idlespinthresh
Definition: sched_ule.c:221
#define TDQ_ID(x)
Definition: sched_ule.c:288
static struct runq runq
Definition: sched_4bsd.c:156
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Definition: kern_switch.c:357
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Definition: kern_switch.c:235
#define SCHED_SLICE_MIN_DIVISOR
Definition: sched_ule.c:192
static int sched_slice_min
Definition: sched_ule.c:209
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Definition: kern_switch.c:442
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Definition: kern_mutex.c:723
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Definition: sched_ule.c:2720
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#define SCHED_SLP_RUN_FORK
Definition: sched_ule.c:183
void sched_lend_user_prio(struct thread *td, u_char prio)
Definition: sched_ule.c:1798
__FBSDID("$FreeBSD: head/sys/kern/sched_ule.c 279999 2015-03-14 18:42:30Z ian $")
DPCPU_DEFINE(sbintime_t, hardclocktime)
#define PRI_MIN_INTERACT
Definition: sched_ule.c:126
static struct thread * tdq_choose(struct tdq *)
Definition: sched_ule.c:1317
static int tickincr
Definition: sched_ule.c:206
int sched_is_bound(struct thread *td)
Definition: sched_ule.c:2557
int mask
Definition: subr_acl_nfs4.c:69
static struct mtx * sched_switch_migrate(struct tdq *tdq, struct thread *td, int flags)
Definition: sched_ule.c:1815
int sysctl_handle_int(SYSCTL_HANDLER_ARGS)
Definition: kern_sysctl.c:1146
void sched_tick(int cnt)
Definition: sched_ule.c:2280
#define TDQ_SELF()
Definition: sched_ule.c:289
#define TDQ_LOADNAME_LEN
Definition: sched_ule.c:84
#define SCHED_TICK_MAX
Definition: sched_ule.c:143
struct runq tdq_timeshare
Definition: sched_ule.c:247
void sched_clock(struct thread *td)
Definition: sched_ule.c:2220
static void runq_print(struct runq *rq)
Definition: sched_ule.c:383
static void sched_thread_priority(struct thread *, u_char)
Definition: sched_ule.c:1667
void runq_remove(struct runq *rq, struct thread *td)
Definition: kern_switch.c:487
struct runq tdq_realtime
Definition: sched_ule.c:246
static __inline void tdq_runq_add(struct tdq *, struct thread *, int)
Definition: sched_ule.c:474
#define SCHED_PRI_NICE(nice)
Definition: sched_ule.c:168
void sched_affinity(struct thread *td)
Definition: sched_ule.c:2489
int printf(const char *fmt,...)
Definition: subr_prf.c:371
void sched_exit(struct proc *p, struct thread *child)
Definition: sched_ule.c:2128
struct runq tdq_idle
Definition: sched_ule.c:248
#define SCHED_PRI_TICKS(ts)
Definition: sched_ule.c:165
void sbuf_delete(struct sbuf *s)
Definition: subr_sbuf.c:790
#define TDQ_LOCK_FLAGS(t, f)
Definition: sched_ule.c:295
SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, CTLTYPE_INT|CTLFLAG_RW, NULL, 0, sysctl_kern_quantum,"I","Quantum for timeshare threads in microseconds")
void sched_idletd(void *dummy)
Definition: sched_ule.c:2616
void sched_unlend_prio(struct thread *td, u_char prio)
Definition: sched_ule.c:1738
int tdq_sysload
Definition: sched_ule.c:238
#define TSF_BOUND
Definition: sched_ule.c:106
#define SCHED_TICK_HZ(ts)
Definition: sched_ule.c:145
static void thread_unblock_switch(struct thread *td, struct mtx *mtx)
Definition: sched_ule.c:1852
int sbuf_finish(struct sbuf *s)
Definition: subr_sbuf.c:725
void sched_preempt(struct thread *td)
Definition: sched_ule.c:2164
static int realstathz
Definition: sched_ule.c:207
volatile int tdq_load
Definition: sched_ule.c:236
#define TDQ_LOCK(t)
Definition: sched_ule.c:294
#define SCHED_SLICE_DEFAULT_DIVISOR
Definition: sched_ule.c:191
SDT_PROBE_DEFINE4(sched,,, enqueue,"struct thread *","struct proc *","void *","int")
SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW, 0,"Scheduler")
#define TDQ_UNLOCK(t)
Definition: sched_ule.c:296
volatile int ticks
Definition: kern_clock.c:380
int sched_load(void)
Definition: sched_ule.c:2578
int hogticks
Definition: kern_synch.c:80
SDT_PROVIDER_DEFINE(sched)
static int sched_interact
Definition: sched_ule.c:205
static int tdq_slice(struct tdq *tdq)
Definition: sched_ule.c:591
static void sched_interact_fork(struct thread *)
Definition: sched_ule.c:1594
int stathz
Definition: kern_clock.c:377
static void sched_priority(struct thread *)
Definition: sched_ule.c:1497
void sched_nice(struct proc *p, int nice)
Definition: sched_ule.c:1982
#define SCHED_SLP_RUN_MAX
Definition: sched_ule.c:182
static void sched_setpreempt(struct thread *td)
Definition: sched_ule.c:2337
int tdq_transferable
Definition: sched_ule.c:239
static int sched_slice
Definition: sched_ule.c:208
char * cpusetobj_strprint(char *buf, const cpuset_t *set)
Definition: kern_cpuset.c:634
void sched_userret(struct thread *td)
Definition: sched_ule.c:2193
#define TDQ_LOCKPTR(t)
Definition: sched_ule.c:297
void sched_fork(struct thread *td, struct thread *child)
Definition: sched_ule.c:2053
#define SCHED_INTERACT_THRESH
Definition: sched_ule.c:186
#define PRI_MAX_BATCH
Definition: sched_ule.c:129
static void tdq_add(struct tdq *, struct thread *, int)
Definition: sched_ule.c:2363
struct mtx * thread_lock_block(struct thread *td)
Definition: kern_mutex.c:702
u_char tdq_idx
Definition: sched_ule.c:244
#define SCHED_TICK_TARG
Definition: sched_ule.c:142
int sched_runnable(void)
Definition: sched_ule.c:2290
void sched_unbind(struct thread *td)
Definition: sched_ule.c:2543
static int preempt_thresh
Definition: sched_ule.c:217
#define PRI_BATCH_RANGE
Definition: sched_ule.c:124
#define THREAD_CAN_MIGRATE(td)
Definition: sched_ule.c:111
void sched_prio(struct thread *td, u_char prio)
Definition: sched_ule.c:1758
SDT_PROBE_DEFINE3(sched,,, change__pri,"struct thread *","struct proc *","uint8_t")
void sched_add(struct thread *td, int flags)
Definition: sched_ule.c:2385
short tdq_switchcnt
Definition: sched_ule.c:240
u_char tdq_lowpri
Definition: sched_ule.c:235
u_char tdq_lowpri
Definition: sched_ule.c:242
static void tdq_load_add(struct tdq *, struct thread *)
Definition: sched_ule.c:551
cpu_tick_f * cpu_ticks
Definition: kern_tc.c:2013
void thread_lock_unblock(struct thread *td, struct mtx *new)
Definition: kern_mutex.c:715
#define TDQ_NAME_LEN
Definition: sched_ule.c:83
static int static_boost
Definition: sched_ule.c:219
void sched_bind(struct thread *td, int cpu)
Definition: sched_ule.c:2520
struct sbuf * sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, struct sysctl_req *req)
Definition: kern_sysctl.c:1840
int hz
Definition: subr_param.c:84
fixpt_t sched_pctcpu(struct thread *td)
Definition: sched_ule.c:2461
int sched_sizeof_proc(void)
Definition: sched_ule.c:2594
static void sched_pctcpu_update(struct td_sched *, int)
Definition: sched_ule.c:1644