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 287166 2015-08-26 16:36:41Z gnn $");
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 /*
360  * Print the threads waiting on a run-queue.
361  */
362 static void
363 runq_print(struct runq *rq)
364 {
365  struct rqhead *rqh;
366  struct thread *td;
367  int pri;
368  int j;
369  int i;
370 
371  for (i = 0; i < RQB_LEN; i++) {
372  printf("\t\trunq bits %d 0x%zx\n",
373  i, rq->rq_status.rqb_bits[i]);
374  for (j = 0; j < RQB_BPW; j++)
375  if (rq->rq_status.rqb_bits[i] & (1ul << j)) {
376  pri = j + (i << RQB_L2BPW);
377  rqh = &rq->rq_queues[pri];
378  TAILQ_FOREACH(td, rqh, td_runq) {
379  printf("\t\t\ttd %p(%s) priority %d rqindex %d pri %d\n",
380  td, td->td_name, td->td_priority,
381  td->td_rqindex, pri);
382  }
383  }
384  }
385 }
386 
387 /*
388  * Print the status of a per-cpu thread queue. Should be a ddb show cmd.
389  */
390 void
391 tdq_print(int cpu)
392 {
393  struct tdq *tdq;
394 
395  tdq = TDQ_CPU(cpu);
396 
397  printf("tdq %d:\n", TDQ_ID(tdq));
398  printf("\tlock %p\n", TDQ_LOCKPTR(tdq));
399  printf("\tLock name: %s\n", tdq->tdq_name);
400  printf("\tload: %d\n", tdq->tdq_load);
401  printf("\tswitch cnt: %d\n", tdq->tdq_switchcnt);
402  printf("\told switch cnt: %d\n", tdq->tdq_oldswitchcnt);
403  printf("\ttimeshare idx: %d\n", tdq->tdq_idx);
404  printf("\ttimeshare ridx: %d\n", tdq->tdq_ridx);
405  printf("\tload transferable: %d\n", tdq->tdq_transferable);
406  printf("\tlowest priority: %d\n", tdq->tdq_lowpri);
407  printf("\trealtime runq:\n");
408  runq_print(&tdq->tdq_realtime);
409  printf("\ttimeshare runq:\n");
410  runq_print(&tdq->tdq_timeshare);
411  printf("\tidle runq:\n");
412  runq_print(&tdq->tdq_idle);
413 }
414 
415 static inline int
416 sched_shouldpreempt(int pri, int cpri, int remote)
417 {
418  /*
419  * If the new priority is not better than the current priority there is
420  * nothing to do.
421  */
422  if (pri >= cpri)
423  return (0);
424  /*
425  * Always preempt idle.
426  */
427  if (cpri >= PRI_MIN_IDLE)
428  return (1);
429  /*
430  * If preemption is disabled don't preempt others.
431  */
432  if (preempt_thresh == 0)
433  return (0);
434  /*
435  * Preempt if we exceed the threshold.
436  */
437  if (pri <= preempt_thresh)
438  return (1);
439  /*
440  * If we're interactive or better and there is non-interactive
441  * or worse running preempt only remote processors.
442  */
443  if (remote && pri <= PRI_MAX_INTERACT && cpri > PRI_MAX_INTERACT)
444  return (1);
445  return (0);
446 }
447 
448 /*
449  * Add a thread to the actual run-queue. Keeps transferable counts up to
450  * date with what is actually on the run-queue. Selects the correct
451  * queue position for timeshare threads.
452  */
453 static __inline void
454 tdq_runq_add(struct tdq *tdq, struct thread *td, int flags)
455 {
456  struct td_sched *ts;
457  u_char pri;
458 
459  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
460  THREAD_LOCK_ASSERT(td, MA_OWNED);
461 
462  pri = td->td_priority;
463  ts = td->td_sched;
464  TD_SET_RUNQ(td);
465  if (THREAD_CAN_MIGRATE(td)) {
466  tdq->tdq_transferable++;
467  ts->ts_flags |= TSF_XFERABLE;
468  }
469  if (pri < PRI_MIN_BATCH) {
470  ts->ts_runq = &tdq->tdq_realtime;
471  } else if (pri <= PRI_MAX_BATCH) {
472  ts->ts_runq = &tdq->tdq_timeshare;
473  KASSERT(pri <= PRI_MAX_BATCH && pri >= PRI_MIN_BATCH,
474  ("Invalid priority %d on timeshare runq", pri));
475  /*
476  * This queue contains only priorities between MIN and MAX
477  * realtime. Use the whole queue to represent these values.
478  */
479  if ((flags & (SRQ_BORROWING|SRQ_PREEMPTED)) == 0) {
480  pri = RQ_NQS * (pri - PRI_MIN_BATCH) / PRI_BATCH_RANGE;
481  pri = (pri + tdq->tdq_idx) % RQ_NQS;
482  /*
483  * This effectively shortens the queue by one so we
484  * can have a one slot difference between idx and
485  * ridx while we wait for threads to drain.
486  */
487  if (tdq->tdq_ridx != tdq->tdq_idx &&
488  pri == tdq->tdq_ridx)
489  pri = (unsigned char)(pri - 1) % RQ_NQS;
490  } else
491  pri = tdq->tdq_ridx;
492  runq_add_pri(ts->ts_runq, td, pri, flags);
493  return;
494  } else
495  ts->ts_runq = &tdq->tdq_idle;
496  runq_add(ts->ts_runq, td, flags);
497 }
498 
499 /*
500  * Remove a thread from a run-queue. This typically happens when a thread
501  * is selected to run. Running threads are not on the queue and the
502  * transferable count does not reflect them.
503  */
504 static __inline void
505 tdq_runq_rem(struct tdq *tdq, struct thread *td)
506 {
507  struct td_sched *ts;
508 
509  ts = td->td_sched;
510  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
511  KASSERT(ts->ts_runq != NULL,
512  ("tdq_runq_remove: thread %p null ts_runq", td));
513  if (ts->ts_flags & TSF_XFERABLE) {
514  tdq->tdq_transferable--;
515  ts->ts_flags &= ~TSF_XFERABLE;
516  }
517  if (ts->ts_runq == &tdq->tdq_timeshare) {
518  if (tdq->tdq_idx != tdq->tdq_ridx)
519  runq_remove_idx(ts->ts_runq, td, &tdq->tdq_ridx);
520  else
521  runq_remove_idx(ts->ts_runq, td, NULL);
522  } else
523  runq_remove(ts->ts_runq, td);
524 }
525 
526 /*
527  * Load is maintained for all threads RUNNING and ON_RUNQ. Add the load
528  * for this thread to the referenced thread queue.
529  */
530 static void
531 tdq_load_add(struct tdq *tdq, struct thread *td)
532 {
533 
534  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
535  THREAD_LOCK_ASSERT(td, MA_OWNED);
536 
537  tdq->tdq_load++;
538  if ((td->td_flags & TDF_NOLOAD) == 0)
539  tdq->tdq_sysload++;
540  KTR_COUNTER0(KTR_SCHED, "load", tdq->tdq_loadname, tdq->tdq_load);
541  SDT_PROBE2(sched, , , load__change, (int)TDQ_ID(tdq), tdq->tdq_load);
542 }
543 
544 /*
545  * Remove the load from a thread that is transitioning to a sleep state or
546  * exiting.
547  */
548 static void
549 tdq_load_rem(struct tdq *tdq, struct thread *td)
550 {
551 
552  THREAD_LOCK_ASSERT(td, MA_OWNED);
553  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
554  KASSERT(tdq->tdq_load != 0,
555  ("tdq_load_rem: Removing with 0 load on queue %d", TDQ_ID(tdq)));
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  * Bound timeshare latency by decreasing slice size as load increases. We
566  * consider the maximum latency as the sum of the threads waiting to run
567  * aside from curthread and target no more than sched_slice latency but
568  * no less than sched_slice_min runtime.
569  */
570 static inline int
571 tdq_slice(struct tdq *tdq)
572 {
573  int load;
574 
575  /*
576  * It is safe to use sys_load here because this is called from
577  * contexts where timeshare threads are running and so there
578  * cannot be higher priority load in the system.
579  */
580  load = tdq->tdq_sysload - 1;
581  if (load >= SCHED_SLICE_MIN_DIVISOR)
582  return (sched_slice_min);
583  if (load <= 1)
584  return (sched_slice);
585  return (sched_slice / load);
586 }
587 
588 /*
589  * Set lowpri to its exact value by searching the run-queue and
590  * evaluating curthread. curthread may be passed as an optimization.
591  */
592 static void
593 tdq_setlowpri(struct tdq *tdq, struct thread *ctd)
594 {
595  struct thread *td;
596 
597  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
598  if (ctd == NULL)
599  ctd = pcpu_find(TDQ_ID(tdq))->pc_curthread;
600  td = tdq_choose(tdq);
601  if (td == NULL || td->td_priority > ctd->td_priority)
602  tdq->tdq_lowpri = ctd->td_priority;
603  else
604  tdq->tdq_lowpri = td->td_priority;
605 }
606 
607 #ifdef SMP
608 /*
609  * We need some randomness. Implement a classic Linear Congruential
610  * Generator X_{n+1}=(aX_n+c) mod m. These values are optimized for
611  * m = 2^32, a = 69069 and c = 5. We only return the upper 16 bits
612  * of the random state (in the low bits of our answer) to keep
613  * the maximum randomness.
614  */
615 static uint32_t
616 sched_random(void)
617 {
618  uint32_t *rndptr;
619 
620  rndptr = DPCPU_PTR(randomval);
621  *rndptr = *rndptr * 69069 + 5;
622 
623  return (*rndptr >> 16);
624 }
625 
626 struct cpu_search {
627  cpuset_t cs_mask;
628  u_int cs_prefer;
629  int cs_pri; /* Min priority for low. */
630  int cs_limit; /* Max load for low, min load for high. */
631  int cs_cpu;
632  int cs_load;
633 };
634 
635 #define CPU_SEARCH_LOWEST 0x1
636 #define CPU_SEARCH_HIGHEST 0x2
637 #define CPU_SEARCH_BOTH (CPU_SEARCH_LOWEST|CPU_SEARCH_HIGHEST)
638 
639 #define CPUSET_FOREACH(cpu, mask) \
640  for ((cpu) = 0; (cpu) <= mp_maxid; (cpu)++) \
641  if (CPU_ISSET(cpu, &mask))
642 
643 static __always_inline int cpu_search(const struct cpu_group *cg,
644  struct cpu_search *low, struct cpu_search *high, const int match);
645 int __noinline cpu_search_lowest(const struct cpu_group *cg,
646  struct cpu_search *low);
647 int __noinline cpu_search_highest(const struct cpu_group *cg,
648  struct cpu_search *high);
649 int __noinline cpu_search_both(const struct cpu_group *cg,
650  struct cpu_search *low, struct cpu_search *high);
651 
652 /*
653  * Search the tree of cpu_groups for the lowest or highest loaded cpu
654  * according to the match argument. This routine actually compares the
655  * load on all paths through the tree and finds the least loaded cpu on
656  * the least loaded path, which may differ from the least loaded cpu in
657  * the system. This balances work among caches and busses.
658  *
659  * This inline is instantiated in three forms below using constants for the
660  * match argument. It is reduced to the minimum set for each case. It is
661  * also recursive to the depth of the tree.
662  */
663 static __always_inline int
664 cpu_search(const struct cpu_group *cg, struct cpu_search *low,
665  struct cpu_search *high, const int match)
666 {
667  struct cpu_search lgroup;
668  struct cpu_search hgroup;
669  cpuset_t cpumask;
670  struct cpu_group *child;
671  struct tdq *tdq;
672  int cpu, i, hload, lload, load, total, rnd;
673 
674  total = 0;
675  cpumask = cg->cg_mask;
676  if (match & CPU_SEARCH_LOWEST) {
677  lload = INT_MAX;
678  lgroup = *low;
679  }
680  if (match & CPU_SEARCH_HIGHEST) {
681  hload = INT_MIN;
682  hgroup = *high;
683  }
684 
685  /* Iterate through the child CPU groups and then remaining CPUs. */
686  for (i = cg->cg_children, cpu = mp_maxid; ; ) {
687  if (i == 0) {
688 #ifdef HAVE_INLINE_FFSL
689  cpu = CPU_FFS(&cpumask) - 1;
690 #else
691  while (cpu >= 0 && !CPU_ISSET(cpu, &cpumask))
692  cpu--;
693 #endif
694  if (cpu < 0)
695  break;
696  child = NULL;
697  } else
698  child = &cg->cg_child[i - 1];
699 
700  if (match & CPU_SEARCH_LOWEST)
701  lgroup.cs_cpu = -1;
702  if (match & CPU_SEARCH_HIGHEST)
703  hgroup.cs_cpu = -1;
704  if (child) { /* Handle child CPU group. */
705  CPU_NAND(&cpumask, &child->cg_mask);
706  switch (match) {
707  case CPU_SEARCH_LOWEST:
708  load = cpu_search_lowest(child, &lgroup);
709  break;
710  case CPU_SEARCH_HIGHEST:
711  load = cpu_search_highest(child, &hgroup);
712  break;
713  case CPU_SEARCH_BOTH:
714  load = cpu_search_both(child, &lgroup, &hgroup);
715  break;
716  }
717  } else { /* Handle child CPU. */
718  CPU_CLR(cpu, &cpumask);
719  tdq = TDQ_CPU(cpu);
720  load = tdq->tdq_load * 256;
721  rnd = sched_random() % 32;
722  if (match & CPU_SEARCH_LOWEST) {
723  if (cpu == low->cs_prefer)
724  load -= 64;
725  /* If that CPU is allowed and get data. */
726  if (tdq->tdq_lowpri > lgroup.cs_pri &&
727  tdq->tdq_load <= lgroup.cs_limit &&
728  CPU_ISSET(cpu, &lgroup.cs_mask)) {
729  lgroup.cs_cpu = cpu;
730  lgroup.cs_load = load - rnd;
731  }
732  }
733  if (match & CPU_SEARCH_HIGHEST)
734  if (tdq->tdq_load >= hgroup.cs_limit &&
735  tdq->tdq_transferable &&
736  CPU_ISSET(cpu, &hgroup.cs_mask)) {
737  hgroup.cs_cpu = cpu;
738  hgroup.cs_load = load - rnd;
739  }
740  }
741  total += load;
742 
743  /* We have info about child item. Compare it. */
744  if (match & CPU_SEARCH_LOWEST) {
745  if (lgroup.cs_cpu >= 0 &&
746  (load < lload ||
747  (load == lload && lgroup.cs_load < low->cs_load))) {
748  lload = load;
749  low->cs_cpu = lgroup.cs_cpu;
750  low->cs_load = lgroup.cs_load;
751  }
752  }
753  if (match & CPU_SEARCH_HIGHEST)
754  if (hgroup.cs_cpu >= 0 &&
755  (load > hload ||
756  (load == hload && hgroup.cs_load > high->cs_load))) {
757  hload = load;
758  high->cs_cpu = hgroup.cs_cpu;
759  high->cs_load = hgroup.cs_load;
760  }
761  if (child) {
762  i--;
763  if (i == 0 && CPU_EMPTY(&cpumask))
764  break;
765  }
766 #ifndef HAVE_INLINE_FFSL
767  else
768  cpu--;
769 #endif
770  }
771  return (total);
772 }
773 
774 /*
775  * cpu_search instantiations must pass constants to maintain the inline
776  * optimization.
777  */
778 int
779 cpu_search_lowest(const struct cpu_group *cg, struct cpu_search *low)
780 {
781  return cpu_search(cg, low, NULL, CPU_SEARCH_LOWEST);
782 }
783 
784 int
785 cpu_search_highest(const struct cpu_group *cg, struct cpu_search *high)
786 {
787  return cpu_search(cg, NULL, high, CPU_SEARCH_HIGHEST);
788 }
789 
790 int
791 cpu_search_both(const struct cpu_group *cg, struct cpu_search *low,
792  struct cpu_search *high)
793 {
794  return cpu_search(cg, low, high, CPU_SEARCH_BOTH);
795 }
796 
797 /*
798  * Find the cpu with the least load via the least loaded path that has a
799  * lowpri greater than pri pri. A pri of -1 indicates any priority is
800  * acceptable.
801  */
802 static inline int
803 sched_lowest(const struct cpu_group *cg, cpuset_t mask, int pri, int maxload,
804  int prefer)
805 {
806  struct cpu_search low;
807 
808  low.cs_cpu = -1;
809  low.cs_prefer = prefer;
810  low.cs_mask = mask;
811  low.cs_pri = pri;
812  low.cs_limit = maxload;
813  cpu_search_lowest(cg, &low);
814  return low.cs_cpu;
815 }
816 
817 /*
818  * Find the cpu with the highest load via the highest loaded path.
819  */
820 static inline int
821 sched_highest(const struct cpu_group *cg, cpuset_t mask, int minload)
822 {
823  struct cpu_search high;
824 
825  high.cs_cpu = -1;
826  high.cs_mask = mask;
827  high.cs_limit = minload;
828  cpu_search_highest(cg, &high);
829  return high.cs_cpu;
830 }
831 
832 static void
833 sched_balance_group(struct cpu_group *cg)
834 {
835  cpuset_t hmask, lmask;
836  int high, low, anylow;
837 
838  CPU_FILL(&hmask);
839  for (;;) {
840  high = sched_highest(cg, hmask, 1);
841  /* Stop if there is no more CPU with transferrable threads. */
842  if (high == -1)
843  break;
844  CPU_CLR(high, &hmask);
845  CPU_COPY(&hmask, &lmask);
846  /* Stop if there is no more CPU left for low. */
847  if (CPU_EMPTY(&lmask))
848  break;
849  anylow = 1;
850 nextlow:
851  low = sched_lowest(cg, lmask, -1,
852  TDQ_CPU(high)->tdq_load - 1, high);
853  /* Stop if we looked well and found no less loaded CPU. */
854  if (anylow && low == -1)
855  break;
856  /* Go to next high if we found no less loaded CPU. */
857  if (low == -1)
858  continue;
859  /* Transfer thread from high to low. */
860  if (sched_balance_pair(TDQ_CPU(high), TDQ_CPU(low))) {
861  /* CPU that got thread can no longer be a donor. */
862  CPU_CLR(low, &hmask);
863  } else {
864  /*
865  * If failed, then there is no threads on high
866  * that can run on this low. Drop low from low
867  * mask and look for different one.
868  */
869  CPU_CLR(low, &lmask);
870  anylow = 0;
871  goto nextlow;
872  }
873  }
874 }
875 
876 static void
877 sched_balance(void)
878 {
879  struct tdq *tdq;
880 
881  if (smp_started == 0 || rebalance == 0)
882  return;
883 
884  balance_ticks = max(balance_interval / 2, 1) +
885  (sched_random() % balance_interval);
886  tdq = TDQ_SELF();
887  TDQ_UNLOCK(tdq);
888  sched_balance_group(cpu_top);
889  TDQ_LOCK(tdq);
890 }
891 
892 /*
893  * Lock two thread queues using their address to maintain lock order.
894  */
895 static void
896 tdq_lock_pair(struct tdq *one, struct tdq *two)
897 {
898  if (one < two) {
899  TDQ_LOCK(one);
900  TDQ_LOCK_FLAGS(two, MTX_DUPOK);
901  } else {
902  TDQ_LOCK(two);
903  TDQ_LOCK_FLAGS(one, MTX_DUPOK);
904  }
905 }
906 
907 /*
908  * Unlock two thread queues. Order is not important here.
909  */
910 static void
911 tdq_unlock_pair(struct tdq *one, struct tdq *two)
912 {
913  TDQ_UNLOCK(one);
914  TDQ_UNLOCK(two);
915 }
916 
917 /*
918  * Transfer load between two imbalanced thread queues.
919  */
920 static int
921 sched_balance_pair(struct tdq *high, struct tdq *low)
922 {
923  int moved;
924  int cpu;
925 
926  tdq_lock_pair(high, low);
927  moved = 0;
928  /*
929  * Determine what the imbalance is and then adjust that to how many
930  * threads we actually have to give up (transferable).
931  */
932  if (high->tdq_transferable != 0 && high->tdq_load > low->tdq_load &&
933  (moved = tdq_move(high, low)) > 0) {
934  /*
935  * In case the target isn't the current cpu IPI it to force a
936  * reschedule with the new workload.
937  */
938  cpu = TDQ_ID(low);
939  if (cpu != PCPU_GET(cpuid))
940  ipi_cpu(cpu, IPI_PREEMPT);
941  }
942  tdq_unlock_pair(high, low);
943  return (moved);
944 }
945 
946 /*
947  * Move a thread from one thread queue to another.
948  */
949 static int
950 tdq_move(struct tdq *from, struct tdq *to)
951 {
952  struct td_sched *ts;
953  struct thread *td;
954  struct tdq *tdq;
955  int cpu;
956 
957  TDQ_LOCK_ASSERT(from, MA_OWNED);
958  TDQ_LOCK_ASSERT(to, MA_OWNED);
959 
960  tdq = from;
961  cpu = TDQ_ID(to);
962  td = tdq_steal(tdq, cpu);
963  if (td == NULL)
964  return (0);
965  ts = td->td_sched;
966  /*
967  * Although the run queue is locked the thread may be blocked. Lock
968  * it to clear this and acquire the run-queue lock.
969  */
970  thread_lock(td);
971  /* Drop recursive lock on from acquired via thread_lock(). */
972  TDQ_UNLOCK(from);
973  sched_rem(td);
974  ts->ts_cpu = cpu;
975  td->td_lock = TDQ_LOCKPTR(to);
976  tdq_add(to, td, SRQ_YIELDING);
977  return (1);
978 }
979 
980 /*
981  * This tdq has idled. Try to steal a thread from another cpu and switch
982  * to it.
983  */
984 static int
985 tdq_idled(struct tdq *tdq)
986 {
987  struct cpu_group *cg;
988  struct tdq *steal;
989  cpuset_t mask;
990  int thresh;
991  int cpu;
992 
993  if (smp_started == 0 || steal_idle == 0)
994  return (1);
995  CPU_FILL(&mask);
996  CPU_CLR(PCPU_GET(cpuid), &mask);
997  /* We don't want to be preempted while we're iterating. */
998  spinlock_enter();
999  for (cg = tdq->tdq_cg; cg != NULL; ) {
1000  if ((cg->cg_flags & CG_FLAG_THREAD) == 0)
1001  thresh = steal_thresh;
1002  else
1003  thresh = 1;
1004  cpu = sched_highest(cg, mask, thresh);
1005  if (cpu == -1) {
1006  cg = cg->cg_parent;
1007  continue;
1008  }
1009  steal = TDQ_CPU(cpu);
1010  CPU_CLR(cpu, &mask);
1011  tdq_lock_pair(tdq, steal);
1012  if (steal->tdq_load < thresh || steal->tdq_transferable == 0) {
1013  tdq_unlock_pair(tdq, steal);
1014  continue;
1015  }
1016  /*
1017  * If a thread was added while interrupts were disabled don't
1018  * steal one here. If we fail to acquire one due to affinity
1019  * restrictions loop again with this cpu removed from the
1020  * set.
1021  */
1022  if (tdq->tdq_load == 0 && tdq_move(steal, tdq) == 0) {
1023  tdq_unlock_pair(tdq, steal);
1024  continue;
1025  }
1026  spinlock_exit();
1027  TDQ_UNLOCK(steal);
1028  mi_switch(SW_VOL | SWT_IDLE, NULL);
1029  thread_unlock(curthread);
1030 
1031  return (0);
1032  }
1033  spinlock_exit();
1034  return (1);
1035 }
1036 
1037 /*
1038  * Notify a remote cpu of new work. Sends an IPI if criteria are met.
1039  */
1040 static void
1041 tdq_notify(struct tdq *tdq, struct thread *td)
1042 {
1043  struct thread *ctd;
1044  int pri;
1045  int cpu;
1046 
1047  if (tdq->tdq_ipipending)
1048  return;
1049  cpu = td->td_sched->ts_cpu;
1050  pri = td->td_priority;
1051  ctd = pcpu_find(cpu)->pc_curthread;
1052  if (!sched_shouldpreempt(pri, ctd->td_priority, 1))
1053  return;
1054 
1055  /*
1056  * Make sure that our caller's earlier update to tdq_load is
1057  * globally visible before we read tdq_cpu_idle. Idle thread
1058  * accesses both of them without locks, and the order is important.
1059  */
1060  atomic_thread_fence_seq_cst();
1061 
1062  if (TD_IS_IDLETHREAD(ctd)) {
1063  /*
1064  * If the MD code has an idle wakeup routine try that before
1065  * falling back to IPI.
1066  */
1067  if (!tdq->tdq_cpu_idle || cpu_idle_wakeup(cpu))
1068  return;
1069  }
1070  tdq->tdq_ipipending = 1;
1071  ipi_cpu(cpu, IPI_PREEMPT);
1072 }
1073 
1074 /*
1075  * Steals load from a timeshare queue. Honors the rotating queue head
1076  * index.
1077  */
1078 static struct thread *
1079 runq_steal_from(struct runq *rq, int cpu, u_char start)
1080 {
1081  struct rqbits *rqb;
1082  struct rqhead *rqh;
1083  struct thread *td, *first;
1084  int bit;
1085  int i;
1086 
1087  rqb = &rq->rq_status;
1088  bit = start & (RQB_BPW -1);
1089  first = NULL;
1090 again:
1091  for (i = RQB_WORD(start); i < RQB_LEN; bit = 0, i++) {
1092  if (rqb->rqb_bits[i] == 0)
1093  continue;
1094  if (bit == 0)
1095  bit = RQB_FFS(rqb->rqb_bits[i]);
1096  for (; bit < RQB_BPW; bit++) {
1097  if ((rqb->rqb_bits[i] & (1ul << bit)) == 0)
1098  continue;
1099  rqh = &rq->rq_queues[bit + (i << RQB_L2BPW)];
1100  TAILQ_FOREACH(td, rqh, td_runq) {
1101  if (first && THREAD_CAN_MIGRATE(td) &&
1102  THREAD_CAN_SCHED(td, cpu))
1103  return (td);
1104  first = td;
1105  }
1106  }
1107  }
1108  if (start != 0) {
1109  start = 0;
1110  goto again;
1111  }
1112 
1113  if (first && THREAD_CAN_MIGRATE(first) &&
1114  THREAD_CAN_SCHED(first, cpu))
1115  return (first);
1116  return (NULL);
1117 }
1118 
1119 /*
1120  * Steals load from a standard linear queue.
1121  */
1122 static struct thread *
1123 runq_steal(struct runq *rq, int cpu)
1124 {
1125  struct rqhead *rqh;
1126  struct rqbits *rqb;
1127  struct thread *td;
1128  int word;
1129  int bit;
1130 
1131  rqb = &rq->rq_status;
1132  for (word = 0; word < RQB_LEN; word++) {
1133  if (rqb->rqb_bits[word] == 0)
1134  continue;
1135  for (bit = 0; bit < RQB_BPW; bit++) {
1136  if ((rqb->rqb_bits[word] & (1ul << bit)) == 0)
1137  continue;
1138  rqh = &rq->rq_queues[bit + (word << RQB_L2BPW)];
1139  TAILQ_FOREACH(td, rqh, td_runq)
1140  if (THREAD_CAN_MIGRATE(td) &&
1141  THREAD_CAN_SCHED(td, cpu))
1142  return (td);
1143  }
1144  }
1145  return (NULL);
1146 }
1147 
1148 /*
1149  * Attempt to steal a thread in priority order from a thread queue.
1150  */
1151 static struct thread *
1152 tdq_steal(struct tdq *tdq, int cpu)
1153 {
1154  struct thread *td;
1155 
1156  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
1157  if ((td = runq_steal(&tdq->tdq_realtime, cpu)) != NULL)
1158  return (td);
1159  if ((td = runq_steal_from(&tdq->tdq_timeshare,
1160  cpu, tdq->tdq_ridx)) != NULL)
1161  return (td);
1162  return (runq_steal(&tdq->tdq_idle, cpu));
1163 }
1164 
1165 /*
1166  * Sets the thread lock and ts_cpu to match the requested cpu. Unlocks the
1167  * current lock and returns with the assigned queue locked.
1168  */
1169 static inline struct tdq *
1170 sched_setcpu(struct thread *td, int cpu, int flags)
1171 {
1172 
1173  struct tdq *tdq;
1174 
1175  THREAD_LOCK_ASSERT(td, MA_OWNED);
1176  tdq = TDQ_CPU(cpu);
1177  td->td_sched->ts_cpu = cpu;
1178  /*
1179  * If the lock matches just return the queue.
1180  */
1181  if (td->td_lock == TDQ_LOCKPTR(tdq))
1182  return (tdq);
1183 #ifdef notyet
1184  /*
1185  * If the thread isn't running its lockptr is a
1186  * turnstile or a sleepqueue. We can just lock_set without
1187  * blocking.
1188  */
1189  if (TD_CAN_RUN(td)) {
1190  TDQ_LOCK(tdq);
1191  thread_lock_set(td, TDQ_LOCKPTR(tdq));
1192  return (tdq);
1193  }
1194 #endif
1195  /*
1196  * The hard case, migration, we need to block the thread first to
1197  * prevent order reversals with other cpus locks.
1198  */
1199  spinlock_enter();
1200  thread_lock_block(td);
1201  TDQ_LOCK(tdq);
1202  thread_lock_unblock(td, TDQ_LOCKPTR(tdq));
1203  spinlock_exit();
1204  return (tdq);
1205 }
1206 
1207 SCHED_STAT_DEFINE(pickcpu_intrbind, "Soft interrupt binding");
1208 SCHED_STAT_DEFINE(pickcpu_idle_affinity, "Picked idle cpu based on affinity");
1209 SCHED_STAT_DEFINE(pickcpu_affinity, "Picked cpu based on affinity");
1210 SCHED_STAT_DEFINE(pickcpu_lowest, "Selected lowest load");
1211 SCHED_STAT_DEFINE(pickcpu_local, "Migrated to current cpu");
1212 SCHED_STAT_DEFINE(pickcpu_migration, "Selection may have caused migration");
1213 
1214 static int
1215 sched_pickcpu(struct thread *td, int flags)
1216 {
1217  struct cpu_group *cg, *ccg;
1218  struct td_sched *ts;
1219  struct tdq *tdq;
1220  cpuset_t mask;
1221  int cpu, pri, self;
1222 
1223  self = PCPU_GET(cpuid);
1224  ts = td->td_sched;
1225  if (smp_started == 0)
1226  return (self);
1227  /*
1228  * Don't migrate a running thread from sched_switch().
1229  */
1230  if ((flags & SRQ_OURSELF) || !THREAD_CAN_MIGRATE(td))
1231  return (ts->ts_cpu);
1232  /*
1233  * Prefer to run interrupt threads on the processors that generate
1234  * the interrupt.
1235  */
1236  pri = td->td_priority;
1237  if (td->td_priority <= PRI_MAX_ITHD && THREAD_CAN_SCHED(td, self) &&
1238  curthread->td_intr_nesting_level && ts->ts_cpu != self) {
1239  SCHED_STAT_INC(pickcpu_intrbind);
1240  ts->ts_cpu = self;
1241  if (TDQ_CPU(self)->tdq_lowpri > pri) {
1242  SCHED_STAT_INC(pickcpu_affinity);
1243  return (ts->ts_cpu);
1244  }
1245  }
1246  /*
1247  * If the thread can run on the last cpu and the affinity has not
1248  * expired or it is idle run it there.
1249  */
1250  tdq = TDQ_CPU(ts->ts_cpu);
1251  cg = tdq->tdq_cg;
1252  if (THREAD_CAN_SCHED(td, ts->ts_cpu) &&
1253  tdq->tdq_lowpri >= PRI_MIN_IDLE &&
1254  SCHED_AFFINITY(ts, CG_SHARE_L2)) {
1255  if (cg->cg_flags & CG_FLAG_THREAD) {
1256  CPUSET_FOREACH(cpu, cg->cg_mask) {
1257  if (TDQ_CPU(cpu)->tdq_lowpri < PRI_MIN_IDLE)
1258  break;
1259  }
1260  } else
1261  cpu = INT_MAX;
1262  if (cpu > mp_maxid) {
1263  SCHED_STAT_INC(pickcpu_idle_affinity);
1264  return (ts->ts_cpu);
1265  }
1266  }
1267  /*
1268  * Search for the last level cache CPU group in the tree.
1269  * Skip caches with expired affinity time and SMT groups.
1270  * Affinity to higher level caches will be handled less aggressively.
1271  */
1272  for (ccg = NULL; cg != NULL; cg = cg->cg_parent) {
1273  if (cg->cg_flags & CG_FLAG_THREAD)
1274  continue;
1275  if (!SCHED_AFFINITY(ts, cg->cg_level))
1276  continue;
1277  ccg = cg;
1278  }
1279  if (ccg != NULL)
1280  cg = ccg;
1281  cpu = -1;
1282  /* Search the group for the less loaded idle CPU we can run now. */
1283  mask = td->td_cpuset->cs_mask;
1284  if (cg != NULL && cg != cpu_top &&
1285  CPU_CMP(&cg->cg_mask, &cpu_top->cg_mask) != 0)
1286  cpu = sched_lowest(cg, mask, max(pri, PRI_MAX_TIMESHARE),
1287  INT_MAX, ts->ts_cpu);
1288  /* Search globally for the less loaded CPU we can run now. */
1289  if (cpu == -1)
1290  cpu = sched_lowest(cpu_top, mask, pri, INT_MAX, ts->ts_cpu);
1291  /* Search globally for the less loaded CPU. */
1292  if (cpu == -1)
1293  cpu = sched_lowest(cpu_top, mask, -1, INT_MAX, ts->ts_cpu);
1294  KASSERT(cpu != -1, ("sched_pickcpu: Failed to find a cpu."));
1295  /*
1296  * Compare the lowest loaded cpu to current cpu.
1297  */
1298  if (THREAD_CAN_SCHED(td, self) && TDQ_CPU(self)->tdq_lowpri > pri &&
1299  TDQ_CPU(cpu)->tdq_lowpri < PRI_MIN_IDLE &&
1300  TDQ_CPU(self)->tdq_load <= TDQ_CPU(cpu)->tdq_load + 1) {
1301  SCHED_STAT_INC(pickcpu_local);
1302  cpu = self;
1303  } else
1304  SCHED_STAT_INC(pickcpu_lowest);
1305  if (cpu != ts->ts_cpu)
1306  SCHED_STAT_INC(pickcpu_migration);
1307  return (cpu);
1308 }
1309 #endif
1310 
1311 /*
1312  * Pick the highest priority task we have and return it.
1313  */
1314 static struct thread *
1315 tdq_choose(struct tdq *tdq)
1316 {
1317  struct thread *td;
1318 
1319  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
1320  td = runq_choose(&tdq->tdq_realtime);
1321  if (td != NULL)
1322  return (td);
1323  td = runq_choose_from(&tdq->tdq_timeshare, tdq->tdq_ridx);
1324  if (td != NULL) {
1325  KASSERT(td->td_priority >= PRI_MIN_BATCH,
1326  ("tdq_choose: Invalid priority on timeshare queue %d",
1327  td->td_priority));
1328  return (td);
1329  }
1330  td = runq_choose(&tdq->tdq_idle);
1331  if (td != NULL) {
1332  KASSERT(td->td_priority >= PRI_MIN_IDLE,
1333  ("tdq_choose: Invalid priority on idle queue %d",
1334  td->td_priority));
1335  return (td);
1336  }
1337 
1338  return (NULL);
1339 }
1340 
1341 /*
1342  * Initialize a thread queue.
1343  */
1344 static void
1345 tdq_setup(struct tdq *tdq)
1346 {
1347 
1348  if (bootverbose)
1349  printf("ULE: setup cpu %d\n", TDQ_ID(tdq));
1350  runq_init(&tdq->tdq_realtime);
1351  runq_init(&tdq->tdq_timeshare);
1352  runq_init(&tdq->tdq_idle);
1353  snprintf(tdq->tdq_name, sizeof(tdq->tdq_name),
1354  "sched lock %d", (int)TDQ_ID(tdq));
1355  mtx_init(&tdq->tdq_lock, tdq->tdq_name, "sched lock",
1356  MTX_SPIN | MTX_RECURSE);
1357 #ifdef KTR
1358  snprintf(tdq->tdq_loadname, sizeof(tdq->tdq_loadname),
1359  "CPU %d load", (int)TDQ_ID(tdq));
1360 #endif
1361 }
1362 
1363 #ifdef SMP
1364 static void
1365 sched_setup_smp(void)
1366 {
1367  struct tdq *tdq;
1368  int i;
1369 
1370  cpu_top = smp_topo();
1371  CPU_FOREACH(i) {
1372  tdq = TDQ_CPU(i);
1373  tdq_setup(tdq);
1374  tdq->tdq_cg = smp_topo_find(cpu_top, i);
1375  if (tdq->tdq_cg == NULL)
1376  panic("Can't find cpu group for %d\n", i);
1377  }
1378  balance_tdq = TDQ_SELF();
1379  sched_balance();
1380 }
1381 #endif
1382 
1383 /*
1384  * Setup the thread queues and initialize the topology based on MD
1385  * information.
1386  */
1387 static void
1389 {
1390  struct tdq *tdq;
1391 
1392  tdq = TDQ_SELF();
1393 #ifdef SMP
1394  sched_setup_smp();
1395 #else
1396  tdq_setup(tdq);
1397 #endif
1398 
1399  /* Add thread0's load since it's running. */
1400  TDQ_LOCK(tdq);
1401  thread0.td_lock = TDQ_LOCKPTR(TDQ_SELF());
1402  tdq_load_add(tdq, &thread0);
1403  tdq->tdq_lowpri = thread0.td_priority;
1404  TDQ_UNLOCK(tdq);
1405 }
1406 
1407 /*
1408  * This routine determines time constants after stathz and hz are setup.
1409  */
1410 /* ARGSUSED */
1411 static void
1413 {
1414  int incr;
1415 
1416  realstathz = stathz ? stathz : hz;
1419  hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) /
1420  realstathz);
1421 
1422  /*
1423  * tickincr is shifted out by 10 to avoid rounding errors due to
1424  * hz not being evenly divisible by stathz on all platforms.
1425  */
1426  incr = (hz << SCHED_TICK_SHIFT) / realstathz;
1427  /*
1428  * This does not work for values of stathz that are more than
1429  * 1 << SCHED_TICK_SHIFT * hz. In practice this does not happen.
1430  */
1431  if (incr == 0)
1432  incr = 1;
1433  tickincr = incr;
1434 #ifdef SMP
1435  /*
1436  * Set the default balance interval now that we know
1437  * what realstathz is.
1438  */
1439  balance_interval = realstathz;
1440  affinity = SCHED_AFFINITY_DEFAULT;
1441 #endif
1442  if (sched_idlespinthresh < 0)
1443  sched_idlespinthresh = 2 * max(10000, 6 * hz) / realstathz;
1444 }
1445 
1446 
1447 /*
1448  * This is the core of the interactivity algorithm. Determines a score based
1449  * on past behavior. It is the ratio of sleep time to run time scaled to
1450  * a [0, 100] integer. This is the voluntary sleep time of a process, which
1451  * differs from the cpu usage because it does not account for time spent
1452  * waiting on a run-queue. Would be prettier if we had floating point.
1453  *
1454  * When a thread's sleep time is greater than its run time the
1455  * calculation is:
1456  *
1457  * scaling factor
1458  * interactivity score = ---------------------
1459  * sleep time / run time
1460  *
1461  *
1462  * When a thread's run time is greater than its sleep time the
1463  * calculation is:
1464  *
1465  * scaling factor
1466  * interactivity score = --------------------- + scaling factor
1467  * run time / sleep time
1468  */
1469 static int
1470 sched_interact_score(struct thread *td)
1471 {
1472  struct td_sched *ts;
1473  int div;
1474 
1475  ts = td->td_sched;
1476  /*
1477  * The score is only needed if this is likely to be an interactive
1478  * task. Don't go through the expense of computing it if there's
1479  * no chance.
1480  */
1482  ts->ts_runtime >= ts->ts_slptime)
1483  return (SCHED_INTERACT_HALF);
1484 
1485  if (ts->ts_runtime > ts->ts_slptime) {
1486  div = max(1, ts->ts_runtime / SCHED_INTERACT_HALF);
1487  return (SCHED_INTERACT_HALF +
1488  (SCHED_INTERACT_HALF - (ts->ts_slptime / div)));
1489  }
1490  if (ts->ts_slptime > ts->ts_runtime) {
1491  div = max(1, ts->ts_slptime / SCHED_INTERACT_HALF);
1492  return (ts->ts_runtime / div);
1493  }
1494  /* runtime == slptime */
1495  if (ts->ts_runtime)
1496  return (SCHED_INTERACT_HALF);
1497 
1498  /*
1499  * This can happen if slptime and runtime are 0.
1500  */
1501  return (0);
1502 
1503 }
1504 
1505 /*
1506  * Scale the scheduling priority according to the "interactivity" of this
1507  * process.
1508  */
1509 static void
1510 sched_priority(struct thread *td)
1511 {
1512  int score;
1513  int pri;
1514 
1515  if (PRI_BASE(td->td_pri_class) != PRI_TIMESHARE)
1516  return;
1517  /*
1518  * If the score is interactive we place the thread in the realtime
1519  * queue with a priority that is less than kernel and interrupt
1520  * priorities. These threads are not subject to nice restrictions.
1521  *
1522  * Scores greater than this are placed on the normal timeshare queue
1523  * where the priority is partially decided by the most recent cpu
1524  * utilization and the rest is decided by nice value.
1525  *
1526  * The nice value of the process has a linear effect on the calculated
1527  * score. Negative nice values make it easier for a thread to be
1528  * considered interactive.
1529  */
1530  score = imax(0, sched_interact_score(td) + td->td_proc->p_nice);
1531  if (score < sched_interact) {
1532  pri = PRI_MIN_INTERACT;
1533  pri += ((PRI_MAX_INTERACT - PRI_MIN_INTERACT + 1) /
1534  sched_interact) * score;
1535  KASSERT(pri >= PRI_MIN_INTERACT && pri <= PRI_MAX_INTERACT,
1536  ("sched_priority: invalid interactive priority %d score %d",
1537  pri, score));
1538  } else {
1539  pri = SCHED_PRI_MIN;
1540  if (td->td_sched->ts_ticks)
1541  pri += min(SCHED_PRI_TICKS(td->td_sched),
1542  SCHED_PRI_RANGE - 1);
1543  pri += SCHED_PRI_NICE(td->td_proc->p_nice);
1544  KASSERT(pri >= PRI_MIN_BATCH && pri <= PRI_MAX_BATCH,
1545  ("sched_priority: invalid priority %d: nice %d, "
1546  "ticks %d ftick %d ltick %d tick pri %d",
1547  pri, td->td_proc->p_nice, td->td_sched->ts_ticks,
1548  td->td_sched->ts_ftick, td->td_sched->ts_ltick,
1549  SCHED_PRI_TICKS(td->td_sched)));
1550  }
1551  sched_user_prio(td, pri);
1552 
1553  return;
1554 }
1555 
1556 /*
1557  * This routine enforces a maximum limit on the amount of scheduling history
1558  * kept. It is called after either the slptime or runtime is adjusted. This
1559  * function is ugly due to integer math.
1560  */
1561 static void
1562 sched_interact_update(struct thread *td)
1563 {
1564  struct td_sched *ts;
1565  u_int sum;
1566 
1567  ts = td->td_sched;
1568  sum = ts->ts_runtime + ts->ts_slptime;
1569  if (sum < SCHED_SLP_RUN_MAX)
1570  return;
1571  /*
1572  * This only happens from two places:
1573  * 1) We have added an unusual amount of run time from fork_exit.
1574  * 2) We have added an unusual amount of sleep time from sched_sleep().
1575  */
1576  if (sum > SCHED_SLP_RUN_MAX * 2) {
1577  if (ts->ts_runtime > ts->ts_slptime) {
1579  ts->ts_slptime = 1;
1580  } else {
1582  ts->ts_runtime = 1;
1583  }
1584  return;
1585  }
1586  /*
1587  * If we have exceeded by more than 1/5th then the algorithm below
1588  * will not bring us back into range. Dividing by two here forces
1589  * us into the range of [4/5 * SCHED_INTERACT_MAX, SCHED_INTERACT_MAX]
1590  */
1591  if (sum > (SCHED_SLP_RUN_MAX / 5) * 6) {
1592  ts->ts_runtime /= 2;
1593  ts->ts_slptime /= 2;
1594  return;
1595  }
1596  ts->ts_runtime = (ts->ts_runtime / 5) * 4;
1597  ts->ts_slptime = (ts->ts_slptime / 5) * 4;
1598 }
1599 
1600 /*
1601  * Scale back the interactivity history when a child thread is created. The
1602  * history is inherited from the parent but the thread may behave totally
1603  * differently. For example, a shell spawning a compiler process. We want
1604  * to learn that the compiler is behaving badly very quickly.
1605  */
1606 static void
1607 sched_interact_fork(struct thread *td)
1608 {
1609  int ratio;
1610  int sum;
1611 
1612  sum = td->td_sched->ts_runtime + td->td_sched->ts_slptime;
1613  if (sum > SCHED_SLP_RUN_FORK) {
1614  ratio = sum / SCHED_SLP_RUN_FORK;
1615  td->td_sched->ts_runtime /= ratio;
1616  td->td_sched->ts_slptime /= ratio;
1617  }
1618 }
1619 
1620 /*
1621  * Called from proc0_init() to setup the scheduler fields.
1622  */
1623 void
1625 {
1626 
1627  /*
1628  * Set up the scheduler specific parts of proc0.
1629  */
1630  proc0.p_sched = NULL; /* XXX */
1631  thread0.td_sched = &td_sched0;
1634  td_sched0.ts_slice = 0;
1635 }
1636 
1637 /*
1638  * This is only somewhat accurate since given many processes of the same
1639  * priority they will switch when their slices run out, which will be
1640  * at most sched_slice stathz ticks.
1641  */
1642 int
1644 {
1645 
1646  /* Convert sched_slice from stathz to hz. */
1647  return (imax(1, (sched_slice * hz + realstathz / 2) / realstathz));
1648 }
1649 
1650 /*
1651  * Update the percent cpu tracking information when it is requested or
1652  * the total history exceeds the maximum. We keep a sliding history of
1653  * tick counts that slowly decays. This is less precise than the 4BSD
1654  * mechanism since it happens with less regular and frequent events.
1655  */
1656 static void
1657 sched_pctcpu_update(struct td_sched *ts, int run)
1658 {
1659  int t = ticks;
1660 
1661  if (t - ts->ts_ltick >= SCHED_TICK_TARG) {
1662  ts->ts_ticks = 0;
1663  ts->ts_ftick = t - SCHED_TICK_TARG;
1664  } else if (t - ts->ts_ftick >= SCHED_TICK_MAX) {
1665  ts->ts_ticks = (ts->ts_ticks / (ts->ts_ltick - ts->ts_ftick)) *
1666  (ts->ts_ltick - (t - SCHED_TICK_TARG));
1667  ts->ts_ftick = t - SCHED_TICK_TARG;
1668  }
1669  if (run)
1670  ts->ts_ticks += (t - ts->ts_ltick) << SCHED_TICK_SHIFT;
1671  ts->ts_ltick = t;
1672 }
1673 
1674 /*
1675  * Adjust the priority of a thread. Move it to the appropriate run-queue
1676  * if necessary. This is the back-end for several priority related
1677  * functions.
1678  */
1679 static void
1680 sched_thread_priority(struct thread *td, u_char prio)
1681 {
1682  struct td_sched *ts;
1683  struct tdq *tdq;
1684  int oldpri;
1685 
1686  KTR_POINT3(KTR_SCHED, "thread", sched_tdname(td), "prio",
1687  "prio:%d", td->td_priority, "new prio:%d", prio,
1688  KTR_ATTR_LINKED, sched_tdname(curthread));
1689  SDT_PROBE3(sched, , , change__pri, td, td->td_proc, prio);
1690  if (td != curthread && prio < td->td_priority) {
1691  KTR_POINT3(KTR_SCHED, "thread", sched_tdname(curthread),
1692  "lend prio", "prio:%d", td->td_priority, "new prio:%d",
1693  prio, KTR_ATTR_LINKED, sched_tdname(td));
1694  SDT_PROBE4(sched, , , lend__pri, td, td->td_proc, prio,
1695  curthread);
1696  }
1697  ts = td->td_sched;
1698  THREAD_LOCK_ASSERT(td, MA_OWNED);
1699  if (td->td_priority == prio)
1700  return;
1701  /*
1702  * If the priority has been elevated due to priority
1703  * propagation, we may have to move ourselves to a new
1704  * queue. This could be optimized to not re-add in some
1705  * cases.
1706  */
1707  if (TD_ON_RUNQ(td) && prio < td->td_priority) {
1708  sched_rem(td);
1709  td->td_priority = prio;
1710  sched_add(td, SRQ_BORROWING);
1711  return;
1712  }
1713  /*
1714  * If the thread is currently running we may have to adjust the lowpri
1715  * information so other cpus are aware of our current priority.
1716  */
1717  if (TD_IS_RUNNING(td)) {
1718  tdq = TDQ_CPU(ts->ts_cpu);
1719  oldpri = td->td_priority;
1720  td->td_priority = prio;
1721  if (prio < tdq->tdq_lowpri)
1722  tdq->tdq_lowpri = prio;
1723  else if (tdq->tdq_lowpri == oldpri)
1724  tdq_setlowpri(tdq, td);
1725  return;
1726  }
1727  td->td_priority = prio;
1728 }
1729 
1730 /*
1731  * Update a thread's priority when it is lent another thread's
1732  * priority.
1733  */
1734 void
1735 sched_lend_prio(struct thread *td, u_char prio)
1736 {
1737 
1738  td->td_flags |= TDF_BORROWING;
1739  sched_thread_priority(td, prio);
1740 }
1741 
1742 /*
1743  * Restore a thread's priority when priority propagation is
1744  * over. The prio argument is the minimum priority the thread
1745  * needs to have to satisfy other possible priority lending
1746  * requests. If the thread's regular priority is less
1747  * important than prio, the thread will keep a priority boost
1748  * of prio.
1749  */
1750 void
1751 sched_unlend_prio(struct thread *td, u_char prio)
1752 {
1753  u_char base_pri;
1754 
1755  if (td->td_base_pri >= PRI_MIN_TIMESHARE &&
1756  td->td_base_pri <= PRI_MAX_TIMESHARE)
1757  base_pri = td->td_user_pri;
1758  else
1759  base_pri = td->td_base_pri;
1760  if (prio >= base_pri) {
1761  td->td_flags &= ~TDF_BORROWING;
1762  sched_thread_priority(td, base_pri);
1763  } else
1764  sched_lend_prio(td, prio);
1765 }
1766 
1767 /*
1768  * Standard entry for setting the priority to an absolute value.
1769  */
1770 void
1771 sched_prio(struct thread *td, u_char prio)
1772 {
1773  u_char oldprio;
1774 
1775  /* First, update the base priority. */
1776  td->td_base_pri = prio;
1777 
1778  /*
1779  * If the thread is borrowing another thread's priority, don't
1780  * ever lower the priority.
1781  */
1782  if (td->td_flags & TDF_BORROWING && td->td_priority < prio)
1783  return;
1784 
1785  /* Change the real priority. */
1786  oldprio = td->td_priority;
1787  sched_thread_priority(td, prio);
1788 
1789  /*
1790  * If the thread is on a turnstile, then let the turnstile update
1791  * its state.
1792  */
1793  if (TD_ON_LOCK(td) && oldprio != prio)
1794  turnstile_adjust(td, oldprio);
1795 }
1796 
1797 /*
1798  * Set the base user priority, does not effect current running priority.
1799  */
1800 void
1801 sched_user_prio(struct thread *td, u_char prio)
1802 {
1803 
1804  td->td_base_user_pri = prio;
1805  if (td->td_lend_user_pri <= prio)
1806  return;
1807  td->td_user_pri = prio;
1808 }
1809 
1810 void
1811 sched_lend_user_prio(struct thread *td, u_char prio)
1812 {
1813 
1814  THREAD_LOCK_ASSERT(td, MA_OWNED);
1815  td->td_lend_user_pri = prio;
1816  td->td_user_pri = min(prio, td->td_base_user_pri);
1817  if (td->td_priority > td->td_user_pri)
1818  sched_prio(td, td->td_user_pri);
1819  else if (td->td_priority != td->td_user_pri)
1820  td->td_flags |= TDF_NEEDRESCHED;
1821 }
1822 
1823 /*
1824  * Handle migration from sched_switch(). This happens only for
1825  * cpu binding.
1826  */
1827 static struct mtx *
1828 sched_switch_migrate(struct tdq *tdq, struct thread *td, int flags)
1829 {
1830  struct tdq *tdn;
1831 
1832  tdn = TDQ_CPU(td->td_sched->ts_cpu);
1833 #ifdef SMP
1834  tdq_load_rem(tdq, td);
1835  /*
1836  * Do the lock dance required to avoid LOR. We grab an extra
1837  * spinlock nesting to prevent preemption while we're
1838  * not holding either run-queue lock.
1839  */
1840  spinlock_enter();
1841  thread_lock_block(td); /* This releases the lock on tdq. */
1842 
1843  /*
1844  * Acquire both run-queue locks before placing the thread on the new
1845  * run-queue to avoid deadlocks created by placing a thread with a
1846  * blocked lock on the run-queue of a remote processor. The deadlock
1847  * occurs when a third processor attempts to lock the two queues in
1848  * question while the target processor is spinning with its own
1849  * run-queue lock held while waiting for the blocked lock to clear.
1850  */
1851  tdq_lock_pair(tdn, tdq);
1852  tdq_add(tdn, td, flags);
1853  tdq_notify(tdn, td);
1854  TDQ_UNLOCK(tdn);
1855  spinlock_exit();
1856 #endif
1857  return (TDQ_LOCKPTR(tdn));
1858 }
1859 
1860 /*
1861  * Variadic version of thread_lock_unblock() that does not assume td_lock
1862  * is blocked.
1863  */
1864 static inline void
1865 thread_unblock_switch(struct thread *td, struct mtx *mtx)
1866 {
1867  atomic_store_rel_ptr((volatile uintptr_t *)&td->td_lock,
1868  (uintptr_t)mtx);
1869 }
1870 
1871 /*
1872  * Switch threads. This function has to handle threads coming in while
1873  * blocked for some reason, running, or idle. It also must deal with
1874  * migrating a thread from one queue to another as running threads may
1875  * be assigned elsewhere via binding.
1876  */
1877 void
1878 sched_switch(struct thread *td, struct thread *newtd, int flags)
1879 {
1880  struct tdq *tdq;
1881  struct td_sched *ts;
1882  struct mtx *mtx;
1883  int srqflag;
1884  int cpuid, preempted;
1885 
1886  THREAD_LOCK_ASSERT(td, MA_OWNED);
1887  KASSERT(newtd == NULL, ("sched_switch: Unsupported newtd argument"));
1888 
1889  cpuid = PCPU_GET(cpuid);
1890  tdq = TDQ_CPU(cpuid);
1891  ts = td->td_sched;
1892  mtx = td->td_lock;
1893  sched_pctcpu_update(ts, 1);
1894  ts->ts_rltick = ticks;
1895  td->td_lastcpu = td->td_oncpu;
1896  td->td_oncpu = NOCPU;
1897  preempted = !((td->td_flags & TDF_SLICEEND) ||
1898  (flags & SWT_RELINQUISH));
1899  td->td_flags &= ~(TDF_NEEDRESCHED | TDF_SLICEEND);
1900  td->td_owepreempt = 0;
1901  if (!TD_IS_IDLETHREAD(td))
1902  tdq->tdq_switchcnt++;
1903  /*
1904  * The lock pointer in an idle thread should never change. Reset it
1905  * to CAN_RUN as well.
1906  */
1907  if (TD_IS_IDLETHREAD(td)) {
1908  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
1909  TD_SET_CAN_RUN(td);
1910  } else if (TD_IS_RUNNING(td)) {
1911  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
1912  srqflag = preempted ?
1913  SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED :
1914  SRQ_OURSELF|SRQ_YIELDING;
1915 #ifdef SMP
1916  if (THREAD_CAN_MIGRATE(td) && !THREAD_CAN_SCHED(td, ts->ts_cpu))
1917  ts->ts_cpu = sched_pickcpu(td, 0);
1918 #endif
1919  if (ts->ts_cpu == cpuid)
1920  tdq_runq_add(tdq, td, srqflag);
1921  else {
1922  KASSERT(THREAD_CAN_MIGRATE(td) ||
1923  (ts->ts_flags & TSF_BOUND) != 0,
1924  ("Thread %p shouldn't migrate", td));
1925  mtx = sched_switch_migrate(tdq, td, srqflag);
1926  }
1927  } else {
1928  /* This thread must be going to sleep. */
1929  TDQ_LOCK(tdq);
1930  mtx = thread_lock_block(td);
1931  tdq_load_rem(tdq, td);
1932  }
1933  /*
1934  * We enter here with the thread blocked and assigned to the
1935  * appropriate cpu run-queue or sleep-queue and with the current
1936  * thread-queue locked.
1937  */
1938  TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED);
1939  newtd = choosethread();
1940  /*
1941  * Call the MD code to switch contexts if necessary.
1942  */
1943  if (td != newtd) {
1944 #ifdef HWPMC_HOOKS
1945  if (PMC_PROC_IS_USING_PMCS(td->td_proc))
1946  PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT);
1947 #endif
1948  SDT_PROBE2(sched, , , off__cpu, newtd, newtd->td_proc);
1949  lock_profile_release_lock(&TDQ_LOCKPTR(tdq)->lock_object);
1950  TDQ_LOCKPTR(tdq)->mtx_lock = (uintptr_t)newtd;
1951  sched_pctcpu_update(newtd->td_sched, 0);
1952 
1953 #ifdef KDTRACE_HOOKS
1954  /*
1955  * If DTrace has set the active vtime enum to anything
1956  * other than INACTIVE (0), then it should have set the
1957  * function to call.
1958  */
1959  if (dtrace_vtime_active)
1960  (*dtrace_vtime_switch_func)(newtd);
1961 #endif
1962 
1963  cpu_switch(td, newtd, mtx);
1964  /*
1965  * We may return from cpu_switch on a different cpu. However,
1966  * we always return with td_lock pointing to the current cpu's
1967  * run queue lock.
1968  */
1969  cpuid = PCPU_GET(cpuid);
1970  tdq = TDQ_CPU(cpuid);
1971  lock_profile_obtain_lock_success(
1972  &TDQ_LOCKPTR(tdq)->lock_object, 0, 0, __FILE__, __LINE__);
1973 
1974  SDT_PROBE0(sched, , , on__cpu);
1975 #ifdef HWPMC_HOOKS
1976  if (PMC_PROC_IS_USING_PMCS(td->td_proc))
1977  PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN);
1978 #endif
1979  } else {
1980  thread_unblock_switch(td, mtx);
1981  SDT_PROBE0(sched, , , remain__cpu);
1982  }
1983  /*
1984  * Assert that all went well and return.
1985  */
1986  TDQ_LOCK_ASSERT(tdq, MA_OWNED|MA_NOTRECURSED);
1987  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
1988  td->td_oncpu = cpuid;
1989 }
1990 
1991 /*
1992  * Adjust thread priorities as a result of a nice request.
1993  */
1994 void
1995 sched_nice(struct proc *p, int nice)
1996 {
1997  struct thread *td;
1998 
1999  PROC_LOCK_ASSERT(p, MA_OWNED);
2000 
2001  p->p_nice = nice;
2002  FOREACH_THREAD_IN_PROC(p, td) {
2003  thread_lock(td);
2004  sched_priority(td);
2005  sched_prio(td, td->td_base_user_pri);
2006  thread_unlock(td);
2007  }
2008 }
2009 
2010 /*
2011  * Record the sleep time for the interactivity scorer.
2012  */
2013 void
2014 sched_sleep(struct thread *td, int prio)
2015 {
2016 
2017  THREAD_LOCK_ASSERT(td, MA_OWNED);
2018 
2019  td->td_slptick = ticks;
2020  if (TD_IS_SUSPENDED(td) || prio >= PSOCK)
2021  td->td_flags |= TDF_CANSWAP;
2022  if (PRI_BASE(td->td_pri_class) != PRI_TIMESHARE)
2023  return;
2024  if (static_boost == 1 && prio)
2025  sched_prio(td, prio);
2026  else if (static_boost && td->td_priority > static_boost)
2027  sched_prio(td, static_boost);
2028 }
2029 
2030 /*
2031  * Schedule a thread to resume execution and record how long it voluntarily
2032  * slept. We also update the pctcpu, interactivity, and priority.
2033  */
2034 void
2035 sched_wakeup(struct thread *td)
2036 {
2037  struct td_sched *ts;
2038  int slptick;
2039 
2040  THREAD_LOCK_ASSERT(td, MA_OWNED);
2041  ts = td->td_sched;
2042  td->td_flags &= ~TDF_CANSWAP;
2043  /*
2044  * If we slept for more than a tick update our interactivity and
2045  * priority.
2046  */
2047  slptick = td->td_slptick;
2048  td->td_slptick = 0;
2049  if (slptick && slptick != ticks) {
2050  ts->ts_slptime += (ticks - slptick) << SCHED_TICK_SHIFT;
2052  sched_pctcpu_update(ts, 0);
2053  }
2054  /*
2055  * Reset the slice value since we slept and advanced the round-robin.
2056  */
2057  ts->ts_slice = 0;
2058  sched_add(td, SRQ_BORING);
2059 }
2060 
2061 /*
2062  * Penalize the parent for creating a new child and initialize the child's
2063  * priority.
2064  */
2065 void
2066 sched_fork(struct thread *td, struct thread *child)
2067 {
2068  THREAD_LOCK_ASSERT(td, MA_OWNED);
2069  sched_pctcpu_update(td->td_sched, 1);
2070  sched_fork_thread(td, child);
2071  /*
2072  * Penalize the parent and child for forking.
2073  */
2074  sched_interact_fork(child);
2075  sched_priority(child);
2076  td->td_sched->ts_runtime += tickincr;
2078  sched_priority(td);
2079 }
2080 
2081 /*
2082  * Fork a new thread, may be within the same process.
2083  */
2084 void
2085 sched_fork_thread(struct thread *td, struct thread *child)
2086 {
2087  struct td_sched *ts;
2088  struct td_sched *ts2;
2089  struct tdq *tdq;
2090 
2091  tdq = TDQ_SELF();
2092  THREAD_LOCK_ASSERT(td, MA_OWNED);
2093  /*
2094  * Initialize child.
2095  */
2096  ts = td->td_sched;
2097  ts2 = child->td_sched;
2098  child->td_oncpu = NOCPU;
2099  child->td_lastcpu = NOCPU;
2100  child->td_lock = TDQ_LOCKPTR(tdq);
2101  child->td_cpuset = cpuset_ref(td->td_cpuset);
2102  ts2->ts_cpu = ts->ts_cpu;
2103  ts2->ts_flags = 0;
2104  /*
2105  * Grab our parents cpu estimation information.
2106  */
2107  ts2->ts_ticks = ts->ts_ticks;
2108  ts2->ts_ltick = ts->ts_ltick;
2109  ts2->ts_ftick = ts->ts_ftick;
2110  /*
2111  * Do not inherit any borrowed priority from the parent.
2112  */
2113  child->td_priority = child->td_base_pri;
2114  /*
2115  * And update interactivity score.
2116  */
2117  ts2->ts_slptime = ts->ts_slptime;
2118  ts2->ts_runtime = ts->ts_runtime;
2119  /* Attempt to quickly learn interactivity. */
2120  ts2->ts_slice = tdq_slice(tdq) - sched_slice_min;
2121 #ifdef KTR
2122  bzero(ts2->ts_name, sizeof(ts2->ts_name));
2123 #endif
2124 }
2125 
2126 /*
2127  * Adjust the priority class of a thread.
2128  */
2129 void
2130 sched_class(struct thread *td, int class)
2131 {
2132 
2133  THREAD_LOCK_ASSERT(td, MA_OWNED);
2134  if (td->td_pri_class == class)
2135  return;
2136  td->td_pri_class = class;
2137 }
2138 
2139 /*
2140  * Return some of the child's priority and interactivity to the parent.
2141  */
2142 void
2143 sched_exit(struct proc *p, struct thread *child)
2144 {
2145  struct thread *td;
2146 
2147  KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "proc exit",
2148  "prio:%d", child->td_priority);
2149  PROC_LOCK_ASSERT(p, MA_OWNED);
2150  td = FIRST_THREAD_IN_PROC(p);
2151  sched_exit_thread(td, child);
2152 }
2153 
2154 /*
2155  * Penalize another thread for the time spent on this one. This helps to
2156  * worsen the priority and interactivity of processes which schedule batch
2157  * jobs such as make. This has little effect on the make process itself but
2158  * causes new processes spawned by it to receive worse scores immediately.
2159  */
2160 void
2161 sched_exit_thread(struct thread *td, struct thread *child)
2162 {
2163 
2164  KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "thread exit",
2165  "prio:%d", child->td_priority);
2166  /*
2167  * Give the child's runtime to the parent without returning the
2168  * sleep time as a penalty to the parent. This causes shells that
2169  * launch expensive things to mark their children as expensive.
2170  */
2171  thread_lock(td);
2172  td->td_sched->ts_runtime += child->td_sched->ts_runtime;
2174  sched_priority(td);
2175  thread_unlock(td);
2176 }
2177 
2178 void
2179 sched_preempt(struct thread *td)
2180 {
2181  struct tdq *tdq;
2182 
2183  SDT_PROBE2(sched, , , surrender, td, td->td_proc);
2184 
2185  thread_lock(td);
2186  tdq = TDQ_SELF();
2187  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
2188  tdq->tdq_ipipending = 0;
2189  if (td->td_priority > tdq->tdq_lowpri) {
2190  int flags;
2191 
2192  flags = SW_INVOL | SW_PREEMPT;
2193  if (td->td_critnest > 1)
2194  td->td_owepreempt = 1;
2195  else if (TD_IS_IDLETHREAD(td))
2196  mi_switch(flags | SWT_REMOTEWAKEIDLE, NULL);
2197  else
2198  mi_switch(flags | SWT_REMOTEPREEMPT, NULL);
2199  }
2200  thread_unlock(td);
2201 }
2202 
2203 /*
2204  * Fix priorities on return to user-space. Priorities may be elevated due
2205  * to static priorities in msleep() or similar.
2206  */
2207 void
2208 sched_userret(struct thread *td)
2209 {
2210  /*
2211  * XXX we cheat slightly on the locking here to avoid locking in
2212  * the usual case. Setting td_priority here is essentially an
2213  * incomplete workaround for not setting it properly elsewhere.
2214  * Now that some interrupt handlers are threads, not setting it
2215  * properly elsewhere can clobber it in the window between setting
2216  * it here and returning to user mode, so don't waste time setting
2217  * it perfectly here.
2218  */
2219  KASSERT((td->td_flags & TDF_BORROWING) == 0,
2220  ("thread with borrowed priority returning to userland"));
2221  if (td->td_priority != td->td_user_pri) {
2222  thread_lock(td);
2223  td->td_priority = td->td_user_pri;
2224  td->td_base_pri = td->td_user_pri;
2225  tdq_setlowpri(TDQ_SELF(), td);
2226  thread_unlock(td);
2227  }
2228 }
2229 
2230 /*
2231  * Handle a stathz tick. This is really only relevant for timeshare
2232  * threads.
2233  */
2234 void
2235 sched_clock(struct thread *td)
2236 {
2237  struct tdq *tdq;
2238  struct td_sched *ts;
2239 
2240  THREAD_LOCK_ASSERT(td, MA_OWNED);
2241  tdq = TDQ_SELF();
2242 #ifdef SMP
2243  /*
2244  * We run the long term load balancer infrequently on the first cpu.
2245  */
2246  if (balance_tdq == tdq) {
2247  if (balance_ticks && --balance_ticks == 0)
2248  sched_balance();
2249  }
2250 #endif
2251  /*
2252  * Save the old switch count so we have a record of the last ticks
2253  * activity. Initialize the new switch count based on our load.
2254  * If there is some activity seed it to reflect that.
2255  */
2256  tdq->tdq_oldswitchcnt = tdq->tdq_switchcnt;
2257  tdq->tdq_switchcnt = tdq->tdq_load;
2258  /*
2259  * Advance the insert index once for each tick to ensure that all
2260  * threads get a chance to run.
2261  */
2262  if (tdq->tdq_idx == tdq->tdq_ridx) {
2263  tdq->tdq_idx = (tdq->tdq_idx + 1) % RQ_NQS;
2264  if (TAILQ_EMPTY(&tdq->tdq_timeshare.rq_queues[tdq->tdq_ridx]))
2265  tdq->tdq_ridx = tdq->tdq_idx;
2266  }
2267  ts = td->td_sched;
2268  sched_pctcpu_update(ts, 1);
2269  if (td->td_pri_class & PRI_FIFO_BIT)
2270  return;
2271  if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) {
2272  /*
2273  * We used a tick; charge it to the thread so
2274  * that we can compute our interactivity.
2275  */
2276  td->td_sched->ts_runtime += tickincr;
2278  sched_priority(td);
2279  }
2280 
2281  /*
2282  * Force a context switch if the current thread has used up a full
2283  * time slice (default is 100ms).
2284  */
2285  if (!TD_IS_IDLETHREAD(td) && ++ts->ts_slice >= tdq_slice(tdq)) {
2286  ts->ts_slice = 0;
2287  td->td_flags |= TDF_NEEDRESCHED | TDF_SLICEEND;
2288  }
2289 }
2290 
2291 /*
2292  * Called once per hz tick.
2293  */
2294 void
2295 sched_tick(int cnt)
2296 {
2297 
2298 }
2299 
2300 /*
2301  * Return whether the current CPU has runnable tasks. Used for in-kernel
2302  * cooperative idle threads.
2303  */
2304 int
2306 {
2307  struct tdq *tdq;
2308  int load;
2309 
2310  load = 1;
2311 
2312  tdq = TDQ_SELF();
2313  if ((curthread->td_flags & TDF_IDLETD) != 0) {
2314  if (tdq->tdq_load > 0)
2315  goto out;
2316  } else
2317  if (tdq->tdq_load - 1 > 0)
2318  goto out;
2319  load = 0;
2320 out:
2321  return (load);
2322 }
2323 
2324 /*
2325  * Choose the highest priority thread to run. The thread is removed from
2326  * the run-queue while running however the load remains. For SMP we set
2327  * the tdq in the global idle bitmask if it idles here.
2328  */
2329 struct thread *
2331 {
2332  struct thread *td;
2333  struct tdq *tdq;
2334 
2335  tdq = TDQ_SELF();
2336  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
2337  td = tdq_choose(tdq);
2338  if (td) {
2339  tdq_runq_rem(tdq, td);
2340  tdq->tdq_lowpri = td->td_priority;
2341  return (td);
2342  }
2343  tdq->tdq_lowpri = PRI_MAX_IDLE;
2344  return (PCPU_GET(idlethread));
2345 }
2346 
2347 /*
2348  * Set owepreempt if necessary. Preemption never happens directly in ULE,
2349  * we always request it once we exit a critical section.
2350  */
2351 static inline void
2352 sched_setpreempt(struct thread *td)
2353 {
2354  struct thread *ctd;
2355  int cpri;
2356  int pri;
2357 
2358  THREAD_LOCK_ASSERT(curthread, MA_OWNED);
2359 
2360  ctd = curthread;
2361  pri = td->td_priority;
2362  cpri = ctd->td_priority;
2363  if (pri < cpri)
2364  ctd->td_flags |= TDF_NEEDRESCHED;
2365  if (panicstr != NULL || pri >= cpri || cold || TD_IS_INHIBITED(ctd))
2366  return;
2367  if (!sched_shouldpreempt(pri, cpri, 0))
2368  return;
2369  ctd->td_owepreempt = 1;
2370 }
2371 
2372 /*
2373  * Add a thread to a thread queue. Select the appropriate runq and add the
2374  * thread to it. This is the internal function called when the tdq is
2375  * predetermined.
2376  */
2377 void
2378 tdq_add(struct tdq *tdq, struct thread *td, int flags)
2379 {
2380 
2381  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
2382  KASSERT((td->td_inhibitors == 0),
2383  ("sched_add: trying to run inhibited thread"));
2384  KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)),
2385  ("sched_add: bad thread state"));
2386  KASSERT(td->td_flags & TDF_INMEM,
2387  ("sched_add: thread swapped out"));
2388 
2389  if (td->td_priority < tdq->tdq_lowpri)
2390  tdq->tdq_lowpri = td->td_priority;
2391  tdq_runq_add(tdq, td, flags);
2392  tdq_load_add(tdq, td);
2393 }
2394 
2395 /*
2396  * Select the target thread queue and add a thread to it. Request
2397  * preemption or IPI a remote processor if required.
2398  */
2399 void
2400 sched_add(struct thread *td, int flags)
2401 {
2402  struct tdq *tdq;
2403 #ifdef SMP
2404  int cpu;
2405 #endif
2406 
2407  KTR_STATE2(KTR_SCHED, "thread", sched_tdname(td), "runq add",
2408  "prio:%d", td->td_priority, KTR_ATTR_LINKED,
2409  sched_tdname(curthread));
2410  KTR_POINT1(KTR_SCHED, "thread", sched_tdname(curthread), "wokeup",
2411  KTR_ATTR_LINKED, sched_tdname(td));
2412  SDT_PROBE4(sched, , , enqueue, td, td->td_proc, NULL,
2413  flags & SRQ_PREEMPTED);
2414  THREAD_LOCK_ASSERT(td, MA_OWNED);
2415  /*
2416  * Recalculate the priority before we select the target cpu or
2417  * run-queue.
2418  */
2419  if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE)
2420  sched_priority(td);
2421 #ifdef SMP
2422  /*
2423  * Pick the destination cpu and if it isn't ours transfer to the
2424  * target cpu.
2425  */
2426  cpu = sched_pickcpu(td, flags);
2427  tdq = sched_setcpu(td, cpu, flags);
2428  tdq_add(tdq, td, flags);
2429  if (cpu != PCPU_GET(cpuid)) {
2430  tdq_notify(tdq, td);
2431  return;
2432  }
2433 #else
2434  tdq = TDQ_SELF();
2435  TDQ_LOCK(tdq);
2436  /*
2437  * Now that the thread is moving to the run-queue, set the lock
2438  * to the scheduler's lock.
2439  */
2440  thread_lock_set(td, TDQ_LOCKPTR(tdq));
2441  tdq_add(tdq, td, flags);
2442 #endif
2443  if (!(flags & SRQ_YIELDING))
2444  sched_setpreempt(td);
2445 }
2446 
2447 /*
2448  * Remove a thread from a run-queue without running it. This is used
2449  * when we're stealing a thread from a remote queue. Otherwise all threads
2450  * exit by calling sched_exit_thread() and sched_throw() themselves.
2451  */
2452 void
2453 sched_rem(struct thread *td)
2454 {
2455  struct tdq *tdq;
2456 
2457  KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "runq rem",
2458  "prio:%d", td->td_priority);
2459  SDT_PROBE3(sched, , , dequeue, td, td->td_proc, NULL);
2460  tdq = TDQ_CPU(td->td_sched->ts_cpu);
2461  TDQ_LOCK_ASSERT(tdq, MA_OWNED);
2462  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
2463  KASSERT(TD_ON_RUNQ(td),
2464  ("sched_rem: thread not on run queue"));
2465  tdq_runq_rem(tdq, td);
2466  tdq_load_rem(tdq, td);
2467  TD_SET_CAN_RUN(td);
2468  if (td->td_priority == tdq->tdq_lowpri)
2469  tdq_setlowpri(tdq, NULL);
2470 }
2471 
2472 /*
2473  * Fetch cpu utilization information. Updates on demand.
2474  */
2475 fixpt_t
2476 sched_pctcpu(struct thread *td)
2477 {
2478  fixpt_t pctcpu;
2479  struct td_sched *ts;
2480 
2481  pctcpu = 0;
2482  ts = td->td_sched;
2483  if (ts == NULL)
2484  return (0);
2485 
2486  THREAD_LOCK_ASSERT(td, MA_OWNED);
2487  sched_pctcpu_update(ts, TD_IS_RUNNING(td));
2488  if (ts->ts_ticks) {
2489  int rtick;
2490 
2491  /* How many rtick per second ? */
2492  rtick = min(SCHED_TICK_HZ(ts) / SCHED_TICK_SECS, hz);
2493  pctcpu = (FSCALE * ((FSCALE * rtick)/hz)) >> FSHIFT;
2494  }
2495 
2496  return (pctcpu);
2497 }
2498 
2499 /*
2500  * Enforce affinity settings for a thread. Called after adjustments to
2501  * cpumask.
2502  */
2503 void
2504 sched_affinity(struct thread *td)
2505 {
2506 #ifdef SMP
2507  struct td_sched *ts;
2508 
2509  THREAD_LOCK_ASSERT(td, MA_OWNED);
2510  ts = td->td_sched;
2511  if (THREAD_CAN_SCHED(td, ts->ts_cpu))
2512  return;
2513  if (TD_ON_RUNQ(td)) {
2514  sched_rem(td);
2515  sched_add(td, SRQ_BORING);
2516  return;
2517  }
2518  if (!TD_IS_RUNNING(td))
2519  return;
2520  /*
2521  * Force a switch before returning to userspace. If the
2522  * target thread is not running locally send an ipi to force
2523  * the issue.
2524  */
2525  td->td_flags |= TDF_NEEDRESCHED;
2526  if (td != curthread)
2527  ipi_cpu(ts->ts_cpu, IPI_PREEMPT);
2528 #endif
2529 }
2530 
2531 /*
2532  * Bind a thread to a target cpu.
2533  */
2534 void
2535 sched_bind(struct thread *td, int cpu)
2536 {
2537  struct td_sched *ts;
2538 
2539  THREAD_LOCK_ASSERT(td, MA_OWNED|MA_NOTRECURSED);
2540  KASSERT(td == curthread, ("sched_bind: can only bind curthread"));
2541  ts = td->td_sched;
2542  if (ts->ts_flags & TSF_BOUND)
2543  sched_unbind(td);
2544  KASSERT(THREAD_CAN_MIGRATE(td), ("%p must be migratable", td));
2545  ts->ts_flags |= TSF_BOUND;
2546  sched_pin();
2547  if (PCPU_GET(cpuid) == cpu)
2548  return;
2549  ts->ts_cpu = cpu;
2550  /* When we return from mi_switch we'll be on the correct cpu. */
2551  mi_switch(SW_VOL, NULL);
2552 }
2553 
2554 /*
2555  * Release a bound thread.
2556  */
2557 void
2558 sched_unbind(struct thread *td)
2559 {
2560  struct td_sched *ts;
2561 
2562  THREAD_LOCK_ASSERT(td, MA_OWNED);
2563  KASSERT(td == curthread, ("sched_unbind: can only bind curthread"));
2564  ts = td->td_sched;
2565  if ((ts->ts_flags & TSF_BOUND) == 0)
2566  return;
2567  ts->ts_flags &= ~TSF_BOUND;
2568  sched_unpin();
2569 }
2570 
2571 int
2572 sched_is_bound(struct thread *td)
2573 {
2574  THREAD_LOCK_ASSERT(td, MA_OWNED);
2575  return (td->td_sched->ts_flags & TSF_BOUND);
2576 }
2577 
2578 /*
2579  * Basic yield call.
2580  */
2581 void
2582 sched_relinquish(struct thread *td)
2583 {
2584  thread_lock(td);
2585  mi_switch(SW_VOL | SWT_RELINQUISH, NULL);
2586  thread_unlock(td);
2587 }
2588 
2589 /*
2590  * Return the total system load.
2591  */
2592 int
2594 {
2595 #ifdef SMP
2596  int total;
2597  int i;
2598 
2599  total = 0;
2600  CPU_FOREACH(i)
2601  total += TDQ_CPU(i)->tdq_sysload;
2602  return (total);
2603 #else
2604  return (TDQ_SELF()->tdq_sysload);
2605 #endif
2606 }
2607 
2608 int
2610 {
2611  return (sizeof(struct proc));
2612 }
2613 
2614 int
2616 {
2617  return (sizeof(struct thread) + sizeof(struct td_sched));
2618 }
2619 
2620 #ifdef SMP
2621 #define TDQ_IDLESPIN(tdq) \
2622  ((tdq)->tdq_cg != NULL && ((tdq)->tdq_cg->cg_flags & CG_FLAG_THREAD) == 0)
2623 #else
2624 #define TDQ_IDLESPIN(tdq) 1
2625 #endif
2626 
2627 /*
2628  * The actual idle process.
2629  */
2630 void
2632 {
2633  struct thread *td;
2634  struct tdq *tdq;
2635  int oldswitchcnt, switchcnt;
2636  int i;
2637 
2638  mtx_assert(&Giant, MA_NOTOWNED);
2639  td = curthread;
2640  tdq = TDQ_SELF();
2641  THREAD_NO_SLEEPING();
2642  oldswitchcnt = -1;
2643  for (;;) {
2644  if (tdq->tdq_load) {
2645  thread_lock(td);
2646  mi_switch(SW_VOL | SWT_IDLE, NULL);
2647  thread_unlock(td);
2648  }
2649  switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
2650 #ifdef SMP
2651  if (switchcnt != oldswitchcnt) {
2652  oldswitchcnt = switchcnt;
2653  if (tdq_idled(tdq) == 0)
2654  continue;
2655  }
2656  switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
2657 #else
2658  oldswitchcnt = switchcnt;
2659 #endif
2660  /*
2661  * If we're switching very frequently, spin while checking
2662  * for load rather than entering a low power state that
2663  * may require an IPI. However, don't do any busy
2664  * loops while on SMT machines as this simply steals
2665  * cycles from cores doing useful work.
2666  */
2667  if (TDQ_IDLESPIN(tdq) && switchcnt > sched_idlespinthresh) {
2668  for (i = 0; i < sched_idlespins; i++) {
2669  if (tdq->tdq_load)
2670  break;
2671  cpu_spinwait();
2672  }
2673  }
2674 
2675  /* If there was context switch during spin, restart it. */
2676  switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
2677  if (tdq->tdq_load != 0 || switchcnt != oldswitchcnt)
2678  continue;
2679 
2680  /* Run main MD idle handler. */
2681  tdq->tdq_cpu_idle = 1;
2682  /*
2683  * Make sure that tdq_cpu_idle update is globally visible
2684  * before cpu_idle() read tdq_load. The order is important
2685  * to avoid race with tdq_notify.
2686  */
2687  atomic_thread_fence_seq_cst();
2688  cpu_idle(switchcnt * 4 > sched_idlespinthresh);
2689  tdq->tdq_cpu_idle = 0;
2690 
2691  /*
2692  * Account thread-less hardware interrupts and
2693  * other wakeup reasons equal to context switches.
2694  */
2695  switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
2696  if (switchcnt != oldswitchcnt)
2697  continue;
2698  tdq->tdq_switchcnt++;
2699  oldswitchcnt++;
2700  }
2701 }
2702 
2703 /*
2704  * A CPU is entering for the first time or a thread is exiting.
2705  */
2706 void
2707 sched_throw(struct thread *td)
2708 {
2709  struct thread *newtd;
2710  struct tdq *tdq;
2711 
2712  tdq = TDQ_SELF();
2713  if (td == NULL) {
2714  /* Correct spinlock nesting and acquire the correct lock. */
2715  TDQ_LOCK(tdq);
2716  spinlock_exit();
2717  PCPU_SET(switchtime, cpu_ticks());
2718  PCPU_SET(switchticks, ticks);
2719  } else {
2720  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
2721  tdq_load_rem(tdq, td);
2722  lock_profile_release_lock(&TDQ_LOCKPTR(tdq)->lock_object);
2723  td->td_lastcpu = td->td_oncpu;
2724  td->td_oncpu = NOCPU;
2725  }
2726  KASSERT(curthread->td_md.md_spinlock_count == 1, ("invalid count"));
2727  newtd = choosethread();
2728  TDQ_LOCKPTR(tdq)->mtx_lock = (uintptr_t)newtd;
2729  cpu_throw(td, newtd); /* doesn't return */
2730 }
2731 
2732 /*
2733  * This is called from fork_exit(). Just acquire the correct locks and
2734  * let fork do the rest of the work.
2735  */
2736 void
2737 sched_fork_exit(struct thread *td)
2738 {
2739  struct tdq *tdq;
2740  int cpuid;
2741 
2742  /*
2743  * Finish setting up thread glue so that it begins execution in a
2744  * non-nested critical section with the scheduler lock held.
2745  */
2746  cpuid = PCPU_GET(cpuid);
2747  tdq = TDQ_CPU(cpuid);
2748  if (TD_IS_IDLETHREAD(td))
2749  td->td_lock = TDQ_LOCKPTR(tdq);
2750  MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
2751  td->td_oncpu = cpuid;
2752  TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED);
2753  lock_profile_obtain_lock_success(
2754  &TDQ_LOCKPTR(tdq)->lock_object, 0, 0, __FILE__, __LINE__);
2755 }
2756 
2757 /*
2758  * Create on first use to catch odd startup conditons.
2759  */
2760 char *
2761 sched_tdname(struct thread *td)
2762 {
2763 #ifdef KTR
2764  struct td_sched *ts;
2765 
2766  ts = td->td_sched;
2767  if (ts->ts_name[0] == '\0')
2768  snprintf(ts->ts_name, sizeof(ts->ts_name),
2769  "%s tid %d", td->td_name, td->td_tid);
2770  return (ts->ts_name);
2771 #else
2772  return (td->td_name);
2773 #endif
2774 }
2775 
2776 #ifdef KTR
2777 void
2778 sched_clear_tdname(struct thread *td)
2779 {
2780  struct td_sched *ts;
2781 
2782  ts = td->td_sched;
2783  ts->ts_name[0] = '\0';
2784 }
2785 #endif
2786 
2787 #ifdef SMP
2788 
2789 /*
2790  * Build the CPU topology dump string. Is recursively called to collect
2791  * the topology tree.
2792  */
2793 static int
2794 sysctl_kern_sched_topology_spec_internal(struct sbuf *sb, struct cpu_group *cg,
2795  int indent)
2796 {
2797  char cpusetbuf[CPUSETBUFSIZ];
2798  int i, first;
2799 
2800  sbuf_printf(sb, "%*s<group level=\"%d\" cache-level=\"%d\">\n", indent,
2801  "", 1 + indent / 2, cg->cg_level);
2802  sbuf_printf(sb, "%*s <cpu count=\"%d\" mask=\"%s\">", indent, "",
2803  cg->cg_count, cpusetobj_strprint(cpusetbuf, &cg->cg_mask));
2804  first = TRUE;
2805  for (i = 0; i < MAXCPU; i++) {
2806  if (CPU_ISSET(i, &cg->cg_mask)) {
2807  if (!first)
2808  sbuf_printf(sb, ", ");
2809  else
2810  first = FALSE;
2811  sbuf_printf(sb, "%d", i);
2812  }
2813  }
2814  sbuf_printf(sb, "</cpu>\n");
2815 
2816  if (cg->cg_flags != 0) {
2817  sbuf_printf(sb, "%*s <flags>", indent, "");
2818  if ((cg->cg_flags & CG_FLAG_HTT) != 0)
2819  sbuf_printf(sb, "<flag name=\"HTT\">HTT group</flag>");
2820  if ((cg->cg_flags & CG_FLAG_THREAD) != 0)
2821  sbuf_printf(sb, "<flag name=\"THREAD\">THREAD group</flag>");
2822  if ((cg->cg_flags & CG_FLAG_SMT) != 0)
2823  sbuf_printf(sb, "<flag name=\"SMT\">SMT group</flag>");
2824  sbuf_printf(sb, "</flags>\n");
2825  }
2826 
2827  if (cg->cg_children > 0) {
2828  sbuf_printf(sb, "%*s <children>\n", indent, "");
2829  for (i = 0; i < cg->cg_children; i++)
2830  sysctl_kern_sched_topology_spec_internal(sb,
2831  &cg->cg_child[i], indent+2);
2832  sbuf_printf(sb, "%*s </children>\n", indent, "");
2833  }
2834  sbuf_printf(sb, "%*s</group>\n", indent, "");
2835  return (0);
2836 }
2837 
2838 /*
2839  * Sysctl handler for retrieving topology dump. It's a wrapper for
2840  * the recursive sysctl_kern_smp_topology_spec_internal().
2841  */
2842 static int
2843 sysctl_kern_sched_topology_spec(SYSCTL_HANDLER_ARGS)
2844 {
2845  struct sbuf *topo;
2846  int err;
2847 
2848  KASSERT(cpu_top != NULL, ("cpu_top isn't initialized"));
2849 
2850  topo = sbuf_new_for_sysctl(NULL, NULL, 512, req);
2851  if (topo == NULL)
2852  return (ENOMEM);
2853 
2854  sbuf_printf(topo, "<groups>\n");
2855  err = sysctl_kern_sched_topology_spec_internal(topo, cpu_top, 1);
2856  sbuf_printf(topo, "</groups>\n");
2857 
2858  if (err == 0) {
2859  err = sbuf_finish(topo);
2860  }
2861  sbuf_delete(topo);
2862  return (err);
2863 }
2864 
2865 #endif
2866 
2867 static int
2868 sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
2869 {
2870  int error, new_val, period;
2871 
2872  period = 1000000 / realstathz;
2873  new_val = period * sched_slice;
2874  error = sysctl_handle_int(oidp, &new_val, 0, req);
2875  if (error != 0 || req->newptr == NULL)
2876  return (error);
2877  if (new_val <= 0)
2878  return (EINVAL);
2879  sched_slice = imax(1, (new_val + period / 2) / period);
2880  sched_slice_min = sched_slice / SCHED_SLICE_MIN_DIVISOR;
2881  hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) /
2882  realstathz);
2883  return (0);
2884 }
2885 
2886 SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW, 0, "Scheduler");
2887 SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "ULE", 0,
2888  "Scheduler name");
2889 SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, CTLTYPE_INT | CTLFLAG_RW,
2890  NULL, 0, sysctl_kern_quantum, "I",
2891  "Quantum for timeshare threads in microseconds");
2892 SYSCTL_INT(_kern_sched, OID_AUTO, slice, CTLFLAG_RW, &sched_slice, 0,
2893  "Quantum for timeshare threads in stathz ticks");
2894 SYSCTL_INT(_kern_sched, OID_AUTO, interact, CTLFLAG_RW, &sched_interact, 0,
2895  "Interactivity score threshold");
2896 SYSCTL_INT(_kern_sched, OID_AUTO, preempt_thresh, CTLFLAG_RW,
2897  &preempt_thresh, 0,
2898  "Maximal (lowest) priority for preemption");
2899 SYSCTL_INT(_kern_sched, OID_AUTO, static_boost, CTLFLAG_RW, &static_boost, 0,
2900  "Assign static kernel priorities to sleeping threads");
2901 SYSCTL_INT(_kern_sched, OID_AUTO, idlespins, CTLFLAG_RW, &sched_idlespins, 0,
2902  "Number of times idle thread will spin waiting for new work");
2903 SYSCTL_INT(_kern_sched, OID_AUTO, idlespinthresh, CTLFLAG_RW,
2905  "Threshold before we will permit idle thread spinning");
2906 #ifdef SMP
2907 SYSCTL_INT(_kern_sched, OID_AUTO, affinity, CTLFLAG_RW, &affinity, 0,
2908  "Number of hz ticks to keep thread affinity for");
2909 SYSCTL_INT(_kern_sched, OID_AUTO, balance, CTLFLAG_RW, &rebalance, 0,
2910  "Enables the long-term load balancer");
2911 SYSCTL_INT(_kern_sched, OID_AUTO, balance_interval, CTLFLAG_RW,
2912  &balance_interval, 0,
2913  "Average period in stathz ticks to run the long-term balancer");
2914 SYSCTL_INT(_kern_sched, OID_AUTO, steal_idle, CTLFLAG_RW, &steal_idle, 0,
2915  "Attempts to steal work from other cores before idling");
2916 SYSCTL_INT(_kern_sched, OID_AUTO, steal_thresh, CTLFLAG_RW, &steal_thresh, 0,
2917  "Minimum load on remote CPU before we'll steal");
2918 SYSCTL_PROC(_kern_sched, OID_AUTO, topology_spec, CTLTYPE_STRING |
2919  CTLFLAG_RD, NULL, 0, sysctl_kern_sched_topology_spec, "A",
2920  "XML dump of detected CPU topology");
2921 #endif
2922 
2923 /* ps compat. All cpu percentages from ULE are weighted. */
2924 static int ccpu = 0;
2925 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:1412
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Definition: sched_ule.c:100
#define TS_NAME_LEN
Definition: sched_ule.c:82
#define TDQ_LOCK_ASSERT(t, type)
Definition: sched_ule.c:293
static int sched_shouldpreempt(int, int, int)
Definition: sched_ule.c:416
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Definition: sched_ule.c:1643
SDT_PROBE_DEFINE2(sched,,, load__change,"int","int")
#define SCHED_TICK_SHIFT
Definition: sched_ule.c:144
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Definition: sched_ule.c:290
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Definition: sched_ule.c:1624
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Definition: sched_ule.c:231
volatile int tdq_cpu_idle
Definition: sched_ule.c:237
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Definition: sched_ule.c:1735
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Definition: sched_ule.c:2330
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Definition: sched_ule.c:2130
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Definition: subr_prf.c:514
struct timespec * ts
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:2161
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Definition: sched_ule.c:2085
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Definition: init_main.c:116
void *** start
Definition: linker_if.m:86
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Definition: subr_smp.c:73
u_int ts_slptime
Definition: sched_ule.c:96
#define SCHED_PRI_MIN
Definition: sched_ule.c:162
#define SCHED_PRI_RANGE
Definition: sched_ule.c:164
static void sched_setup(void *dummy)
Definition: sched_ule.c:1388
#define THREAD_CAN_SCHED(td, cpu)
Definition: sched_ule.c:112
static int sched_interact_score(struct thread *)
Definition: sched_ule.c:1470
static __inline void tdq_runq_rem(struct tdq *, struct thread *)
Definition: sched_ule.c:505
void sched_user_prio(struct thread *td, u_char prio)
Definition: sched_ule.c:1801
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:2868
struct proc proc0
Definition: init_main.c:101
short tdq_oldswitchcnt
Definition: sched_ule.c:241
void panic(const char *fmt,...)
static void sched_interact_update(struct thread *)
Definition: sched_ule.c:1562
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Definition: kern_switch.c:154
struct mtx_padalign tdq_lock
Definition: sched_ule.c:234
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Definition: sched_ule.c:243
struct tdq __aligned(64)
#define PRI_MIN_BATCH
Definition: sched_ule.c:128
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Definition: kern_switch.c:494
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Definition: sched_ule.c:2761
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Definition: subr_pcpu.c:278
static int ccpu
Definition: sched_ule.c:2924
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Definition: sched_4bsd.c:97
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Definition: sched_ule.c:99
static void tdq_setup(struct tdq *)
Definition: sched_ule.c:1345
const char * name
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Definition: sched_4bsd.c:95
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Definition: kern_synch.c:413
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Definition: sched_ule.c:2014
#define TSF_XFERABLE
Definition: sched_ule.c:107
int ts_rltick
Definition: sched_ule.c:94
SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL)
static void tdq_load_rem(struct tdq *, struct thread *)
Definition: sched_ule.c:549
SDT_PROBE_DEFINE(sched,,, on__cpu)
u_char tdq_ridx
Definition: sched_ule.c:245
int ts_ltick
Definition: sched_ule.c:98
volatile int tdq_load
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struct thread * runq_choose_from(struct runq *rq, u_char idx)
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static int sched_idlespins
Definition: sched_ule.c:220
#define PRI_MAX_INTERACT
Definition: sched_ule.c:127
int ts_slice
Definition: sched_4bsd.c:96
char tdq_name[TDQ_NAME_LEN]
Definition: sched_ule.c:249
#define SCHED_INTERACT_HALF
Definition: sched_ule.c:185
#define TDQ_IDLESPIN(tdq)
Definition: sched_ule.c:2624
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
void runq_add_pri(struct runq *rq, struct thread *td, u_char pri, int flags)
Definition: kern_switch.c:357
void runq_init(struct runq *rq)
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
static void tdq_setlowpri(struct tdq *tdq, struct thread *ctd)
Definition: sched_ule.c:593
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Definition: sched_ule.c:2707
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Definition: kern_switch.c:442
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Definition: kern_mutex.c:742
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Definition: sched_ule.c:2737
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Definition: kern_cpuset.c:126
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Definition: sched_ule.c:2582
static int dummy
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Definition: sched_ule.c:391
Definition: sched_ule.c:228
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Definition: kern_mutex.c:145
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Definition: sched_ule.c:2035
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static struct td_sched td_sched0
Definition: sched_ule.c:109
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Definition: sched_ule.c:2615
void sched_switch(struct thread *td, struct thread *newtd, int flags)
Definition: sched_ule.c:1878
void sched_rem(struct thread *td)
Definition: sched_ule.c:2453
u_long flags
#define SCHED_TICK_SECS
Definition: sched_ule.c:141
struct cpu_group * tdq_cg
Definition: sched_ule.c:235
int ts_cpu
Definition: sched_ule.c:93
SYSCTL_INT(_kern_sched, OID_AUTO, slice, CTLFLAG_RW,&sched_slice, 0,"Quantum for timeshare threads in stathz ticks")
int sbuf_printf(struct sbuf *s, const char *fmt,...)
Definition: subr_sbuf.c:663
#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:1811
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:1315
static int tickincr
Definition: sched_ule.c:206
int sched_is_bound(struct thread *td)
Definition: sched_ule.c:2572
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:1828
int sysctl_handle_int(SYSCTL_HANDLER_ARGS)
Definition: kern_sysctl.c:1146
void sched_tick(int cnt)
Definition: sched_ule.c:2295
#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:2235
static void runq_print(struct runq *rq)
Definition: sched_ule.c:363
static void sched_thread_priority(struct thread *, u_char)
Definition: sched_ule.c:1680
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:454
#define SCHED_PRI_NICE(nice)
Definition: sched_ule.c:168
void sched_affinity(struct thread *td)
Definition: sched_ule.c:2504
int printf(const char *fmt,...)
Definition: subr_prf.c:378
void sched_exit(struct proc *p, struct thread *child)
Definition: sched_ule.c:2143
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:2631
void sched_unlend_prio(struct thread *td, u_char prio)
Definition: sched_ule.c:1751
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:1865
int sbuf_finish(struct sbuf *s)
Definition: subr_sbuf.c:725
void sched_preempt(struct thread *td)
Definition: sched_ule.c:2179
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:2593
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:571
static void sched_interact_fork(struct thread *)
Definition: sched_ule.c:1607
int stathz
Definition: kern_clock.c:377
static void sched_priority(struct thread *)
Definition: sched_ule.c:1510
void sched_nice(struct proc *p, int nice)
Definition: sched_ule.c:1995
#define SCHED_SLP_RUN_MAX
Definition: sched_ule.c:182
static void sched_setpreempt(struct thread *td)
Definition: sched_ule.c:2352
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:2208
#define TDQ_LOCKPTR(t)
Definition: sched_ule.c:297
void sched_fork(struct thread *td, struct thread *child)
Definition: sched_ule.c:2066
#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:2378
struct mtx * thread_lock_block(struct thread *td)
Definition: kern_mutex.c:721
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:2305
void sched_unbind(struct thread *td)
Definition: sched_ule.c:2558
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:1771
SDT_PROBE_DEFINE3(sched,,, change__pri,"struct thread *","struct proc *","uint8_t")
void sched_add(struct thread *td, int flags)
Definition: sched_ule.c:2400
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:531
cpu_tick_f * cpu_ticks
Definition: kern_tc.c:2053
void thread_lock_unblock(struct thread *td, struct mtx *new)
Definition: kern_mutex.c:734
#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:2535
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:2476
int sched_sizeof_proc(void)
Definition: sched_ule.c:2609
static void sched_pctcpu_update(struct td_sched *, int)
Definition: sched_ule.c:1657
__FBSDID("$FreeBSD: head/sys/kern/sched_ule.c 287166 2015-08-26 16:36:41Z gnn $")