FreeBSD kernel kern code
sched_4bsd.c
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1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1990, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD$");
39
40#include "opt_hwpmc_hooks.h"
41#include "opt_sched.h"
42
43#include <sys/param.h>
44#include <sys/systm.h>
45#include <sys/cpuset.h>
46#include <sys/kernel.h>
47#include <sys/ktr.h>
48#include <sys/lock.h>
49#include <sys/kthread.h>
50#include <sys/mutex.h>
51#include <sys/proc.h>
52#include <sys/resourcevar.h>
53#include <sys/sched.h>
54#include <sys/sdt.h>
55#include <sys/smp.h>
56#include <sys/sysctl.h>
57#include <sys/sx.h>
58#include <sys/turnstile.h>
59#include <sys/umtxvar.h>
60#include <machine/pcb.h>
61#include <machine/smp.h>
62
63#ifdef HWPMC_HOOKS
64#include <sys/pmckern.h>
65#endif
66
67#ifdef KDTRACE_HOOKS
68#include <sys/dtrace_bsd.h>
69int __read_mostly dtrace_vtime_active;
70dtrace_vtime_switch_func_t dtrace_vtime_switch_func;
71#endif
72
73/*
74 * INVERSE_ESTCPU_WEIGHT is only suitable for statclock() frequencies in
75 * the range 100-256 Hz (approximately).
76 */
77#define ESTCPULIM(e) \
78 min((e), INVERSE_ESTCPU_WEIGHT * (NICE_WEIGHT * (PRIO_MAX - PRIO_MIN) - \
79 RQ_PPQ) + INVERSE_ESTCPU_WEIGHT - 1)
80#ifdef SMP
81#define INVERSE_ESTCPU_WEIGHT (8 * smp_cpus)
82#else
83#define INVERSE_ESTCPU_WEIGHT 8 /* 1 / (priorities per estcpu level). */
84#endif
85#define NICE_WEIGHT 1 /* Priorities per nice level. */
86
87#define TS_NAME_LEN (MAXCOMLEN + sizeof(" td ") + sizeof(__XSTRING(UINT_MAX)))
88
89/*
90 * The schedulable entity that runs a context.
91 * This is an extension to the thread structure and is tailored to
92 * the requirements of this scheduler.
93 * All fields are protected by the scheduler lock.
94 */
95struct td_sched {
96 fixpt_t ts_pctcpu; /* %cpu during p_swtime. */
97 u_int ts_estcpu; /* Estimated cpu utilization. */
98 int ts_cpticks; /* Ticks of cpu time. */
99 int ts_slptime; /* Seconds !RUNNING. */
100 int ts_slice; /* Remaining part of time slice. */
102 struct runq *ts_runq; /* runq the thread is currently on */
103#ifdef KTR
104 char ts_name[TS_NAME_LEN];
105#endif
106};
107
108/* flags kept in td_flags */
109#define TDF_DIDRUN TDF_SCHED0 /* thread actually ran. */
110#define TDF_BOUND TDF_SCHED1 /* Bound to one CPU. */
111#define TDF_SLICEEND TDF_SCHED2 /* Thread time slice is over. */
112
113/* flags kept in ts_flags */
114#define TSF_AFFINITY 0x0001 /* Has a non-"full" CPU set. */
115
116#define SKE_RUNQ_PCPU(ts) \
117 ((ts)->ts_runq != 0 && (ts)->ts_runq != &runq)
118
119#define THREAD_CAN_SCHED(td, cpu) \
120 CPU_ISSET((cpu), &(td)->td_cpuset->cs_mask)
121
122_Static_assert(sizeof(struct thread) + sizeof(struct td_sched) <=
123 sizeof(struct thread0_storage),
124 "increase struct thread0_storage.t0st_sched size");
125
126static struct mtx sched_lock;
127
128static int realstathz = 127; /* stathz is sometimes 0 and run off of hz. */
129static int sched_tdcnt; /* Total runnable threads in the system. */
130static int sched_slice = 12; /* Thread run time before rescheduling. */
131
132static void setup_runqs(void);
133static void schedcpu(void);
134static void schedcpu_thread(void);
135static void sched_priority(struct thread *td, u_char prio);
136static void sched_setup(void *dummy);
137static void maybe_resched(struct thread *td);
138static void updatepri(struct thread *td);
139static void resetpriority(struct thread *td);
140static void resetpriority_thread(struct thread *td);
141#ifdef SMP
142static int sched_pickcpu(struct thread *td);
143static int forward_wakeup(int cpunum);
144static void kick_other_cpu(int pri, int cpuid);
145#endif
146
147static struct kproc_desc sched_kp = {
148 "schedcpu",
150 NULL
151};
152SYSINIT(schedcpu, SI_SUB_LAST, SI_ORDER_FIRST, kproc_start,
153 &sched_kp);
154SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL);
155
156static void sched_initticks(void *dummy);
157SYSINIT(sched_initticks, SI_SUB_CLOCKS, SI_ORDER_THIRD, sched_initticks,
158 NULL);
159
160/*
161 * Global run queue.
162 */
163static struct runq runq;
164
165#ifdef SMP
166/*
167 * Per-CPU run queues
168 */
169static struct runq runq_pcpu[MAXCPU];
170long runq_length[MAXCPU];
171
172static cpuset_t idle_cpus_mask;
173#endif
174
178};
180
181static void
183{
184#ifdef SMP
185 int i;
186
187 for (i = 0; i < MAXCPU; ++i)
188 runq_init(&runq_pcpu[i]);
189#endif
190
191 runq_init(&runq);
192}
193
194static int
195sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
196{
197 int error, new_val, period;
198
199 period = 1000000 / realstathz;
200 new_val = period * sched_slice;
201 error = sysctl_handle_int(oidp, &new_val, 0, req);
202 if (error != 0 || req->newptr == NULL)
203 return (error);
204 if (new_val <= 0)
205 return (EINVAL);
206 sched_slice = imax(1, (new_val + period / 2) / period);
207 hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) /
208 realstathz);
209 return (0);
210}
211
212SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
213 "Scheduler");
214
215SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "4BSD", 0,
216 "Scheduler name");
217SYSCTL_PROC(_kern_sched, OID_AUTO, quantum,
218 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 0,
220 "Quantum for timeshare threads in microseconds");
221SYSCTL_INT(_kern_sched, OID_AUTO, slice, CTLFLAG_RW, &sched_slice, 0,
222 "Quantum for timeshare threads in stathz ticks");
223#ifdef SMP
224/* Enable forwarding of wakeups to all other cpus */
225static SYSCTL_NODE(_kern_sched, OID_AUTO, ipiwakeup,
226 CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
227 "Kernel SMP");
228
229static int runq_fuzz = 1;
230SYSCTL_INT(_kern_sched, OID_AUTO, runq_fuzz, CTLFLAG_RW, &runq_fuzz, 0, "");
231
232static int forward_wakeup_enabled = 1;
233SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, enabled, CTLFLAG_RW,
234 &forward_wakeup_enabled, 0,
235 "Forwarding of wakeup to idle CPUs");
236
237static int forward_wakeups_requested = 0;
238SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, requested, CTLFLAG_RD,
239 &forward_wakeups_requested, 0,
240 "Requests for Forwarding of wakeup to idle CPUs");
241
242static int forward_wakeups_delivered = 0;
243SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, delivered, CTLFLAG_RD,
244 &forward_wakeups_delivered, 0,
245 "Completed Forwarding of wakeup to idle CPUs");
246
247static int forward_wakeup_use_mask = 1;
248SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, usemask, CTLFLAG_RW,
249 &forward_wakeup_use_mask, 0,
250 "Use the mask of idle cpus");
251
252static int forward_wakeup_use_loop = 0;
253SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, useloop, CTLFLAG_RW,
254 &forward_wakeup_use_loop, 0,
255 "Use a loop to find idle cpus");
256
257#endif
258#if 0
259static int sched_followon = 0;
260SYSCTL_INT(_kern_sched, OID_AUTO, followon, CTLFLAG_RW,
261 &sched_followon, 0,
262 "allow threads to share a quantum");
263#endif
264
266
267SDT_PROBE_DEFINE3(sched, , , change__pri, "struct thread *",
268 "struct proc *", "uint8_t");
269SDT_PROBE_DEFINE3(sched, , , dequeue, "struct thread *",
270 "struct proc *", "void *");
271SDT_PROBE_DEFINE4(sched, , , enqueue, "struct thread *",
272 "struct proc *", "void *", "int");
273SDT_PROBE_DEFINE4(sched, , , lend__pri, "struct thread *",
274 "struct proc *", "uint8_t", "struct thread *");
275SDT_PROBE_DEFINE2(sched, , , load__change, "int", "int");
276SDT_PROBE_DEFINE2(sched, , , off__cpu, "struct thread *",
277 "struct proc *");
278SDT_PROBE_DEFINE(sched, , , on__cpu);
279SDT_PROBE_DEFINE(sched, , , remain__cpu);
280SDT_PROBE_DEFINE2(sched, , , surrender, "struct thread *",
281 "struct proc *");
282
283static __inline void
285{
286
287 sched_tdcnt++;
288 KTR_COUNTER0(KTR_SCHED, "load", "global load", sched_tdcnt);
289 SDT_PROBE2(sched, , , load__change, NOCPU, sched_tdcnt);
290}
291
292static __inline void
294{
295
296 sched_tdcnt--;
297 KTR_COUNTER0(KTR_SCHED, "load", "global load", sched_tdcnt);
298 SDT_PROBE2(sched, , , load__change, NOCPU, sched_tdcnt);
299}
300/*
301 * Arrange to reschedule if necessary, taking the priorities and
302 * schedulers into account.
303 */
304static void
305maybe_resched(struct thread *td)
306{
307
308 THREAD_LOCK_ASSERT(td, MA_OWNED);
309 if (td->td_priority < curthread->td_priority)
310 curthread->td_flags |= TDF_NEEDRESCHED;
311}
312
313/*
314 * This function is called when a thread is about to be put on run queue
315 * because it has been made runnable or its priority has been adjusted. It
316 * determines if the new thread should preempt the current thread. If so,
317 * it sets td_owepreempt to request a preemption.
318 */
319int
320maybe_preempt(struct thread *td)
321{
322#ifdef PREEMPTION
323 struct thread *ctd;
324 int cpri, pri;
325
326 /*
327 * The new thread should not preempt the current thread if any of the
328 * following conditions are true:
329 *
330 * - The kernel is in the throes of crashing (panicstr).
331 * - The current thread has a higher (numerically lower) or
332 * equivalent priority. Note that this prevents curthread from
333 * trying to preempt to itself.
334 * - The current thread has an inhibitor set or is in the process of
335 * exiting. In this case, the current thread is about to switch
336 * out anyways, so there's no point in preempting. If we did,
337 * the current thread would not be properly resumed as well, so
338 * just avoid that whole landmine.
339 * - If the new thread's priority is not a realtime priority and
340 * the current thread's priority is not an idle priority and
341 * FULL_PREEMPTION is disabled.
342 *
343 * If all of these conditions are false, but the current thread is in
344 * a nested critical section, then we have to defer the preemption
345 * until we exit the critical section. Otherwise, switch immediately
346 * to the new thread.
347 */
348 ctd = curthread;
349 THREAD_LOCK_ASSERT(td, MA_OWNED);
350 KASSERT((td->td_inhibitors == 0),
351 ("maybe_preempt: trying to run inhibited thread"));
352 pri = td->td_priority;
353 cpri = ctd->td_priority;
354 if (KERNEL_PANICKED() || pri >= cpri /* || dumping */ ||
355 TD_IS_INHIBITED(ctd))
356 return (0);
357#ifndef FULL_PREEMPTION
358 if (pri > PRI_MAX_ITHD && cpri < PRI_MIN_IDLE)
359 return (0);
360#endif
361
362 CTR0(KTR_PROC, "maybe_preempt: scheduling preemption");
363 ctd->td_owepreempt = 1;
364 return (1);
365#else
366 return (0);
367#endif
368}
369
370/*
371 * Constants for digital decay and forget:
372 * 90% of (ts_estcpu) usage in 5 * loadav time
373 * 95% of (ts_pctcpu) usage in 60 seconds (load insensitive)
374 * Note that, as ps(1) mentions, this can let percentages
375 * total over 100% (I've seen 137.9% for 3 processes).
376 *
377 * Note that schedclock() updates ts_estcpu and p_cpticks asynchronously.
378 *
379 * We wish to decay away 90% of ts_estcpu in (5 * loadavg) seconds.
380 * That is, the system wants to compute a value of decay such
381 * that the following for loop:
382 * for (i = 0; i < (5 * loadavg); i++)
383 * ts_estcpu *= decay;
384 * will compute
385 * ts_estcpu *= 0.1;
386 * for all values of loadavg:
387 *
388 * Mathematically this loop can be expressed by saying:
389 * decay ** (5 * loadavg) ~= .1
390 *
391 * The system computes decay as:
392 * decay = (2 * loadavg) / (2 * loadavg + 1)
393 *
394 * We wish to prove that the system's computation of decay
395 * will always fulfill the equation:
396 * decay ** (5 * loadavg) ~= .1
397 *
398 * If we compute b as:
399 * b = 2 * loadavg
400 * then
401 * decay = b / (b + 1)
402 *
403 * We now need to prove two things:
404 * 1) Given factor ** (5 * loadavg) ~= .1, prove factor == b/(b+1)
405 * 2) Given b/(b+1) ** power ~= .1, prove power == (5 * loadavg)
406 *
407 * Facts:
408 * For x close to zero, exp(x) =~ 1 + x, since
409 * exp(x) = 0! + x**1/1! + x**2/2! + ... .
410 * therefore exp(-1/b) =~ 1 - (1/b) = (b-1)/b.
411 * For x close to zero, ln(1+x) =~ x, since
412 * ln(1+x) = x - x**2/2 + x**3/3 - ... -1 < x < 1
413 * therefore ln(b/(b+1)) = ln(1 - 1/(b+1)) =~ -1/(b+1).
414 * ln(.1) =~ -2.30
415 *
416 * Proof of (1):
417 * Solve (factor)**(power) =~ .1 given power (5*loadav):
418 * solving for factor,
419 * ln(factor) =~ (-2.30/5*loadav), or
420 * factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) =
421 * exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED
422 *
423 * Proof of (2):
424 * Solve (factor)**(power) =~ .1 given factor == (b/(b+1)):
425 * solving for power,
426 * power*ln(b/(b+1)) =~ -2.30, or
427 * power =~ 2.3 * (b + 1) = 4.6*loadav + 2.3 =~ 5*loadav. QED
428 *
429 * Actual power values for the implemented algorithm are as follows:
430 * loadav: 1 2 3 4
431 * power: 5.68 10.32 14.94 19.55
432 */
433
434/* calculations for digital decay to forget 90% of usage in 5*loadav sec */
435#define loadfactor(loadav) (2 * (loadav))
436#define decay_cpu(loadfac, cpu) (((loadfac) * (cpu)) / ((loadfac) + FSCALE))
437
438/* decay 95% of `ts_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */
439static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
440SYSCTL_UINT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0,
441 "Decay factor used for updating %CPU");
442
443/*
444 * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the
445 * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below
446 * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT).
447 *
448 * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used:
449 * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits).
450 *
451 * If you don't want to bother with the faster/more-accurate formula, you
452 * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate
453 * (more general) method of calculating the %age of CPU used by a process.
454 */
455#define CCPU_SHIFT 11
456
457/*
458 * Recompute process priorities, every hz ticks.
459 * MP-safe, called without the Giant mutex.
460 */
461/* ARGSUSED */
462static void
464{
465 fixpt_t loadfac = loadfactor(averunnable.ldavg[0]);
466 struct thread *td;
467 struct proc *p;
468 struct td_sched *ts;
469 int awake;
470
471 sx_slock(&allproc_lock);
472 FOREACH_PROC_IN_SYSTEM(p) {
473 PROC_LOCK(p);
474 if (p->p_state == PRS_NEW) {
475 PROC_UNLOCK(p);
476 continue;
477 }
478 FOREACH_THREAD_IN_PROC(p, td) {
479 awake = 0;
480 ts = td_get_sched(td);
481 thread_lock(td);
482 /*
483 * Increment sleep time (if sleeping). We
484 * ignore overflow, as above.
485 */
486 /*
487 * The td_sched slptimes are not touched in wakeup
488 * because the thread may not HAVE everything in
489 * memory? XXX I think this is out of date.
490 */
491 if (TD_ON_RUNQ(td)) {
492 awake = 1;
493 td->td_flags &= ~TDF_DIDRUN;
494 } else if (TD_IS_RUNNING(td)) {
495 awake = 1;
496 /* Do not clear TDF_DIDRUN */
497 } else if (td->td_flags & TDF_DIDRUN) {
498 awake = 1;
499 td->td_flags &= ~TDF_DIDRUN;
500 }
501
502 /*
503 * ts_pctcpu is only for ps and ttyinfo().
504 */
505 ts->ts_pctcpu = (ts->ts_pctcpu * ccpu) >> FSHIFT;
506 /*
507 * If the td_sched has been idle the entire second,
508 * stop recalculating its priority until
509 * it wakes up.
510 */
511 if (ts->ts_cpticks != 0) {
512#if (FSHIFT >= CCPU_SHIFT)
513 ts->ts_pctcpu += (realstathz == 100)
514 ? ((fixpt_t) ts->ts_cpticks) <<
515 (FSHIFT - CCPU_SHIFT) :
516 100 * (((fixpt_t) ts->ts_cpticks)
517 << (FSHIFT - CCPU_SHIFT)) / realstathz;
518#else
519 ts->ts_pctcpu += ((FSCALE - ccpu) *
520 (ts->ts_cpticks *
521 FSCALE / realstathz)) >> FSHIFT;
522#endif
523 ts->ts_cpticks = 0;
524 }
525 /*
526 * If there are ANY running threads in this process,
527 * then don't count it as sleeping.
528 * XXX: this is broken.
529 */
530 if (awake) {
531 if (ts->ts_slptime > 1) {
532 /*
533 * In an ideal world, this should not
534 * happen, because whoever woke us
535 * up from the long sleep should have
536 * unwound the slptime and reset our
537 * priority before we run at the stale
538 * priority. Should KASSERT at some
539 * point when all the cases are fixed.
540 */
541 updatepri(td);
542 }
543 ts->ts_slptime = 0;
544 } else
545 ts->ts_slptime++;
546 if (ts->ts_slptime > 1) {
547 thread_unlock(td);
548 continue;
549 }
550 ts->ts_estcpu = decay_cpu(loadfac, ts->ts_estcpu);
551 resetpriority(td);
553 thread_unlock(td);
554 }
555 PROC_UNLOCK(p);
556 }
557 sx_sunlock(&allproc_lock);
558}
559
560/*
561 * Main loop for a kthread that executes schedcpu once a second.
562 */
563static void
565{
566
567 for (;;) {
568 schedcpu();
569 pause("-", hz);
570 }
571}
572
573/*
574 * Recalculate the priority of a process after it has slept for a while.
575 * For all load averages >= 1 and max ts_estcpu of 255, sleeping for at
576 * least six times the loadfactor will decay ts_estcpu to zero.
577 */
578static void
579updatepri(struct thread *td)
580{
581 struct td_sched *ts;
582 fixpt_t loadfac;
583 unsigned int newcpu;
584
585 ts = td_get_sched(td);
586 loadfac = loadfactor(averunnable.ldavg[0]);
587 if (ts->ts_slptime > 5 * loadfac)
588 ts->ts_estcpu = 0;
589 else {
590 newcpu = ts->ts_estcpu;
591 ts->ts_slptime--; /* was incremented in schedcpu() */
592 while (newcpu && --ts->ts_slptime)
593 newcpu = decay_cpu(loadfac, newcpu);
594 ts->ts_estcpu = newcpu;
595 }
596}
597
598/*
599 * Compute the priority of a process when running in user mode.
600 * Arrange to reschedule if the resulting priority is better
601 * than that of the current process.
602 */
603static void
604resetpriority(struct thread *td)
605{
606 u_int newpriority;
607
608 if (td->td_pri_class != PRI_TIMESHARE)
609 return;
610 newpriority = PUSER +
611 td_get_sched(td)->ts_estcpu / INVERSE_ESTCPU_WEIGHT +
612 NICE_WEIGHT * (td->td_proc->p_nice - PRIO_MIN);
613 newpriority = min(max(newpriority, PRI_MIN_TIMESHARE),
614 PRI_MAX_TIMESHARE);
615 sched_user_prio(td, newpriority);
616}
617
618/*
619 * Update the thread's priority when the associated process's user
620 * priority changes.
621 */
622static void
623resetpriority_thread(struct thread *td)
624{
625
626 /* Only change threads with a time sharing user priority. */
627 if (td->td_priority < PRI_MIN_TIMESHARE ||
628 td->td_priority > PRI_MAX_TIMESHARE)
629 return;
630
631 /* XXX the whole needresched thing is broken, but not silly. */
632 maybe_resched(td);
633
634 sched_prio(td, td->td_user_pri);
635}
636
637/* ARGSUSED */
638static void
640{
641
642 setup_runqs();
643
644 /* Account for thread0. */
646}
647
648/*
649 * This routine determines time constants after stathz and hz are setup.
650 */
651static void
653{
654
656 sched_slice = realstathz / 10; /* ~100ms */
657 hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) /
658 realstathz);
659}
660
661/* External interfaces start here */
662
663/*
664 * Very early in the boot some setup of scheduler-specific
665 * parts of proc0 and of some scheduler resources needs to be done.
666 * Called from:
667 * proc0_init()
668 */
669void
671{
672
673 /*
674 * Set up the scheduler specific parts of thread0.
675 */
676 thread0.td_lock = &sched_lock;
677 td_get_sched(&thread0)->ts_slice = sched_slice;
678 mtx_init(&sched_lock, "sched lock", NULL, MTX_SPIN);
679}
680
681void
683{
684
685 /* Nothing needed. */
686}
687
688int
690{
691#ifdef SMP
692 return runq_check(&runq) + runq_check(&runq_pcpu[PCPU_GET(cpuid)]);
693#else
694 return runq_check(&runq);
695#endif
696}
697
698int
700{
701
702 /* Convert sched_slice from stathz to hz. */
703 return (imax(1, (sched_slice * hz + realstathz / 2) / realstathz));
704}
705
706/*
707 * We adjust the priority of the current process. The priority of a
708 * process gets worse as it accumulates CPU time. The cpu usage
709 * estimator (ts_estcpu) is increased here. resetpriority() will
710 * compute a different priority each time ts_estcpu increases by
711 * INVERSE_ESTCPU_WEIGHT (until PRI_MAX_TIMESHARE is reached). The
712 * cpu usage estimator ramps up quite quickly when the process is
713 * running (linearly), and decays away exponentially, at a rate which
714 * is proportionally slower when the system is busy. The basic
715 * principle is that the system will 90% forget that the process used
716 * a lot of CPU time in 5 * loadav seconds. This causes the system to
717 * favor processes which haven't run much recently, and to round-robin
718 * among other processes.
719 */
720static void
721sched_clock_tick(struct thread *td)
722{
723 struct pcpuidlestat *stat;
724 struct td_sched *ts;
725
726 THREAD_LOCK_ASSERT(td, MA_OWNED);
727 ts = td_get_sched(td);
728
729 ts->ts_cpticks++;
730 ts->ts_estcpu = ESTCPULIM(ts->ts_estcpu + 1);
731 if ((ts->ts_estcpu % INVERSE_ESTCPU_WEIGHT) == 0) {
732 resetpriority(td);
734 }
735
736 /*
737 * Force a context switch if the current thread has used up a full
738 * time slice (default is 100ms).
739 */
740 if (!TD_IS_IDLETHREAD(td) && --ts->ts_slice <= 0) {
741 ts->ts_slice = sched_slice;
742 td->td_flags |= TDF_NEEDRESCHED | TDF_SLICEEND;
743 }
744
745 stat = DPCPU_PTR(idlestat);
746 stat->oldidlecalls = stat->idlecalls;
747 stat->idlecalls = 0;
748}
749
750void
751sched_clock(struct thread *td, int cnt)
752{
753
754 for ( ; cnt > 0; cnt--)
756}
757
758/*
759 * Charge child's scheduling CPU usage to parent.
760 */
761void
762sched_exit(struct proc *p, struct thread *td)
763{
764
765 KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "proc exit",
766 "prio:%d", td->td_priority);
767
768 PROC_LOCK_ASSERT(p, MA_OWNED);
769 sched_exit_thread(FIRST_THREAD_IN_PROC(p), td);
770}
771
772void
773sched_exit_thread(struct thread *td, struct thread *child)
774{
775
776 KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "exit",
777 "prio:%d", child->td_priority);
778 thread_lock(td);
779 td_get_sched(td)->ts_estcpu = ESTCPULIM(td_get_sched(td)->ts_estcpu +
780 td_get_sched(child)->ts_estcpu);
781 thread_unlock(td);
782 thread_lock(child);
783 if ((child->td_flags & TDF_NOLOAD) == 0)
785 thread_unlock(child);
786}
787
788void
789sched_fork(struct thread *td, struct thread *childtd)
790{
791 sched_fork_thread(td, childtd);
792}
793
794void
795sched_fork_thread(struct thread *td, struct thread *childtd)
796{
797 struct td_sched *ts, *tsc;
798
799 childtd->td_oncpu = NOCPU;
800 childtd->td_lastcpu = NOCPU;
801 childtd->td_lock = &sched_lock;
802 childtd->td_cpuset = cpuset_ref(td->td_cpuset);
803 childtd->td_domain.dr_policy = td->td_cpuset->cs_domain;
804 childtd->td_priority = childtd->td_base_pri;
805 ts = td_get_sched(childtd);
806 bzero(ts, sizeof(*ts));
807 tsc = td_get_sched(td);
808 ts->ts_estcpu = tsc->ts_estcpu;
809 ts->ts_flags |= (tsc->ts_flags & TSF_AFFINITY);
810 ts->ts_slice = 1;
811}
812
813void
814sched_nice(struct proc *p, int nice)
815{
816 struct thread *td;
817
818 PROC_LOCK_ASSERT(p, MA_OWNED);
819 p->p_nice = nice;
820 FOREACH_THREAD_IN_PROC(p, td) {
821 thread_lock(td);
822 resetpriority(td);
824 thread_unlock(td);
825 }
826}
827
828void
829sched_class(struct thread *td, int class)
830{
831 THREAD_LOCK_ASSERT(td, MA_OWNED);
832 td->td_pri_class = class;
833}
834
835/*
836 * Adjust the priority of a thread.
837 */
838static void
839sched_priority(struct thread *td, u_char prio)
840{
841
842 KTR_POINT3(KTR_SCHED, "thread", sched_tdname(td), "priority change",
843 "prio:%d", td->td_priority, "new prio:%d", prio, KTR_ATTR_LINKED,
844 sched_tdname(curthread));
845 SDT_PROBE3(sched, , , change__pri, td, td->td_proc, prio);
846 if (td != curthread && prio > td->td_priority) {
847 KTR_POINT3(KTR_SCHED, "thread", sched_tdname(curthread),
848 "lend prio", "prio:%d", td->td_priority, "new prio:%d",
849 prio, KTR_ATTR_LINKED, sched_tdname(td));
850 SDT_PROBE4(sched, , , lend__pri, td, td->td_proc, prio,
851 curthread);
852 }
853 THREAD_LOCK_ASSERT(td, MA_OWNED);
854 if (td->td_priority == prio)
855 return;
856 td->td_priority = prio;
857 if (TD_ON_RUNQ(td) && td->td_rqindex != (prio / RQ_PPQ)) {
858 sched_rem(td);
859 sched_add(td, SRQ_BORING | SRQ_HOLDTD);
860 }
861}
862
863/*
864 * Update a thread's priority when it is lent another thread's
865 * priority.
866 */
867void
868sched_lend_prio(struct thread *td, u_char prio)
869{
870
871 td->td_flags |= TDF_BORROWING;
872 sched_priority(td, prio);
873}
874
875/*
876 * Restore a thread's priority when priority propagation is
877 * over. The prio argument is the minimum priority the thread
878 * needs to have to satisfy other possible priority lending
879 * requests. If the thread's regulary priority is less
880 * important than prio the thread will keep a priority boost
881 * of prio.
882 */
883void
884sched_unlend_prio(struct thread *td, u_char prio)
885{
886 u_char base_pri;
887
888 if (td->td_base_pri >= PRI_MIN_TIMESHARE &&
889 td->td_base_pri <= PRI_MAX_TIMESHARE)
890 base_pri = td->td_user_pri;
891 else
892 base_pri = td->td_base_pri;
893 if (prio >= base_pri) {
894 td->td_flags &= ~TDF_BORROWING;
895 sched_prio(td, base_pri);
896 } else
897 sched_lend_prio(td, prio);
898}
899
900void
901sched_prio(struct thread *td, u_char prio)
902{
903 u_char oldprio;
904
905 /* First, update the base priority. */
906 td->td_base_pri = prio;
907
908 /*
909 * If the thread is borrowing another thread's priority, don't ever
910 * lower the priority.
911 */
912 if (td->td_flags & TDF_BORROWING && td->td_priority < prio)
913 return;
914
915 /* Change the real priority. */
916 oldprio = td->td_priority;
917 sched_priority(td, prio);
918
919 /*
920 * If the thread is on a turnstile, then let the turnstile update
921 * its state.
922 */
923 if (TD_ON_LOCK(td) && oldprio != prio)
924 turnstile_adjust(td, oldprio);
925}
926
927void
928sched_user_prio(struct thread *td, u_char prio)
929{
930
931 THREAD_LOCK_ASSERT(td, MA_OWNED);
932 td->td_base_user_pri = prio;
933 if (td->td_lend_user_pri <= prio)
934 return;
935 td->td_user_pri = prio;
936}
937
938void
939sched_lend_user_prio(struct thread *td, u_char prio)
940{
941
942 THREAD_LOCK_ASSERT(td, MA_OWNED);
943 td->td_lend_user_pri = prio;
944 td->td_user_pri = min(prio, td->td_base_user_pri);
945 if (td->td_priority > td->td_user_pri)
946 sched_prio(td, td->td_user_pri);
947 else if (td->td_priority != td->td_user_pri)
948 td->td_flags |= TDF_NEEDRESCHED;
949}
950
951/*
952 * Like the above but first check if there is anything to do.
953 */
954void
955sched_lend_user_prio_cond(struct thread *td, u_char prio)
956{
957
958 if (td->td_lend_user_pri != prio)
959 goto lend;
960 if (td->td_user_pri != min(prio, td->td_base_user_pri))
961 goto lend;
962 if (td->td_priority != td->td_user_pri)
963 goto lend;
964 return;
965
966lend:
967 thread_lock(td);
968 sched_lend_user_prio(td, prio);
969 thread_unlock(td);
970}
971
972void
973sched_sleep(struct thread *td, int pri)
974{
975
976 THREAD_LOCK_ASSERT(td, MA_OWNED);
977 td->td_slptick = ticks;
978 td_get_sched(td)->ts_slptime = 0;
979 if (pri != 0 && PRI_BASE(td->td_pri_class) == PRI_TIMESHARE)
980 sched_prio(td, pri);
981 if (TD_IS_SUSPENDED(td) || pri >= PSOCK)
982 td->td_flags |= TDF_CANSWAP;
983}
984
985void
986sched_switch(struct thread *td, int flags)
987{
988 struct thread *newtd;
989 struct mtx *tmtx;
990 struct td_sched *ts;
991 struct proc *p;
992 int preempted;
993
994 tmtx = &sched_lock;
995 ts = td_get_sched(td);
996 p = td->td_proc;
997
998 THREAD_LOCK_ASSERT(td, MA_OWNED);
999
1000 td->td_lastcpu = td->td_oncpu;
1001 preempted = (td->td_flags & TDF_SLICEEND) == 0 &&
1002 (flags & SW_PREEMPT) != 0;
1003 td->td_flags &= ~(TDF_NEEDRESCHED | TDF_SLICEEND);
1004 td->td_owepreempt = 0;
1005 td->td_oncpu = NOCPU;
1006
1007 /*
1008 * At the last moment, if this thread is still marked RUNNING,
1009 * then put it back on the run queue as it has not been suspended
1010 * or stopped or any thing else similar. We never put the idle
1011 * threads on the run queue, however.
1012 */
1013 if (td->td_flags & TDF_IDLETD) {
1014 TD_SET_CAN_RUN(td);
1015#ifdef SMP
1016 CPU_CLR(PCPU_GET(cpuid), &idle_cpus_mask);
1017#endif
1018 } else {
1019 if (TD_IS_RUNNING(td)) {
1020 /* Put us back on the run queue. */
1021 sched_add(td, preempted ?
1022 SRQ_HOLDTD|SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED :
1023 SRQ_HOLDTD|SRQ_OURSELF|SRQ_YIELDING);
1024 }
1025 }
1026
1027 /*
1028 * Switch to the sched lock to fix things up and pick
1029 * a new thread. Block the td_lock in order to avoid
1030 * breaking the critical path.
1031 */
1032 if (td->td_lock != &sched_lock) {
1033 mtx_lock_spin(&sched_lock);
1034 tmtx = thread_lock_block(td);
1035 mtx_unlock_spin(tmtx);
1036 }
1037
1038 if ((td->td_flags & TDF_NOLOAD) == 0)
1040
1041 newtd = choosethread();
1042 MPASS(newtd->td_lock == &sched_lock);
1043
1044#if (KTR_COMPILE & KTR_SCHED) != 0
1045 if (TD_IS_IDLETHREAD(td))
1046 KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "idle",
1047 "prio:%d", td->td_priority);
1048 else
1049 KTR_STATE3(KTR_SCHED, "thread", sched_tdname(td), KTDSTATE(td),
1050 "prio:%d", td->td_priority, "wmesg:\"%s\"", td->td_wmesg,
1051 "lockname:\"%s\"", td->td_lockname);
1052#endif
1053
1054 if (td != newtd) {
1055#ifdef HWPMC_HOOKS
1056 if (PMC_PROC_IS_USING_PMCS(td->td_proc))
1057 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT);
1058#endif
1059
1060 SDT_PROBE2(sched, , , off__cpu, newtd, newtd->td_proc);
1061
1062 /* I feel sleepy */
1063 lock_profile_release_lock(&sched_lock.lock_object, true);
1064#ifdef KDTRACE_HOOKS
1065 /*
1066 * If DTrace has set the active vtime enum to anything
1067 * other than INACTIVE (0), then it should have set the
1068 * function to call.
1069 */
1070 if (dtrace_vtime_active)
1071 (*dtrace_vtime_switch_func)(newtd);
1072#endif
1073
1074 cpu_switch(td, newtd, tmtx);
1075 lock_profile_obtain_lock_success(&sched_lock.lock_object, true,
1076 0, 0, __FILE__, __LINE__);
1077 /*
1078 * Where am I? What year is it?
1079 * We are in the same thread that went to sleep above,
1080 * but any amount of time may have passed. All our context
1081 * will still be available as will local variables.
1082 * PCPU values however may have changed as we may have
1083 * changed CPU so don't trust cached values of them.
1084 * New threads will go to fork_exit() instead of here
1085 * so if you change things here you may need to change
1086 * things there too.
1087 *
1088 * If the thread above was exiting it will never wake
1089 * up again here, so either it has saved everything it
1090 * needed to, or the thread_wait() or wait() will
1091 * need to reap it.
1092 */
1093
1094 SDT_PROBE0(sched, , , on__cpu);
1095#ifdef HWPMC_HOOKS
1096 if (PMC_PROC_IS_USING_PMCS(td->td_proc))
1097 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN);
1098#endif
1099 } else {
1100 td->td_lock = &sched_lock;
1101 SDT_PROBE0(sched, , , remain__cpu);
1102 }
1103
1104 KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "running",
1105 "prio:%d", td->td_priority);
1106
1107#ifdef SMP
1108 if (td->td_flags & TDF_IDLETD)
1109 CPU_SET(PCPU_GET(cpuid), &idle_cpus_mask);
1110#endif
1111 sched_lock.mtx_lock = (uintptr_t)td;
1112 td->td_oncpu = PCPU_GET(cpuid);
1113 spinlock_enter();
1114 mtx_unlock_spin(&sched_lock);
1115}
1116
1117void
1118sched_wakeup(struct thread *td, int srqflags)
1119{
1120 struct td_sched *ts;
1121
1122 THREAD_LOCK_ASSERT(td, MA_OWNED);
1123 ts = td_get_sched(td);
1124 td->td_flags &= ~TDF_CANSWAP;
1125 if (ts->ts_slptime > 1) {
1126 updatepri(td);
1127 resetpriority(td);
1128 }
1129 td->td_slptick = 0;
1130 ts->ts_slptime = 0;
1131 ts->ts_slice = sched_slice;
1132 sched_add(td, srqflags);
1133}
1134
1135#ifdef SMP
1136static int
1137forward_wakeup(int cpunum)
1138{
1139 struct pcpu *pc;
1140 cpuset_t dontuse, map, map2;
1141 u_int id, me;
1142 int iscpuset;
1143
1144 mtx_assert(&sched_lock, MA_OWNED);
1145
1146 CTR0(KTR_RUNQ, "forward_wakeup()");
1147
1148 if ((!forward_wakeup_enabled) ||
1149 (forward_wakeup_use_mask == 0 && forward_wakeup_use_loop == 0))
1150 return (0);
1151 if (!smp_started || KERNEL_PANICKED())
1152 return (0);
1153
1154 forward_wakeups_requested++;
1155
1156 /*
1157 * Check the idle mask we received against what we calculated
1158 * before in the old version.
1159 */
1160 me = PCPU_GET(cpuid);
1161
1162 /* Don't bother if we should be doing it ourself. */
1163 if (CPU_ISSET(me, &idle_cpus_mask) &&
1164 (cpunum == NOCPU || me == cpunum))
1165 return (0);
1166
1167 CPU_SETOF(me, &dontuse);
1168 CPU_OR(&dontuse, &dontuse, &stopped_cpus);
1169 CPU_OR(&dontuse, &dontuse, &hlt_cpus_mask);
1170 CPU_ZERO(&map2);
1171 if (forward_wakeup_use_loop) {
1172 STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
1173 id = pc->pc_cpuid;
1174 if (!CPU_ISSET(id, &dontuse) &&
1175 pc->pc_curthread == pc->pc_idlethread) {
1176 CPU_SET(id, &map2);
1177 }
1178 }
1179 }
1180
1181 if (forward_wakeup_use_mask) {
1182 map = idle_cpus_mask;
1183 CPU_ANDNOT(&map, &map, &dontuse);
1184
1185 /* If they are both on, compare and use loop if different. */
1186 if (forward_wakeup_use_loop) {
1187 if (CPU_CMP(&map, &map2)) {
1188 printf("map != map2, loop method preferred\n");
1189 map = map2;
1190 }
1191 }
1192 } else {
1193 map = map2;
1194 }
1195
1196 /* If we only allow a specific CPU, then mask off all the others. */
1197 if (cpunum != NOCPU) {
1198 KASSERT((cpunum <= mp_maxcpus),("forward_wakeup: bad cpunum."));
1199 iscpuset = CPU_ISSET(cpunum, &map);
1200 if (iscpuset == 0)
1201 CPU_ZERO(&map);
1202 else
1203 CPU_SETOF(cpunum, &map);
1204 }
1205 if (!CPU_EMPTY(&map)) {
1206 forward_wakeups_delivered++;
1207 STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
1208 id = pc->pc_cpuid;
1209 if (!CPU_ISSET(id, &map))
1210 continue;
1211 if (cpu_idle_wakeup(pc->pc_cpuid))
1212 CPU_CLR(id, &map);
1213 }
1214 if (!CPU_EMPTY(&map))
1215 ipi_selected(map, IPI_AST);
1216 return (1);
1217 }
1218 if (cpunum == NOCPU)
1219 printf("forward_wakeup: Idle processor not found\n");
1220 return (0);
1221}
1222
1223static void
1224kick_other_cpu(int pri, int cpuid)
1225{
1226 struct pcpu *pcpu;
1227 int cpri;
1228
1229 pcpu = pcpu_find(cpuid);
1230 if (CPU_ISSET(cpuid, &idle_cpus_mask)) {
1231 forward_wakeups_delivered++;
1232 if (!cpu_idle_wakeup(cpuid))
1233 ipi_cpu(cpuid, IPI_AST);
1234 return;
1235 }
1236
1237 cpri = pcpu->pc_curthread->td_priority;
1238 if (pri >= cpri)
1239 return;
1240
1241#if defined(IPI_PREEMPTION) && defined(PREEMPTION)
1242#if !defined(FULL_PREEMPTION)
1243 if (pri <= PRI_MAX_ITHD)
1244#endif /* ! FULL_PREEMPTION */
1245 {
1246 ipi_cpu(cpuid, IPI_PREEMPT);
1247 return;
1248 }
1249#endif /* defined(IPI_PREEMPTION) && defined(PREEMPTION) */
1250
1251 pcpu->pc_curthread->td_flags |= TDF_NEEDRESCHED;
1252 ipi_cpu(cpuid, IPI_AST);
1253 return;
1254}
1255#endif /* SMP */
1256
1257#ifdef SMP
1258static int
1259sched_pickcpu(struct thread *td)
1260{
1261 int best, cpu;
1262
1263 mtx_assert(&sched_lock, MA_OWNED);
1264
1265 if (td->td_lastcpu != NOCPU && THREAD_CAN_SCHED(td, td->td_lastcpu))
1266 best = td->td_lastcpu;
1267 else
1268 best = NOCPU;
1269 CPU_FOREACH(cpu) {
1270 if (!THREAD_CAN_SCHED(td, cpu))
1271 continue;
1272
1273 if (best == NOCPU)
1274 best = cpu;
1275 else if (runq_length[cpu] < runq_length[best])
1276 best = cpu;
1277 }
1278 KASSERT(best != NOCPU, ("no valid CPUs"));
1279
1280 return (best);
1281}
1282#endif
1283
1284void
1285sched_add(struct thread *td, int flags)
1286#ifdef SMP
1287{
1288 cpuset_t tidlemsk;
1289 struct td_sched *ts;
1290 u_int cpu, cpuid;
1291 int forwarded = 0;
1292 int single_cpu = 0;
1293
1294 ts = td_get_sched(td);
1295 THREAD_LOCK_ASSERT(td, MA_OWNED);
1296 KASSERT((td->td_inhibitors == 0),
1297 ("sched_add: trying to run inhibited thread"));
1298 KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)),
1299 ("sched_add: bad thread state"));
1300 KASSERT(td->td_flags & TDF_INMEM,
1301 ("sched_add: thread swapped out"));
1302
1303 KTR_STATE2(KTR_SCHED, "thread", sched_tdname(td), "runq add",
1304 "prio:%d", td->td_priority, KTR_ATTR_LINKED,
1305 sched_tdname(curthread));
1306 KTR_POINT1(KTR_SCHED, "thread", sched_tdname(curthread), "wokeup",
1307 KTR_ATTR_LINKED, sched_tdname(td));
1308 SDT_PROBE4(sched, , , enqueue, td, td->td_proc, NULL,
1309 flags & SRQ_PREEMPTED);
1310
1311 /*
1312 * Now that the thread is moving to the run-queue, set the lock
1313 * to the scheduler's lock.
1314 */
1315 if (td->td_lock != &sched_lock) {
1316 mtx_lock_spin(&sched_lock);
1317 if ((flags & SRQ_HOLD) != 0)
1318 td->td_lock = &sched_lock;
1319 else
1321 }
1322 TD_SET_RUNQ(td);
1323
1324 /*
1325 * If SMP is started and the thread is pinned or otherwise limited to
1326 * a specific set of CPUs, queue the thread to a per-CPU run queue.
1327 * Otherwise, queue the thread to the global run queue.
1328 *
1329 * If SMP has not yet been started we must use the global run queue
1330 * as per-CPU state may not be initialized yet and we may crash if we
1331 * try to access the per-CPU run queues.
1332 */
1333 if (smp_started && (td->td_pinned != 0 || td->td_flags & TDF_BOUND ||
1334 ts->ts_flags & TSF_AFFINITY)) {
1335 if (td->td_pinned != 0)
1336 cpu = td->td_lastcpu;
1337 else if (td->td_flags & TDF_BOUND) {
1338 /* Find CPU from bound runq. */
1339 KASSERT(SKE_RUNQ_PCPU(ts),
1340 ("sched_add: bound td_sched not on cpu runq"));
1341 cpu = ts->ts_runq - &runq_pcpu[0];
1342 } else
1343 /* Find a valid CPU for our cpuset */
1344 cpu = sched_pickcpu(td);
1345 ts->ts_runq = &runq_pcpu[cpu];
1346 single_cpu = 1;
1347 CTR3(KTR_RUNQ,
1348 "sched_add: Put td_sched:%p(td:%p) on cpu%d runq", ts, td,
1349 cpu);
1350 } else {
1351 CTR2(KTR_RUNQ,
1352 "sched_add: adding td_sched:%p (td:%p) to gbl runq", ts,
1353 td);
1354 cpu = NOCPU;
1355 ts->ts_runq = &runq;
1356 }
1357
1358 if ((td->td_flags & TDF_NOLOAD) == 0)
1360 runq_add(ts->ts_runq, td, flags);
1361 if (cpu != NOCPU)
1362 runq_length[cpu]++;
1363
1364 cpuid = PCPU_GET(cpuid);
1365 if (single_cpu && cpu != cpuid) {
1366 kick_other_cpu(td->td_priority, cpu);
1367 } else {
1368 if (!single_cpu) {
1369 tidlemsk = idle_cpus_mask;
1370 CPU_ANDNOT(&tidlemsk, &tidlemsk, &hlt_cpus_mask);
1371 CPU_CLR(cpuid, &tidlemsk);
1372
1373 if (!CPU_ISSET(cpuid, &idle_cpus_mask) &&
1374 ((flags & SRQ_INTR) == 0) &&
1375 !CPU_EMPTY(&tidlemsk))
1376 forwarded = forward_wakeup(cpu);
1377 }
1378
1379 if (!forwarded) {
1380 if (!maybe_preempt(td))
1381 maybe_resched(td);
1382 }
1383 }
1384 if ((flags & SRQ_HOLDTD) == 0)
1385 thread_unlock(td);
1386}
1387#else /* SMP */
1388{
1389 struct td_sched *ts;
1390
1391 ts = td_get_sched(td);
1392 THREAD_LOCK_ASSERT(td, MA_OWNED);
1393 KASSERT((td->td_inhibitors == 0),
1394 ("sched_add: trying to run inhibited thread"));
1395 KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)),
1396 ("sched_add: bad thread state"));
1397 KASSERT(td->td_flags & TDF_INMEM,
1398 ("sched_add: thread swapped out"));
1399 KTR_STATE2(KTR_SCHED, "thread", sched_tdname(td), "runq add",
1400 "prio:%d", td->td_priority, KTR_ATTR_LINKED,
1401 sched_tdname(curthread));
1402 KTR_POINT1(KTR_SCHED, "thread", sched_tdname(curthread), "wokeup",
1403 KTR_ATTR_LINKED, sched_tdname(td));
1404 SDT_PROBE4(sched, , , enqueue, td, td->td_proc, NULL,
1405 flags & SRQ_PREEMPTED);
1406
1407 /*
1408 * Now that the thread is moving to the run-queue, set the lock
1409 * to the scheduler's lock.
1410 */
1411 if (td->td_lock != &sched_lock) {
1412 mtx_lock_spin(&sched_lock);
1413 if ((flags & SRQ_HOLD) != 0)
1414 td->td_lock = &sched_lock;
1415 else
1417 }
1418 TD_SET_RUNQ(td);
1419 CTR2(KTR_RUNQ, "sched_add: adding td_sched:%p (td:%p) to runq", ts, td);
1420 ts->ts_runq = &runq;
1421
1422 if ((td->td_flags & TDF_NOLOAD) == 0)
1424 runq_add(ts->ts_runq, td, flags);
1425 if (!maybe_preempt(td))
1426 maybe_resched(td);
1427 if ((flags & SRQ_HOLDTD) == 0)
1428 thread_unlock(td);
1429}
1430#endif /* SMP */
1431
1432void
1433sched_rem(struct thread *td)
1434{
1435 struct td_sched *ts;
1436
1437 ts = td_get_sched(td);
1438 KASSERT(td->td_flags & TDF_INMEM,
1439 ("sched_rem: thread swapped out"));
1440 KASSERT(TD_ON_RUNQ(td),
1441 ("sched_rem: thread not on run queue"));
1442 mtx_assert(&sched_lock, MA_OWNED);
1443 KTR_STATE2(KTR_SCHED, "thread", sched_tdname(td), "runq rem",
1444 "prio:%d", td->td_priority, KTR_ATTR_LINKED,
1445 sched_tdname(curthread));
1446 SDT_PROBE3(sched, , , dequeue, td, td->td_proc, NULL);
1447
1448 if ((td->td_flags & TDF_NOLOAD) == 0)
1450#ifdef SMP
1451 if (ts->ts_runq != &runq)
1452 runq_length[ts->ts_runq - runq_pcpu]--;
1453#endif
1454 runq_remove(ts->ts_runq, td);
1455 TD_SET_CAN_RUN(td);
1456}
1457
1458/*
1459 * Select threads to run. Note that running threads still consume a
1460 * slot.
1461 */
1462struct thread *
1464{
1465 struct thread *td;
1466 struct runq *rq;
1467
1468 mtx_assert(&sched_lock, MA_OWNED);
1469#ifdef SMP
1470 struct thread *tdcpu;
1471
1472 rq = &runq;
1473 td = runq_choose_fuzz(&runq, runq_fuzz);
1474 tdcpu = runq_choose(&runq_pcpu[PCPU_GET(cpuid)]);
1475
1476 if (td == NULL ||
1477 (tdcpu != NULL &&
1478 tdcpu->td_priority < td->td_priority)) {
1479 CTR2(KTR_RUNQ, "choosing td %p from pcpu runq %d", tdcpu,
1480 PCPU_GET(cpuid));
1481 td = tdcpu;
1482 rq = &runq_pcpu[PCPU_GET(cpuid)];
1483 } else {
1484 CTR1(KTR_RUNQ, "choosing td_sched %p from main runq", td);
1485 }
1486
1487#else
1488 rq = &runq;
1489 td = runq_choose(&runq);
1490#endif
1491
1492 if (td) {
1493#ifdef SMP
1494 if (td == tdcpu)
1495 runq_length[PCPU_GET(cpuid)]--;
1496#endif
1497 runq_remove(rq, td);
1498 td->td_flags |= TDF_DIDRUN;
1499
1500 KASSERT(td->td_flags & TDF_INMEM,
1501 ("sched_choose: thread swapped out"));
1502 return (td);
1503 }
1504 return (PCPU_GET(idlethread));
1505}
1506
1507void
1508sched_preempt(struct thread *td)
1509{
1510
1511 SDT_PROBE2(sched, , , surrender, td, td->td_proc);
1512 if (td->td_critnest > 1) {
1513 td->td_owepreempt = 1;
1514 } else {
1515 thread_lock(td);
1516 mi_switch(SW_INVOL | SW_PREEMPT | SWT_PREEMPT);
1517 }
1518}
1519
1520void
1521sched_userret_slowpath(struct thread *td)
1522{
1523
1524 thread_lock(td);
1525 td->td_priority = td->td_user_pri;
1526 td->td_base_pri = td->td_user_pri;
1527 thread_unlock(td);
1528}
1529
1530void
1531sched_bind(struct thread *td, int cpu)
1532{
1533 struct td_sched *ts;
1534
1535 THREAD_LOCK_ASSERT(td, MA_OWNED|MA_NOTRECURSED);
1536 KASSERT(td == curthread, ("sched_bind: can only bind curthread"));
1537
1538 ts = td_get_sched(td);
1539
1540 td->td_flags |= TDF_BOUND;
1541#ifdef SMP
1542 ts->ts_runq = &runq_pcpu[cpu];
1543 if (PCPU_GET(cpuid) == cpu)
1544 return;
1545
1546 mi_switch(SW_VOL);
1547 thread_lock(td);
1548#endif
1549}
1550
1551void
1552sched_unbind(struct thread* td)
1553{
1554 THREAD_LOCK_ASSERT(td, MA_OWNED);
1555 KASSERT(td == curthread, ("sched_unbind: can only bind curthread"));
1556 td->td_flags &= ~TDF_BOUND;
1557}
1558
1559int
1560sched_is_bound(struct thread *td)
1561{
1562 THREAD_LOCK_ASSERT(td, MA_OWNED);
1563 return (td->td_flags & TDF_BOUND);
1564}
1565
1566void
1567sched_relinquish(struct thread *td)
1568{
1569 thread_lock(td);
1570 mi_switch(SW_VOL | SWT_RELINQUISH);
1571}
1572
1573int
1575{
1576 return (sched_tdcnt);
1577}
1578
1579int
1581{
1582 return (sizeof(struct proc));
1583}
1584
1585int
1587{
1588 return (sizeof(struct thread) + sizeof(struct td_sched));
1589}
1590
1591fixpt_t
1592sched_pctcpu(struct thread *td)
1593{
1594 struct td_sched *ts;
1595
1596 THREAD_LOCK_ASSERT(td, MA_OWNED);
1597 ts = td_get_sched(td);
1598 return (ts->ts_pctcpu);
1599}
1600
1601#ifdef RACCT
1602/*
1603 * Calculates the contribution to the thread cpu usage for the latest
1604 * (unfinished) second.
1605 */
1606fixpt_t
1607sched_pctcpu_delta(struct thread *td)
1608{
1609 struct td_sched *ts;
1610 fixpt_t delta;
1611 int realstathz;
1612
1613 THREAD_LOCK_ASSERT(td, MA_OWNED);
1614 ts = td_get_sched(td);
1615 delta = 0;
1616 realstathz = stathz ? stathz : hz;
1617 if (ts->ts_cpticks != 0) {
1618#if (FSHIFT >= CCPU_SHIFT)
1619 delta = (realstathz == 100)
1620 ? ((fixpt_t) ts->ts_cpticks) <<
1621 (FSHIFT - CCPU_SHIFT) :
1622 100 * (((fixpt_t) ts->ts_cpticks)
1623 << (FSHIFT - CCPU_SHIFT)) / realstathz;
1624#else
1625 delta = ((FSCALE - ccpu) *
1626 (ts->ts_cpticks *
1627 FSCALE / realstathz)) >> FSHIFT;
1628#endif
1629 }
1630
1631 return (delta);
1632}
1633#endif
1634
1635u_int
1636sched_estcpu(struct thread *td)
1637{
1638
1639 return (td_get_sched(td)->ts_estcpu);
1640}
1641
1642/*
1643 * The actual idle process.
1644 */
1645void
1647{
1648 struct pcpuidlestat *stat;
1649
1650 THREAD_NO_SLEEPING();
1651 stat = DPCPU_PTR(idlestat);
1652 for (;;) {
1653 mtx_assert(&Giant, MA_NOTOWNED);
1654
1655 while (sched_runnable() == 0) {
1656 cpu_idle(stat->idlecalls + stat->oldidlecalls > 64);
1657 stat->idlecalls++;
1658 }
1659
1660 mtx_lock_spin(&sched_lock);
1661 mi_switch(SW_VOL | SWT_IDLE);
1662 }
1663}
1664
1665static void
1666sched_throw_tail(struct thread *td)
1667{
1668
1669 mtx_assert(&sched_lock, MA_OWNED);
1670 KASSERT(curthread->td_md.md_spinlock_count == 1, ("invalid count"));
1671 cpu_throw(td, choosethread()); /* doesn't return */
1672}
1673
1674/*
1675 * A CPU is entering for the first time.
1676 */
1677void
1679{
1680
1681 /*
1682 * Correct spinlock nesting. The idle thread context that we are
1683 * borrowing was created so that it would start out with a single
1684 * spin lock (sched_lock) held in fork_trampoline(). Since we've
1685 * explicitly acquired locks in this function, the nesting count
1686 * is now 2 rather than 1. Since we are nested, calling
1687 * spinlock_exit() will simply adjust the counts without allowing
1688 * spin lock using code to interrupt us.
1689 */
1690 mtx_lock_spin(&sched_lock);
1691 spinlock_exit();
1692 PCPU_SET(switchtime, cpu_ticks());
1693 PCPU_SET(switchticks, ticks);
1694
1695 sched_throw_tail(NULL);
1696}
1697
1698/*
1699 * A thread is exiting.
1700 */
1701void
1702sched_throw(struct thread *td)
1703{
1704
1705 MPASS(td != NULL);
1706 MPASS(td->td_lock == &sched_lock);
1707
1708 lock_profile_release_lock(&sched_lock.lock_object, true);
1709 td->td_lastcpu = td->td_oncpu;
1710 td->td_oncpu = NOCPU;
1711
1712 sched_throw_tail(td);
1713}
1714
1715void
1716sched_fork_exit(struct thread *td)
1717{
1718
1719 /*
1720 * Finish setting up thread glue so that it begins execution in a
1721 * non-nested critical section with sched_lock held but not recursed.
1722 */
1723 td->td_oncpu = PCPU_GET(cpuid);
1724 sched_lock.mtx_lock = (uintptr_t)td;
1725 lock_profile_obtain_lock_success(&sched_lock.lock_object, true,
1726 0, 0, __FILE__, __LINE__);
1727 THREAD_LOCK_ASSERT(td, MA_OWNED | MA_NOTRECURSED);
1728
1729 KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "running",
1730 "prio:%d", td->td_priority);
1731 SDT_PROBE0(sched, , , on__cpu);
1732}
1733
1734char *
1735sched_tdname(struct thread *td)
1736{
1737#ifdef KTR
1738 struct td_sched *ts;
1739
1740 ts = td_get_sched(td);
1741 if (ts->ts_name[0] == '\0')
1742 snprintf(ts->ts_name, sizeof(ts->ts_name),
1743 "%s tid %d", td->td_name, td->td_tid);
1744 return (ts->ts_name);
1745#else
1746 return (td->td_name);
1747#endif
1748}
1749
1750#ifdef KTR
1751void
1752sched_clear_tdname(struct thread *td)
1753{
1754 struct td_sched *ts;
1755
1756 ts = td_get_sched(td);
1757 ts->ts_name[0] = '\0';
1758}
1759#endif
1760
1761void
1762sched_affinity(struct thread *td)
1763{
1764#ifdef SMP
1765 struct td_sched *ts;
1766 int cpu;
1767
1768 THREAD_LOCK_ASSERT(td, MA_OWNED);
1769
1770 /*
1771 * Set the TSF_AFFINITY flag if there is at least one CPU this
1772 * thread can't run on.
1773 */
1774 ts = td_get_sched(td);
1775 ts->ts_flags &= ~TSF_AFFINITY;
1776 CPU_FOREACH(cpu) {
1777 if (!THREAD_CAN_SCHED(td, cpu)) {
1778 ts->ts_flags |= TSF_AFFINITY;
1779 break;
1780 }
1781 }
1782
1783 /*
1784 * If this thread can run on all CPUs, nothing else to do.
1785 */
1786 if (!(ts->ts_flags & TSF_AFFINITY))
1787 return;
1788
1789 /* Pinned threads and bound threads should be left alone. */
1790 if (td->td_pinned != 0 || td->td_flags & TDF_BOUND)
1791 return;
1792
1793 switch (TD_GET_STATE(td)) {
1794 case TDS_RUNQ:
1795 /*
1796 * If we are on a per-CPU runqueue that is in the set,
1797 * then nothing needs to be done.
1798 */
1799 if (ts->ts_runq != &runq &&
1800 THREAD_CAN_SCHED(td, ts->ts_runq - runq_pcpu))
1801 return;
1802
1803 /* Put this thread on a valid per-CPU runqueue. */
1804 sched_rem(td);
1805 sched_add(td, SRQ_HOLDTD | SRQ_BORING);
1806 break;
1807 case TDS_RUNNING:
1808 /*
1809 * See if our current CPU is in the set. If not, force a
1810 * context switch.
1811 */
1812 if (THREAD_CAN_SCHED(td, td->td_oncpu))
1813 return;
1814
1815 td->td_flags |= TDF_NEEDRESCHED;
1816 if (td != curthread)
1817 ipi_cpu(cpu, IPI_AST);
1818 break;
1819 default:
1820 break;
1821 }
1822#endif
1823}
struct timespec * ts
Definition: clock_if.m:39
const char * name
Definition: kern_fail.c:145
int stathz
Definition: kern_clock.c:377
volatile int ticks
Definition: kern_clock.c:380
struct cpuset * cpuset_ref(struct cpuset *set)
Definition: kern_cpuset.c:174
void kproc_start(const void *udata)
Definition: kern_kthread.c:62
void thread_lock_set(struct thread *td, struct mtx *new)
Definition: kern_mutex.c:997
struct mtx __exclusive_cache_line Giant
Definition: kern_mutex.c:181
struct mtx * thread_lock_block(struct thread *td)
Definition: kern_mutex.c:963
struct sx __exclusive_cache_line allproc_lock
Definition: kern_proc.c:134
void runq_add(struct runq *rq, struct thread *td, int flags)
Definition: kern_switch.c:369
struct thread * choosethread(void)
Definition: kern_switch.c:180
void runq_remove(struct runq *rq, struct thread *td)
Definition: kern_switch.c:518
void runq_init(struct runq *rq)
Definition: kern_switch.c:266
struct thread * runq_choose_fuzz(struct runq *rq, int fuzz)
Definition: kern_switch.c:431
struct thread * runq_choose(struct runq *rq)
Definition: kern_switch.c:473
int runq_check(struct runq *rq)
Definition: kern_switch.c:410
void mi_switch(int flags)
Definition: kern_synch.c:491
struct loadavg averunnable
Definition: kern_synch.c:84
int hogticks
Definition: kern_synch.c:79
int sysctl_handle_int(SYSCTL_HANDLER_ARGS)
Definition: kern_sysctl.c:1644
cpu_tick_f * cpu_ticks
Definition: kern_tc.c:2174
device_t child
Definition: msi_if.m:58
struct thread * sched_choose(void)
Definition: sched_4bsd.c:1463
static void schedcpu(void)
Definition: sched_4bsd.c:463
static struct runq runq
Definition: sched_4bsd.c:163
void sched_bind(struct thread *td, int cpu)
Definition: sched_4bsd.c:1531
fixpt_t sched_pctcpu(struct thread *td)
Definition: sched_4bsd.c:1592
int sched_rr_interval(void)
Definition: sched_4bsd.c:699
void sched_idletd(void *dummy)
Definition: sched_4bsd.c:1646
void schedinit(void)
Definition: sched_4bsd.c:670
void sched_exit_thread(struct thread *td, struct thread *child)
Definition: sched_4bsd.c:773
void sched_userret_slowpath(struct thread *td)
Definition: sched_4bsd.c:1521
void sched_lend_user_prio(struct thread *td, u_char prio)
Definition: sched_4bsd.c:939
void sched_relinquish(struct thread *td)
Definition: sched_4bsd.c:1567
static void resetpriority_thread(struct thread *td)
Definition: sched_4bsd.c:623
#define TSF_AFFINITY
Definition: sched_4bsd.c:114
#define TDF_SLICEEND
Definition: sched_4bsd.c:111
void sched_throw(struct thread *td)
Definition: sched_4bsd.c:1702
void sched_fork(struct thread *td, struct thread *childtd)
Definition: sched_4bsd.c:789
#define SKE_RUNQ_PCPU(ts)
Definition: sched_4bsd.c:116
#define loadfactor(loadav)
Definition: sched_4bsd.c:435
static void sched_priority(struct thread *td, u_char prio)
Definition: sched_4bsd.c:839
void sched_unbind(struct thread *td)
Definition: sched_4bsd.c:1552
static int realstathz
Definition: sched_4bsd.c:128
u_int sched_estcpu(struct thread *td)
Definition: sched_4bsd.c:1636
DPCPU_DEFINE_STATIC(struct pcpuidlestat, idlestat)
void sched_fork_thread(struct thread *td, struct thread *childtd)
Definition: sched_4bsd.c:795
SDT_PROBE_DEFINE(sched,,, on__cpu)
SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "4BSD", 0, "Scheduler name")
static int sched_slice
Definition: sched_4bsd.c:130
static void resetpriority(struct thread *td)
Definition: sched_4bsd.c:604
SYSINIT(schedcpu, SI_SUB_LAST, SI_ORDER_FIRST, kproc_start, &sched_kp)
static void schedcpu_thread(void)
Definition: sched_4bsd.c:564
void sched_unlend_prio(struct thread *td, u_char prio)
Definition: sched_4bsd.c:884
_Static_assert(sizeof(struct thread)+sizeof(struct td_sched)<=sizeof(struct thread0_storage), "increase struct thread0_storage.t0st_sched size")
static void setup_runqs(void)
Definition: sched_4bsd.c:182
#define TDF_DIDRUN
Definition: sched_4bsd.c:109
void sched_rem(struct thread *td)
Definition: sched_4bsd.c:1433
#define THREAD_CAN_SCHED(td, cpu)
Definition: sched_4bsd.c:119
void sched_class(struct thread *td, int class)
Definition: sched_4bsd.c:829
void sched_prio(struct thread *td, u_char prio)
Definition: sched_4bsd.c:901
static struct mtx sched_lock
Definition: sched_4bsd.c:126
static int sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
Definition: sched_4bsd.c:195
SYSCTL_UINT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "Decay factor used for updating %CPU")
void schedinit_ap(void)
Definition: sched_4bsd.c:682
SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_quantum, "I", "Quantum for timeshare threads in microseconds")
SDT_PROVIDER_DEFINE(sched)
void sched_ap_entry(void)
Definition: sched_4bsd.c:1678
int maybe_preempt(struct thread *td)
Definition: sched_4bsd.c:320
#define NICE_WEIGHT
Definition: sched_4bsd.c:85
void sched_lend_user_prio_cond(struct thread *td, u_char prio)
Definition: sched_4bsd.c:955
__FBSDID("$FreeBSD$")
static fixpt_t ccpu
Definition: sched_4bsd.c:439
void sched_preempt(struct thread *td)
Definition: sched_4bsd.c:1508
void sched_clock(struct thread *td, int cnt)
Definition: sched_4bsd.c:751
static void updatepri(struct thread *td)
Definition: sched_4bsd.c:579
char * sched_tdname(struct thread *td)
Definition: sched_4bsd.c:1735
static __inline void sched_load_add(void)
Definition: sched_4bsd.c:284
int sched_sizeof_proc(void)
Definition: sched_4bsd.c:1580
static void sched_clock_tick(struct thread *td)
Definition: sched_4bsd.c:721
static __inline void sched_load_rem(void)
Definition: sched_4bsd.c:293
static void sched_setup(void *dummy)
Definition: sched_4bsd.c:639
int sched_sizeof_thread(void)
Definition: sched_4bsd.c:1586
#define ESTCPULIM(e)
Definition: sched_4bsd.c:77
void sched_nice(struct proc *p, int nice)
Definition: sched_4bsd.c:814
#define INVERSE_ESTCPU_WEIGHT
Definition: sched_4bsd.c:83
void sched_lend_prio(struct thread *td, u_char prio)
Definition: sched_4bsd.c:868
int sched_runnable(void)
Definition: sched_4bsd.c:689
static void sched_initticks(void *dummy)
Definition: sched_4bsd.c:652
void sched_affinity(struct thread *td)
Definition: sched_4bsd.c:1762
SDT_PROBE_DEFINE2(sched,,, load__change, "int", "int")
int sched_load(void)
Definition: sched_4bsd.c:1574
SDT_PROBE_DEFINE3(sched,,, change__pri, "struct thread *", "struct proc *", "uint8_t")
void sched_fork_exit(struct thread *td)
Definition: sched_4bsd.c:1716
#define TDF_BOUND
Definition: sched_4bsd.c:110
void sched_sleep(struct thread *td, int pri)
Definition: sched_4bsd.c:973
void sched_add(struct thread *td, int flags)
Definition: sched_4bsd.c:1285
SDT_PROBE_DEFINE4(sched,,, enqueue, "struct thread *", "struct proc *", "void *", "int")
static int sched_tdcnt
Definition: sched_4bsd.c:129
#define CCPU_SHIFT
Definition: sched_4bsd.c:455
static struct kproc_desc sched_kp
Definition: sched_4bsd.c:147
static void maybe_resched(struct thread *td)
Definition: sched_4bsd.c:305
void sched_exit(struct proc *p, struct thread *td)
Definition: sched_4bsd.c:762
SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RD|CTLFLAG_MPSAFE, 0, "Scheduler")
#define TS_NAME_LEN
Definition: sched_4bsd.c:87
void sched_switch(struct thread *td, int flags)
Definition: sched_4bsd.c:986
SYSCTL_INT(_kern_sched, OID_AUTO, slice, CTLFLAG_RW, &sched_slice, 0, "Quantum for timeshare threads in stathz ticks")
void sched_wakeup(struct thread *td, int srqflags)
Definition: sched_4bsd.c:1118
int sched_is_bound(struct thread *td)
Definition: sched_4bsd.c:1560
void sched_user_prio(struct thread *td, u_char prio)
Definition: sched_4bsd.c:928
static void sched_throw_tail(struct thread *td)
Definition: sched_4bsd.c:1666
#define decay_cpu(loadfac, cpu)
Definition: sched_4bsd.c:436
u_int idlecalls
Definition: sched_4bsd.c:176
u_int oldidlecalls
Definition: sched_4bsd.c:177
int ts_slptime
Definition: sched_4bsd.c:99
int ts_flags
Definition: sched_4bsd.c:101
int ts_slice
Definition: sched_4bsd.c:100
int ts_cpticks
Definition: sched_4bsd.c:98
fixpt_t ts_pctcpu
Definition: sched_4bsd.c:96
struct runq * ts_runq
Definition: sched_4bsd.c:102
u_int ts_estcpu
Definition: sched_4bsd.c:97
static bool kasan_enabled __read_mostly
Definition: subr_asan.c:95
int hz
Definition: subr_param.c:85
struct pcpu * pcpu_find(u_int cpuid)
Definition: subr_pcpu.c:283
int printf(const char *fmt,...)
Definition: subr_prf.c:397
int snprintf(char *str, size_t size, const char *format,...)
Definition: subr_prf.c:550
int mp_maxcpus
Definition: subr_smp.c:74
volatile int smp_started
Definition: subr_smp.c:76
uint16_t flags
Definition: subr_stats.c:2
void turnstile_adjust(struct thread *td, u_char oldpri)
struct mtx mtx
Definition: uipc_ktls.c:0
static int dummy