2 * Copyright (c) 1982, 1986, 1990, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
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35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
38 #include "opt_hwpmc_hooks.h"
39 #include "opt_sched.h"
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/cpuset.h>
44 #include <sys/kernel.h>
47 #include <sys/kthread.h>
48 #include <sys/mutex.h>
50 #include <sys/resourcevar.h>
51 #include <sys/sched.h>
54 #include <sys/sysctl.h>
56 #include <sys/turnstile.h>
58 #include <machine/pcb.h>
59 #include <machine/smp.h>
62 #include <sys/pmckern.h>
66 #include <sys/dtrace_bsd.h>
67 int dtrace_vtime_active;
68 dtrace_vtime_switch_func_t dtrace_vtime_switch_func;
72 * INVERSE_ESTCPU_WEIGHT is only suitable for statclock() frequencies in
73 * the range 100-256 Hz (approximately).
75 #define ESTCPULIM(e) \
76 min((e), INVERSE_ESTCPU_WEIGHT * (NICE_WEIGHT * (PRIO_MAX - PRIO_MIN) - \
77 RQ_PPQ) + INVERSE_ESTCPU_WEIGHT - 1)
79 #define INVERSE_ESTCPU_WEIGHT (8 * smp_cpus)
81 #define INVERSE_ESTCPU_WEIGHT 8 /* 1 / (priorities per estcpu level). */
83 #define NICE_WEIGHT 1 /* Priorities per nice level. */
85 #define TS_NAME_LEN (MAXCOMLEN + sizeof(" td ") + sizeof(__XSTRING(UINT_MAX)))
88 * The schedulable entity that runs a context.
89 * This is an extension to the thread structure and is tailored to
90 * the requirements of this scheduler.
91 * All fields are protected by the scheduler lock.
94 fixpt_t ts_pctcpu; /* %cpu during p_swtime. */
95 u_int ts_estcpu; /* Estimated cpu utilization. */
96 int ts_cpticks; /* Ticks of cpu time. */
97 int ts_slptime; /* Seconds !RUNNING. */
98 int ts_slice; /* Remaining part of time slice. */
100 struct runq *ts_runq; /* runq the thread is currently on */
102 char ts_name[TS_NAME_LEN];
106 /* flags kept in td_flags */
107 #define TDF_DIDRUN TDF_SCHED0 /* thread actually ran. */
108 #define TDF_BOUND TDF_SCHED1 /* Bound to one CPU. */
109 #define TDF_SLICEEND TDF_SCHED2 /* Thread time slice is over. */
111 /* flags kept in ts_flags */
112 #define TSF_AFFINITY 0x0001 /* Has a non-"full" CPU set. */
114 #define SKE_RUNQ_PCPU(ts) \
115 ((ts)->ts_runq != 0 && (ts)->ts_runq != &runq)
117 #define THREAD_CAN_SCHED(td, cpu) \
118 CPU_ISSET((cpu), &(td)->td_cpuset->cs_mask)
120 static struct td_sched td_sched0;
121 static struct mtx sched_lock;
123 static int realstathz = 127; /* stathz is sometimes 0 and run off of hz. */
124 static int sched_tdcnt; /* Total runnable threads in the system. */
125 static int sched_slice = 12; /* Thread run time before rescheduling. */
127 static void setup_runqs(void);
128 static void schedcpu(void);
129 static void schedcpu_thread(void);
130 static void sched_priority(struct thread *td, u_char prio);
131 static void sched_setup(void *dummy);
132 static void maybe_resched(struct thread *td);
133 static void updatepri(struct thread *td);
134 static void resetpriority(struct thread *td);
135 static void resetpriority_thread(struct thread *td);
137 static int sched_pickcpu(struct thread *td);
138 static int forward_wakeup(int cpunum);
139 static void kick_other_cpu(int pri, int cpuid);
142 static struct kproc_desc sched_kp = {
147 SYSINIT(schedcpu, SI_SUB_LAST, SI_ORDER_FIRST, kproc_start,
149 SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL);
151 static void sched_initticks(void *dummy);
152 SYSINIT(sched_initticks, SI_SUB_CLOCKS, SI_ORDER_THIRD, sched_initticks,
158 static struct runq runq;
164 static struct runq runq_pcpu[MAXCPU];
165 long runq_length[MAXCPU];
167 static cpuset_t idle_cpus_mask;
170 struct pcpuidlestat {
174 static DPCPU_DEFINE(struct pcpuidlestat, idlestat);
182 for (i = 0; i < MAXCPU; ++i)
183 runq_init(&runq_pcpu[i]);
190 sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
192 int error, new_val, period;
194 period = 1000000 / realstathz;
195 new_val = period * sched_slice;
196 error = sysctl_handle_int(oidp, &new_val, 0, req);
197 if (error != 0 || req->newptr == NULL)
201 sched_slice = imax(1, (new_val + period / 2) / period);
202 hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) /
207 SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RD, 0, "Scheduler");
209 SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "4BSD", 0,
211 SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, CTLTYPE_INT | CTLFLAG_RW,
212 NULL, 0, sysctl_kern_quantum, "I",
213 "Quantum for timeshare threads in microseconds");
214 SYSCTL_INT(_kern_sched, OID_AUTO, slice, CTLFLAG_RW, &sched_slice, 0,
215 "Quantum for timeshare threads in stathz ticks");
217 /* Enable forwarding of wakeups to all other cpus */
218 static SYSCTL_NODE(_kern_sched, OID_AUTO, ipiwakeup, CTLFLAG_RD, NULL,
221 static int runq_fuzz = 1;
222 SYSCTL_INT(_kern_sched, OID_AUTO, runq_fuzz, CTLFLAG_RW, &runq_fuzz, 0, "");
224 static int forward_wakeup_enabled = 1;
225 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, enabled, CTLFLAG_RW,
226 &forward_wakeup_enabled, 0,
227 "Forwarding of wakeup to idle CPUs");
229 static int forward_wakeups_requested = 0;
230 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, requested, CTLFLAG_RD,
231 &forward_wakeups_requested, 0,
232 "Requests for Forwarding of wakeup to idle CPUs");
234 static int forward_wakeups_delivered = 0;
235 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, delivered, CTLFLAG_RD,
236 &forward_wakeups_delivered, 0,
237 "Completed Forwarding of wakeup to idle CPUs");
239 static int forward_wakeup_use_mask = 1;
240 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, usemask, CTLFLAG_RW,
241 &forward_wakeup_use_mask, 0,
242 "Use the mask of idle cpus");
244 static int forward_wakeup_use_loop = 0;
245 SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, useloop, CTLFLAG_RW,
246 &forward_wakeup_use_loop, 0,
247 "Use a loop to find idle cpus");
251 static int sched_followon = 0;
252 SYSCTL_INT(_kern_sched, OID_AUTO, followon, CTLFLAG_RW,
254 "allow threads to share a quantum");
257 SDT_PROVIDER_DEFINE(sched);
259 SDT_PROBE_DEFINE3(sched, , , change__pri, "struct thread *",
260 "struct proc *", "uint8_t");
261 SDT_PROBE_DEFINE3(sched, , , dequeue, "struct thread *",
262 "struct proc *", "void *");
263 SDT_PROBE_DEFINE4(sched, , , enqueue, "struct thread *",
264 "struct proc *", "void *", "int");
265 SDT_PROBE_DEFINE4(sched, , , lend__pri, "struct thread *",
266 "struct proc *", "uint8_t", "struct thread *");
267 SDT_PROBE_DEFINE2(sched, , , load__change, "int", "int");
268 SDT_PROBE_DEFINE2(sched, , , off__cpu, "struct thread *",
270 SDT_PROBE_DEFINE(sched, , , on__cpu);
271 SDT_PROBE_DEFINE(sched, , , remain__cpu);
272 SDT_PROBE_DEFINE2(sched, , , surrender, "struct thread *",
280 KTR_COUNTER0(KTR_SCHED, "load", "global load", sched_tdcnt);
281 SDT_PROBE2(sched, , , load__change, NOCPU, sched_tdcnt);
289 KTR_COUNTER0(KTR_SCHED, "load", "global load", sched_tdcnt);
290 SDT_PROBE2(sched, , , load__change, NOCPU, sched_tdcnt);
293 * Arrange to reschedule if necessary, taking the priorities and
294 * schedulers into account.
297 maybe_resched(struct thread *td)
300 THREAD_LOCK_ASSERT(td, MA_OWNED);
301 if (td->td_priority < curthread->td_priority)
302 curthread->td_flags |= TDF_NEEDRESCHED;
306 * This function is called when a thread is about to be put on run queue
307 * because it has been made runnable or its priority has been adjusted. It
308 * determines if the new thread should be immediately preempted to. If so,
309 * it switches to it and eventually returns true. If not, it returns false
310 * so that the caller may place the thread on an appropriate run queue.
313 maybe_preempt(struct thread *td)
320 * The new thread should not preempt the current thread if any of the
321 * following conditions are true:
323 * - The kernel is in the throes of crashing (panicstr).
324 * - The current thread has a higher (numerically lower) or
325 * equivalent priority. Note that this prevents curthread from
326 * trying to preempt to itself.
327 * - It is too early in the boot for context switches (cold is set).
328 * - The current thread has an inhibitor set or is in the process of
329 * exiting. In this case, the current thread is about to switch
330 * out anyways, so there's no point in preempting. If we did,
331 * the current thread would not be properly resumed as well, so
332 * just avoid that whole landmine.
333 * - If the new thread's priority is not a realtime priority and
334 * the current thread's priority is not an idle priority and
335 * FULL_PREEMPTION is disabled.
337 * If all of these conditions are false, but the current thread is in
338 * a nested critical section, then we have to defer the preemption
339 * until we exit the critical section. Otherwise, switch immediately
343 THREAD_LOCK_ASSERT(td, MA_OWNED);
344 KASSERT((td->td_inhibitors == 0),
345 ("maybe_preempt: trying to run inhibited thread"));
346 pri = td->td_priority;
347 cpri = ctd->td_priority;
348 if (panicstr != NULL || pri >= cpri || cold /* || dumping */ ||
349 TD_IS_INHIBITED(ctd))
351 #ifndef FULL_PREEMPTION
352 if (pri > PRI_MAX_ITHD && cpri < PRI_MIN_IDLE)
356 if (ctd->td_critnest > 1) {
357 CTR1(KTR_PROC, "maybe_preempt: in critical section %d",
359 ctd->td_owepreempt = 1;
363 * Thread is runnable but not yet put on system run queue.
365 MPASS(ctd->td_lock == td->td_lock);
366 MPASS(TD_ON_RUNQ(td));
368 CTR3(KTR_PROC, "preempting to thread %p (pid %d, %s)\n", td,
369 td->td_proc->p_pid, td->td_name);
370 mi_switch(SW_INVOL | SW_PREEMPT | SWT_PREEMPT, td);
372 * td's lock pointer may have changed. We have to return with it
386 * Constants for digital decay and forget:
387 * 90% of (ts_estcpu) usage in 5 * loadav time
388 * 95% of (ts_pctcpu) usage in 60 seconds (load insensitive)
389 * Note that, as ps(1) mentions, this can let percentages
390 * total over 100% (I've seen 137.9% for 3 processes).
392 * Note that schedclock() updates ts_estcpu and p_cpticks asynchronously.
394 * We wish to decay away 90% of ts_estcpu in (5 * loadavg) seconds.
395 * That is, the system wants to compute a value of decay such
396 * that the following for loop:
397 * for (i = 0; i < (5 * loadavg); i++)
398 * ts_estcpu *= decay;
401 * for all values of loadavg:
403 * Mathematically this loop can be expressed by saying:
404 * decay ** (5 * loadavg) ~= .1
406 * The system computes decay as:
407 * decay = (2 * loadavg) / (2 * loadavg + 1)
409 * We wish to prove that the system's computation of decay
410 * will always fulfill the equation:
411 * decay ** (5 * loadavg) ~= .1
413 * If we compute b as:
416 * decay = b / (b + 1)
418 * We now need to prove two things:
419 * 1) Given factor ** (5 * loadavg) ~= .1, prove factor == b/(b+1)
420 * 2) Given b/(b+1) ** power ~= .1, prove power == (5 * loadavg)
423 * For x close to zero, exp(x) =~ 1 + x, since
424 * exp(x) = 0! + x**1/1! + x**2/2! + ... .
425 * therefore exp(-1/b) =~ 1 - (1/b) = (b-1)/b.
426 * For x close to zero, ln(1+x) =~ x, since
427 * ln(1+x) = x - x**2/2 + x**3/3 - ... -1 < x < 1
428 * therefore ln(b/(b+1)) = ln(1 - 1/(b+1)) =~ -1/(b+1).
432 * Solve (factor)**(power) =~ .1 given power (5*loadav):
433 * solving for factor,
434 * ln(factor) =~ (-2.30/5*loadav), or
435 * factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) =
436 * exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED
439 * Solve (factor)**(power) =~ .1 given factor == (b/(b+1)):
441 * power*ln(b/(b+1)) =~ -2.30, or
442 * power =~ 2.3 * (b + 1) = 4.6*loadav + 2.3 =~ 5*loadav. QED
444 * Actual power values for the implemented algorithm are as follows:
446 * power: 5.68 10.32 14.94 19.55
449 /* calculations for digital decay to forget 90% of usage in 5*loadav sec */
450 #define loadfactor(loadav) (2 * (loadav))
451 #define decay_cpu(loadfac, cpu) (((loadfac) * (cpu)) / ((loadfac) + FSCALE))
453 /* decay 95% of `ts_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */
454 static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
455 SYSCTL_UINT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
458 * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the
459 * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below
460 * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT).
462 * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used:
463 * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits).
465 * If you don't want to bother with the faster/more-accurate formula, you
466 * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate
467 * (more general) method of calculating the %age of CPU used by a process.
469 #define CCPU_SHIFT 11
472 * Recompute process priorities, every hz ticks.
473 * MP-safe, called without the Giant mutex.
479 register fixpt_t loadfac = loadfactor(averunnable.ldavg[0]);
485 sx_slock(&allproc_lock);
486 FOREACH_PROC_IN_SYSTEM(p) {
488 if (p->p_state == PRS_NEW) {
492 FOREACH_THREAD_IN_PROC(p, td) {
497 * Increment sleep time (if sleeping). We
498 * ignore overflow, as above.
501 * The td_sched slptimes are not touched in wakeup
502 * because the thread may not HAVE everything in
503 * memory? XXX I think this is out of date.
505 if (TD_ON_RUNQ(td)) {
507 td->td_flags &= ~TDF_DIDRUN;
508 } else if (TD_IS_RUNNING(td)) {
510 /* Do not clear TDF_DIDRUN */
511 } else if (td->td_flags & TDF_DIDRUN) {
513 td->td_flags &= ~TDF_DIDRUN;
517 * ts_pctcpu is only for ps and ttyinfo().
519 ts->ts_pctcpu = (ts->ts_pctcpu * ccpu) >> FSHIFT;
521 * If the td_sched has been idle the entire second,
522 * stop recalculating its priority until
525 if (ts->ts_cpticks != 0) {
526 #if (FSHIFT >= CCPU_SHIFT)
527 ts->ts_pctcpu += (realstathz == 100)
528 ? ((fixpt_t) ts->ts_cpticks) <<
529 (FSHIFT - CCPU_SHIFT) :
530 100 * (((fixpt_t) ts->ts_cpticks)
531 << (FSHIFT - CCPU_SHIFT)) / realstathz;
533 ts->ts_pctcpu += ((FSCALE - ccpu) *
535 FSCALE / realstathz)) >> FSHIFT;
540 * If there are ANY running threads in this process,
541 * then don't count it as sleeping.
542 * XXX: this is broken.
545 if (ts->ts_slptime > 1) {
547 * In an ideal world, this should not
548 * happen, because whoever woke us
549 * up from the long sleep should have
550 * unwound the slptime and reset our
551 * priority before we run at the stale
552 * priority. Should KASSERT at some
553 * point when all the cases are fixed.
560 if (ts->ts_slptime > 1) {
564 ts->ts_estcpu = decay_cpu(loadfac, ts->ts_estcpu);
566 resetpriority_thread(td);
571 sx_sunlock(&allproc_lock);
575 * Main loop for a kthread that executes schedcpu once a second.
578 schedcpu_thread(void)
588 * Recalculate the priority of a process after it has slept for a while.
589 * For all load averages >= 1 and max ts_estcpu of 255, sleeping for at
590 * least six times the loadfactor will decay ts_estcpu to zero.
593 updatepri(struct thread *td)
600 loadfac = loadfactor(averunnable.ldavg[0]);
601 if (ts->ts_slptime > 5 * loadfac)
604 newcpu = ts->ts_estcpu;
605 ts->ts_slptime--; /* was incremented in schedcpu() */
606 while (newcpu && --ts->ts_slptime)
607 newcpu = decay_cpu(loadfac, newcpu);
608 ts->ts_estcpu = newcpu;
613 * Compute the priority of a process when running in user mode.
614 * Arrange to reschedule if the resulting priority is better
615 * than that of the current process.
618 resetpriority(struct thread *td)
622 if (td->td_pri_class != PRI_TIMESHARE)
624 newpriority = PUSER + td->td_sched->ts_estcpu / INVERSE_ESTCPU_WEIGHT +
625 NICE_WEIGHT * (td->td_proc->p_nice - PRIO_MIN);
626 newpriority = min(max(newpriority, PRI_MIN_TIMESHARE),
628 sched_user_prio(td, newpriority);
632 * Update the thread's priority when the associated process's user
636 resetpriority_thread(struct thread *td)
639 /* Only change threads with a time sharing user priority. */
640 if (td->td_priority < PRI_MIN_TIMESHARE ||
641 td->td_priority > PRI_MAX_TIMESHARE)
644 /* XXX the whole needresched thing is broken, but not silly. */
647 sched_prio(td, td->td_user_pri);
652 sched_setup(void *dummy)
657 /* Account for thread0. */
662 * This routine determines time constants after stathz and hz are setup.
665 sched_initticks(void *dummy)
668 realstathz = stathz ? stathz : hz;
669 sched_slice = realstathz / 10; /* ~100ms */
670 hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) /
674 /* External interfaces start here */
677 * Very early in the boot some setup of scheduler-specific
678 * parts of proc0 and of some scheduler resources needs to be done.
686 * Set up the scheduler specific parts of proc0.
688 proc0.p_sched = NULL; /* XXX */
689 thread0.td_sched = &td_sched0;
690 thread0.td_lock = &sched_lock;
691 td_sched0.ts_slice = sched_slice;
692 mtx_init(&sched_lock, "sched lock", NULL, MTX_SPIN | MTX_RECURSE);
699 return runq_check(&runq) + runq_check(&runq_pcpu[PCPU_GET(cpuid)]);
701 return runq_check(&runq);
706 sched_rr_interval(void)
709 /* Convert sched_slice from stathz to hz. */
710 return (imax(1, (sched_slice * hz + realstathz / 2) / realstathz));
714 * We adjust the priority of the current process. The priority of a
715 * process gets worse as it accumulates CPU time. The cpu usage
716 * estimator (ts_estcpu) is increased here. resetpriority() will
717 * compute a different priority each time ts_estcpu increases by
718 * INVERSE_ESTCPU_WEIGHT (until PRI_MAX_TIMESHARE is reached). The
719 * cpu usage estimator ramps up quite quickly when the process is
720 * running (linearly), and decays away exponentially, at a rate which
721 * is proportionally slower when the system is busy. The basic
722 * principle is that the system will 90% forget that the process used
723 * a lot of CPU time in 5 * loadav seconds. This causes the system to
724 * favor processes which haven't run much recently, and to round-robin
725 * among other processes.
728 sched_clock(struct thread *td)
730 struct pcpuidlestat *stat;
733 THREAD_LOCK_ASSERT(td, MA_OWNED);
737 ts->ts_estcpu = ESTCPULIM(ts->ts_estcpu + 1);
738 if ((ts->ts_estcpu % INVERSE_ESTCPU_WEIGHT) == 0) {
740 resetpriority_thread(td);
744 * Force a context switch if the current thread has used up a full
745 * time slice (default is 100ms).
747 if (!TD_IS_IDLETHREAD(td) && --ts->ts_slice <= 0) {
748 ts->ts_slice = sched_slice;
749 td->td_flags |= TDF_NEEDRESCHED | TDF_SLICEEND;
752 stat = DPCPU_PTR(idlestat);
753 stat->oldidlecalls = stat->idlecalls;
758 * Charge child's scheduling CPU usage to parent.
761 sched_exit(struct proc *p, struct thread *td)
764 KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "proc exit",
765 "prio:%d", td->td_priority);
767 PROC_LOCK_ASSERT(p, MA_OWNED);
768 sched_exit_thread(FIRST_THREAD_IN_PROC(p), td);
772 sched_exit_thread(struct thread *td, struct thread *child)
775 KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "exit",
776 "prio:%d", child->td_priority);
778 td->td_sched->ts_estcpu = ESTCPULIM(td->td_sched->ts_estcpu +
779 child->td_sched->ts_estcpu);
782 if ((child->td_flags & TDF_NOLOAD) == 0)
784 thread_unlock(child);
788 sched_fork(struct thread *td, struct thread *childtd)
790 sched_fork_thread(td, childtd);
794 sched_fork_thread(struct thread *td, struct thread *childtd)
798 childtd->td_oncpu = NOCPU;
799 childtd->td_lastcpu = NOCPU;
800 childtd->td_lock = &sched_lock;
801 childtd->td_cpuset = cpuset_ref(td->td_cpuset);
802 childtd->td_priority = childtd->td_base_pri;
803 ts = childtd->td_sched;
804 bzero(ts, sizeof(*ts));
805 ts->ts_estcpu = td->td_sched->ts_estcpu;
806 ts->ts_flags |= (td->td_sched->ts_flags & TSF_AFFINITY);
811 sched_nice(struct proc *p, int nice)
815 PROC_LOCK_ASSERT(p, MA_OWNED);
817 FOREACH_THREAD_IN_PROC(p, td) {
820 resetpriority_thread(td);
826 sched_class(struct thread *td, int class)
828 THREAD_LOCK_ASSERT(td, MA_OWNED);
829 td->td_pri_class = class;
833 * Adjust the priority of a thread.
836 sched_priority(struct thread *td, u_char prio)
840 KTR_POINT3(KTR_SCHED, "thread", sched_tdname(td), "priority change",
841 "prio:%d", td->td_priority, "new prio:%d", prio, KTR_ATTR_LINKED,
842 sched_tdname(curthread));
843 SDT_PROBE3(sched, , , change__pri, td, td->td_proc, prio);
844 if (td != curthread && prio > td->td_priority) {
845 KTR_POINT3(KTR_SCHED, "thread", sched_tdname(curthread),
846 "lend prio", "prio:%d", td->td_priority, "new prio:%d",
847 prio, KTR_ATTR_LINKED, sched_tdname(td));
848 SDT_PROBE4(sched, , , lend__pri, td, td->td_proc, prio,
851 THREAD_LOCK_ASSERT(td, MA_OWNED);
852 if (td->td_priority == prio)
854 td->td_priority = prio;
855 if (TD_ON_RUNQ(td) && td->td_rqindex != (prio / RQ_PPQ)) {
857 sched_add(td, SRQ_BORING);
862 * Update a thread's priority when it is lent another thread's
866 sched_lend_prio(struct thread *td, u_char prio)
869 td->td_flags |= TDF_BORROWING;
870 sched_priority(td, prio);
874 * Restore a thread's priority when priority propagation is
875 * over. The prio argument is the minimum priority the thread
876 * needs to have to satisfy other possible priority lending
877 * requests. If the thread's regulary priority is less
878 * important than prio the thread will keep a priority boost
882 sched_unlend_prio(struct thread *td, u_char prio)
886 if (td->td_base_pri >= PRI_MIN_TIMESHARE &&
887 td->td_base_pri <= PRI_MAX_TIMESHARE)
888 base_pri = td->td_user_pri;
890 base_pri = td->td_base_pri;
891 if (prio >= base_pri) {
892 td->td_flags &= ~TDF_BORROWING;
893 sched_prio(td, base_pri);
895 sched_lend_prio(td, prio);
899 sched_prio(struct thread *td, u_char prio)
903 /* First, update the base priority. */
904 td->td_base_pri = prio;
907 * If the thread is borrowing another thread's priority, don't ever
908 * lower the priority.
910 if (td->td_flags & TDF_BORROWING && td->td_priority < prio)
913 /* Change the real priority. */
914 oldprio = td->td_priority;
915 sched_priority(td, prio);
918 * If the thread is on a turnstile, then let the turnstile update
921 if (TD_ON_LOCK(td) && oldprio != prio)
922 turnstile_adjust(td, oldprio);
926 sched_user_prio(struct thread *td, u_char prio)
929 THREAD_LOCK_ASSERT(td, MA_OWNED);
930 td->td_base_user_pri = prio;
931 if (td->td_lend_user_pri <= prio)
933 td->td_user_pri = prio;
937 sched_lend_user_prio(struct thread *td, u_char prio)
940 THREAD_LOCK_ASSERT(td, MA_OWNED);
941 td->td_lend_user_pri = prio;
942 td->td_user_pri = min(prio, td->td_base_user_pri);
943 if (td->td_priority > td->td_user_pri)
944 sched_prio(td, td->td_user_pri);
945 else if (td->td_priority != td->td_user_pri)
946 td->td_flags |= TDF_NEEDRESCHED;
950 sched_sleep(struct thread *td, int pri)
953 THREAD_LOCK_ASSERT(td, MA_OWNED);
954 td->td_slptick = ticks;
955 td->td_sched->ts_slptime = 0;
956 if (pri != 0 && PRI_BASE(td->td_pri_class) == PRI_TIMESHARE)
958 if (TD_IS_SUSPENDED(td) || pri >= PSOCK)
959 td->td_flags |= TDF_CANSWAP;
963 sched_switch(struct thread *td, struct thread *newtd, int flags)
974 THREAD_LOCK_ASSERT(td, MA_OWNED);
977 * Switch to the sched lock to fix things up and pick
979 * Block the td_lock in order to avoid breaking the critical path.
981 if (td->td_lock != &sched_lock) {
982 mtx_lock_spin(&sched_lock);
983 tmtx = thread_lock_block(td);
986 if ((td->td_flags & TDF_NOLOAD) == 0)
989 td->td_lastcpu = td->td_oncpu;
990 preempted = !((td->td_flags & TDF_SLICEEND) ||
991 (flags & SWT_RELINQUISH));
992 td->td_flags &= ~(TDF_NEEDRESCHED | TDF_SLICEEND);
993 td->td_owepreempt = 0;
994 td->td_oncpu = NOCPU;
997 * At the last moment, if this thread is still marked RUNNING,
998 * then put it back on the run queue as it has not been suspended
999 * or stopped or any thing else similar. We never put the idle
1000 * threads on the run queue, however.
1002 if (td->td_flags & TDF_IDLETD) {
1005 CPU_CLR(PCPU_GET(cpuid), &idle_cpus_mask);
1008 if (TD_IS_RUNNING(td)) {
1009 /* Put us back on the run queue. */
1010 sched_add(td, preempted ?
1011 SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED :
1012 SRQ_OURSELF|SRQ_YIELDING);
1017 * The thread we are about to run needs to be counted
1018 * as if it had been added to the run queue and selected.
1024 KASSERT((newtd->td_inhibitors == 0),
1025 ("trying to run inhibited thread"));
1026 newtd->td_flags |= TDF_DIDRUN;
1027 TD_SET_RUNNING(newtd);
1028 if ((newtd->td_flags & TDF_NOLOAD) == 0)
1031 newtd = choosethread();
1032 MPASS(newtd->td_lock == &sched_lock);
1037 if (PMC_PROC_IS_USING_PMCS(td->td_proc))
1038 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT);
1041 SDT_PROBE2(sched, , , off__cpu, newtd, newtd->td_proc);
1044 lock_profile_release_lock(&sched_lock.lock_object);
1045 #ifdef KDTRACE_HOOKS
1047 * If DTrace has set the active vtime enum to anything
1048 * other than INACTIVE (0), then it should have set the
1051 if (dtrace_vtime_active)
1052 (*dtrace_vtime_switch_func)(newtd);
1055 cpu_switch(td, newtd, tmtx != NULL ? tmtx : td->td_lock);
1056 lock_profile_obtain_lock_success(&sched_lock.lock_object,
1057 0, 0, __FILE__, __LINE__);
1059 * Where am I? What year is it?
1060 * We are in the same thread that went to sleep above,
1061 * but any amount of time may have passed. All our context
1062 * will still be available as will local variables.
1063 * PCPU values however may have changed as we may have
1064 * changed CPU so don't trust cached values of them.
1065 * New threads will go to fork_exit() instead of here
1066 * so if you change things here you may need to change
1069 * If the thread above was exiting it will never wake
1070 * up again here, so either it has saved everything it
1071 * needed to, or the thread_wait() or wait() will
1075 SDT_PROBE0(sched, , , on__cpu);
1077 if (PMC_PROC_IS_USING_PMCS(td->td_proc))
1078 PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN);
1081 SDT_PROBE0(sched, , , remain__cpu);
1084 if (td->td_flags & TDF_IDLETD)
1085 CPU_SET(PCPU_GET(cpuid), &idle_cpus_mask);
1087 sched_lock.mtx_lock = (uintptr_t)td;
1088 td->td_oncpu = PCPU_GET(cpuid);
1089 MPASS(td->td_lock == &sched_lock);
1093 sched_wakeup(struct thread *td)
1095 struct td_sched *ts;
1097 THREAD_LOCK_ASSERT(td, MA_OWNED);
1099 td->td_flags &= ~TDF_CANSWAP;
1100 if (ts->ts_slptime > 1) {
1106 ts->ts_slice = sched_slice;
1107 sched_add(td, SRQ_BORING);
1112 forward_wakeup(int cpunum)
1115 cpuset_t dontuse, map, map2;
1119 mtx_assert(&sched_lock, MA_OWNED);
1121 CTR0(KTR_RUNQ, "forward_wakeup()");
1123 if ((!forward_wakeup_enabled) ||
1124 (forward_wakeup_use_mask == 0 && forward_wakeup_use_loop == 0))
1126 if (!smp_started || cold || panicstr)
1129 forward_wakeups_requested++;
1132 * Check the idle mask we received against what we calculated
1133 * before in the old version.
1135 me = PCPU_GET(cpuid);
1137 /* Don't bother if we should be doing it ourself. */
1138 if (CPU_ISSET(me, &idle_cpus_mask) &&
1139 (cpunum == NOCPU || me == cpunum))
1142 CPU_SETOF(me, &dontuse);
1143 CPU_OR(&dontuse, &stopped_cpus);
1144 CPU_OR(&dontuse, &hlt_cpus_mask);
1146 if (forward_wakeup_use_loop) {
1147 STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
1149 if (!CPU_ISSET(id, &dontuse) &&
1150 pc->pc_curthread == pc->pc_idlethread) {
1156 if (forward_wakeup_use_mask) {
1157 map = idle_cpus_mask;
1158 CPU_NAND(&map, &dontuse);
1160 /* If they are both on, compare and use loop if different. */
1161 if (forward_wakeup_use_loop) {
1162 if (CPU_CMP(&map, &map2)) {
1163 printf("map != map2, loop method preferred\n");
1171 /* If we only allow a specific CPU, then mask off all the others. */
1172 if (cpunum != NOCPU) {
1173 KASSERT((cpunum <= mp_maxcpus),("forward_wakeup: bad cpunum."));
1174 iscpuset = CPU_ISSET(cpunum, &map);
1178 CPU_SETOF(cpunum, &map);
1180 if (!CPU_EMPTY(&map)) {
1181 forward_wakeups_delivered++;
1182 STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
1184 if (!CPU_ISSET(id, &map))
1186 if (cpu_idle_wakeup(pc->pc_cpuid))
1189 if (!CPU_EMPTY(&map))
1190 ipi_selected(map, IPI_AST);
1193 if (cpunum == NOCPU)
1194 printf("forward_wakeup: Idle processor not found\n");
1199 kick_other_cpu(int pri, int cpuid)
1204 pcpu = pcpu_find(cpuid);
1205 if (CPU_ISSET(cpuid, &idle_cpus_mask)) {
1206 forward_wakeups_delivered++;
1207 if (!cpu_idle_wakeup(cpuid))
1208 ipi_cpu(cpuid, IPI_AST);
1212 cpri = pcpu->pc_curthread->td_priority;
1216 #if defined(IPI_PREEMPTION) && defined(PREEMPTION)
1217 #if !defined(FULL_PREEMPTION)
1218 if (pri <= PRI_MAX_ITHD)
1219 #endif /* ! FULL_PREEMPTION */
1221 ipi_cpu(cpuid, IPI_PREEMPT);
1224 #endif /* defined(IPI_PREEMPTION) && defined(PREEMPTION) */
1226 pcpu->pc_curthread->td_flags |= TDF_NEEDRESCHED;
1227 ipi_cpu(cpuid, IPI_AST);
1234 sched_pickcpu(struct thread *td)
1238 mtx_assert(&sched_lock, MA_OWNED);
1240 if (THREAD_CAN_SCHED(td, td->td_lastcpu))
1241 best = td->td_lastcpu;
1245 if (!THREAD_CAN_SCHED(td, cpu))
1250 else if (runq_length[cpu] < runq_length[best])
1253 KASSERT(best != NOCPU, ("no valid CPUs"));
1260 sched_add(struct thread *td, int flags)
1264 struct td_sched *ts;
1270 THREAD_LOCK_ASSERT(td, MA_OWNED);
1271 KASSERT((td->td_inhibitors == 0),
1272 ("sched_add: trying to run inhibited thread"));
1273 KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)),
1274 ("sched_add: bad thread state"));
1275 KASSERT(td->td_flags & TDF_INMEM,
1276 ("sched_add: thread swapped out"));
1278 KTR_STATE2(KTR_SCHED, "thread", sched_tdname(td), "runq add",
1279 "prio:%d", td->td_priority, KTR_ATTR_LINKED,
1280 sched_tdname(curthread));
1281 KTR_POINT1(KTR_SCHED, "thread", sched_tdname(curthread), "wokeup",
1282 KTR_ATTR_LINKED, sched_tdname(td));
1283 SDT_PROBE4(sched, , , enqueue, td, td->td_proc, NULL,
1284 flags & SRQ_PREEMPTED);
1288 * Now that the thread is moving to the run-queue, set the lock
1289 * to the scheduler's lock.
1291 if (td->td_lock != &sched_lock) {
1292 mtx_lock_spin(&sched_lock);
1293 thread_lock_set(td, &sched_lock);
1298 * If SMP is started and the thread is pinned or otherwise limited to
1299 * a specific set of CPUs, queue the thread to a per-CPU run queue.
1300 * Otherwise, queue the thread to the global run queue.
1302 * If SMP has not yet been started we must use the global run queue
1303 * as per-CPU state may not be initialized yet and we may crash if we
1304 * try to access the per-CPU run queues.
1306 if (smp_started && (td->td_pinned != 0 || td->td_flags & TDF_BOUND ||
1307 ts->ts_flags & TSF_AFFINITY)) {
1308 if (td->td_pinned != 0)
1309 cpu = td->td_lastcpu;
1310 else if (td->td_flags & TDF_BOUND) {
1311 /* Find CPU from bound runq. */
1312 KASSERT(SKE_RUNQ_PCPU(ts),
1313 ("sched_add: bound td_sched not on cpu runq"));
1314 cpu = ts->ts_runq - &runq_pcpu[0];
1316 /* Find a valid CPU for our cpuset */
1317 cpu = sched_pickcpu(td);
1318 ts->ts_runq = &runq_pcpu[cpu];
1321 "sched_add: Put td_sched:%p(td:%p) on cpu%d runq", ts, td,
1325 "sched_add: adding td_sched:%p (td:%p) to gbl runq", ts,
1328 ts->ts_runq = &runq;
1331 cpuid = PCPU_GET(cpuid);
1332 if (single_cpu && cpu != cpuid) {
1333 kick_other_cpu(td->td_priority, cpu);
1336 tidlemsk = idle_cpus_mask;
1337 CPU_NAND(&tidlemsk, &hlt_cpus_mask);
1338 CPU_CLR(cpuid, &tidlemsk);
1340 if (!CPU_ISSET(cpuid, &idle_cpus_mask) &&
1341 ((flags & SRQ_INTR) == 0) &&
1342 !CPU_EMPTY(&tidlemsk))
1343 forwarded = forward_wakeup(cpu);
1347 if ((flags & SRQ_YIELDING) == 0 && maybe_preempt(td))
1354 if ((td->td_flags & TDF_NOLOAD) == 0)
1356 runq_add(ts->ts_runq, td, flags);
1362 struct td_sched *ts;
1365 THREAD_LOCK_ASSERT(td, MA_OWNED);
1366 KASSERT((td->td_inhibitors == 0),
1367 ("sched_add: trying to run inhibited thread"));
1368 KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)),
1369 ("sched_add: bad thread state"));
1370 KASSERT(td->td_flags & TDF_INMEM,
1371 ("sched_add: thread swapped out"));
1372 KTR_STATE2(KTR_SCHED, "thread", sched_tdname(td), "runq add",
1373 "prio:%d", td->td_priority, KTR_ATTR_LINKED,
1374 sched_tdname(curthread));
1375 KTR_POINT1(KTR_SCHED, "thread", sched_tdname(curthread), "wokeup",
1376 KTR_ATTR_LINKED, sched_tdname(td));
1377 SDT_PROBE4(sched, , , enqueue, td, td->td_proc, NULL,
1378 flags & SRQ_PREEMPTED);
1381 * Now that the thread is moving to the run-queue, set the lock
1382 * to the scheduler's lock.
1384 if (td->td_lock != &sched_lock) {
1385 mtx_lock_spin(&sched_lock);
1386 thread_lock_set(td, &sched_lock);
1389 CTR2(KTR_RUNQ, "sched_add: adding td_sched:%p (td:%p) to runq", ts, td);
1390 ts->ts_runq = &runq;
1393 * If we are yielding (on the way out anyhow) or the thread
1394 * being saved is US, then don't try be smart about preemption
1395 * or kicking off another CPU as it won't help and may hinder.
1396 * In the YIEDLING case, we are about to run whoever is being
1397 * put in the queue anyhow, and in the OURSELF case, we are
1398 * putting ourself on the run queue which also only happens
1399 * when we are about to yield.
1401 if ((flags & SRQ_YIELDING) == 0) {
1402 if (maybe_preempt(td))
1405 if ((td->td_flags & TDF_NOLOAD) == 0)
1407 runq_add(ts->ts_runq, td, flags);
1413 sched_rem(struct thread *td)
1415 struct td_sched *ts;
1418 KASSERT(td->td_flags & TDF_INMEM,
1419 ("sched_rem: thread swapped out"));
1420 KASSERT(TD_ON_RUNQ(td),
1421 ("sched_rem: thread not on run queue"));
1422 mtx_assert(&sched_lock, MA_OWNED);
1423 KTR_STATE2(KTR_SCHED, "thread", sched_tdname(td), "runq rem",
1424 "prio:%d", td->td_priority, KTR_ATTR_LINKED,
1425 sched_tdname(curthread));
1426 SDT_PROBE3(sched, , , dequeue, td, td->td_proc, NULL);
1428 if ((td->td_flags & TDF_NOLOAD) == 0)
1431 if (ts->ts_runq != &runq)
1432 runq_length[ts->ts_runq - runq_pcpu]--;
1434 runq_remove(ts->ts_runq, td);
1439 * Select threads to run. Note that running threads still consume a
1448 mtx_assert(&sched_lock, MA_OWNED);
1450 struct thread *tdcpu;
1453 td = runq_choose_fuzz(&runq, runq_fuzz);
1454 tdcpu = runq_choose(&runq_pcpu[PCPU_GET(cpuid)]);
1458 tdcpu->td_priority < td->td_priority)) {
1459 CTR2(KTR_RUNQ, "choosing td %p from pcpu runq %d", tdcpu,
1462 rq = &runq_pcpu[PCPU_GET(cpuid)];
1464 CTR1(KTR_RUNQ, "choosing td_sched %p from main runq", td);
1469 td = runq_choose(&runq);
1475 runq_length[PCPU_GET(cpuid)]--;
1477 runq_remove(rq, td);
1478 td->td_flags |= TDF_DIDRUN;
1480 KASSERT(td->td_flags & TDF_INMEM,
1481 ("sched_choose: thread swapped out"));
1484 return (PCPU_GET(idlethread));
1488 sched_preempt(struct thread *td)
1491 SDT_PROBE2(sched, , , surrender, td, td->td_proc);
1493 if (td->td_critnest > 1)
1494 td->td_owepreempt = 1;
1496 mi_switch(SW_INVOL | SW_PREEMPT | SWT_PREEMPT, NULL);
1501 sched_userret(struct thread *td)
1504 * XXX we cheat slightly on the locking here to avoid locking in
1505 * the usual case. Setting td_priority here is essentially an
1506 * incomplete workaround for not setting it properly elsewhere.
1507 * Now that some interrupt handlers are threads, not setting it
1508 * properly elsewhere can clobber it in the window between setting
1509 * it here and returning to user mode, so don't waste time setting
1510 * it perfectly here.
1512 KASSERT((td->td_flags & TDF_BORROWING) == 0,
1513 ("thread with borrowed priority returning to userland"));
1514 if (td->td_priority != td->td_user_pri) {
1516 td->td_priority = td->td_user_pri;
1517 td->td_base_pri = td->td_user_pri;
1523 sched_bind(struct thread *td, int cpu)
1525 struct td_sched *ts;
1527 THREAD_LOCK_ASSERT(td, MA_OWNED|MA_NOTRECURSED);
1528 KASSERT(td == curthread, ("sched_bind: can only bind curthread"));
1532 td->td_flags |= TDF_BOUND;
1534 ts->ts_runq = &runq_pcpu[cpu];
1535 if (PCPU_GET(cpuid) == cpu)
1538 mi_switch(SW_VOL, NULL);
1543 sched_unbind(struct thread* td)
1545 THREAD_LOCK_ASSERT(td, MA_OWNED);
1546 KASSERT(td == curthread, ("sched_unbind: can only bind curthread"));
1547 td->td_flags &= ~TDF_BOUND;
1551 sched_is_bound(struct thread *td)
1553 THREAD_LOCK_ASSERT(td, MA_OWNED);
1554 return (td->td_flags & TDF_BOUND);
1558 sched_relinquish(struct thread *td)
1561 mi_switch(SW_VOL | SWT_RELINQUISH, NULL);
1568 return (sched_tdcnt);
1572 sched_sizeof_proc(void)
1574 return (sizeof(struct proc));
1578 sched_sizeof_thread(void)
1580 return (sizeof(struct thread) + sizeof(struct td_sched));
1584 sched_pctcpu(struct thread *td)
1586 struct td_sched *ts;
1588 THREAD_LOCK_ASSERT(td, MA_OWNED);
1590 return (ts->ts_pctcpu);
1595 * Calculates the contribution to the thread cpu usage for the latest
1596 * (unfinished) second.
1599 sched_pctcpu_delta(struct thread *td)
1601 struct td_sched *ts;
1605 THREAD_LOCK_ASSERT(td, MA_OWNED);
1608 realstathz = stathz ? stathz : hz;
1609 if (ts->ts_cpticks != 0) {
1610 #if (FSHIFT >= CCPU_SHIFT)
1611 delta = (realstathz == 100)
1612 ? ((fixpt_t) ts->ts_cpticks) <<
1613 (FSHIFT - CCPU_SHIFT) :
1614 100 * (((fixpt_t) ts->ts_cpticks)
1615 << (FSHIFT - CCPU_SHIFT)) / realstathz;
1617 delta = ((FSCALE - ccpu) *
1619 FSCALE / realstathz)) >> FSHIFT;
1628 sched_estcpu(struct thread *td)
1631 return (td->td_sched->ts_estcpu);
1635 * The actual idle process.
1638 sched_idletd(void *dummy)
1640 struct pcpuidlestat *stat;
1642 THREAD_NO_SLEEPING();
1643 stat = DPCPU_PTR(idlestat);
1645 mtx_assert(&Giant, MA_NOTOWNED);
1647 while (sched_runnable() == 0) {
1648 cpu_idle(stat->idlecalls + stat->oldidlecalls > 64);
1652 mtx_lock_spin(&sched_lock);
1653 mi_switch(SW_VOL | SWT_IDLE, NULL);
1654 mtx_unlock_spin(&sched_lock);
1659 * A CPU is entering for the first time or a thread is exiting.
1662 sched_throw(struct thread *td)
1665 * Correct spinlock nesting. The idle thread context that we are
1666 * borrowing was created so that it would start out with a single
1667 * spin lock (sched_lock) held in fork_trampoline(). Since we've
1668 * explicitly acquired locks in this function, the nesting count
1669 * is now 2 rather than 1. Since we are nested, calling
1670 * spinlock_exit() will simply adjust the counts without allowing
1671 * spin lock using code to interrupt us.
1674 mtx_lock_spin(&sched_lock);
1676 PCPU_SET(switchtime, cpu_ticks());
1677 PCPU_SET(switchticks, ticks);
1679 lock_profile_release_lock(&sched_lock.lock_object);
1680 MPASS(td->td_lock == &sched_lock);
1681 td->td_lastcpu = td->td_oncpu;
1682 td->td_oncpu = NOCPU;
1684 mtx_assert(&sched_lock, MA_OWNED);
1685 KASSERT(curthread->td_md.md_spinlock_count == 1, ("invalid count"));
1686 cpu_throw(td, choosethread()); /* doesn't return */
1690 sched_fork_exit(struct thread *td)
1694 * Finish setting up thread glue so that it begins execution in a
1695 * non-nested critical section with sched_lock held but not recursed.
1697 td->td_oncpu = PCPU_GET(cpuid);
1698 sched_lock.mtx_lock = (uintptr_t)td;
1699 lock_profile_obtain_lock_success(&sched_lock.lock_object,
1700 0, 0, __FILE__, __LINE__);
1701 THREAD_LOCK_ASSERT(td, MA_OWNED | MA_NOTRECURSED);
1705 sched_tdname(struct thread *td)
1708 struct td_sched *ts;
1711 if (ts->ts_name[0] == '\0')
1712 snprintf(ts->ts_name, sizeof(ts->ts_name),
1713 "%s tid %d", td->td_name, td->td_tid);
1714 return (ts->ts_name);
1716 return (td->td_name);
1722 sched_clear_tdname(struct thread *td)
1724 struct td_sched *ts;
1727 ts->ts_name[0] = '\0';
1732 sched_affinity(struct thread *td)
1735 struct td_sched *ts;
1738 THREAD_LOCK_ASSERT(td, MA_OWNED);
1741 * Set the TSF_AFFINITY flag if there is at least one CPU this
1742 * thread can't run on.
1745 ts->ts_flags &= ~TSF_AFFINITY;
1747 if (!THREAD_CAN_SCHED(td, cpu)) {
1748 ts->ts_flags |= TSF_AFFINITY;
1754 * If this thread can run on all CPUs, nothing else to do.
1756 if (!(ts->ts_flags & TSF_AFFINITY))
1759 /* Pinned threads and bound threads should be left alone. */
1760 if (td->td_pinned != 0 || td->td_flags & TDF_BOUND)
1763 switch (td->td_state) {
1766 * If we are on a per-CPU runqueue that is in the set,
1767 * then nothing needs to be done.
1769 if (ts->ts_runq != &runq &&
1770 THREAD_CAN_SCHED(td, ts->ts_runq - runq_pcpu))
1773 /* Put this thread on a valid per-CPU runqueue. */
1775 sched_add(td, SRQ_BORING);
1779 * See if our current CPU is in the set. If not, force a
1782 if (THREAD_CAN_SCHED(td, td->td_oncpu))
1785 td->td_flags |= TDF_NEEDRESCHED;
1786 if (td != curthread)
1787 ipi_cpu(cpu, IPI_AST);