FreeBSD/Linux Kernel Cross Reference
sys/kern/sched_4bsd.c
1 /*-
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
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD: releng/5.2/sys/kern/sched_4bsd.c 122355 2003-11-09 13:45:54Z bde $");
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/ktr.h>
46 #include <sys/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/proc.h>
49 #include <sys/resourcevar.h>
50 #include <sys/sched.h>
51 #include <sys/smp.h>
52 #include <sys/sysctl.h>
53 #include <sys/sx.h>
54
55 /*
56 * INVERSE_ESTCPU_WEIGHT is only suitable for statclock() frequencies in
57 * the range 100-256 Hz (approximately).
58 */
59 #define ESTCPULIM(e) \
60 min((e), INVERSE_ESTCPU_WEIGHT * (NICE_WEIGHT * (PRIO_MAX - PRIO_MIN) - \
61 RQ_PPQ) + INVERSE_ESTCPU_WEIGHT - 1)
62 #ifdef SMP
63 #define INVERSE_ESTCPU_WEIGHT (8 * smp_cpus)
64 #else
65 #define INVERSE_ESTCPU_WEIGHT 8 /* 1 / (priorities per estcpu level). */
66 #endif
67 #define NICE_WEIGHT 1 /* Priorities per nice level. */
68
69 struct ke_sched {
70 int ske_cpticks; /* (j) Ticks of cpu time. */
71 };
72
73 static struct ke_sched ke_sched;
74
75 struct ke_sched *kse0_sched = &ke_sched;
76 struct kg_sched *ksegrp0_sched = NULL;
77 struct p_sched *proc0_sched = NULL;
78 struct td_sched *thread0_sched = NULL;
79
80 static int sched_quantum; /* Roundrobin scheduling quantum in ticks. */
81 #define SCHED_QUANTUM (hz / 10) /* Default sched quantum */
82
83 static struct callout schedcpu_callout;
84 static struct callout roundrobin_callout;
85
86 static void roundrobin(void *arg);
87 static void schedcpu(void *arg);
88 static void sched_setup(void *dummy);
89 static void maybe_resched(struct thread *td);
90 static void updatepri(struct ksegrp *kg);
91 static void resetpriority(struct ksegrp *kg);
92
93 SYSINIT(sched_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, sched_setup, NULL)
94
95 /*
96 * Global run queue.
97 */
98 static struct runq runq;
99 SYSINIT(runq, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, runq_init, &runq)
100
101 static int
102 sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
103 {
104 int error, new_val;
105
106 new_val = sched_quantum * tick;
107 error = sysctl_handle_int(oidp, &new_val, 0, req);
108 if (error != 0 || req->newptr == NULL)
109 return (error);
110 if (new_val < tick)
111 return (EINVAL);
112 sched_quantum = new_val / tick;
113 hogticks = 2 * sched_quantum;
114 return (0);
115 }
116
117 SYSCTL_PROC(_kern, OID_AUTO, quantum, CTLTYPE_INT|CTLFLAG_RW,
118 0, sizeof sched_quantum, sysctl_kern_quantum, "I",
119 "Roundrobin scheduling quantum in microseconds");
120
121 /*
122 * Arrange to reschedule if necessary, taking the priorities and
123 * schedulers into account.
124 */
125 static void
126 maybe_resched(struct thread *td)
127 {
128
129 mtx_assert(&sched_lock, MA_OWNED);
130 if (td->td_priority < curthread->td_priority && curthread->td_kse)
131 curthread->td_flags |= TDF_NEEDRESCHED;
132 }
133
134 /*
135 * Force switch among equal priority processes every 100ms.
136 * We don't actually need to force a context switch of the current process.
137 * The act of firing the event triggers a context switch to softclock() and
138 * then switching back out again which is equivalent to a preemption, thus
139 * no further work is needed on the local CPU.
140 */
141 /* ARGSUSED */
142 static void
143 roundrobin(void *arg)
144 {
145
146 #ifdef SMP
147 mtx_lock_spin(&sched_lock);
148 forward_roundrobin();
149 mtx_unlock_spin(&sched_lock);
150 #endif
151
152 callout_reset(&roundrobin_callout, sched_quantum, roundrobin, NULL);
153 }
154
155 /*
156 * Constants for digital decay and forget:
157 * 90% of (kg_estcpu) usage in 5 * loadav time
158 * 95% of (ke_pctcpu) usage in 60 seconds (load insensitive)
159 * Note that, as ps(1) mentions, this can let percentages
160 * total over 100% (I've seen 137.9% for 3 processes).
161 *
162 * Note that schedclock() updates kg_estcpu and p_cpticks asynchronously.
163 *
164 * We wish to decay away 90% of kg_estcpu in (5 * loadavg) seconds.
165 * That is, the system wants to compute a value of decay such
166 * that the following for loop:
167 * for (i = 0; i < (5 * loadavg); i++)
168 * kg_estcpu *= decay;
169 * will compute
170 * kg_estcpu *= 0.1;
171 * for all values of loadavg:
172 *
173 * Mathematically this loop can be expressed by saying:
174 * decay ** (5 * loadavg) ~= .1
175 *
176 * The system computes decay as:
177 * decay = (2 * loadavg) / (2 * loadavg + 1)
178 *
179 * We wish to prove that the system's computation of decay
180 * will always fulfill the equation:
181 * decay ** (5 * loadavg) ~= .1
182 *
183 * If we compute b as:
184 * b = 2 * loadavg
185 * then
186 * decay = b / (b + 1)
187 *
188 * We now need to prove two things:
189 * 1) Given factor ** (5 * loadavg) ~= .1, prove factor == b/(b+1)
190 * 2) Given b/(b+1) ** power ~= .1, prove power == (5 * loadavg)
191 *
192 * Facts:
193 * For x close to zero, exp(x) =~ 1 + x, since
194 * exp(x) = 0! + x**1/1! + x**2/2! + ... .
195 * therefore exp(-1/b) =~ 1 - (1/b) = (b-1)/b.
196 * For x close to zero, ln(1+x) =~ x, since
197 * ln(1+x) = x - x**2/2 + x**3/3 - ... -1 < x < 1
198 * therefore ln(b/(b+1)) = ln(1 - 1/(b+1)) =~ -1/(b+1).
199 * ln(.1) =~ -2.30
200 *
201 * Proof of (1):
202 * Solve (factor)**(power) =~ .1 given power (5*loadav):
203 * solving for factor,
204 * ln(factor) =~ (-2.30/5*loadav), or
205 * factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) =
206 * exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED
207 *
208 * Proof of (2):
209 * Solve (factor)**(power) =~ .1 given factor == (b/(b+1)):
210 * solving for power,
211 * power*ln(b/(b+1)) =~ -2.30, or
212 * power =~ 2.3 * (b + 1) = 4.6*loadav + 2.3 =~ 5*loadav. QED
213 *
214 * Actual power values for the implemented algorithm are as follows:
215 * loadav: 1 2 3 4
216 * power: 5.68 10.32 14.94 19.55
217 */
218
219 /* calculations for digital decay to forget 90% of usage in 5*loadav sec */
220 #define loadfactor(loadav) (2 * (loadav))
221 #define decay_cpu(loadfac, cpu) (((loadfac) * (cpu)) / ((loadfac) + FSCALE))
222
223 /* decay 95% of `ke_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */
224 static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
225 SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
226
227 /*
228 * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the
229 * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below
230 * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT).
231 *
232 * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used:
233 * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits).
234 *
235 * If you don't want to bother with the faster/more-accurate formula, you
236 * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate
237 * (more general) method of calculating the %age of CPU used by a process.
238 */
239 #define CCPU_SHIFT 11
240
241 /*
242 * Recompute process priorities, every hz ticks.
243 * MP-safe, called without the Giant mutex.
244 */
245 /* ARGSUSED */
246 static void
247 schedcpu(void *arg)
248 {
249 register fixpt_t loadfac = loadfactor(averunnable.ldavg[0]);
250 struct thread *td;
251 struct proc *p;
252 struct kse *ke;
253 struct ksegrp *kg;
254 int awake, realstathz;
255
256 realstathz = stathz ? stathz : hz;
257 sx_slock(&allproc_lock);
258 FOREACH_PROC_IN_SYSTEM(p) {
259 /*
260 * Prevent state changes and protect run queue.
261 */
262 mtx_lock_spin(&sched_lock);
263 /*
264 * Increment time in/out of memory. We ignore overflow; with
265 * 16-bit int's (remember them?) overflow takes 45 days.
266 */
267 p->p_swtime++;
268 FOREACH_KSEGRP_IN_PROC(p, kg) {
269 awake = 0;
270 FOREACH_KSE_IN_GROUP(kg, ke) {
271 /*
272 * Increment sleep time (if sleeping). We
273 * ignore overflow, as above.
274 */
275 /*
276 * The kse slptimes are not touched in wakeup
277 * because the thread may not HAVE a KSE.
278 */
279 if (ke->ke_state == KES_ONRUNQ) {
280 awake = 1;
281 ke->ke_flags &= ~KEF_DIDRUN;
282 } else if ((ke->ke_state == KES_THREAD) &&
283 (TD_IS_RUNNING(ke->ke_thread))) {
284 awake = 1;
285 /* Do not clear KEF_DIDRUN */
286 } else if (ke->ke_flags & KEF_DIDRUN) {
287 awake = 1;
288 ke->ke_flags &= ~KEF_DIDRUN;
289 }
290
291 /*
292 * ke_pctcpu is only for ps and ttyinfo().
293 * Do it per kse, and add them up at the end?
294 * XXXKSE
295 */
296 ke->ke_pctcpu = (ke->ke_pctcpu * ccpu) >>
297 FSHIFT;
298 /*
299 * If the kse has been idle the entire second,
300 * stop recalculating its priority until
301 * it wakes up.
302 */
303 if (ke->ke_sched->ske_cpticks == 0)
304 continue;
305 #if (FSHIFT >= CCPU_SHIFT)
306 ke->ke_pctcpu += (realstathz == 100)
307 ? ((fixpt_t) ke->ke_sched->ske_cpticks) <<
308 (FSHIFT - CCPU_SHIFT) :
309 100 * (((fixpt_t) ke->ke_sched->ske_cpticks)
310 << (FSHIFT - CCPU_SHIFT)) / realstathz;
311 #else
312 ke->ke_pctcpu += ((FSCALE - ccpu) *
313 (ke->ke_sched->ske_cpticks *
314 FSCALE / realstathz)) >> FSHIFT;
315 #endif
316 ke->ke_sched->ske_cpticks = 0;
317 } /* end of kse loop */
318 /*
319 * If there are ANY running threads in this KSEGRP,
320 * then don't count it as sleeping.
321 */
322 if (awake) {
323 if (kg->kg_slptime > 1) {
324 /*
325 * In an ideal world, this should not
326 * happen, because whoever woke us
327 * up from the long sleep should have
328 * unwound the slptime and reset our
329 * priority before we run at the stale
330 * priority. Should KASSERT at some
331 * point when all the cases are fixed.
332 */
333 updatepri(kg);
334 }
335 kg->kg_slptime = 0;
336 } else
337 kg->kg_slptime++;
338 if (kg->kg_slptime > 1)
339 continue;
340 kg->kg_estcpu = decay_cpu(loadfac, kg->kg_estcpu);
341 resetpriority(kg);
342 FOREACH_THREAD_IN_GROUP(kg, td) {
343 if (td->td_priority >= PUSER) {
344 sched_prio(td, kg->kg_user_pri);
345 }
346 }
347 } /* end of ksegrp loop */
348 mtx_unlock_spin(&sched_lock);
349 } /* end of process loop */
350 sx_sunlock(&allproc_lock);
351 callout_reset(&schedcpu_callout, hz, schedcpu, NULL);
352 }
353
354 /*
355 * Recalculate the priority of a process after it has slept for a while.
356 * For all load averages >= 1 and max kg_estcpu of 255, sleeping for at
357 * least six times the loadfactor will decay kg_estcpu to zero.
358 */
359 static void
360 updatepri(struct ksegrp *kg)
361 {
362 register fixpt_t loadfac;
363 register unsigned int newcpu;
364
365 loadfac = loadfactor(averunnable.ldavg[0]);
366 if (kg->kg_slptime > 5 * loadfac)
367 kg->kg_estcpu = 0;
368 else {
369 newcpu = kg->kg_estcpu;
370 kg->kg_slptime--; /* was incremented in schedcpu() */
371 while (newcpu && --kg->kg_slptime)
372 newcpu = decay_cpu(loadfac, newcpu);
373 kg->kg_estcpu = newcpu;
374 }
375 resetpriority(kg);
376 }
377
378 /*
379 * Compute the priority of a process when running in user mode.
380 * Arrange to reschedule if the resulting priority is better
381 * than that of the current process.
382 */
383 static void
384 resetpriority(struct ksegrp *kg)
385 {
386 register unsigned int newpriority;
387 struct thread *td;
388
389 if (kg->kg_pri_class == PRI_TIMESHARE) {
390 newpriority = PUSER + kg->kg_estcpu / INVERSE_ESTCPU_WEIGHT +
391 NICE_WEIGHT * (kg->kg_nice - PRIO_MIN);
392 newpriority = min(max(newpriority, PRI_MIN_TIMESHARE),
393 PRI_MAX_TIMESHARE);
394 kg->kg_user_pri = newpriority;
395 }
396 FOREACH_THREAD_IN_GROUP(kg, td) {
397 maybe_resched(td); /* XXXKSE silly */
398 }
399 }
400
401 /* ARGSUSED */
402 static void
403 sched_setup(void *dummy)
404 {
405
406 if (sched_quantum == 0)
407 sched_quantum = SCHED_QUANTUM;
408 hogticks = 2 * sched_quantum;
409
410 callout_init(&schedcpu_callout, CALLOUT_MPSAFE);
411 callout_init(&roundrobin_callout, 0);
412
413 /* Kick off timeout driven events by calling first time. */
414 roundrobin(NULL);
415 schedcpu(NULL);
416 }
417
418 /* External interfaces start here */
419 int
420 sched_runnable(void)
421 {
422 return runq_check(&runq);
423 }
424
425 int
426 sched_rr_interval(void)
427 {
428 if (sched_quantum == 0)
429 sched_quantum = SCHED_QUANTUM;
430 return (sched_quantum);
431 }
432
433 /*
434 * We adjust the priority of the current process. The priority of
435 * a process gets worse as it accumulates CPU time. The cpu usage
436 * estimator (kg_estcpu) is increased here. resetpriority() will
437 * compute a different priority each time kg_estcpu increases by
438 * INVERSE_ESTCPU_WEIGHT
439 * (until MAXPRI is reached). The cpu usage estimator ramps up
440 * quite quickly when the process is running (linearly), and decays
441 * away exponentially, at a rate which is proportionally slower when
442 * the system is busy. The basic principle is that the system will
443 * 90% forget that the process used a lot of CPU time in 5 * loadav
444 * seconds. This causes the system to favor processes which haven't
445 * run much recently, and to round-robin among other processes.
446 */
447 void
448 sched_clock(struct thread *td)
449 {
450 struct ksegrp *kg;
451 struct kse *ke;
452
453 mtx_assert(&sched_lock, MA_OWNED);
454 kg = td->td_ksegrp;
455 ke = td->td_kse;
456
457 ke->ke_sched->ske_cpticks++;
458 kg->kg_estcpu = ESTCPULIM(kg->kg_estcpu + 1);
459 if ((kg->kg_estcpu % INVERSE_ESTCPU_WEIGHT) == 0) {
460 resetpriority(kg);
461 if (td->td_priority >= PUSER)
462 td->td_priority = kg->kg_user_pri;
463 }
464 }
465
466 /*
467 * charge childs scheduling cpu usage to parent.
468 *
469 * XXXKSE assume only one thread & kse & ksegrp keep estcpu in each ksegrp.
470 * Charge it to the ksegrp that did the wait since process estcpu is sum of
471 * all ksegrps, this is strictly as expected. Assume that the child process
472 * aggregated all the estcpu into the 'built-in' ksegrp.
473 */
474 void
475 sched_exit(struct proc *p, struct proc *p1)
476 {
477 sched_exit_kse(FIRST_KSE_IN_PROC(p), FIRST_KSE_IN_PROC(p1));
478 sched_exit_ksegrp(FIRST_KSEGRP_IN_PROC(p), FIRST_KSEGRP_IN_PROC(p1));
479 sched_exit_thread(FIRST_THREAD_IN_PROC(p), FIRST_THREAD_IN_PROC(p1));
480 }
481
482 void
483 sched_exit_kse(struct kse *ke, struct kse *child)
484 {
485 }
486
487 void
488 sched_exit_ksegrp(struct ksegrp *kg, struct ksegrp *child)
489 {
490
491 mtx_assert(&sched_lock, MA_OWNED);
492 kg->kg_estcpu = ESTCPULIM(kg->kg_estcpu + child->kg_estcpu);
493 }
494
495 void
496 sched_exit_thread(struct thread *td, struct thread *child)
497 {
498 }
499
500 void
501 sched_fork(struct proc *p, struct proc *p1)
502 {
503 sched_fork_kse(FIRST_KSE_IN_PROC(p), FIRST_KSE_IN_PROC(p1));
504 sched_fork_ksegrp(FIRST_KSEGRP_IN_PROC(p), FIRST_KSEGRP_IN_PROC(p1));
505 sched_fork_thread(FIRST_THREAD_IN_PROC(p), FIRST_THREAD_IN_PROC(p1));
506 }
507
508 void
509 sched_fork_kse(struct kse *ke, struct kse *child)
510 {
511 child->ke_sched->ske_cpticks = 0;
512 }
513
514 void
515 sched_fork_ksegrp(struct ksegrp *kg, struct ksegrp *child)
516 {
517 mtx_assert(&sched_lock, MA_OWNED);
518 child->kg_estcpu = kg->kg_estcpu;
519 }
520
521 void
522 sched_fork_thread(struct thread *td, struct thread *child)
523 {
524 }
525
526 void
527 sched_nice(struct ksegrp *kg, int nice)
528 {
529
530 PROC_LOCK_ASSERT(kg->kg_proc, MA_OWNED);
531 mtx_assert(&sched_lock, MA_OWNED);
532 kg->kg_nice = nice;
533 resetpriority(kg);
534 }
535
536 void
537 sched_class(struct ksegrp *kg, int class)
538 {
539 mtx_assert(&sched_lock, MA_OWNED);
540 kg->kg_pri_class = class;
541 }
542
543 /*
544 * Adjust the priority of a thread.
545 * This may include moving the thread within the KSEGRP,
546 * changing the assignment of a kse to the thread,
547 * and moving a KSE in the system run queue.
548 */
549 void
550 sched_prio(struct thread *td, u_char prio)
551 {
552
553 mtx_assert(&sched_lock, MA_OWNED);
554 if (TD_ON_RUNQ(td)) {
555 adjustrunqueue(td, prio);
556 } else {
557 td->td_priority = prio;
558 }
559 }
560
561 void
562 sched_sleep(struct thread *td, u_char prio)
563 {
564
565 mtx_assert(&sched_lock, MA_OWNED);
566 td->td_ksegrp->kg_slptime = 0;
567 td->td_priority = prio;
568 }
569
570 void
571 sched_switch(struct thread *td)
572 {
573 struct thread *newtd;
574 struct kse *ke;
575 struct proc *p;
576
577 ke = td->td_kse;
578 p = td->td_proc;
579
580 mtx_assert(&sched_lock, MA_OWNED);
581 KASSERT((ke->ke_state == KES_THREAD), ("mi_switch: kse state?"));
582
583 td->td_lastcpu = td->td_oncpu;
584 td->td_last_kse = ke;
585 td->td_oncpu = NOCPU;
586 td->td_flags &= ~TDF_NEEDRESCHED;
587 /*
588 * At the last moment, if this thread is still marked RUNNING,
589 * then put it back on the run queue as it has not been suspended
590 * or stopped or any thing else similar.
591 */
592 if (TD_IS_RUNNING(td)) {
593 /* Put us back on the run queue (kse and all). */
594 setrunqueue(td);
595 } else if (p->p_flag & P_SA) {
596 /*
597 * We will not be on the run queue. So we must be
598 * sleeping or similar. As it's available,
599 * someone else can use the KSE if they need it.
600 */
601 kse_reassign(ke);
602 }
603 newtd = choosethread();
604 if (td != newtd)
605 cpu_switch(td, newtd);
606 sched_lock.mtx_lock = (uintptr_t)td;
607 td->td_oncpu = PCPU_GET(cpuid);
608 }
609
610 void
611 sched_wakeup(struct thread *td)
612 {
613 struct ksegrp *kg;
614
615 mtx_assert(&sched_lock, MA_OWNED);
616 kg = td->td_ksegrp;
617 if (kg->kg_slptime > 1)
618 updatepri(kg);
619 kg->kg_slptime = 0;
620 setrunqueue(td);
621 maybe_resched(td);
622 }
623
624 void
625 sched_add(struct thread *td)
626 {
627 struct kse *ke;
628
629 ke = td->td_kse;
630 mtx_assert(&sched_lock, MA_OWNED);
631 KASSERT((ke->ke_thread != NULL), ("runq_add: No thread on KSE"));
632 KASSERT((ke->ke_thread->td_kse != NULL),
633 ("runq_add: No KSE on thread"));
634 KASSERT(ke->ke_state != KES_ONRUNQ,
635 ("runq_add: kse %p (%s) already in run queue", ke,
636 ke->ke_proc->p_comm));
637 KASSERT(ke->ke_proc->p_sflag & PS_INMEM,
638 ("runq_add: process swapped out"));
639 ke->ke_ksegrp->kg_runq_kses++;
640 ke->ke_state = KES_ONRUNQ;
641
642 runq_add(&runq, ke);
643 }
644
645 void
646 sched_rem(struct thread *td)
647 {
648 struct kse *ke;
649
650 ke = td->td_kse;
651 KASSERT(ke->ke_proc->p_sflag & PS_INMEM,
652 ("runq_remove: process swapped out"));
653 KASSERT((ke->ke_state == KES_ONRUNQ), ("KSE not on run queue"));
654 mtx_assert(&sched_lock, MA_OWNED);
655
656 runq_remove(&runq, ke);
657 ke->ke_state = KES_THREAD;
658 ke->ke_ksegrp->kg_runq_kses--;
659 }
660
661 struct kse *
662 sched_choose(void)
663 {
664 struct kse *ke;
665
666 ke = runq_choose(&runq);
667
668 if (ke != NULL) {
669 runq_remove(&runq, ke);
670 ke->ke_state = KES_THREAD;
671
672 KASSERT((ke->ke_thread != NULL),
673 ("runq_choose: No thread on KSE"));
674 KASSERT((ke->ke_thread->td_kse != NULL),
675 ("runq_choose: No KSE on thread"));
676 KASSERT(ke->ke_proc->p_sflag & PS_INMEM,
677 ("runq_choose: process swapped out"));
678 }
679 return (ke);
680 }
681
682 void
683 sched_userret(struct thread *td)
684 {
685 struct ksegrp *kg;
686 /*
687 * XXX we cheat slightly on the locking here to avoid locking in
688 * the usual case. Setting td_priority here is essentially an
689 * incomplete workaround for not setting it properly elsewhere.
690 * Now that some interrupt handlers are threads, not setting it
691 * properly elsewhere can clobber it in the window between setting
692 * it here and returning to user mode, so don't waste time setting
693 * it perfectly here.
694 */
695 kg = td->td_ksegrp;
696 if (td->td_priority != kg->kg_user_pri) {
697 mtx_lock_spin(&sched_lock);
698 td->td_priority = kg->kg_user_pri;
699 mtx_unlock_spin(&sched_lock);
700 }
701 }
702
703 int
704 sched_sizeof_kse(void)
705 {
706 return (sizeof(struct kse) + sizeof(struct ke_sched));
707 }
708 int
709 sched_sizeof_ksegrp(void)
710 {
711 return (sizeof(struct ksegrp));
712 }
713 int
714 sched_sizeof_proc(void)
715 {
716 return (sizeof(struct proc));
717 }
718 int
719 sched_sizeof_thread(void)
720 {
721 return (sizeof(struct thread));
722 }
723
724 fixpt_t
725 sched_pctcpu(struct thread *td)
726 {
727 struct kse *ke;
728
729 ke = td->td_kse;
730 if (ke == NULL)
731 ke = td->td_last_kse;
732 if (ke)
733 return (ke->ke_pctcpu);
734
735 return (0);
736 }
Cache object: 9756184873834b727e684c3d080ead02
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