kernel: Make SMP support default (and non-optional).
[dragonfly.git] / sys / kern / kern_synch.c
CommitLineData
984263bc
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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 * @(#)kern_synch.c 8.9 (Berkeley) 5/19/95
39 * $FreeBSD: src/sys/kern/kern_synch.c,v 1.87.2.6 2002/10/13 07:29:53 kbyanc Exp $
40 */
41
42#include "opt_ktrace.h"
43
44#include <sys/param.h>
45#include <sys/systm.h>
46#include <sys/proc.h>
47#include <sys/kernel.h>
48#include <sys/signalvar.h>
49#include <sys/resourcevar.h>
50#include <sys/vmmeter.h>
51#include <sys/sysctl.h>
344ad853 52#include <sys/lock.h>
984263bc 53#include <sys/uio.h>
fc9ae81d 54#ifdef KTRACE
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55#include <sys/ktrace.h>
56#endif
f1d1c3fa 57#include <sys/xwait.h>
9afb0ffd 58#include <sys/ktr.h>
684a93c4 59#include <sys/serialize.h>
984263bc 60
684a93c4 61#include <sys/signal2.h>
bf765287
MD
62#include <sys/thread2.h>
63#include <sys/spinlock2.h>
7f6220a9 64#include <sys/mutex2.h>
bf765287 65
984263bc 66#include <machine/cpu.h>
984263bc
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67#include <machine/smp.h>
68
fc17ad60
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69TAILQ_HEAD(tslpque, thread);
70
402ed7e1 71static void sched_setup (void *dummy);
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72SYSINIT(sched_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, sched_setup, NULL)
73
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74int hogticks;
75int lbolt;
50e4012a 76void *lbolt_syncer;
984263bc 77int sched_quantum; /* Roundrobin scheduling quantum in ticks. */
17a9f566 78int ncpus;
da23a592
MD
79int ncpus2, ncpus2_shift, ncpus2_mask; /* note: mask not cpumask_t */
80int ncpus_fit, ncpus_fit_mask; /* note: mask not cpumask_t */
e43a034f 81int safepri;
dbcd0c9b 82int tsleep_now_works;
5ea440eb 83int tsleep_crypto_dump = 0;
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84
85static struct callout loadav_callout;
35f9d051 86static struct callout schedcpu_callout;
fc17ad60 87MALLOC_DEFINE(M_TSLEEP, "tslpque", "tsleep queues");
984263bc 88
5decebc7
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89#define __DEALL(ident) __DEQUALIFY(void *, ident)
90
9afb0ffd
MD
91#if !defined(KTR_TSLEEP)
92#define KTR_TSLEEP KTR_ALL
93#endif
94KTR_INFO_MASTER(tsleep);
5bf48697
AE
95KTR_INFO(KTR_TSLEEP, tsleep, tsleep_beg, 0, "tsleep enter %p", const volatile void *ident);
96KTR_INFO(KTR_TSLEEP, tsleep, tsleep_end, 1, "tsleep exit");
97KTR_INFO(KTR_TSLEEP, tsleep, wakeup_beg, 2, "wakeup enter %p", const volatile void *ident);
98KTR_INFO(KTR_TSLEEP, tsleep, wakeup_end, 3, "wakeup exit");
99KTR_INFO(KTR_TSLEEP, tsleep, ilockfail, 4, "interlock failed %p", const volatile void *ident);
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100
101#define logtsleep1(name) KTR_LOG(tsleep_ ## name)
102#define logtsleep2(name, val) KTR_LOG(tsleep_ ## name, val)
9afb0ffd 103
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104struct loadavg averunnable =
105 { {0, 0, 0}, FSCALE }; /* load average, of runnable procs */
106/*
107 * Constants for averages over 1, 5, and 15 minutes
108 * when sampling at 5 second intervals.
109 */
110static fixpt_t cexp[3] = {
111 0.9200444146293232 * FSCALE, /* exp(-1/12) */
112 0.9834714538216174 * FSCALE, /* exp(-1/60) */
113 0.9944598480048967 * FSCALE, /* exp(-1/180) */
114};
115
402ed7e1
RG
116static void endtsleep (void *);
117static void loadav (void *arg);
402ed7e1 118static void schedcpu (void *arg);
984263bc 119
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120/*
121 * Adjust the scheduler quantum. The quantum is specified in microseconds.
122 * Note that 'tick' is in microseconds per tick.
123 */
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124static int
125sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
126{
127 int error, new_val;
128
a591f597 129 new_val = sched_quantum * ustick;
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130 error = sysctl_handle_int(oidp, &new_val, 0, req);
131 if (error != 0 || req->newptr == NULL)
132 return (error);
a591f597 133 if (new_val < ustick)
984263bc 134 return (EINVAL);
a591f597 135 sched_quantum = new_val / ustick;
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136 hogticks = 2 * sched_quantum;
137 return (0);
138}
139
140SYSCTL_PROC(_kern, OID_AUTO, quantum, CTLTYPE_INT|CTLFLAG_RW,
141 0, sizeof sched_quantum, sysctl_kern_quantum, "I", "");
142
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143static int pctcpu_decay = 10;
144SYSCTL_INT(_kern, OID_AUTO, pctcpu_decay, CTLFLAG_RW, &pctcpu_decay, 0, "");
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145
146/*
147 * kernel uses `FSCALE', userland (SHOULD) use kern.fscale
984263bc 148 */
460426e6 149int fscale __unused = FSCALE; /* exported to systat */
dcc99b62 150SYSCTL_INT(_kern, OID_AUTO, fscale, CTLFLAG_RD, 0, FSCALE, "");
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151
152/*
0a3f9b47 153 * Recompute process priorities, once a second.
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154 *
155 * Since the userland schedulers are typically event oriented, if the
156 * estcpu calculation at wakeup() time is not sufficient to make a
157 * process runnable relative to other processes in the system we have
158 * a 1-second recalc to help out.
159 *
160 * This code also allows us to store sysclock_t data in the process structure
161 * without fear of an overrun, since sysclock_t are guarenteed to hold
162 * several seconds worth of count.
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163 *
164 * WARNING! callouts can preempt normal threads. However, they will not
165 * preempt a thread holding a spinlock so we *can* safely use spinlocks.
984263bc 166 */
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167static int schedcpu_stats(struct proc *p, void *data __unused);
168static int schedcpu_resource(struct proc *p, void *data __unused);
169
984263bc 170static void
26a0694b 171schedcpu(void *arg)
984263bc 172{
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173 allproc_scan(schedcpu_stats, NULL);
174 allproc_scan(schedcpu_resource, NULL);
175 wakeup((caddr_t)&lbolt);
50e4012a 176 wakeup(lbolt_syncer);
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177 callout_reset(&schedcpu_callout, hz, schedcpu, NULL);
178}
179
180/*
181 * General process statistics once a second
182 */
183static int
184schedcpu_stats(struct proc *p, void *data __unused)
185{
08f2f1bb
SS
186 struct lwp *lp;
187
7bea4e64
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188 /*
189 * Threads may not be completely set up if process in SIDL state.
190 */
191 if (p->p_stat == SIDL)
192 return(0);
193
0d78b86e 194 PHOLD(p);
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195 if (lwkt_trytoken(&p->p_token) == FALSE) {
196 PRELE(p);
197 return(0);
198 }
0d78b86e 199
8fa76237 200 p->p_swtime++;
c7e98b2f 201 FOREACH_LWP_IN_PROC(lp, p) {
de4d4cb0
MD
202 if (lp->lwp_stat == LSSLEEP) {
203 ++lp->lwp_slptime;
204 if (lp->lwp_slptime == 1)
205 p->p_usched->uload_update(lp);
206 }
4b5f931b 207
c7e98b2f
SS
208 /*
209 * Only recalculate processes that are active or have slept
210 * less then 2 seconds. The schedulers understand this.
bc55d64f 211 * Otherwise decay by 50% per second.
c7e98b2f
SS
212 */
213 if (lp->lwp_slptime <= 1) {
214 p->p_usched->recalculate(lp);
215 } else {
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216 int decay;
217
218 decay = pctcpu_decay;
219 cpu_ccfence();
220 if (decay <= 1)
221 decay = 1;
222 if (decay > 100)
223 decay = 100;
224 lp->lwp_pctcpu = (lp->lwp_pctcpu * (decay - 1)) / decay;
c7e98b2f 225 }
8fa76237 226 }
0d78b86e 227 lwkt_reltoken(&p->p_token);
d2d8515b 228 lwkt_yield();
0d78b86e 229 PRELE(p);
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230 return(0);
231}
a46fac56 232
8fa76237 233/*
84204577 234 * Resource checks. XXX break out since ksignal/killproc can block,
8fa76237
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235 * limiting us to one process killed per second. There is probably
236 * a better way.
237 */
238static int
239schedcpu_resource(struct proc *p, void *data __unused)
240{
241 u_int64_t ttime;
08f2f1bb 242 struct lwp *lp;
8fa76237 243
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MD
244 if (p->p_stat == SIDL)
245 return(0);
246
247 PHOLD(p);
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248 if (lwkt_trytoken(&p->p_token) == FALSE) {
249 PRELE(p);
250 return(0);
251 }
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252
253 if (p->p_stat == SZOMB || p->p_limit == NULL) {
254 lwkt_reltoken(&p->p_token);
255 PRELE(p);
8fa76237 256 return(0);
984263bc 257 }
344ad853 258
c7e98b2f
SS
259 ttime = 0;
260 FOREACH_LWP_IN_PROC(lp, p) {
e595c6cd
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261 /*
262 * We may have caught an lp in the middle of being
263 * created, lwp_thread can be NULL.
264 */
265 if (lp->lwp_thread) {
266 ttime += lp->lwp_thread->td_sticks;
267 ttime += lp->lwp_thread->td_uticks;
268 }
c7e98b2f 269 }
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270
271 switch(plimit_testcpulimit(p->p_limit, ttime)) {
272 case PLIMIT_TESTCPU_KILL:
273 killproc(p, "exceeded maximum CPU limit");
274 break;
275 case PLIMIT_TESTCPU_XCPU:
4643740a
MD
276 if ((p->p_flags & P_XCPU) == 0) {
277 p->p_flags |= P_XCPU;
84204577 278 ksignal(p, SIGXCPU);
344ad853 279 }
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280 break;
281 default:
c0b8a06d 282 break;
344ad853 283 }
0d78b86e 284 lwkt_reltoken(&p->p_token);
d2d8515b 285 lwkt_yield();
0d78b86e 286 PRELE(p);
8fa76237 287 return(0);
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288}
289
290/*
dcc99b62
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291 * This is only used by ps. Generate a cpu percentage use over
292 * a period of one second.
984263bc 293 */
dcc99b62 294void
553ea3c8 295updatepcpu(struct lwp *lp, int cpticks, int ttlticks)
984263bc 296{
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MD
297 fixpt_t acc;
298 int remticks;
299
300 acc = (cpticks << FSHIFT) / ttlticks;
301 if (ttlticks >= ESTCPUFREQ) {
553ea3c8 302 lp->lwp_pctcpu = acc;
dcc99b62
MD
303 } else {
304 remticks = ESTCPUFREQ - ttlticks;
553ea3c8 305 lp->lwp_pctcpu = (acc * ttlticks + lp->lwp_pctcpu * remticks) /
dcc99b62 306 ESTCPUFREQ;
a46fac56 307 }
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308}
309
310/*
8aa3430c
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311 * tsleep/wakeup hash table parameters. Try to find the sweet spot for
312 * like addresses being slept on.
984263bc 313 */
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314#define TABLESIZE 4001
315#define LOOKUP(x) (((u_int)(uintptr_t)(x)) % TABLESIZE)
984263bc 316
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317static cpumask_t slpque_cpumasks[TABLESIZE];
318
984263bc 319/*
a46fac56 320 * General scheduler initialization. We force a reschedule 25 times
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MD
321 * a second by default. Note that cpu0 is initialized in early boot and
322 * cannot make any high level calls.
323 *
324 * Each cpu has its own sleep queue.
984263bc 325 */
984263bc 326void
fc17ad60 327sleep_gdinit(globaldata_t gd)
984263bc 328{
fc17ad60 329 static struct tslpque slpque_cpu0[TABLESIZE];
9c1fad94 330 int i;
984263bc 331
fc17ad60
MD
332 if (gd->gd_cpuid == 0) {
333 sched_quantum = (hz + 24) / 25;
334 hogticks = 2 * sched_quantum;
335
336 gd->gd_tsleep_hash = slpque_cpu0;
337 } else {
77652cad 338 gd->gd_tsleep_hash = kmalloc(sizeof(slpque_cpu0),
fc17ad60
MD
339 M_TSLEEP, M_WAITOK | M_ZERO);
340 }
341 for (i = 0; i < TABLESIZE; ++i)
342 TAILQ_INIT(&gd->gd_tsleep_hash[i]);
984263bc
MD
343}
344
ae8e83e6
MD
345/*
346 * This is a dandy function that allows us to interlock tsleep/wakeup
347 * operations with unspecified upper level locks, such as lockmgr locks,
348 * simply by holding a critical section. The sequence is:
349 *
350 * (acquire upper level lock)
351 * tsleep_interlock(blah)
352 * (release upper level lock)
353 * tsleep(blah, ...)
354 *
355 * Basically this functions queues us on the tsleep queue without actually
356 * descheduling us. When tsleep() is later called with PINTERLOCK it
357 * assumes the thread was already queued, otherwise it queues it there.
358 *
359 * Thus it is possible to receive the wakeup prior to going to sleep and
360 * the race conditions are covered.
361 */
362static __inline void
5decebc7 363_tsleep_interlock(globaldata_t gd, const volatile void *ident, int flags)
ae8e83e6
MD
364{
365 thread_t td = gd->gd_curthread;
366 int id;
367
368 crit_enter_quick(td);
369 if (td->td_flags & TDF_TSLEEPQ) {
370 id = LOOKUP(td->td_wchan);
371 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
b12defdc
MD
372 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL) {
373 atomic_clear_cpumask(&slpque_cpumasks[id],
374 gd->gd_cpumask);
375 }
ae8e83e6
MD
376 } else {
377 td->td_flags |= TDF_TSLEEPQ;
378 }
379 id = LOOKUP(ident);
380 TAILQ_INSERT_TAIL(&gd->gd_tsleep_hash[id], td, td_sleepq);
da23a592 381 atomic_set_cpumask(&slpque_cpumasks[id], gd->gd_cpumask);
ae8e83e6
MD
382 td->td_wchan = ident;
383 td->td_wdomain = flags & PDOMAIN_MASK;
ae8e83e6
MD
384 crit_exit_quick(td);
385}
386
387void
5decebc7 388tsleep_interlock(const volatile void *ident, int flags)
ae8e83e6
MD
389{
390 _tsleep_interlock(mycpu, ident, flags);
391}
392
393/*
394 * Remove thread from sleepq. Must be called with a critical section held.
4643740a 395 * The thread must not be migrating.
ae8e83e6
MD
396 */
397static __inline void
398_tsleep_remove(thread_t td)
399{
400 globaldata_t gd = mycpu;
401 int id;
402
957625b2 403 KKASSERT(td->td_gd == gd && IN_CRITICAL_SECT(td));
4643740a 404 KKASSERT((td->td_flags & TDF_MIGRATING) == 0);
ae8e83e6
MD
405 if (td->td_flags & TDF_TSLEEPQ) {
406 td->td_flags &= ~TDF_TSLEEPQ;
407 id = LOOKUP(td->td_wchan);
408 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
409 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL)
da23a592 410 atomic_clear_cpumask(&slpque_cpumasks[id], gd->gd_cpumask);
ae8e83e6
MD
411 td->td_wchan = NULL;
412 td->td_wdomain = 0;
413 }
414}
415
416void
417tsleep_remove(thread_t td)
418{
419 _tsleep_remove(td);
420}
421
984263bc
MD
422/*
423 * General sleep call. Suspends the current process until a wakeup is
424 * performed on the specified identifier. The process will then be made
425 * runnable with the specified priority. Sleeps at most timo/hz seconds
377d4740 426 * (0 means no timeout). If flags includes PCATCH flag, signals are checked
984263bc
MD
427 * before and after sleeping, else signals are not checked. Returns 0 if
428 * awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a
429 * signal needs to be delivered, ERESTART is returned if the current system
430 * call should be restarted if possible, and EINTR is returned if the system
431 * call should be interrupted by the signal (return EINTR).
26a0694b 432 *
0a3f9b47
MD
433 * Note that if we are a process, we release_curproc() before messing with
434 * the LWKT scheduler.
a46fac56
MD
435 *
436 * During autoconfiguration or after a panic, a sleep will simply
437 * lower the priority briefly to allow interrupts, then return.
94f98873
MD
438 *
439 * WARNING! This code can't block (short of switching away), or bad things
440 * will happen. No getting tokens, no blocking locks, etc.
984263bc
MD
441 */
442int
5decebc7 443tsleep(const volatile void *ident, int flags, const char *wmesg, int timo)
984263bc 444{
dadab5e9 445 struct thread *td = curthread;
08f2f1bb 446 struct lwp *lp = td->td_lwp;
0cfcada1 447 struct proc *p = td->td_proc; /* may be NULL */
fc17ad60 448 globaldata_t gd;
344ad853
MD
449 int sig;
450 int catch;
344ad853 451 int error;
e43a034f 452 int oldpri;
076fecef 453 struct callout thandle;
984263bc 454
b0da0c88
MD
455 /*
456 * Currently a severe hack. Make sure any delayed wakeups
457 * are flushed before we sleep or we might deadlock on whatever
458 * event we are sleeping on.
459 */
460 if (td->td_flags & TDF_DELAYED_WAKEUP)
461 wakeup_end_delayed();
462
0cfcada1
MD
463 /*
464 * NOTE: removed KTRPOINT, it could cause races due to blocking
465 * even in stable. Just scrap it for now.
466 */
5ea440eb 467 if (!tsleep_crypto_dump && (tsleep_now_works == 0 || panicstr)) {
984263bc 468 /*
dbcd0c9b
MD
469 * After a panic, or before we actually have an operational
470 * softclock, just give interrupts a chance, then just return;
471 *
984263bc
MD
472 * don't run any other procs or panic below,
473 * in case this is the idle process and already asleep.
474 */
e43a034f 475 splz();
f9235b6d 476 oldpri = td->td_pri;
e43a034f
MD
477 lwkt_setpri_self(safepri);
478 lwkt_switch();
479 lwkt_setpri_self(oldpri);
984263bc
MD
480 return (0);
481 }
8aa3430c 482 logtsleep2(tsleep_beg, ident);
fc17ad60
MD
483 gd = td->td_gd;
484 KKASSERT(td != &gd->gd_idlethread); /* you must be kidding! */
de4d4cb0 485 td->td_wakefromcpu = -1; /* overwritten by _wakeup */
344ad853
MD
486
487 /*
488 * NOTE: all of this occurs on the current cpu, including any
489 * callout-based wakeups, so a critical section is a sufficient
490 * interlock.
491 *
492 * The entire sequence through to where we actually sleep must
493 * run without breaking the critical section.
494 */
344ad853
MD
495 catch = flags & PCATCH;
496 error = 0;
497 sig = 0;
498
37af14fe 499 crit_enter_quick(td);
344ad853 500
0cfcada1 501 KASSERT(ident != NULL, ("tsleep: no ident"));
7278a846
SS
502 KASSERT(lp == NULL ||
503 lp->lwp_stat == LSRUN || /* Obvious */
504 lp->lwp_stat == LSSTOP, /* Set in tstop */
505 ("tsleep %p %s %d",
506 ident, wmesg, lp->lwp_stat));
0cfcada1 507
5686ec5a
MD
508 /*
509 * We interlock the sleep queue if the caller has not already done
510 * it for us. This must be done before we potentially acquire any
511 * tokens or we can loose the wakeup.
512 */
513 if ((flags & PINTERLOCKED) == 0) {
5686ec5a
MD
514 _tsleep_interlock(gd, ident, flags);
515 }
516
344ad853 517 /*
4643740a
MD
518 * Setup for the current process (if this is a process). We must
519 * interlock with lwp_token to avoid remote wakeup races via
520 * setrunnable()
344ad853 521 */
08f2f1bb 522 if (lp) {
4643740a 523 lwkt_gettoken(&lp->lwp_token);
344ad853
MD
524 if (catch) {
525 /*
526 * Early termination if PCATCH was set and a
527 * signal is pending, interlocked with the
528 * critical section.
529 *
530 * Early termination only occurs when tsleep() is
164b8401 531 * entered while in a normal LSRUN state.
344ad853 532 */
08f2f1bb 533 if ((sig = CURSIG(lp)) != 0)
344ad853
MD
534 goto resume;
535
536 /*
5686ec5a
MD
537 * Causes ksignal to wake us up if a signal is
538 * received (interlocked with p->p_token).
344ad853 539 */
4643740a 540 lp->lwp_flags |= LWP_SINTR;
344ad853 541 }
5686ec5a
MD
542 } else {
543 KKASSERT(p == NULL);
4ecd8190 544 }
344ad853 545
4ecd8190 546 /*
4ecd8190
MD
547 * Make sure the current process has been untangled from
548 * the userland scheduler and initialize slptime to start
5686ec5a 549 * counting.
c75e41b7
MD
550 *
551 * NOTE: td->td_wakefromcpu is pre-set by the release function
552 * for the dfly scheduler, and then adjusted by _wakeup()
4ecd8190
MD
553 */
554 if (lp) {
08f2f1bb
SS
555 p->p_usched->release_curproc(lp);
556 lp->lwp_slptime = 0;
0a3f9b47 557 }
fc17ad60 558
d9345d3a
MD
559 /*
560 * If the interlocked flag is set but our cpu bit in the slpqueue
561 * is no longer set, then a wakeup was processed inbetween the
4ecd8190
MD
562 * tsleep_interlock() (ours or the callers), and here. This can
563 * occur under numerous circumstances including when we release the
564 * current process.
d9345d3a 565 *
4ecd8190
MD
566 * Extreme loads can cause the sending of an IPI (e.g. wakeup()'s)
567 * to process incoming IPIs, thus draining incoming wakeups.
d9345d3a 568 */
4ecd8190
MD
569 if ((td->td_flags & TDF_TSLEEPQ) == 0) {
570 logtsleep2(ilockfail, ident);
571 goto resume;
d9345d3a 572 }
4ecd8190
MD
573
574 /*
575 * scheduling is blocked while in a critical section. Coincide
576 * the descheduled-by-tsleep flag with the descheduling of the
577 * lwkt.
8d446850
MD
578 *
579 * The timer callout is localized on our cpu and interlocked by
580 * our critical section.
4ecd8190 581 */
37af14fe 582 lwkt_deschedule_self(td);
ae8e83e6 583 td->td_flags |= TDF_TSLEEP_DESCHEDULED;
344ad853 584 td->td_wmesg = wmesg;
344ad853
MD
585
586 /*
8d446850
MD
587 * Setup the timeout, if any. The timeout is only operable while
588 * the thread is flagged descheduled.
344ad853 589 */
8d446850 590 KKASSERT((td->td_flags & TDF_TIMEOUT) == 0);
076fecef 591 if (timo) {
8d446850 592 callout_init_mp(&thandle);
076fecef
MD
593 callout_reset(&thandle, timo, endtsleep, td);
594 }
344ad853 595
984263bc 596 /*
344ad853 597 * Beddy bye bye.
984263bc 598 */
08f2f1bb 599 if (lp) {
26a0694b 600 /*
52eedfb5 601 * Ok, we are sleeping. Place us in the SSLEEP state.
26a0694b 602 */
4643740a 603 KKASSERT((lp->lwp_mpflags & LWP_MP_ONRUNQ) == 0);
6b4d33c2 604
7278a846
SS
605 /*
606 * tstop() sets LSSTOP, so don't fiddle with that.
607 */
608 if (lp->lwp_stat != LSSTOP)
609 lp->lwp_stat = LSSLEEP;
08f2f1bb 610 lp->lwp_ru.ru_nvcsw++;
e28d8b15 611 p->p_usched->uload_update(lp);
de4d4cb0 612 lwkt_switch();
ab554892
MD
613
614 /*
164b8401 615 * And when we are woken up, put us back in LSRUN. If we
ab554892
MD
616 * slept for over a second, recalculate our estcpu.
617 */
164b8401 618 lp->lwp_stat = LSRUN;
de4d4cb0
MD
619 if (lp->lwp_slptime) {
620 p->p_usched->uload_update(lp);
08f2f1bb 621 p->p_usched->recalculate(lp);
de4d4cb0 622 }
08f2f1bb 623 lp->lwp_slptime = 0;
0cfcada1
MD
624 } else {
625 lwkt_switch();
626 }
344ad853 627
fc17ad60
MD
628 /*
629 * Make sure we haven't switched cpus while we were asleep. It's
344ad853 630 * not supposed to happen. Cleanup our temporary flags.
fc17ad60
MD
631 */
632 KKASSERT(gd == td->td_gd);
344ad853
MD
633
634 /*
8d446850 635 * Cleanup the timeout. If the timeout has already occured thandle
4643740a
MD
636 * has already been stopped, otherwise stop thandle. If the timeout
637 * is running (the callout thread must be blocked trying to get
638 * lwp_token) then wait for us to get scheduled.
344ad853
MD
639 */
640 if (timo) {
4643740a
MD
641 while (td->td_flags & TDF_TIMEOUT_RUNNING) {
642 lwkt_deschedule_self(td);
643 td->td_wmesg = "tsrace";
644 lwkt_switch();
645 kprintf("td %p %s: timeout race\n", td, td->td_comm);
646 }
344ad853
MD
647 if (td->td_flags & TDF_TIMEOUT) {
648 td->td_flags &= ~TDF_TIMEOUT;
a40da8f0 649 error = EWOULDBLOCK;
344ad853 650 } else {
8d446850 651 /* does not block when on same cpu */
344ad853
MD
652 callout_stop(&thandle);
653 }
0cfcada1 654 }
4643740a 655 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
344ad853
MD
656
657 /*
8d446850
MD
658 * Make sure we have been removed from the sleepq. In most
659 * cases this will have been done for us already but it is
660 * possible for a scheduling IPI to be in-flight from a
661 * previous tsleep/tsleep_interlock() or due to a straight-out
662 * call to lwkt_schedule() (in the case of an interrupt thread),
663 * causing a spurious wakeup.
344ad853 664 */
ae8e83e6 665 _tsleep_remove(td);
344ad853 666 td->td_wmesg = NULL;
344ad853
MD
667
668 /*
7c1212ec
MD
669 * Figure out the correct error return. If interrupted by a
670 * signal we want to return EINTR or ERESTART.
344ad853
MD
671 */
672resume:
4643740a 673 if (lp) {
7c1212ec 674 if (catch && error == 0) {
94f98873 675 if (sig != 0 || (sig = CURSIG(lp))) {
7c1212ec
MD
676 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
677 error = EINTR;
678 else
679 error = ERESTART;
680 }
984263bc 681 }
4643740a
MD
682 lp->lwp_flags &= ~LWP_SINTR;
683 lwkt_reltoken(&lp->lwp_token);
984263bc 684 }
8aa3430c 685 logtsleep1(tsleep_end);
344ad853
MD
686 crit_exit_quick(td);
687 return (error);
984263bc
MD
688}
689
bf765287
MD
690/*
691 * Interlocked spinlock sleep. An exclusively held spinlock must
e590ee86 692 * be passed to ssleep(). The function will atomically release the
bf765287
MD
693 * spinlock and tsleep on the ident, then reacquire the spinlock and
694 * return.
695 *
696 * This routine is fairly important along the critical path, so optimize it
697 * heavily.
698 */
699int
5decebc7 700ssleep(const volatile void *ident, struct spinlock *spin, int flags,
bf765287
MD
701 const char *wmesg, int timo)
702{
703 globaldata_t gd = mycpu;
704 int error;
16523a43 705
ae8e83e6 706 _tsleep_interlock(gd, ident, flags);
7cfe2b28 707 spin_unlock_quick(gd, spin);
ef48be0d 708 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
7cfe2b28 709 spin_lock_quick(gd, spin);
bf765287
MD
710
711 return (error);
16523a43
MD
712}
713
bed060de 714int
5decebc7
MD
715lksleep(const volatile void *ident, struct lock *lock, int flags,
716 const char *wmesg, int timo)
bed060de
AH
717{
718 globaldata_t gd = mycpu;
719 int error;
720
721 _tsleep_interlock(gd, ident, flags);
722 lockmgr(lock, LK_RELEASE);
723 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
724 lockmgr(lock, LK_EXCLUSIVE);
725
726 return (error);
727}
728
7f6220a9
MD
729/*
730 * Interlocked mutex sleep. An exclusively held mutex must be passed
731 * to mtxsleep(). The function will atomically release the mutex
732 * and tsleep on the ident, then reacquire the mutex and return.
733 */
734int
5decebc7 735mtxsleep(const volatile void *ident, struct mtx *mtx, int flags,
7f6220a9
MD
736 const char *wmesg, int timo)
737{
738 globaldata_t gd = mycpu;
739 int error;
740
741 _tsleep_interlock(gd, ident, flags);
742 mtx_unlock(mtx);
743 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
744 mtx_lock_ex_quick(mtx, wmesg);
745
746 return (error);
747}
748
362e59be
SZ
749/*
750 * Interlocked serializer sleep. An exclusively held serializer must
ed3f6624 751 * be passed to zsleep(). The function will atomically release
362e59be
SZ
752 * the serializer and tsleep on the ident, then reacquire the serializer
753 * and return.
754 */
755int
5decebc7 756zsleep(const volatile void *ident, struct lwkt_serialize *slz, int flags,
ed3f6624 757 const char *wmesg, int timo)
362e59be 758{
ae8e83e6 759 globaldata_t gd = mycpu;
362e59be
SZ
760 int ret;
761
762 ASSERT_SERIALIZED(slz);
763
ae8e83e6 764 _tsleep_interlock(gd, ident, flags);
362e59be 765 lwkt_serialize_exit(slz);
ef48be0d 766 ret = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
362e59be 767 lwkt_serialize_enter(slz);
362e59be
SZ
768
769 return ret;
770}
771
a22c590e
MD
772/*
773 * Directly block on the LWKT thread by descheduling it. This
774 * is much faster then tsleep(), but the only legal way to wake
775 * us up is to directly schedule the thread.
776 *
777 * Setting TDF_SINTR will cause new signals to directly schedule us.
778 *
ae8e83e6 779 * This routine must be called while in a critical section.
a22c590e
MD
780 */
781int
782lwkt_sleep(const char *wmesg, int flags)
783{
784 thread_t td = curthread;
785 int sig;
786
787 if ((flags & PCATCH) == 0 || td->td_lwp == NULL) {
788 td->td_flags |= TDF_BLOCKED;
789 td->td_wmesg = wmesg;
790 lwkt_deschedule_self(td);
791 lwkt_switch();
792 td->td_wmesg = NULL;
793 td->td_flags &= ~TDF_BLOCKED;
794 return(0);
795 }
796 if ((sig = CURSIG(td->td_lwp)) != 0) {
797 if (SIGISMEMBER(td->td_proc->p_sigacts->ps_sigintr, sig))
798 return(EINTR);
799 else
800 return(ERESTART);
801
802 }
803 td->td_flags |= TDF_BLOCKED | TDF_SINTR;
804 td->td_wmesg = wmesg;
805 lwkt_deschedule_self(td);
806 lwkt_switch();
807 td->td_flags &= ~(TDF_BLOCKED | TDF_SINTR);
808 td->td_wmesg = NULL;
809 return(0);
810}
811
984263bc 812/*
344ad853 813 * Implement the timeout for tsleep.
fc17ad60 814 *
344ad853
MD
815 * This type of callout timeout is scheduled on the same cpu the process
816 * is sleeping on. Also, at the moment, the MP lock is held.
984263bc
MD
817 */
818static void
0cfcada1 819endtsleep(void *arg)
984263bc 820{
0cfcada1 821 thread_t td = arg;
9a379a4a 822 struct lwp *lp;
984263bc 823
8d446850 824 /*
4643740a
MD
825 * We are going to have to get the lwp_token, which means we might
826 * block. This can race a tsleep getting woken up by other means
827 * so set TDF_TIMEOUT_RUNNING to force the tsleep to wait for our
828 * processing to complete (sorry tsleep!).
829 *
830 * We can safely set td_flags because td MUST be on the same cpu
831 * as we are.
8d446850 832 */
4643740a
MD
833 KKASSERT(td->td_gd == mycpu);
834 crit_enter();
835 td->td_flags |= TDF_TIMEOUT_RUNNING | TDF_TIMEOUT;
344ad853
MD
836
837 /*
4643740a
MD
838 * This can block but TDF_TIMEOUT_RUNNING will prevent the thread
839 * from exiting the tsleep on us. The flag is interlocked by virtue
840 * of lp being on the same cpu as we are.
344ad853 841 */
8d446850 842 if ((lp = td->td_lwp) != NULL)
e2b148c6 843 lwkt_gettoken(&lp->lwp_token);
344ad853 844
4643740a
MD
845 KKASSERT(td->td_flags & TDF_TSLEEP_DESCHEDULED);
846
847 if (lp) {
848 if (lp->lwp_proc->p_stat != SSTOP)
849 setrunnable(lp);
e2b148c6 850 lwkt_reltoken(&lp->lwp_token);
4643740a
MD
851 } else {
852 _tsleep_remove(td);
853 lwkt_schedule(td);
854 }
855 KKASSERT(td->td_gd == mycpu);
856 td->td_flags &= ~TDF_TIMEOUT_RUNNING;
37af14fe 857 crit_exit();
984263bc
MD
858}
859
8fb8bca6
EN
860/*
861 * Make all processes sleeping on the specified identifier runnable.
fc17ad60
MD
862 * count may be zero or one only.
863 *
c75e41b7
MD
864 * The domain encodes the sleep/wakeup domain, flags, plus the originating
865 * cpu.
344ad853
MD
866 *
867 * This call may run without the MP lock held. We can only manipulate thread
868 * state on the cpu owning the thread. We CANNOT manipulate process state
869 * at all.
5decebc7
MD
870 *
871 * _wakeup() can be passed to an IPI so we can't use (const volatile
872 * void *ident).
8fb8bca6
EN
873 */
874static void
fc17ad60 875_wakeup(void *ident, int domain)
984263bc 876{
fc17ad60 877 struct tslpque *qp;
0cfcada1
MD
878 struct thread *td;
879 struct thread *ntd;
fc17ad60 880 globaldata_t gd;
fc17ad60 881 cpumask_t mask;
fc17ad60 882 int id;
984263bc 883
37af14fe 884 crit_enter();
8aa3430c 885 logtsleep2(wakeup_beg, ident);
fc17ad60
MD
886 gd = mycpu;
887 id = LOOKUP(ident);
888 qp = &gd->gd_tsleep_hash[id];
984263bc 889restart:
0cfcada1 890 for (td = TAILQ_FIRST(qp); td != NULL; td = ntd) {
ae8e83e6 891 ntd = TAILQ_NEXT(td, td_sleepq);
fc17ad60
MD
892 if (td->td_wchan == ident &&
893 td->td_wdomain == (domain & PDOMAIN_MASK)
894 ) {
ae8e83e6
MD
895 KKASSERT(td->td_gd == gd);
896 _tsleep_remove(td);
c75e41b7 897 td->td_wakefromcpu = PWAKEUP_DECODE(domain);
ae8e83e6 898 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
ae8e83e6
MD
899 lwkt_schedule(td);
900 if (domain & PWAKEUP_ONE)
901 goto done;
fc17ad60 902 }
0cfcada1 903 goto restart;
984263bc
MD
904 }
905 }
fc17ad60 906
fc17ad60
MD
907 /*
908 * We finished checking the current cpu but there still may be
909 * more work to do. Either wakeup_one was requested and no matching
910 * thread was found, or a normal wakeup was requested and we have
911 * to continue checking cpus.
912 *
fc17ad60
MD
913 * It should be noted that this scheme is actually less expensive then
914 * the old scheme when waking up multiple threads, since we send
915 * only one IPI message per target candidate which may then schedule
916 * multiple threads. Before we could have wound up sending an IPI
917 * message for each thread on the target cpu (!= current cpu) that
918 * needed to be woken up.
919 *
920 * NOTE: Wakeups occuring on remote cpus are asynchronous. This
921 * should be ok since we are passing idents in the IPI rather then
922 * thread pointers.
923 */
1f4f6e0b
MD
924 if ((domain & PWAKEUP_MYCPU) == 0 &&
925 (mask = slpque_cpumasks[id] & gd->gd_other_cpus) != 0) {
926 lwkt_send_ipiq2_mask(mask, _wakeup, ident,
927 domain | PWAKEUP_MYCPU);
fc17ad60 928 }
fc17ad60 929done:
8aa3430c 930 logtsleep1(wakeup_end);
37af14fe 931 crit_exit();
984263bc
MD
932}
933
b336a9b1
MD
934/*
935 * Wakeup all threads tsleep()ing on the specified ident, on all cpus
936 */
984263bc 937void
5decebc7 938wakeup(const volatile void *ident)
984263bc 939{
b0da0c88
MD
940 globaldata_t gd = mycpu;
941 thread_t td = gd->gd_curthread;
942
943 if (td && (td->td_flags & TDF_DELAYED_WAKEUP)) {
944 if (!atomic_cmpset_ptr(&gd->gd_delayed_wakeup[0], NULL, ident)) {
945 if (!atomic_cmpset_ptr(&gd->gd_delayed_wakeup[1], NULL, ident))
946 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, gd->gd_cpuid));
947 }
948 return;
949 }
950 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, gd->gd_cpuid));
0cfcada1 951}
984263bc 952
b336a9b1
MD
953/*
954 * Wakeup one thread tsleep()ing on the specified ident, on any cpu.
955 */
0cfcada1 956void
5decebc7 957wakeup_one(const volatile void *ident)
0cfcada1 958{
fc17ad60 959 /* XXX potentially round-robin the first responding cpu */
c75e41b7
MD
960 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid) |
961 PWAKEUP_ONE);
da5fb9ef
MD
962}
963
b336a9b1
MD
964/*
965 * Wakeup threads tsleep()ing on the specified ident on the current cpu
966 * only.
967 */
968void
5decebc7 969wakeup_mycpu(const volatile void *ident)
b336a9b1 970{
c75e41b7
MD
971 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid) |
972 PWAKEUP_MYCPU);
b336a9b1
MD
973}
974
975/*
976 * Wakeup one thread tsleep()ing on the specified ident on the current cpu
977 * only.
978 */
979void
5decebc7 980wakeup_mycpu_one(const volatile void *ident)
b336a9b1
MD
981{
982 /* XXX potentially round-robin the first responding cpu */
c75e41b7
MD
983 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid) |
984 PWAKEUP_MYCPU | PWAKEUP_ONE);
b336a9b1
MD
985}
986
987/*
988 * Wakeup all thread tsleep()ing on the specified ident on the specified cpu
989 * only.
990 */
991void
5decebc7 992wakeup_oncpu(globaldata_t gd, const volatile void *ident)
b336a9b1 993{
c75e41b7 994 globaldata_t mygd = mycpu;
b336a9b1 995 if (gd == mycpu) {
c75e41b7
MD
996 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mygd->gd_cpuid) |
997 PWAKEUP_MYCPU);
b336a9b1 998 } else {
c75e41b7
MD
999 lwkt_send_ipiq2(gd, _wakeup, __DEALL(ident),
1000 PWAKEUP_ENCODE(0, mygd->gd_cpuid) |
1001 PWAKEUP_MYCPU);
b336a9b1
MD
1002 }
1003}
1004
1005/*
1006 * Wakeup one thread tsleep()ing on the specified ident on the specified cpu
1007 * only.
1008 */
1009void
5decebc7 1010wakeup_oncpu_one(globaldata_t gd, const volatile void *ident)
b336a9b1 1011{
c75e41b7
MD
1012 globaldata_t mygd = mycpu;
1013 if (gd == mygd) {
1014 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mygd->gd_cpuid) |
1015 PWAKEUP_MYCPU | PWAKEUP_ONE);
b336a9b1 1016 } else {
5decebc7 1017 lwkt_send_ipiq2(gd, _wakeup, __DEALL(ident),
c75e41b7 1018 PWAKEUP_ENCODE(0, mygd->gd_cpuid) |
5decebc7 1019 PWAKEUP_MYCPU | PWAKEUP_ONE);
b336a9b1
MD
1020 }
1021}
1022
1023/*
1024 * Wakeup all threads waiting on the specified ident that slept using
1025 * the specified domain, on all cpus.
1026 */
da5fb9ef 1027void
5decebc7 1028wakeup_domain(const volatile void *ident, int domain)
da5fb9ef 1029{
5decebc7 1030 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(domain, mycpu->gd_cpuid));
da5fb9ef
MD
1031}
1032
b336a9b1
MD
1033/*
1034 * Wakeup one thread waiting on the specified ident that slept using
1035 * the specified domain, on any cpu.
1036 */
da5fb9ef 1037void
5decebc7 1038wakeup_domain_one(const volatile void *ident, int domain)
da5fb9ef 1039{
fc17ad60 1040 /* XXX potentially round-robin the first responding cpu */
5decebc7
MD
1041 _wakeup(__DEALL(ident),
1042 PWAKEUP_ENCODE(domain, mycpu->gd_cpuid) | PWAKEUP_ONE);
984263bc
MD
1043}
1044
b0da0c88
MD
1045void
1046wakeup_start_delayed(void)
1047{
1048 globaldata_t gd = mycpu;
1049
1050 crit_enter();
1051 gd->gd_curthread->td_flags |= TDF_DELAYED_WAKEUP;
1052 crit_exit();
1053}
1054
1055void
1056wakeup_end_delayed(void)
1057{
1058 globaldata_t gd = mycpu;
1059
1060 if (gd->gd_curthread->td_flags & TDF_DELAYED_WAKEUP) {
1061 crit_enter();
1062 gd->gd_curthread->td_flags &= ~TDF_DELAYED_WAKEUP;
1063 if (gd->gd_delayed_wakeup[0] || gd->gd_delayed_wakeup[1]) {
1064 if (gd->gd_delayed_wakeup[0]) {
1065 wakeup(gd->gd_delayed_wakeup[0]);
1066 gd->gd_delayed_wakeup[0] = NULL;
1067 }
1068 if (gd->gd_delayed_wakeup[1]) {
1069 wakeup(gd->gd_delayed_wakeup[1]);
1070 gd->gd_delayed_wakeup[1] = NULL;
1071 }
1072 }
1073 crit_exit();
1074 }
1075}
1076
984263bc 1077/*
344ad853
MD
1078 * setrunnable()
1079 *
4643740a
MD
1080 * Make a process runnable. lp->lwp_token must be held on call and this
1081 * function must be called from the cpu owning lp.
37af14fe 1082 *
4643740a 1083 * This only has an effect if we are in LSSTOP or LSSLEEP.
984263bc
MD
1084 */
1085void
9a379a4a 1086setrunnable(struct lwp *lp)
984263bc 1087{
4643740a
MD
1088 thread_t td = lp->lwp_thread;
1089
e2b148c6 1090 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_token);
4643740a 1091 KKASSERT(td->td_gd == mycpu);
344ad853 1092 crit_enter();
2daf83b0
SS
1093 if (lp->lwp_stat == LSSTOP)
1094 lp->lwp_stat = LSSLEEP;
4643740a
MD
1095 if (lp->lwp_stat == LSSLEEP) {
1096 _tsleep_remove(td);
1097 lwkt_schedule(td);
1098 } else if (td->td_flags & TDF_SINTR) {
1099 lwkt_schedule(td);
1100 }
344ad853 1101 crit_exit();
984263bc
MD
1102}
1103
1104/*
164b8401
SS
1105 * The process is stopped due to some condition, usually because p_stat is
1106 * set to SSTOP, but also possibly due to being traced.
fc17ad60 1107 *
4643740a
MD
1108 * Caller must hold p->p_token
1109 *
164b8401 1110 * NOTE! If the caller sets SSTOP, the caller must also clear P_WAITED
344ad853
MD
1111 * because the parent may check the child's status before the child actually
1112 * gets to this routine.
1113 *
9a379a4a 1114 * This routine is called with the current lwp only, typically just
4643740a
MD
1115 * before returning to userland if the process state is detected as
1116 * possibly being in a stopped state.
984263bc
MD
1117 */
1118void
9a379a4a 1119tstop(void)
984263bc 1120{
9a379a4a 1121 struct lwp *lp = curthread->td_lwp;
7278a846 1122 struct proc *p = lp->lwp_proc;
8c986a82 1123 struct proc *q;
9a379a4a 1124
4643740a 1125 lwkt_gettoken(&lp->lwp_token);
7278a846 1126 crit_enter();
4643740a 1127
f33e8653 1128 /*
4643740a 1129 * If LWP_MP_WSTOP is set, we were sleeping
f33e8653
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1130 * while our process was stopped. At this point
1131 * we were already counted as stopped.
1132 */
4643740a 1133 if ((lp->lwp_mpflags & LWP_MP_WSTOP) == 0) {
f33e8653
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1134 /*
1135 * If we're the last thread to stop, signal
1136 * our parent.
1137 */
1138 p->p_nstopped++;
4643740a 1139 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WSTOP);
ea59a697 1140 wakeup(&p->p_nstopped);
f33e8653 1141 if (p->p_nstopped == p->p_nthreads) {
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1142 /*
1143 * Token required to interlock kern_wait()
1144 */
1145 q = p->p_pptr;
1146 PHOLD(q);
1147 lwkt_gettoken(&q->p_token);
4643740a 1148 p->p_flags &= ~P_WAITED;
f33e8653 1149 wakeup(p->p_pptr);
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1150 if ((q->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1151 ksignal(q, SIGCHLD);
1152 lwkt_reltoken(&q->p_token);
1153 PRELE(q);
f33e8653
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1154 }
1155 }
ea59a697 1156 while (p->p_stat == SSTOP) {
ea59a697
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1157 lp->lwp_stat = LSSTOP;
1158 tsleep(p, 0, "stop", 0);
1159 }
7278a846 1160 p->p_nstopped--;
4643740a 1161 atomic_clear_int(&lp->lwp_mpflags, LWP_MP_WSTOP);
7278a846 1162 crit_exit();
4643740a 1163 lwkt_reltoken(&lp->lwp_token);
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1164}
1165
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1166/*
1167 * Compute a tenex style load average of a quantity on
1168 * 1, 5 and 15 minute intervals.
1169 */
c7e98b2f 1170static int loadav_count_runnable(struct lwp *p, void *data);
8fa76237 1171
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1172static void
1173loadav(void *arg)
1174{
984263bc 1175 struct loadavg *avg;
8fa76237 1176 int i, nrun;
984263bc 1177
984263bc 1178 nrun = 0;
c7e98b2f 1179 alllwp_scan(loadav_count_runnable, &nrun);
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1180 avg = &averunnable;
1181 for (i = 0; i < 3; i++) {
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1182 avg->ldavg[i] = (cexp[i] * avg->ldavg[i] +
1183 nrun * FSCALE * (FSCALE - cexp[i])) >> FSHIFT;
8fa76237 1184 }
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1185
1186 /*
1187 * Schedule the next update to occur after 5 seconds, but add a
1188 * random variation to avoid synchronisation with processes that
1189 * run at regular intervals.
1190 */
cddfb7bb 1191 callout_reset(&loadav_callout, hz * 4 + (int)(krandom() % (hz * 2 + 1)),
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1192 loadav, NULL);
1193}
1194
1195static int
c7e98b2f 1196loadav_count_runnable(struct lwp *lp, void *data)
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1197{
1198 int *nrunp = data;
1199 thread_t td;
1200
164b8401
SS
1201 switch (lp->lwp_stat) {
1202 case LSRUN:
08f2f1bb 1203 if ((td = lp->lwp_thread) == NULL)
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1204 break;
1205 if (td->td_flags & TDF_BLOCKED)
1206 break;
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1207 ++*nrunp;
1208 break;
1209 default:
1210 break;
1211 }
d2d8515b 1212 lwkt_yield();
8fa76237 1213 return(0);
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1214}
1215
1216/* ARGSUSED */
1217static void
6656cd91 1218sched_setup(void *dummy)
984263bc 1219{
8d446850
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1220 callout_init_mp(&loadav_callout);
1221 callout_init_mp(&schedcpu_callout);
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1222
1223 /* Kick off timeout driven events by calling first time. */
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1224 schedcpu(NULL);
1225 loadav(NULL);
1226}
1227