vkernel - Fix problem where cpu-bound user process cannot be interrupted
[dragonfly.git] / sys / kern / kern_synch.c
CommitLineData
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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 $
c730be20 40 * $DragonFly: src/sys/kern/kern_synch.c,v 1.91 2008/09/09 04:06:13 dillon Exp $
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41 */
42
43#include "opt_ktrace.h"
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/proc.h>
48#include <sys/kernel.h>
49#include <sys/signalvar.h>
50#include <sys/resourcevar.h>
51#include <sys/vmmeter.h>
52#include <sys/sysctl.h>
344ad853 53#include <sys/lock.h>
984263bc 54#include <sys/uio.h>
fc9ae81d 55#ifdef KTRACE
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56#include <sys/ktrace.h>
57#endif
f1d1c3fa 58#include <sys/xwait.h>
9afb0ffd 59#include <sys/ktr.h>
684a93c4 60#include <sys/serialize.h>
984263bc 61
684a93c4 62#include <sys/signal2.h>
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63#include <sys/thread2.h>
64#include <sys/spinlock2.h>
7f6220a9 65#include <sys/mutex2.h>
bf765287 66
984263bc 67#include <machine/cpu.h>
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68#include <machine/smp.h>
69
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70TAILQ_HEAD(tslpque, thread);
71
402ed7e1 72static void sched_setup (void *dummy);
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73SYSINIT(sched_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, sched_setup, NULL)
74
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75int hogticks;
76int lbolt;
344ad853 77int lbolt_syncer;
984263bc 78int sched_quantum; /* Roundrobin scheduling quantum in ticks. */
17a9f566 79int ncpus;
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80int ncpus2, ncpus2_shift, ncpus2_mask; /* note: mask not cpumask_t */
81int ncpus_fit, ncpus_fit_mask; /* note: mask not cpumask_t */
e43a034f 82int safepri;
dbcd0c9b 83int tsleep_now_works;
5ea440eb 84int tsleep_crypto_dump = 0;
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85
86static struct callout loadav_callout;
35f9d051 87static struct callout schedcpu_callout;
fc17ad60 88MALLOC_DEFINE(M_TSLEEP, "tslpque", "tsleep queues");
984263bc 89
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90#define __DEALL(ident) __DEQUALIFY(void *, ident)
91
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92#if !defined(KTR_TSLEEP)
93#define KTR_TSLEEP KTR_ALL
94#endif
95KTR_INFO_MASTER(tsleep);
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96KTR_INFO(KTR_TSLEEP, tsleep, tsleep_beg, 0, "tsleep enter %p", sizeof(void *));
97KTR_INFO(KTR_TSLEEP, tsleep, tsleep_end, 1, "tsleep exit", 0);
98KTR_INFO(KTR_TSLEEP, tsleep, wakeup_beg, 2, "wakeup enter %p", sizeof(void *));
99KTR_INFO(KTR_TSLEEP, tsleep, wakeup_end, 3, "wakeup exit", 0);
d9345d3a 100KTR_INFO(KTR_TSLEEP, tsleep, ilockfail, 4, "interlock failed %p", sizeof(void *));
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101
102#define logtsleep1(name) KTR_LOG(tsleep_ ## name)
103#define logtsleep2(name, val) KTR_LOG(tsleep_ ## name, val)
9afb0ffd 104
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105struct loadavg averunnable =
106 { {0, 0, 0}, FSCALE }; /* load average, of runnable procs */
107/*
108 * Constants for averages over 1, 5, and 15 minutes
109 * when sampling at 5 second intervals.
110 */
111static fixpt_t cexp[3] = {
112 0.9200444146293232 * FSCALE, /* exp(-1/12) */
113 0.9834714538216174 * FSCALE, /* exp(-1/60) */
114 0.9944598480048967 * FSCALE, /* exp(-1/180) */
115};
116
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117static void endtsleep (void *);
118static void loadav (void *arg);
402ed7e1 119static void schedcpu (void *arg);
ce4b5045 120#ifdef SMP
74c9628e 121static void tsleep_wakeup_remote(struct thread *td);
ce4b5045 122#endif
984263bc 123
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124/*
125 * Adjust the scheduler quantum. The quantum is specified in microseconds.
126 * Note that 'tick' is in microseconds per tick.
127 */
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128static int
129sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
130{
131 int error, new_val;
132
a591f597 133 new_val = sched_quantum * ustick;
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134 error = sysctl_handle_int(oidp, &new_val, 0, req);
135 if (error != 0 || req->newptr == NULL)
136 return (error);
a591f597 137 if (new_val < ustick)
984263bc 138 return (EINVAL);
a591f597 139 sched_quantum = new_val / ustick;
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140 hogticks = 2 * sched_quantum;
141 return (0);
142}
143
144SYSCTL_PROC(_kern, OID_AUTO, quantum, CTLTYPE_INT|CTLFLAG_RW,
145 0, sizeof sched_quantum, sysctl_kern_quantum, "I", "");
146
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147/*
148 * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the
149 * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below
150 * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT).
151 *
152 * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used:
dcc99b62 153 * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits).
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154 *
155 * If you don't want to bother with the faster/more-accurate formula, you
156 * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate
157 * (more general) method of calculating the %age of CPU used by a process.
dcc99b62 158 *
08f2f1bb 159 * decay 95% of `lwp_pctcpu' in 60 seconds; see CCPU_SHIFT before changing
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160 */
161#define CCPU_SHIFT 11
162
163static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
164SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
165
166/*
167 * kernel uses `FSCALE', userland (SHOULD) use kern.fscale
984263bc 168 */
460426e6 169int fscale __unused = FSCALE; /* exported to systat */
dcc99b62 170SYSCTL_INT(_kern, OID_AUTO, fscale, CTLFLAG_RD, 0, FSCALE, "");
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171
172/*
0a3f9b47 173 * Recompute process priorities, once a second.
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174 *
175 * Since the userland schedulers are typically event oriented, if the
176 * estcpu calculation at wakeup() time is not sufficient to make a
177 * process runnable relative to other processes in the system we have
178 * a 1-second recalc to help out.
179 *
180 * This code also allows us to store sysclock_t data in the process structure
181 * without fear of an overrun, since sysclock_t are guarenteed to hold
182 * several seconds worth of count.
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183 *
184 * WARNING! callouts can preempt normal threads. However, they will not
185 * preempt a thread holding a spinlock so we *can* safely use spinlocks.
984263bc 186 */
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187static int schedcpu_stats(struct proc *p, void *data __unused);
188static int schedcpu_resource(struct proc *p, void *data __unused);
189
984263bc 190static void
26a0694b 191schedcpu(void *arg)
984263bc 192{
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193 allproc_scan(schedcpu_stats, NULL);
194 allproc_scan(schedcpu_resource, NULL);
195 wakeup((caddr_t)&lbolt);
196 wakeup((caddr_t)&lbolt_syncer);
197 callout_reset(&schedcpu_callout, hz, schedcpu, NULL);
198}
199
200/*
201 * General process statistics once a second
202 */
203static int
204schedcpu_stats(struct proc *p, void *data __unused)
205{
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206 struct lwp *lp;
207
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208 /*
209 * Threads may not be completely set up if process in SIDL state.
210 */
211 if (p->p_stat == SIDL)
212 return(0);
213
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214 PHOLD(p);
215 lwkt_gettoken(&p->p_token);
216
8fa76237 217 p->p_swtime++;
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218 FOREACH_LWP_IN_PROC(lp, p) {
219 if (lp->lwp_stat == LSSLEEP)
220 lp->lwp_slptime++;
4b5f931b 221
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222 /*
223 * Only recalculate processes that are active or have slept
224 * less then 2 seconds. The schedulers understand this.
225 */
226 if (lp->lwp_slptime <= 1) {
227 p->p_usched->recalculate(lp);
228 } else {
229 lp->lwp_pctcpu = (lp->lwp_pctcpu * ccpu) >> FSHIFT;
230 }
8fa76237 231 }
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232 lwkt_reltoken(&p->p_token);
233 PRELE(p);
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234 return(0);
235}
a46fac56 236
8fa76237 237/*
84204577 238 * Resource checks. XXX break out since ksignal/killproc can block,
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239 * limiting us to one process killed per second. There is probably
240 * a better way.
241 */
242static int
243schedcpu_resource(struct proc *p, void *data __unused)
244{
245 u_int64_t ttime;
08f2f1bb 246 struct lwp *lp;
8fa76237 247
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248 if (p->p_stat == SIDL)
249 return(0);
250
251 PHOLD(p);
252 lwkt_gettoken(&p->p_token);
253
254 if (p->p_stat == SZOMB || p->p_limit == NULL) {
255 lwkt_reltoken(&p->p_token);
256 PRELE(p);
8fa76237 257 return(0);
984263bc 258 }
344ad853 259
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260 ttime = 0;
261 FOREACH_LWP_IN_PROC(lp, p) {
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262 /*
263 * We may have caught an lp in the middle of being
264 * created, lwp_thread can be NULL.
265 */
266 if (lp->lwp_thread) {
267 ttime += lp->lwp_thread->td_sticks;
268 ttime += lp->lwp_thread->td_uticks;
269 }
c7e98b2f 270 }
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271
272 switch(plimit_testcpulimit(p->p_limit, ttime)) {
273 case PLIMIT_TESTCPU_KILL:
274 killproc(p, "exceeded maximum CPU limit");
275 break;
276 case PLIMIT_TESTCPU_XCPU:
277 if ((p->p_flag & P_XCPU) == 0) {
278 p->p_flag |= P_XCPU;
84204577 279 ksignal(p, SIGXCPU);
344ad853 280 }
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281 break;
282 default:
c0b8a06d 283 break;
344ad853 284 }
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285 lwkt_reltoken(&p->p_token);
286 PRELE(p);
8fa76237 287 return(0);
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288}
289
290/*
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291 * This is only used by ps. Generate a cpu percentage use over
292 * a period of one second.
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293 *
294 * MPSAFE
984263bc 295 */
dcc99b62 296void
553ea3c8 297updatepcpu(struct lwp *lp, int cpticks, int ttlticks)
984263bc 298{
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299 fixpt_t acc;
300 int remticks;
301
302 acc = (cpticks << FSHIFT) / ttlticks;
303 if (ttlticks >= ESTCPUFREQ) {
553ea3c8 304 lp->lwp_pctcpu = acc;
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305 } else {
306 remticks = ESTCPUFREQ - ttlticks;
553ea3c8 307 lp->lwp_pctcpu = (acc * ttlticks + lp->lwp_pctcpu * remticks) /
dcc99b62 308 ESTCPUFREQ;
a46fac56 309 }
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310}
311
312/*
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313 * tsleep/wakeup hash table parameters. Try to find the sweet spot for
314 * like addresses being slept on.
984263bc 315 */
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316#define TABLESIZE 1024
317#define LOOKUP(x) (((intptr_t)(x) >> 6) & (TABLESIZE - 1))
984263bc 318
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319static cpumask_t slpque_cpumasks[TABLESIZE];
320
984263bc 321/*
a46fac56 322 * General scheduler initialization. We force a reschedule 25 times
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323 * a second by default. Note that cpu0 is initialized in early boot and
324 * cannot make any high level calls.
325 *
326 * Each cpu has its own sleep queue.
984263bc 327 */
984263bc 328void
fc17ad60 329sleep_gdinit(globaldata_t gd)
984263bc 330{
fc17ad60 331 static struct tslpque slpque_cpu0[TABLESIZE];
9c1fad94 332 int i;
984263bc 333
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334 if (gd->gd_cpuid == 0) {
335 sched_quantum = (hz + 24) / 25;
336 hogticks = 2 * sched_quantum;
337
338 gd->gd_tsleep_hash = slpque_cpu0;
339 } else {
77652cad 340 gd->gd_tsleep_hash = kmalloc(sizeof(slpque_cpu0),
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341 M_TSLEEP, M_WAITOK | M_ZERO);
342 }
343 for (i = 0; i < TABLESIZE; ++i)
344 TAILQ_INIT(&gd->gd_tsleep_hash[i]);
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345}
346
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347/*
348 * This is a dandy function that allows us to interlock tsleep/wakeup
349 * operations with unspecified upper level locks, such as lockmgr locks,
350 * simply by holding a critical section. The sequence is:
351 *
352 * (acquire upper level lock)
353 * tsleep_interlock(blah)
354 * (release upper level lock)
355 * tsleep(blah, ...)
356 *
357 * Basically this functions queues us on the tsleep queue without actually
358 * descheduling us. When tsleep() is later called with PINTERLOCK it
359 * assumes the thread was already queued, otherwise it queues it there.
360 *
361 * Thus it is possible to receive the wakeup prior to going to sleep and
362 * the race conditions are covered.
363 */
364static __inline void
5decebc7 365_tsleep_interlock(globaldata_t gd, const volatile void *ident, int flags)
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366{
367 thread_t td = gd->gd_curthread;
368 int id;
369
370 crit_enter_quick(td);
371 if (td->td_flags & TDF_TSLEEPQ) {
372 id = LOOKUP(td->td_wchan);
373 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
374 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL)
da23a592 375 atomic_clear_cpumask(&slpque_cpumasks[id], gd->gd_cpumask);
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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);
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382 td->td_wchan = ident;
383 td->td_wdomain = flags & PDOMAIN_MASK;
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384 crit_exit_quick(td);
385}
386
387void
5decebc7 388tsleep_interlock(const volatile void *ident, int flags)
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389{
390 _tsleep_interlock(mycpu, ident, flags);
391}
392
393/*
394 * Remove thread from sleepq. Must be called with a critical section held.
395 */
396static __inline void
397_tsleep_remove(thread_t td)
398{
399 globaldata_t gd = mycpu;
400 int id;
401
402 KKASSERT(td->td_gd == gd);
403 if (td->td_flags & TDF_TSLEEPQ) {
404 td->td_flags &= ~TDF_TSLEEPQ;
405 id = LOOKUP(td->td_wchan);
406 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
407 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL)
da23a592 408 atomic_clear_cpumask(&slpque_cpumasks[id], gd->gd_cpumask);
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409 td->td_wchan = NULL;
410 td->td_wdomain = 0;
411 }
412}
413
414void
415tsleep_remove(thread_t td)
416{
417 _tsleep_remove(td);
418}
419
420/*
421 * This function removes a thread from the tsleep queue and schedules
422 * it. This function may act asynchronously. The target thread may be
423 * sleeping on a different cpu.
424 *
425 * This function mus be called while in a critical section but if the
426 * target thread is sleeping on a different cpu we cannot safely probe
427 * td_flags.
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428 *
429 * This function is only called from a different cpu via setrunnable()
430 * when the thread is in a known sleep. However, multiple wakeups are
431 * possible and we must hold the td to prevent a race against the thread
432 * exiting.
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433 */
434static __inline
435void
436_tsleep_wakeup(struct thread *td)
437{
c4e34360 438#ifdef SMP
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439 globaldata_t gd = mycpu;
440
ae8e83e6 441 if (td->td_gd != gd) {
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442 lwkt_hold(td);
443 lwkt_send_ipiq(td->td_gd, (ipifunc1_t)tsleep_wakeup_remote, td);
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444 return;
445 }
446#endif
447 _tsleep_remove(td);
448 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
449 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
450 lwkt_schedule(td);
451 }
452}
453
ce4b5045 454#ifdef SMP
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455static
456void
74c9628e 457tsleep_wakeup_remote(struct thread *td)
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458{
459 _tsleep_wakeup(td);
74c9628e 460 lwkt_rele(td);
ae8e83e6 461}
ce4b5045 462#endif
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463
464
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465/*
466 * General sleep call. Suspends the current process until a wakeup is
467 * performed on the specified identifier. The process will then be made
468 * runnable with the specified priority. Sleeps at most timo/hz seconds
377d4740 469 * (0 means no timeout). If flags includes PCATCH flag, signals are checked
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470 * before and after sleeping, else signals are not checked. Returns 0 if
471 * awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a
472 * signal needs to be delivered, ERESTART is returned if the current system
473 * call should be restarted if possible, and EINTR is returned if the system
474 * call should be interrupted by the signal (return EINTR).
26a0694b 475 *
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476 * Note that if we are a process, we release_curproc() before messing with
477 * the LWKT scheduler.
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478 *
479 * During autoconfiguration or after a panic, a sleep will simply
480 * lower the priority briefly to allow interrupts, then return.
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481 */
482int
5decebc7 483tsleep(const volatile void *ident, int flags, const char *wmesg, int timo)
984263bc 484{
dadab5e9 485 struct thread *td = curthread;
08f2f1bb 486 struct lwp *lp = td->td_lwp;
0cfcada1 487 struct proc *p = td->td_proc; /* may be NULL */
fc17ad60 488 globaldata_t gd;
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489 int sig;
490 int catch;
491 int id;
492 int error;
e43a034f 493 int oldpri;
076fecef 494 struct callout thandle;
984263bc 495
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496 /*
497 * NOTE: removed KTRPOINT, it could cause races due to blocking
498 * even in stable. Just scrap it for now.
499 */
5ea440eb 500 if (!tsleep_crypto_dump && (tsleep_now_works == 0 || panicstr)) {
984263bc 501 /*
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502 * After a panic, or before we actually have an operational
503 * softclock, just give interrupts a chance, then just return;
504 *
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505 * don't run any other procs or panic below,
506 * in case this is the idle process and already asleep.
507 */
e43a034f 508 splz();
f9235b6d 509 oldpri = td->td_pri;
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510 lwkt_setpri_self(safepri);
511 lwkt_switch();
512 lwkt_setpri_self(oldpri);
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513 return (0);
514 }
8aa3430c 515 logtsleep2(tsleep_beg, ident);
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516 gd = td->td_gd;
517 KKASSERT(td != &gd->gd_idlethread); /* you must be kidding! */
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518
519 /*
520 * NOTE: all of this occurs on the current cpu, including any
521 * callout-based wakeups, so a critical section is a sufficient
522 * interlock.
523 *
524 * The entire sequence through to where we actually sleep must
525 * run without breaking the critical section.
526 */
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527 catch = flags & PCATCH;
528 error = 0;
529 sig = 0;
530
37af14fe 531 crit_enter_quick(td);
344ad853 532
0cfcada1 533 KASSERT(ident != NULL, ("tsleep: no ident"));
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534 KASSERT(lp == NULL ||
535 lp->lwp_stat == LSRUN || /* Obvious */
536 lp->lwp_stat == LSSTOP, /* Set in tstop */
537 ("tsleep %p %s %d",
538 ident, wmesg, lp->lwp_stat));
0cfcada1 539
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540 /*
541 * We interlock the sleep queue if the caller has not already done
542 * it for us. This must be done before we potentially acquire any
543 * tokens or we can loose the wakeup.
544 */
545 if ((flags & PINTERLOCKED) == 0) {
546 id = LOOKUP(ident);
547 _tsleep_interlock(gd, ident, flags);
548 }
549
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550 /*
551 * Setup for the current process (if this is a process).
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552 *
553 * We hold the process token if lp && catch. The resume
554 * code will release it.
344ad853 555 */
08f2f1bb 556 if (lp) {
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557 if (catch) {
558 /*
559 * Early termination if PCATCH was set and a
560 * signal is pending, interlocked with the
561 * critical section.
562 *
563 * Early termination only occurs when tsleep() is
164b8401 564 * entered while in a normal LSRUN state.
344ad853 565 */
5686ec5a 566 lwkt_gettoken(&p->p_token);
08f2f1bb 567 if ((sig = CURSIG(lp)) != 0)
344ad853
MD
568 goto resume;
569
7c1212ec
MD
570 /*
571 * Early termination if PCATCH was set and a
572 * mailbox signal was possibly delivered prior to
573 * the system call even being made, in order to
574 * allow the user to interlock without having to
575 * make additional system calls.
576 */
577 if (p->p_flag & P_MAILBOX)
578 goto resume;
579
344ad853 580 /*
5686ec5a
MD
581 * Causes ksignal to wake us up if a signal is
582 * received (interlocked with p->p_token).
344ad853 583 */
9a379a4a 584 lp->lwp_flag |= LWP_SINTR;
344ad853 585 }
5686ec5a
MD
586 } else {
587 KKASSERT(p == NULL);
4ecd8190 588 }
344ad853 589
4ecd8190 590 /*
4ecd8190
MD
591 * Make sure the current process has been untangled from
592 * the userland scheduler and initialize slptime to start
5686ec5a 593 * counting.
4ecd8190
MD
594 */
595 if (lp) {
08f2f1bb
SS
596 p->p_usched->release_curproc(lp);
597 lp->lwp_slptime = 0;
0a3f9b47 598 }
fc17ad60 599
d9345d3a
MD
600 /*
601 * If the interlocked flag is set but our cpu bit in the slpqueue
602 * is no longer set, then a wakeup was processed inbetween the
4ecd8190
MD
603 * tsleep_interlock() (ours or the callers), and here. This can
604 * occur under numerous circumstances including when we release the
605 * current process.
d9345d3a 606 *
4ecd8190
MD
607 * Extreme loads can cause the sending of an IPI (e.g. wakeup()'s)
608 * to process incoming IPIs, thus draining incoming wakeups.
d9345d3a 609 */
4ecd8190
MD
610 if ((td->td_flags & TDF_TSLEEPQ) == 0) {
611 logtsleep2(ilockfail, ident);
612 goto resume;
d9345d3a 613 }
4ecd8190
MD
614
615 /*
616 * scheduling is blocked while in a critical section. Coincide
617 * the descheduled-by-tsleep flag with the descheduling of the
618 * lwkt.
619 */
37af14fe 620 lwkt_deschedule_self(td);
ae8e83e6 621 td->td_flags |= TDF_TSLEEP_DESCHEDULED;
344ad853 622 td->td_wmesg = wmesg;
344ad853
MD
623
624 /*
625 * Setup the timeout, if any
626 */
076fecef
MD
627 if (timo) {
628 callout_init(&thandle);
629 callout_reset(&thandle, timo, endtsleep, td);
630 }
344ad853 631
984263bc 632 /*
344ad853 633 * Beddy bye bye.
984263bc 634 */
08f2f1bb 635 if (lp) {
26a0694b 636 /*
52eedfb5 637 * Ok, we are sleeping. Place us in the SSLEEP state.
26a0694b 638 */
9388413d 639 KKASSERT((lp->lwp_flag & LWP_ONRUNQ) == 0);
7278a846
SS
640 /*
641 * tstop() sets LSSTOP, so don't fiddle with that.
642 */
643 if (lp->lwp_stat != LSSTOP)
644 lp->lwp_stat = LSSLEEP;
08f2f1bb 645 lp->lwp_ru.ru_nvcsw++;
344ad853 646 lwkt_switch();
ab554892
MD
647
648 /*
164b8401 649 * And when we are woken up, put us back in LSRUN. If we
ab554892
MD
650 * slept for over a second, recalculate our estcpu.
651 */
164b8401 652 lp->lwp_stat = LSRUN;
08f2f1bb
SS
653 if (lp->lwp_slptime)
654 p->p_usched->recalculate(lp);
655 lp->lwp_slptime = 0;
0cfcada1
MD
656 } else {
657 lwkt_switch();
658 }
344ad853 659
fc17ad60
MD
660 /*
661 * Make sure we haven't switched cpus while we were asleep. It's
344ad853 662 * not supposed to happen. Cleanup our temporary flags.
fc17ad60
MD
663 */
664 KKASSERT(gd == td->td_gd);
344ad853
MD
665
666 /*
667 * Cleanup the timeout.
668 */
669 if (timo) {
670 if (td->td_flags & TDF_TIMEOUT) {
671 td->td_flags &= ~TDF_TIMEOUT;
a40da8f0 672 error = EWOULDBLOCK;
344ad853
MD
673 } else {
674 callout_stop(&thandle);
675 }
0cfcada1 676 }
344ad853
MD
677
678 /*
ae8e83e6
MD
679 * Make sure we have been removed from the sleepq. This should
680 * have been done for us already.
f022a370
MD
681 *
682 * However, it is possible for a scheduling IPI to be in flight
683 * from a previous tsleep/tsleep_interlock or due to a straight-out
684 * call to lwkt_schedule() (in the case of an interrupt thread).
685 * So don't complain if DESCHEDULED is still set.
344ad853 686 */
ae8e83e6 687 _tsleep_remove(td);
344ad853 688 td->td_wmesg = NULL;
ae8e83e6
MD
689 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
690 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
ae8e83e6 691 }
344ad853
MD
692
693 /*
7c1212ec
MD
694 * Figure out the correct error return. If interrupted by a
695 * signal we want to return EINTR or ERESTART.
696 *
697 * If P_MAILBOX is set no automatic system call restart occurs
698 * and we return EINTR. P_MAILBOX is meant to be used as an
699 * interlock, the user must poll it prior to any system call
700 * that it wishes to interlock a mailbox signal against since
701 * the flag is cleared on *any* system call that sleeps.
5686ec5a
MD
702 *
703 * p->p_token is held in the p && catch case.
344ad853
MD
704 */
705resume:
0cfcada1 706 if (p) {
7c1212ec
MD
707 if (catch && error == 0) {
708 if ((p->p_flag & P_MAILBOX) && sig == 0) {
344ad853 709 error = EINTR;
08f2f1bb 710 } else if (sig != 0 || (sig = CURSIG(lp))) {
7c1212ec
MD
711 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
712 error = EINTR;
713 else
714 error = ERESTART;
715 }
984263bc 716 }
5686ec5a
MD
717 if (catch)
718 lwkt_reltoken(&p->p_token);
9a379a4a
SS
719 lp->lwp_flag &= ~(LWP_BREAKTSLEEP | LWP_SINTR);
720 p->p_flag &= ~P_MAILBOX;
984263bc 721 }
8aa3430c 722 logtsleep1(tsleep_end);
344ad853
MD
723 crit_exit_quick(td);
724 return (error);
984263bc
MD
725}
726
bf765287
MD
727/*
728 * Interlocked spinlock sleep. An exclusively held spinlock must
e590ee86 729 * be passed to ssleep(). The function will atomically release the
bf765287
MD
730 * spinlock and tsleep on the ident, then reacquire the spinlock and
731 * return.
732 *
733 * This routine is fairly important along the critical path, so optimize it
734 * heavily.
735 */
736int
5decebc7 737ssleep(const volatile void *ident, struct spinlock *spin, int flags,
bf765287
MD
738 const char *wmesg, int timo)
739{
740 globaldata_t gd = mycpu;
741 int error;
16523a43 742
ae8e83e6 743 _tsleep_interlock(gd, ident, flags);
7cfe2b28 744 spin_unlock_quick(gd, spin);
ef48be0d 745 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
7cfe2b28 746 spin_lock_quick(gd, spin);
bf765287
MD
747
748 return (error);
16523a43
MD
749}
750
bed060de 751int
5decebc7
MD
752lksleep(const volatile void *ident, struct lock *lock, int flags,
753 const char *wmesg, int timo)
bed060de
AH
754{
755 globaldata_t gd = mycpu;
756 int error;
757
758 _tsleep_interlock(gd, ident, flags);
759 lockmgr(lock, LK_RELEASE);
760 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
761 lockmgr(lock, LK_EXCLUSIVE);
762
763 return (error);
764}
765
7f6220a9
MD
766/*
767 * Interlocked mutex sleep. An exclusively held mutex must be passed
768 * to mtxsleep(). The function will atomically release the mutex
769 * and tsleep on the ident, then reacquire the mutex and return.
770 */
771int
5decebc7 772mtxsleep(const volatile void *ident, struct mtx *mtx, int flags,
7f6220a9
MD
773 const char *wmesg, int timo)
774{
775 globaldata_t gd = mycpu;
776 int error;
777
778 _tsleep_interlock(gd, ident, flags);
779 mtx_unlock(mtx);
780 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
781 mtx_lock_ex_quick(mtx, wmesg);
782
783 return (error);
784}
785
362e59be
SZ
786/*
787 * Interlocked serializer sleep. An exclusively held serializer must
ed3f6624 788 * be passed to zsleep(). The function will atomically release
362e59be
SZ
789 * the serializer and tsleep on the ident, then reacquire the serializer
790 * and return.
791 */
792int
5decebc7 793zsleep(const volatile void *ident, struct lwkt_serialize *slz, int flags,
ed3f6624 794 const char *wmesg, int timo)
362e59be 795{
ae8e83e6 796 globaldata_t gd = mycpu;
362e59be
SZ
797 int ret;
798
799 ASSERT_SERIALIZED(slz);
800
ae8e83e6 801 _tsleep_interlock(gd, ident, flags);
362e59be 802 lwkt_serialize_exit(slz);
ef48be0d 803 ret = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
362e59be 804 lwkt_serialize_enter(slz);
362e59be
SZ
805
806 return ret;
807}
808
a22c590e
MD
809/*
810 * Directly block on the LWKT thread by descheduling it. This
811 * is much faster then tsleep(), but the only legal way to wake
812 * us up is to directly schedule the thread.
813 *
814 * Setting TDF_SINTR will cause new signals to directly schedule us.
815 *
ae8e83e6 816 * This routine must be called while in a critical section.
a22c590e
MD
817 */
818int
819lwkt_sleep(const char *wmesg, int flags)
820{
821 thread_t td = curthread;
822 int sig;
823
824 if ((flags & PCATCH) == 0 || td->td_lwp == NULL) {
825 td->td_flags |= TDF_BLOCKED;
826 td->td_wmesg = wmesg;
827 lwkt_deschedule_self(td);
828 lwkt_switch();
829 td->td_wmesg = NULL;
830 td->td_flags &= ~TDF_BLOCKED;
831 return(0);
832 }
833 if ((sig = CURSIG(td->td_lwp)) != 0) {
834 if (SIGISMEMBER(td->td_proc->p_sigacts->ps_sigintr, sig))
835 return(EINTR);
836 else
837 return(ERESTART);
838
839 }
840 td->td_flags |= TDF_BLOCKED | TDF_SINTR;
841 td->td_wmesg = wmesg;
842 lwkt_deschedule_self(td);
843 lwkt_switch();
844 td->td_flags &= ~(TDF_BLOCKED | TDF_SINTR);
845 td->td_wmesg = NULL;
846 return(0);
847}
848
984263bc 849/*
344ad853 850 * Implement the timeout for tsleep.
fc17ad60 851 *
9a379a4a 852 * We set LWP_BREAKTSLEEP to indicate that an event has occured, but
344ad853
MD
853 * we only call setrunnable if the process is not stopped.
854 *
855 * This type of callout timeout is scheduled on the same cpu the process
856 * is sleeping on. Also, at the moment, the MP lock is held.
984263bc
MD
857 */
858static void
0cfcada1 859endtsleep(void *arg)
984263bc 860{
0cfcada1 861 thread_t td = arg;
9a379a4a 862 struct lwp *lp;
984263bc 863
37af14fe 864 crit_enter();
5686ec5a
MD
865 lp = td->td_lwp;
866
867 if (lp)
868 lwkt_gettoken(&lp->lwp_proc->p_token);
344ad853
MD
869
870 /*
871 * cpu interlock. Thread flags are only manipulated on
872 * the cpu owning the thread. proc flags are only manipulated
5686ec5a 873 * by the holder of p->p_token. We have both.
344ad853 874 */
ae8e83e6 875 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
0cfcada1 876 td->td_flags |= TDF_TIMEOUT;
344ad853 877
5686ec5a 878 if (lp) {
9a379a4a
SS
879 lp->lwp_flag |= LWP_BREAKTSLEEP;
880 if (lp->lwp_proc->p_stat != SSTOP)
881 setrunnable(lp);
0cfcada1 882 } else {
ae8e83e6 883 _tsleep_wakeup(td);
0cfcada1 884 }
984263bc 885 }
5686ec5a
MD
886 if (lp)
887 lwkt_reltoken(&lp->lwp_proc->p_token);
37af14fe 888 crit_exit();
984263bc
MD
889}
890
8fb8bca6
EN
891/*
892 * Make all processes sleeping on the specified identifier runnable.
fc17ad60
MD
893 * count may be zero or one only.
894 *
895 * The domain encodes the sleep/wakeup domain AND the first cpu to check
896 * (which is always the current cpu). As we iterate across cpus
344ad853
MD
897 *
898 * This call may run without the MP lock held. We can only manipulate thread
899 * state on the cpu owning the thread. We CANNOT manipulate process state
900 * at all.
5decebc7
MD
901 *
902 * _wakeup() can be passed to an IPI so we can't use (const volatile
903 * void *ident).
8fb8bca6
EN
904 */
905static void
fc17ad60 906_wakeup(void *ident, int domain)
984263bc 907{
fc17ad60 908 struct tslpque *qp;
0cfcada1
MD
909 struct thread *td;
910 struct thread *ntd;
fc17ad60 911 globaldata_t gd;
fc17ad60
MD
912#ifdef SMP
913 cpumask_t mask;
fc17ad60
MD
914#endif
915 int id;
984263bc 916
37af14fe 917 crit_enter();
8aa3430c 918 logtsleep2(wakeup_beg, ident);
fc17ad60
MD
919 gd = mycpu;
920 id = LOOKUP(ident);
921 qp = &gd->gd_tsleep_hash[id];
984263bc 922restart:
0cfcada1 923 for (td = TAILQ_FIRST(qp); td != NULL; td = ntd) {
ae8e83e6 924 ntd = TAILQ_NEXT(td, td_sleepq);
fc17ad60
MD
925 if (td->td_wchan == ident &&
926 td->td_wdomain == (domain & PDOMAIN_MASK)
927 ) {
ae8e83e6
MD
928 KKASSERT(td->td_gd == gd);
929 _tsleep_remove(td);
930 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
931 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
932 lwkt_schedule(td);
933 if (domain & PWAKEUP_ONE)
934 goto done;
fc17ad60 935 }
0cfcada1 936 goto restart;
984263bc
MD
937 }
938 }
fc17ad60
MD
939
940#ifdef SMP
941 /*
942 * We finished checking the current cpu but there still may be
943 * more work to do. Either wakeup_one was requested and no matching
944 * thread was found, or a normal wakeup was requested and we have
945 * to continue checking cpus.
946 *
fc17ad60
MD
947 * It should be noted that this scheme is actually less expensive then
948 * the old scheme when waking up multiple threads, since we send
949 * only one IPI message per target candidate which may then schedule
950 * multiple threads. Before we could have wound up sending an IPI
951 * message for each thread on the target cpu (!= current cpu) that
952 * needed to be woken up.
953 *
954 * NOTE: Wakeups occuring on remote cpus are asynchronous. This
955 * should be ok since we are passing idents in the IPI rather then
956 * thread pointers.
957 */
1f4f6e0b
MD
958 if ((domain & PWAKEUP_MYCPU) == 0 &&
959 (mask = slpque_cpumasks[id] & gd->gd_other_cpus) != 0) {
960 lwkt_send_ipiq2_mask(mask, _wakeup, ident,
961 domain | PWAKEUP_MYCPU);
fc17ad60
MD
962 }
963#endif
964done:
8aa3430c 965 logtsleep1(wakeup_end);
37af14fe 966 crit_exit();
984263bc
MD
967}
968
b336a9b1
MD
969/*
970 * Wakeup all threads tsleep()ing on the specified ident, on all cpus
971 */
984263bc 972void
5decebc7 973wakeup(const volatile void *ident)
984263bc 974{
5decebc7 975 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid));
0cfcada1 976}
984263bc 977
b336a9b1
MD
978/*
979 * Wakeup one thread tsleep()ing on the specified ident, on any cpu.
980 */
0cfcada1 981void
5decebc7 982wakeup_one(const volatile void *ident)
0cfcada1 983{
fc17ad60 984 /* XXX potentially round-robin the first responding cpu */
5decebc7 985 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid) | PWAKEUP_ONE);
da5fb9ef
MD
986}
987
b336a9b1
MD
988/*
989 * Wakeup threads tsleep()ing on the specified ident on the current cpu
990 * only.
991 */
992void
5decebc7 993wakeup_mycpu(const volatile void *ident)
b336a9b1 994{
5decebc7 995 _wakeup(__DEALL(ident), PWAKEUP_MYCPU);
b336a9b1
MD
996}
997
998/*
999 * Wakeup one thread tsleep()ing on the specified ident on the current cpu
1000 * only.
1001 */
1002void
5decebc7 1003wakeup_mycpu_one(const volatile void *ident)
b336a9b1
MD
1004{
1005 /* XXX potentially round-robin the first responding cpu */
5decebc7 1006 _wakeup(__DEALL(ident), PWAKEUP_MYCPU|PWAKEUP_ONE);
b336a9b1
MD
1007}
1008
1009/*
1010 * Wakeup all thread tsleep()ing on the specified ident on the specified cpu
1011 * only.
1012 */
1013void
5decebc7 1014wakeup_oncpu(globaldata_t gd, const volatile void *ident)
b336a9b1 1015{
1699d292 1016#ifdef SMP
b336a9b1 1017 if (gd == mycpu) {
5decebc7 1018 _wakeup(__DEALL(ident), PWAKEUP_MYCPU);
b336a9b1 1019 } else {
5decebc7 1020 lwkt_send_ipiq2(gd, _wakeup, __DEALL(ident), PWAKEUP_MYCPU);
b336a9b1 1021 }
1699d292 1022#else
8e44b950 1023 _wakeup(__DEALL(ident), PWAKEUP_MYCPU);
1699d292 1024#endif
b336a9b1
MD
1025}
1026
1027/*
1028 * Wakeup one thread tsleep()ing on the specified ident on the specified cpu
1029 * only.
1030 */
1031void
5decebc7 1032wakeup_oncpu_one(globaldata_t gd, const volatile void *ident)
b336a9b1 1033{
1699d292 1034#ifdef SMP
b336a9b1 1035 if (gd == mycpu) {
5decebc7 1036 _wakeup(__DEALL(ident), PWAKEUP_MYCPU | PWAKEUP_ONE);
b336a9b1 1037 } else {
5decebc7
MD
1038 lwkt_send_ipiq2(gd, _wakeup, __DEALL(ident),
1039 PWAKEUP_MYCPU | PWAKEUP_ONE);
b336a9b1 1040 }
1699d292 1041#else
8e44b950 1042 _wakeup(__DEALL(ident), PWAKEUP_MYCPU | PWAKEUP_ONE);
1699d292 1043#endif
b336a9b1
MD
1044}
1045
1046/*
1047 * Wakeup all threads waiting on the specified ident that slept using
1048 * the specified domain, on all cpus.
1049 */
da5fb9ef 1050void
5decebc7 1051wakeup_domain(const volatile void *ident, int domain)
da5fb9ef 1052{
5decebc7 1053 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(domain, mycpu->gd_cpuid));
da5fb9ef
MD
1054}
1055
b336a9b1
MD
1056/*
1057 * Wakeup one thread waiting on the specified ident that slept using
1058 * the specified domain, on any cpu.
1059 */
da5fb9ef 1060void
5decebc7 1061wakeup_domain_one(const volatile void *ident, int domain)
da5fb9ef 1062{
fc17ad60 1063 /* XXX potentially round-robin the first responding cpu */
5decebc7
MD
1064 _wakeup(__DEALL(ident),
1065 PWAKEUP_ENCODE(domain, mycpu->gd_cpuid) | PWAKEUP_ONE);
984263bc
MD
1066}
1067
1068/*
344ad853
MD
1069 * setrunnable()
1070 *
5686ec5a
MD
1071 * Make a process runnable. lp->lwp_proc->p_token must be held on call.
1072 * This only has an effect if we are in SSLEEP. We only break out of the
9a379a4a 1073 * tsleep if LWP_BREAKTSLEEP is set, otherwise we just fix-up the state.
37af14fe 1074 *
5686ec5a 1075 * NOTE: With p_token held we can only safely manipulate the process
74c9628e 1076 * structure and the lp's lwp_stat.
984263bc
MD
1077 */
1078void
9a379a4a 1079setrunnable(struct lwp *lp)
984263bc 1080{
5686ec5a 1081 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_proc->p_token);
344ad853 1082 crit_enter();
2daf83b0
SS
1083 if (lp->lwp_stat == LSSTOP)
1084 lp->lwp_stat = LSSLEEP;
1085 if (lp->lwp_stat == LSSLEEP && (lp->lwp_flag & LWP_BREAKTSLEEP))
ae8e83e6 1086 _tsleep_wakeup(lp->lwp_thread);
344ad853 1087 crit_exit();
984263bc
MD
1088}
1089
1090/*
164b8401
SS
1091 * The process is stopped due to some condition, usually because p_stat is
1092 * set to SSTOP, but also possibly due to being traced.
fc17ad60 1093 *
164b8401 1094 * NOTE! If the caller sets SSTOP, the caller must also clear P_WAITED
344ad853
MD
1095 * because the parent may check the child's status before the child actually
1096 * gets to this routine.
1097 *
9a379a4a 1098 * This routine is called with the current lwp only, typically just
344ad853
MD
1099 * before returning to userland.
1100 *
9a379a4a 1101 * Setting LWP_BREAKTSLEEP before entering the tsleep will cause a passive
344ad853 1102 * SIGCONT to break out of the tsleep.
984263bc
MD
1103 */
1104void
9a379a4a 1105tstop(void)
984263bc 1106{
9a379a4a 1107 struct lwp *lp = curthread->td_lwp;
7278a846 1108 struct proc *p = lp->lwp_proc;
9a379a4a 1109
7278a846 1110 crit_enter();
f33e8653
SS
1111 /*
1112 * If LWP_WSTOP is set, we were sleeping
1113 * while our process was stopped. At this point
1114 * we were already counted as stopped.
1115 */
1116 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1117 /*
1118 * If we're the last thread to stop, signal
1119 * our parent.
1120 */
1121 p->p_nstopped++;
1122 lp->lwp_flag |= LWP_WSTOP;
ea59a697 1123 wakeup(&p->p_nstopped);
f33e8653
SS
1124 if (p->p_nstopped == p->p_nthreads) {
1125 p->p_flag &= ~P_WAITED;
1126 wakeup(p->p_pptr);
1127 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1128 ksignal(p->p_pptr, SIGCHLD);
1129 }
1130 }
ea59a697
SS
1131 while (p->p_stat == SSTOP) {
1132 lp->lwp_flag |= LWP_BREAKTSLEEP;
1133 lp->lwp_stat = LSSTOP;
1134 tsleep(p, 0, "stop", 0);
1135 }
7278a846 1136 p->p_nstopped--;
a5ff9d37 1137 lp->lwp_flag &= ~LWP_WSTOP;
7278a846 1138 crit_exit();
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1139}
1140
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1141/*
1142 * Compute a tenex style load average of a quantity on
1143 * 1, 5 and 15 minute intervals.
1144 */
c7e98b2f 1145static int loadav_count_runnable(struct lwp *p, void *data);
8fa76237 1146
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1147static void
1148loadav(void *arg)
1149{
984263bc 1150 struct loadavg *avg;
8fa76237 1151 int i, nrun;
984263bc 1152
984263bc 1153 nrun = 0;
c7e98b2f 1154 alllwp_scan(loadav_count_runnable, &nrun);
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1155 avg = &averunnable;
1156 for (i = 0; i < 3; i++) {
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1157 avg->ldavg[i] = (cexp[i] * avg->ldavg[i] +
1158 nrun * FSCALE * (FSCALE - cexp[i])) >> FSHIFT;
8fa76237 1159 }
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1160
1161 /*
1162 * Schedule the next update to occur after 5 seconds, but add a
1163 * random variation to avoid synchronisation with processes that
1164 * run at regular intervals.
1165 */
cddfb7bb 1166 callout_reset(&loadav_callout, hz * 4 + (int)(krandom() % (hz * 2 + 1)),
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1167 loadav, NULL);
1168}
1169
1170static int
c7e98b2f 1171loadav_count_runnable(struct lwp *lp, void *data)
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1172{
1173 int *nrunp = data;
1174 thread_t td;
1175
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1176 switch (lp->lwp_stat) {
1177 case LSRUN:
08f2f1bb 1178 if ((td = lp->lwp_thread) == NULL)
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1179 break;
1180 if (td->td_flags & TDF_BLOCKED)
1181 break;
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1182 ++*nrunp;
1183 break;
1184 default:
1185 break;
1186 }
1187 return(0);
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1188}
1189
1190/* ARGSUSED */
1191static void
6656cd91 1192sched_setup(void *dummy)
984263bc 1193{
984263bc 1194 callout_init(&loadav_callout);
35f9d051 1195 callout_init(&schedcpu_callout);
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1196
1197 /* Kick off timeout driven events by calling first time. */
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1198 schedcpu(NULL);
1199 loadav(NULL);
1200}
1201