Resurrect code mistakenly #ifdef'd out before.
[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 $
a5ff9d37 40 * $DragonFly: src/sys/kern/kern_synch.c,v 1.88 2007/12/06 15:03:25 corecode 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>
b1b4e5a6 50#include <sys/signal2.h>
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51#include <sys/resourcevar.h>
52#include <sys/vmmeter.h>
53#include <sys/sysctl.h>
344ad853 54#include <sys/lock.h>
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55#ifdef KTRACE
56#include <sys/uio.h>
57#include <sys/ktrace.h>
58#endif
f1d1c3fa 59#include <sys/xwait.h>
9afb0ffd 60#include <sys/ktr.h>
984263bc 61
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62#include <sys/thread2.h>
63#include <sys/spinlock2.h>
64
984263bc 65#include <machine/cpu.h>
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66#include <machine/smp.h>
67
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68TAILQ_HEAD(tslpque, thread);
69
402ed7e1 70static void sched_setup (void *dummy);
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71SYSINIT(sched_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, sched_setup, NULL)
72
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73int hogticks;
74int lbolt;
344ad853 75int lbolt_syncer;
984263bc 76int sched_quantum; /* Roundrobin scheduling quantum in ticks. */
17a9f566 77int ncpus;
90100055 78int ncpus2, ncpus2_shift, ncpus2_mask;
b45759e1 79int ncpus_fit, ncpus_fit_mask;
e43a034f 80int safepri;
dbcd0c9b 81int tsleep_now_works;
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82
83static struct callout loadav_callout;
35f9d051 84static struct callout schedcpu_callout;
fc17ad60 85MALLOC_DEFINE(M_TSLEEP, "tslpque", "tsleep queues");
984263bc 86
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87#if !defined(KTR_TSLEEP)
88#define KTR_TSLEEP KTR_ALL
89#endif
90KTR_INFO_MASTER(tsleep);
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91KTR_INFO(KTR_TSLEEP, tsleep, tsleep_beg, 0, "tsleep enter %p", sizeof(void *));
92KTR_INFO(KTR_TSLEEP, tsleep, tsleep_end, 1, "tsleep exit", 0);
93KTR_INFO(KTR_TSLEEP, tsleep, wakeup_beg, 2, "wakeup enter %p", sizeof(void *));
94KTR_INFO(KTR_TSLEEP, tsleep, wakeup_end, 3, "wakeup exit", 0);
95
96#define logtsleep1(name) KTR_LOG(tsleep_ ## name)
97#define logtsleep2(name, val) KTR_LOG(tsleep_ ## name, val)
9afb0ffd 98
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99struct loadavg averunnable =
100 { {0, 0, 0}, FSCALE }; /* load average, of runnable procs */
101/*
102 * Constants for averages over 1, 5, and 15 minutes
103 * when sampling at 5 second intervals.
104 */
105static fixpt_t cexp[3] = {
106 0.9200444146293232 * FSCALE, /* exp(-1/12) */
107 0.9834714538216174 * FSCALE, /* exp(-1/60) */
108 0.9944598480048967 * FSCALE, /* exp(-1/180) */
109};
110
402ed7e1 111static void endtsleep (void *);
344ad853 112static void unsleep_and_wakeup_thread(struct thread *td);
402ed7e1 113static void loadav (void *arg);
402ed7e1 114static void schedcpu (void *arg);
984263bc 115
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116/*
117 * Adjust the scheduler quantum. The quantum is specified in microseconds.
118 * Note that 'tick' is in microseconds per tick.
119 */
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120static int
121sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
122{
123 int error, new_val;
124
125 new_val = sched_quantum * tick;
126 error = sysctl_handle_int(oidp, &new_val, 0, req);
127 if (error != 0 || req->newptr == NULL)
128 return (error);
129 if (new_val < tick)
130 return (EINVAL);
131 sched_quantum = new_val / tick;
132 hogticks = 2 * sched_quantum;
133 return (0);
134}
135
136SYSCTL_PROC(_kern, OID_AUTO, quantum, CTLTYPE_INT|CTLFLAG_RW,
137 0, sizeof sched_quantum, sysctl_kern_quantum, "I", "");
138
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139/*
140 * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the
141 * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below
142 * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT).
143 *
144 * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used:
dcc99b62 145 * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits).
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146 *
147 * If you don't want to bother with the faster/more-accurate formula, you
148 * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate
149 * (more general) method of calculating the %age of CPU used by a process.
dcc99b62 150 *
08f2f1bb 151 * decay 95% of `lwp_pctcpu' in 60 seconds; see CCPU_SHIFT before changing
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152 */
153#define CCPU_SHIFT 11
154
155static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
156SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
157
158/*
159 * kernel uses `FSCALE', userland (SHOULD) use kern.fscale
984263bc 160 */
460426e6 161int fscale __unused = FSCALE; /* exported to systat */
dcc99b62 162SYSCTL_INT(_kern, OID_AUTO, fscale, CTLFLAG_RD, 0, FSCALE, "");
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163
164/*
0a3f9b47 165 * Recompute process priorities, once a second.
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166 *
167 * Since the userland schedulers are typically event oriented, if the
168 * estcpu calculation at wakeup() time is not sufficient to make a
169 * process runnable relative to other processes in the system we have
170 * a 1-second recalc to help out.
171 *
172 * This code also allows us to store sysclock_t data in the process structure
173 * without fear of an overrun, since sysclock_t are guarenteed to hold
174 * several seconds worth of count.
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175 *
176 * WARNING! callouts can preempt normal threads. However, they will not
177 * preempt a thread holding a spinlock so we *can* safely use spinlocks.
984263bc 178 */
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179static int schedcpu_stats(struct proc *p, void *data __unused);
180static int schedcpu_resource(struct proc *p, void *data __unused);
181
984263bc 182static void
26a0694b 183schedcpu(void *arg)
984263bc 184{
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185 allproc_scan(schedcpu_stats, NULL);
186 allproc_scan(schedcpu_resource, NULL);
187 wakeup((caddr_t)&lbolt);
188 wakeup((caddr_t)&lbolt_syncer);
189 callout_reset(&schedcpu_callout, hz, schedcpu, NULL);
190}
191
192/*
193 * General process statistics once a second
194 */
195static int
196schedcpu_stats(struct proc *p, void *data __unused)
197{
08f2f1bb
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198 struct lwp *lp;
199
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200 crit_enter();
201 p->p_swtime++;
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202 FOREACH_LWP_IN_PROC(lp, p) {
203 if (lp->lwp_stat == LSSLEEP)
204 lp->lwp_slptime++;
4b5f931b 205
c7e98b2f
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206 /*
207 * Only recalculate processes that are active or have slept
208 * less then 2 seconds. The schedulers understand this.
209 */
210 if (lp->lwp_slptime <= 1) {
211 p->p_usched->recalculate(lp);
212 } else {
213 lp->lwp_pctcpu = (lp->lwp_pctcpu * ccpu) >> FSHIFT;
214 }
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215 }
216 crit_exit();
217 return(0);
218}
a46fac56 219
8fa76237 220/*
84204577 221 * Resource checks. XXX break out since ksignal/killproc can block,
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222 * limiting us to one process killed per second. There is probably
223 * a better way.
224 */
225static int
226schedcpu_resource(struct proc *p, void *data __unused)
227{
228 u_int64_t ttime;
08f2f1bb 229 struct lwp *lp;
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230
231 crit_enter();
232 if (p->p_stat == SIDL ||
416d05d7 233 p->p_stat == SZOMB ||
c7e98b2f 234 p->p_limit == NULL
8fa76237 235 ) {
e43a034f 236 crit_exit();
8fa76237 237 return(0);
984263bc 238 }
344ad853 239
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240 ttime = 0;
241 FOREACH_LWP_IN_PROC(lp, p) {
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242 /*
243 * We may have caught an lp in the middle of being
244 * created, lwp_thread can be NULL.
245 */
246 if (lp->lwp_thread) {
247 ttime += lp->lwp_thread->td_sticks;
248 ttime += lp->lwp_thread->td_uticks;
249 }
c7e98b2f 250 }
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251
252 switch(plimit_testcpulimit(p->p_limit, ttime)) {
253 case PLIMIT_TESTCPU_KILL:
254 killproc(p, "exceeded maximum CPU limit");
255 break;
256 case PLIMIT_TESTCPU_XCPU:
257 if ((p->p_flag & P_XCPU) == 0) {
258 p->p_flag |= P_XCPU;
84204577 259 ksignal(p, SIGXCPU);
344ad853 260 }
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261 break;
262 default:
c0b8a06d 263 break;
344ad853 264 }
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265 crit_exit();
266 return(0);
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267}
268
269/*
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270 * This is only used by ps. Generate a cpu percentage use over
271 * a period of one second.
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272 *
273 * MPSAFE
984263bc 274 */
dcc99b62 275void
553ea3c8 276updatepcpu(struct lwp *lp, int cpticks, int ttlticks)
984263bc 277{
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278 fixpt_t acc;
279 int remticks;
280
281 acc = (cpticks << FSHIFT) / ttlticks;
282 if (ttlticks >= ESTCPUFREQ) {
553ea3c8 283 lp->lwp_pctcpu = acc;
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284 } else {
285 remticks = ESTCPUFREQ - ttlticks;
553ea3c8 286 lp->lwp_pctcpu = (acc * ttlticks + lp->lwp_pctcpu * remticks) /
dcc99b62 287 ESTCPUFREQ;
a46fac56 288 }
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289}
290
291/*
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292 * tsleep/wakeup hash table parameters. Try to find the sweet spot for
293 * like addresses being slept on.
984263bc 294 */
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295#define TABLESIZE 1024
296#define LOOKUP(x) (((intptr_t)(x) >> 6) & (TABLESIZE - 1))
984263bc 297
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298static cpumask_t slpque_cpumasks[TABLESIZE];
299
984263bc 300/*
a46fac56 301 * General scheduler initialization. We force a reschedule 25 times
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302 * a second by default. Note that cpu0 is initialized in early boot and
303 * cannot make any high level calls.
304 *
305 * Each cpu has its own sleep queue.
984263bc 306 */
984263bc 307void
fc17ad60 308sleep_gdinit(globaldata_t gd)
984263bc 309{
fc17ad60 310 static struct tslpque slpque_cpu0[TABLESIZE];
9c1fad94 311 int i;
984263bc 312
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313 if (gd->gd_cpuid == 0) {
314 sched_quantum = (hz + 24) / 25;
315 hogticks = 2 * sched_quantum;
316
317 gd->gd_tsleep_hash = slpque_cpu0;
318 } else {
77652cad 319 gd->gd_tsleep_hash = kmalloc(sizeof(slpque_cpu0),
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320 M_TSLEEP, M_WAITOK | M_ZERO);
321 }
322 for (i = 0; i < TABLESIZE; ++i)
323 TAILQ_INIT(&gd->gd_tsleep_hash[i]);
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324}
325
326/*
327 * General sleep call. Suspends the current process until a wakeup is
328 * performed on the specified identifier. The process will then be made
329 * runnable with the specified priority. Sleeps at most timo/hz seconds
377d4740 330 * (0 means no timeout). If flags includes PCATCH flag, signals are checked
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331 * before and after sleeping, else signals are not checked. Returns 0 if
332 * awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a
333 * signal needs to be delivered, ERESTART is returned if the current system
334 * call should be restarted if possible, and EINTR is returned if the system
335 * call should be interrupted by the signal (return EINTR).
26a0694b 336 *
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337 * Note that if we are a process, we release_curproc() before messing with
338 * the LWKT scheduler.
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339 *
340 * During autoconfiguration or after a panic, a sleep will simply
341 * lower the priority briefly to allow interrupts, then return.
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342 */
343int
6656cd91 344tsleep(void *ident, int flags, const char *wmesg, int timo)
984263bc 345{
dadab5e9 346 struct thread *td = curthread;
08f2f1bb 347 struct lwp *lp = td->td_lwp;
0cfcada1 348 struct proc *p = td->td_proc; /* may be NULL */
fc17ad60 349 globaldata_t gd;
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350 int sig;
351 int catch;
352 int id;
353 int error;
e43a034f 354 int oldpri;
076fecef 355 struct callout thandle;
984263bc 356
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357 /*
358 * NOTE: removed KTRPOINT, it could cause races due to blocking
359 * even in stable. Just scrap it for now.
360 */
dbcd0c9b 361 if (tsleep_now_works == 0 || panicstr) {
984263bc 362 /*
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363 * After a panic, or before we actually have an operational
364 * softclock, just give interrupts a chance, then just return;
365 *
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366 * don't run any other procs or panic below,
367 * in case this is the idle process and already asleep.
368 */
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369 splz();
370 oldpri = td->td_pri & TDPRI_MASK;
371 lwkt_setpri_self(safepri);
372 lwkt_switch();
373 lwkt_setpri_self(oldpri);
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374 return (0);
375 }
8aa3430c 376 logtsleep2(tsleep_beg, ident);
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377 gd = td->td_gd;
378 KKASSERT(td != &gd->gd_idlethread); /* you must be kidding! */
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379
380 /*
381 * NOTE: all of this occurs on the current cpu, including any
382 * callout-based wakeups, so a critical section is a sufficient
383 * interlock.
384 *
385 * The entire sequence through to where we actually sleep must
386 * run without breaking the critical section.
387 */
388 id = LOOKUP(ident);
389 catch = flags & PCATCH;
390 error = 0;
391 sig = 0;
392
37af14fe 393 crit_enter_quick(td);
344ad853 394
0cfcada1 395 KASSERT(ident != NULL, ("tsleep: no ident"));
7278a846
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396 KASSERT(lp == NULL ||
397 lp->lwp_stat == LSRUN || /* Obvious */
398 lp->lwp_stat == LSSTOP, /* Set in tstop */
399 ("tsleep %p %s %d",
400 ident, wmesg, lp->lwp_stat));
0cfcada1 401
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402 /*
403 * Setup for the current process (if this is a process).
404 */
08f2f1bb 405 if (lp) {
344ad853
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406 if (catch) {
407 /*
408 * Early termination if PCATCH was set and a
409 * signal is pending, interlocked with the
410 * critical section.
411 *
412 * Early termination only occurs when tsleep() is
164b8401 413 * entered while in a normal LSRUN state.
344ad853 414 */
08f2f1bb 415 if ((sig = CURSIG(lp)) != 0)
344ad853
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416 goto resume;
417
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418 /*
419 * Early termination if PCATCH was set and a
420 * mailbox signal was possibly delivered prior to
421 * the system call even being made, in order to
422 * allow the user to interlock without having to
423 * make additional system calls.
424 */
425 if (p->p_flag & P_MAILBOX)
426 goto resume;
427
344ad853 428 /*
84204577 429 * Causes ksignal to wake us up when.
344ad853 430 */
9a379a4a 431 lp->lwp_flag |= LWP_SINTR;
344ad853
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432 }
433
434 /*
435 * Make sure the current process has been untangled from
436 * the userland scheduler and initialize slptime to start
437 * counting.
438 */
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439 if (flags & PNORESCHED)
440 td->td_flags |= TDF_NORESCHED;
08f2f1bb
SS
441 p->p_usched->release_curproc(lp);
442 lp->lwp_slptime = 0;
0a3f9b47 443 }
fc17ad60
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444
445 /*
344ad853 446 * Move our thread to the correct queue and setup our wchan, etc.
fc17ad60 447 */
37af14fe 448 lwkt_deschedule_self(td);
344ad853 449 td->td_flags |= TDF_TSLEEPQ;
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450 TAILQ_INSERT_TAIL(&gd->gd_tsleep_hash[id], td, td_threadq);
451 atomic_set_int(&slpque_cpumasks[id], gd->gd_cpumask);
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452
453 td->td_wchan = ident;
454 td->td_wmesg = wmesg;
455 td->td_wdomain = flags & PDOMAIN_MASK;
456
457 /*
458 * Setup the timeout, if any
459 */
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460 if (timo) {
461 callout_init(&thandle);
462 callout_reset(&thandle, timo, endtsleep, td);
463 }
344ad853 464
984263bc 465 /*
344ad853 466 * Beddy bye bye.
984263bc 467 */
08f2f1bb 468 if (lp) {
26a0694b 469 /*
52eedfb5 470 * Ok, we are sleeping. Place us in the SSLEEP state.
26a0694b 471 */
9388413d 472 KKASSERT((lp->lwp_flag & LWP_ONRUNQ) == 0);
7278a846
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473 /*
474 * tstop() sets LSSTOP, so don't fiddle with that.
475 */
476 if (lp->lwp_stat != LSSTOP)
477 lp->lwp_stat = LSSLEEP;
08f2f1bb 478 lp->lwp_ru.ru_nvcsw++;
344ad853 479 lwkt_switch();
ab554892
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480
481 /*
164b8401 482 * And when we are woken up, put us back in LSRUN. If we
ab554892
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483 * slept for over a second, recalculate our estcpu.
484 */
164b8401 485 lp->lwp_stat = LSRUN;
08f2f1bb
SS
486 if (lp->lwp_slptime)
487 p->p_usched->recalculate(lp);
488 lp->lwp_slptime = 0;
0cfcada1
MD
489 } else {
490 lwkt_switch();
491 }
344ad853 492
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493 /*
494 * Make sure we haven't switched cpus while we were asleep. It's
344ad853 495 * not supposed to happen. Cleanup our temporary flags.
fc17ad60
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496 */
497 KKASSERT(gd == td->td_gd);
0a3f9b47 498 td->td_flags &= ~TDF_NORESCHED;
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499
500 /*
501 * Cleanup the timeout.
502 */
503 if (timo) {
504 if (td->td_flags & TDF_TIMEOUT) {
505 td->td_flags &= ~TDF_TIMEOUT;
a40da8f0 506 error = EWOULDBLOCK;
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507 } else {
508 callout_stop(&thandle);
509 }
0cfcada1 510 }
344ad853
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511
512 /*
513 * Since td_threadq is used both for our run queue AND for the
514 * tsleep hash queue, we can't still be on it at this point because
515 * we've gotten cpu back.
516 */
afbfc034 517 KASSERT((td->td_flags & TDF_TSLEEPQ) == 0, ("tsleep: impossible thread flags %08x", td->td_flags));
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518 td->td_wchan = NULL;
519 td->td_wmesg = NULL;
520 td->td_wdomain = 0;
521
522 /*
7c1212ec
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523 * Figure out the correct error return. If interrupted by a
524 * signal we want to return EINTR or ERESTART.
525 *
526 * If P_MAILBOX is set no automatic system call restart occurs
527 * and we return EINTR. P_MAILBOX is meant to be used as an
528 * interlock, the user must poll it prior to any system call
529 * that it wishes to interlock a mailbox signal against since
530 * the flag is cleared on *any* system call that sleeps.
344ad853
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531 */
532resume:
0cfcada1 533 if (p) {
7c1212ec
MD
534 if (catch && error == 0) {
535 if ((p->p_flag & P_MAILBOX) && sig == 0) {
344ad853 536 error = EINTR;
08f2f1bb 537 } else if (sig != 0 || (sig = CURSIG(lp))) {
7c1212ec
MD
538 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
539 error = EINTR;
540 else
541 error = ERESTART;
542 }
984263bc 543 }
9a379a4a
SS
544 lp->lwp_flag &= ~(LWP_BREAKTSLEEP | LWP_SINTR);
545 p->p_flag &= ~P_MAILBOX;
984263bc 546 }
8aa3430c 547 logtsleep1(tsleep_end);
344ad853
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548 crit_exit_quick(td);
549 return (error);
984263bc
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550}
551
16523a43
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552/*
553 * This is a dandy function that allows us to interlock tsleep/wakeup
554 * operations with unspecified upper level locks, such as lockmgr locks,
555 * simply by holding a critical section. The sequence is:
556 *
557 * (enter critical section)
558 * (acquire upper level lock)
559 * tsleep_interlock(blah)
560 * (release upper level lock)
561 * tsleep(blah, ...)
562 * (exit critical section)
563 *
564 * Basically this function sets our cpumask for the ident which informs
565 * other cpus that our cpu 'might' be waiting (or about to wait on) the
566 * hash index related to the ident. The critical section prevents another
567 * cpu's wakeup() from being processed on our cpu until we are actually
568 * able to enter the tsleep(). Thus, no race occurs between our attempt
569 * to release a resource and sleep, and another cpu's attempt to acquire
570 * a resource and call wakeup.
571 *
572 * There isn't much of a point to this function unless you call it while
573 * holding a critical section.
574 */
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575static __inline void
576_tsleep_interlock(globaldata_t gd, void *ident)
577{
578 int id = LOOKUP(ident);
579
580 atomic_set_int(&slpque_cpumasks[id], gd->gd_cpumask);
581}
582
16523a43
MD
583void
584tsleep_interlock(void *ident)
585{
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MD
586 _tsleep_interlock(mycpu, ident);
587}
588
589/*
590 * Interlocked spinlock sleep. An exclusively held spinlock must
591 * be passed to msleep(). The function will atomically release the
592 * spinlock and tsleep on the ident, then reacquire the spinlock and
593 * return.
594 *
595 * This routine is fairly important along the critical path, so optimize it
596 * heavily.
597 */
598int
599msleep(void *ident, struct spinlock *spin, int flags,
600 const char *wmesg, int timo)
601{
602 globaldata_t gd = mycpu;
603 int error;
16523a43 604
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605 crit_enter_gd(gd);
606 _tsleep_interlock(gd, ident);
607 spin_unlock_wr_quick(gd, spin);
608 error = tsleep(ident, flags, wmesg, timo);
609 spin_lock_wr_quick(gd, spin);
610 crit_exit_gd(gd);
611
612 return (error);
16523a43
MD
613}
614
a22c590e
MD
615/*
616 * Directly block on the LWKT thread by descheduling it. This
617 * is much faster then tsleep(), but the only legal way to wake
618 * us up is to directly schedule the thread.
619 *
620 * Setting TDF_SINTR will cause new signals to directly schedule us.
621 *
622 * This routine is typically called while in a critical section.
623 */
624int
625lwkt_sleep(const char *wmesg, int flags)
626{
627 thread_t td = curthread;
628 int sig;
629
630 if ((flags & PCATCH) == 0 || td->td_lwp == NULL) {
631 td->td_flags |= TDF_BLOCKED;
632 td->td_wmesg = wmesg;
633 lwkt_deschedule_self(td);
634 lwkt_switch();
635 td->td_wmesg = NULL;
636 td->td_flags &= ~TDF_BLOCKED;
637 return(0);
638 }
639 if ((sig = CURSIG(td->td_lwp)) != 0) {
640 if (SIGISMEMBER(td->td_proc->p_sigacts->ps_sigintr, sig))
641 return(EINTR);
642 else
643 return(ERESTART);
644
645 }
646 td->td_flags |= TDF_BLOCKED | TDF_SINTR;
647 td->td_wmesg = wmesg;
648 lwkt_deschedule_self(td);
649 lwkt_switch();
650 td->td_flags &= ~(TDF_BLOCKED | TDF_SINTR);
651 td->td_wmesg = NULL;
652 return(0);
653}
654
984263bc 655/*
344ad853 656 * Implement the timeout for tsleep.
fc17ad60 657 *
9a379a4a 658 * We set LWP_BREAKTSLEEP to indicate that an event has occured, but
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MD
659 * we only call setrunnable if the process is not stopped.
660 *
661 * This type of callout timeout is scheduled on the same cpu the process
662 * is sleeping on. Also, at the moment, the MP lock is held.
984263bc
MD
663 */
664static void
0cfcada1 665endtsleep(void *arg)
984263bc 666{
0cfcada1 667 thread_t td = arg;
9a379a4a 668 struct lwp *lp;
984263bc 669
344ad853 670 ASSERT_MP_LOCK_HELD(curthread);
37af14fe 671 crit_enter();
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672
673 /*
674 * cpu interlock. Thread flags are only manipulated on
675 * the cpu owning the thread. proc flags are only manipulated
676 * by the older of the MP lock. We have both.
677 */
678 if (td->td_flags & TDF_TSLEEPQ) {
0cfcada1 679 td->td_flags |= TDF_TIMEOUT;
344ad853 680
9a379a4a
SS
681 if ((lp = td->td_lwp) != NULL) {
682 lp->lwp_flag |= LWP_BREAKTSLEEP;
683 if (lp->lwp_proc->p_stat != SSTOP)
684 setrunnable(lp);
0cfcada1 685 } else {
344ad853 686 unsleep_and_wakeup_thread(td);
0cfcada1 687 }
984263bc 688 }
37af14fe 689 crit_exit();
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MD
690}
691
984263bc 692/*
344ad853
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693 * Unsleep and wakeup a thread. This function runs without the MP lock
694 * which means that it can only manipulate thread state on the owning cpu,
695 * and cannot touch the process state at all.
984263bc 696 */
344ad853 697static
8fb8bca6 698void
344ad853 699unsleep_and_wakeup_thread(struct thread *td)
8fb8bca6 700{
344ad853 701 globaldata_t gd = mycpu;
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702 int id;
703
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704#ifdef SMP
705 if (td->td_gd != gd) {
706 lwkt_send_ipiq(td->td_gd, (ipifunc1_t)unsleep_and_wakeup_thread, td);
707 return;
708 }
709#endif
9c1fad94 710 crit_enter();
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711 if (td->td_flags & TDF_TSLEEPQ) {
712 td->td_flags &= ~TDF_TSLEEPQ;
713 id = LOOKUP(td->td_wchan);
714 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_threadq);
715 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL)
716 atomic_clear_int(&slpque_cpumasks[id], gd->gd_cpumask);
717 lwkt_schedule(td);
8fb8bca6 718 }
9c1fad94 719 crit_exit();
8fb8bca6 720}
8fb8bca6
EN
721
722/*
723 * Make all processes sleeping on the specified identifier runnable.
fc17ad60
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724 * count may be zero or one only.
725 *
726 * The domain encodes the sleep/wakeup domain AND the first cpu to check
727 * (which is always the current cpu). As we iterate across cpus
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728 *
729 * This call may run without the MP lock held. We can only manipulate thread
730 * state on the cpu owning the thread. We CANNOT manipulate process state
731 * at all.
8fb8bca6
EN
732 */
733static void
fc17ad60 734_wakeup(void *ident, int domain)
984263bc 735{
fc17ad60 736 struct tslpque *qp;
0cfcada1
MD
737 struct thread *td;
738 struct thread *ntd;
fc17ad60 739 globaldata_t gd;
fc17ad60
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740#ifdef SMP
741 cpumask_t mask;
742 cpumask_t tmask;
743 int startcpu;
744 int nextcpu;
745#endif
746 int id;
984263bc 747
37af14fe 748 crit_enter();
8aa3430c 749 logtsleep2(wakeup_beg, ident);
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MD
750 gd = mycpu;
751 id = LOOKUP(ident);
752 qp = &gd->gd_tsleep_hash[id];
984263bc 753restart:
0cfcada1
MD
754 for (td = TAILQ_FIRST(qp); td != NULL; td = ntd) {
755 ntd = TAILQ_NEXT(td, td_threadq);
fc17ad60
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756 if (td->td_wchan == ident &&
757 td->td_wdomain == (domain & PDOMAIN_MASK)
758 ) {
344ad853
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759 KKASSERT(td->td_flags & TDF_TSLEEPQ);
760 td->td_flags &= ~TDF_TSLEEPQ;
0cfcada1 761 TAILQ_REMOVE(qp, td, td_threadq);
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MD
762 if (TAILQ_FIRST(qp) == NULL) {
763 atomic_clear_int(&slpque_cpumasks[id],
764 gd->gd_cpumask);
765 }
344ad853 766 lwkt_schedule(td);
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MD
767 if (domain & PWAKEUP_ONE)
768 goto done;
0cfcada1 769 goto restart;
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770 }
771 }
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MD
772
773#ifdef SMP
774 /*
775 * We finished checking the current cpu but there still may be
776 * more work to do. Either wakeup_one was requested and no matching
777 * thread was found, or a normal wakeup was requested and we have
778 * to continue checking cpus.
779 *
780 * The cpu that started the wakeup sequence is encoded in the domain.
781 * We use this information to determine which cpus still need to be
782 * checked, locate a candidate cpu, and chain the wakeup
783 * asynchronously with an IPI message.
784 *
785 * It should be noted that this scheme is actually less expensive then
786 * the old scheme when waking up multiple threads, since we send
787 * only one IPI message per target candidate which may then schedule
788 * multiple threads. Before we could have wound up sending an IPI
789 * message for each thread on the target cpu (!= current cpu) that
790 * needed to be woken up.
791 *
792 * NOTE: Wakeups occuring on remote cpus are asynchronous. This
793 * should be ok since we are passing idents in the IPI rather then
794 * thread pointers.
795 */
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MD
796 if ((domain & PWAKEUP_MYCPU) == 0 &&
797 (mask = slpque_cpumasks[id]) != 0
798 ) {
fc17ad60
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799 /*
800 * Look for a cpu that might have work to do. Mask out cpus
801 * which have already been processed.
802 *
803 * 31xxxxxxxxxxxxxxxxxxxxxxxxxxxxx0
804 * ^ ^ ^
805 * start currentcpu start
806 * case2 case1
807 * * * *
808 * 11111111111111110000000000000111 case1
809 * 00000000111111110000000000000000 case2
810 *
811 * case1: We started at start_case1 and processed through
812 * to the current cpu. We have to check any bits
813 * after the current cpu, then check bits before
814 * the starting cpu.
815 *
816 * case2: We have already checked all the bits from
817 * start_case2 to the end, and from 0 to the current
818 * cpu. We just have the bits from the current cpu
819 * to start_case2 left to check.
820 */
821 startcpu = PWAKEUP_DECODE(domain);
822 if (gd->gd_cpuid >= startcpu) {
823 /*
824 * CASE1
825 */
826 tmask = mask & ~((gd->gd_cpumask << 1) - 1);
827 if (mask & tmask) {
828 nextcpu = bsfl(mask & tmask);
829 lwkt_send_ipiq2(globaldata_find(nextcpu),
830 _wakeup, ident, domain);
831 } else {
832 tmask = (1 << startcpu) - 1;
833 if (mask & tmask) {
834 nextcpu = bsfl(mask & tmask);
835 lwkt_send_ipiq2(
836 globaldata_find(nextcpu),
837 _wakeup, ident, domain);
838 }
839 }
840 } else {
841 /*
842 * CASE2
843 */
844 tmask = ~((gd->gd_cpumask << 1) - 1) &
845 ((1 << startcpu) - 1);
846 if (mask & tmask) {
847 nextcpu = bsfl(mask & tmask);
848 lwkt_send_ipiq2(globaldata_find(nextcpu),
849 _wakeup, ident, domain);
850 }
851 }
852 }
853#endif
854done:
8aa3430c 855 logtsleep1(wakeup_end);
37af14fe 856 crit_exit();
984263bc
MD
857}
858
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MD
859/*
860 * Wakeup all threads tsleep()ing on the specified ident, on all cpus
861 */
984263bc 862void
0cfcada1 863wakeup(void *ident)
984263bc 864{
fc17ad60 865 _wakeup(ident, PWAKEUP_ENCODE(0, mycpu->gd_cpuid));
0cfcada1 866}
984263bc 867
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MD
868/*
869 * Wakeup one thread tsleep()ing on the specified ident, on any cpu.
870 */
0cfcada1
MD
871void
872wakeup_one(void *ident)
873{
fc17ad60
MD
874 /* XXX potentially round-robin the first responding cpu */
875 _wakeup(ident, PWAKEUP_ENCODE(0, mycpu->gd_cpuid) | PWAKEUP_ONE);
da5fb9ef
MD
876}
877
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878/*
879 * Wakeup threads tsleep()ing on the specified ident on the current cpu
880 * only.
881 */
882void
883wakeup_mycpu(void *ident)
884{
885 _wakeup(ident, PWAKEUP_MYCPU);
886}
887
888/*
889 * Wakeup one thread tsleep()ing on the specified ident on the current cpu
890 * only.
891 */
892void
893wakeup_mycpu_one(void *ident)
894{
895 /* XXX potentially round-robin the first responding cpu */
896 _wakeup(ident, PWAKEUP_MYCPU|PWAKEUP_ONE);
897}
898
899/*
900 * Wakeup all thread tsleep()ing on the specified ident on the specified cpu
901 * only.
902 */
903void
904wakeup_oncpu(globaldata_t gd, void *ident)
905{
1699d292 906#ifdef SMP
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MD
907 if (gd == mycpu) {
908 _wakeup(ident, PWAKEUP_MYCPU);
909 } else {
910 lwkt_send_ipiq2(gd, _wakeup, ident, PWAKEUP_MYCPU);
911 }
1699d292
MD
912#else
913 _wakeup(ident, PWAKEUP_MYCPU);
914#endif
b336a9b1
MD
915}
916
917/*
918 * Wakeup one thread tsleep()ing on the specified ident on the specified cpu
919 * only.
920 */
921void
922wakeup_oncpu_one(globaldata_t gd, void *ident)
923{
1699d292 924#ifdef SMP
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MD
925 if (gd == mycpu) {
926 _wakeup(ident, PWAKEUP_MYCPU | PWAKEUP_ONE);
927 } else {
928 lwkt_send_ipiq2(gd, _wakeup, ident, PWAKEUP_MYCPU | PWAKEUP_ONE);
929 }
1699d292
MD
930#else
931 _wakeup(ident, PWAKEUP_MYCPU | PWAKEUP_ONE);
932#endif
b336a9b1
MD
933}
934
935/*
936 * Wakeup all threads waiting on the specified ident that slept using
937 * the specified domain, on all cpus.
938 */
da5fb9ef
MD
939void
940wakeup_domain(void *ident, int domain)
941{
fc17ad60 942 _wakeup(ident, PWAKEUP_ENCODE(domain, mycpu->gd_cpuid));
da5fb9ef
MD
943}
944
b336a9b1
MD
945/*
946 * Wakeup one thread waiting on the specified ident that slept using
947 * the specified domain, on any cpu.
948 */
da5fb9ef
MD
949void
950wakeup_domain_one(void *ident, int domain)
951{
fc17ad60
MD
952 /* XXX potentially round-robin the first responding cpu */
953 _wakeup(ident, PWAKEUP_ENCODE(domain, mycpu->gd_cpuid) | PWAKEUP_ONE);
984263bc
MD
954}
955
956/*
344ad853
MD
957 * setrunnable()
958 *
959 * Make a process runnable. The MP lock must be held on call. This only
960 * has an effect if we are in SSLEEP. We only break out of the
9a379a4a 961 * tsleep if LWP_BREAKTSLEEP is set, otherwise we just fix-up the state.
37af14fe 962 *
344ad853
MD
963 * NOTE: With the MP lock held we can only safely manipulate the process
964 * structure. We cannot safely manipulate the thread structure.
984263bc
MD
965 */
966void
9a379a4a 967setrunnable(struct lwp *lp)
984263bc 968{
344ad853
MD
969 crit_enter();
970 ASSERT_MP_LOCK_HELD(curthread);
2daf83b0
SS
971 if (lp->lwp_stat == LSSTOP)
972 lp->lwp_stat = LSSLEEP;
973 if (lp->lwp_stat == LSSLEEP && (lp->lwp_flag & LWP_BREAKTSLEEP))
08f2f1bb 974 unsleep_and_wakeup_thread(lp->lwp_thread);
344ad853 975 crit_exit();
984263bc
MD
976}
977
978/*
164b8401
SS
979 * The process is stopped due to some condition, usually because p_stat is
980 * set to SSTOP, but also possibly due to being traced.
fc17ad60 981 *
164b8401 982 * NOTE! If the caller sets SSTOP, the caller must also clear P_WAITED
344ad853
MD
983 * because the parent may check the child's status before the child actually
984 * gets to this routine.
985 *
9a379a4a 986 * This routine is called with the current lwp only, typically just
344ad853
MD
987 * before returning to userland.
988 *
9a379a4a 989 * Setting LWP_BREAKTSLEEP before entering the tsleep will cause a passive
344ad853 990 * SIGCONT to break out of the tsleep.
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MD
991 */
992void
9a379a4a 993tstop(void)
984263bc 994{
9a379a4a 995 struct lwp *lp = curthread->td_lwp;
7278a846 996 struct proc *p = lp->lwp_proc;
9a379a4a
SS
997
998 lp->lwp_flag |= LWP_BREAKTSLEEP;
7278a846
SS
999 lp->lwp_stat = LSSTOP;
1000 crit_enter();
f33e8653
SS
1001 /*
1002 * If LWP_WSTOP is set, we were sleeping
1003 * while our process was stopped. At this point
1004 * we were already counted as stopped.
1005 */
1006 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1007 /*
1008 * If we're the last thread to stop, signal
1009 * our parent.
1010 */
1011 p->p_nstopped++;
1012 lp->lwp_flag |= LWP_WSTOP;
1013 if (p->p_nstopped == p->p_nthreads) {
1014 p->p_flag &= ~P_WAITED;
1015 wakeup(p->p_pptr);
1016 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1017 ksignal(p->p_pptr, SIGCHLD);
1018 }
1019 }
9a379a4a 1020 tsleep(lp->lwp_proc, 0, "stop", 0);
7278a846 1021 p->p_nstopped--;
a5ff9d37 1022 lp->lwp_flag &= ~LWP_WSTOP;
7278a846 1023 crit_exit();
26a0694b
MD
1024}
1025
a77ac49d
MD
1026/*
1027 * Yield / synchronous reschedule. This is a bit tricky because the trap
1028 * code might have set a lazy release on the switch function. Setting
1029 * P_PASSIVE_ACQ will ensure that the lazy release executes when we call
1030 * switch, and that we are given a greater chance of affinity with our
1031 * current cpu.
1032 *
1033 * We call lwkt_setpri_self() to rotate our thread to the end of the lwkt
1034 * run queue. lwkt_switch() will also execute any assigned passive release
1035 * (which usually calls release_curproc()), allowing a same/higher priority
1036 * process to be designated as the current process.
1037 *
1038 * While it is possible for a lower priority process to be designated,
1039 * it's call to lwkt_maybe_switch() in acquire_curproc() will likely
1040 * round-robin back to us and we will be able to re-acquire the current
1041 * process designation.
1042 */
1043void
1044uio_yield(void)
1045{
1046 struct thread *td = curthread;
1047 struct proc *p = td->td_proc;
1048
1049 lwkt_setpri_self(td->td_pri & TDPRI_MASK);
1050 if (p) {
1051 p->p_flag |= P_PASSIVE_ACQ;
1052 lwkt_switch();
1053 p->p_flag &= ~P_PASSIVE_ACQ;
1054 } else {
1055 lwkt_switch();
1056 }
1057}
1058
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1059/*
1060 * Compute a tenex style load average of a quantity on
1061 * 1, 5 and 15 minute intervals.
1062 */
c7e98b2f 1063static int loadav_count_runnable(struct lwp *p, void *data);
8fa76237 1064
984263bc
MD
1065static void
1066loadav(void *arg)
1067{
984263bc 1068 struct loadavg *avg;
8fa76237 1069 int i, nrun;
984263bc 1070
984263bc 1071 nrun = 0;
c7e98b2f 1072 alllwp_scan(loadav_count_runnable, &nrun);
8fa76237
MD
1073 avg = &averunnable;
1074 for (i = 0; i < 3; i++) {
984263bc
MD
1075 avg->ldavg[i] = (cexp[i] * avg->ldavg[i] +
1076 nrun * FSCALE * (FSCALE - cexp[i])) >> FSHIFT;
8fa76237 1077 }
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MD
1078
1079 /*
1080 * Schedule the next update to occur after 5 seconds, but add a
1081 * random variation to avoid synchronisation with processes that
1082 * run at regular intervals.
1083 */
cddfb7bb 1084 callout_reset(&loadav_callout, hz * 4 + (int)(krandom() % (hz * 2 + 1)),
8fa76237
MD
1085 loadav, NULL);
1086}
1087
1088static int
c7e98b2f 1089loadav_count_runnable(struct lwp *lp, void *data)
8fa76237
MD
1090{
1091 int *nrunp = data;
1092 thread_t td;
1093
164b8401
SS
1094 switch (lp->lwp_stat) {
1095 case LSRUN:
08f2f1bb 1096 if ((td = lp->lwp_thread) == NULL)
8fa76237
MD
1097 break;
1098 if (td->td_flags & TDF_BLOCKED)
1099 break;
8fa76237
MD
1100 ++*nrunp;
1101 break;
1102 default:
1103 break;
1104 }
1105 return(0);
984263bc
MD
1106}
1107
1108/* ARGSUSED */
1109static void
6656cd91 1110sched_setup(void *dummy)
984263bc 1111{
984263bc 1112 callout_init(&loadav_callout);
35f9d051 1113 callout_init(&schedcpu_callout);
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MD
1114
1115 /* Kick off timeout driven events by calling first time. */
984263bc
MD
1116 schedcpu(NULL);
1117 loadav(NULL);
1118}
1119