Allow the kernel to be compile without KTRACE option.
[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>
3185a7fd 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>
684a93c4 66#include <sys/mplock2.h>
bf765287 67
984263bc 68#include <machine/cpu.h>
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69#include <machine/smp.h>
70
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71TAILQ_HEAD(tslpque, thread);
72
402ed7e1 73static void sched_setup (void *dummy);
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74SYSINIT(sched_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, sched_setup, NULL)
75
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76int hogticks;
77int lbolt;
344ad853 78int lbolt_syncer;
984263bc 79int sched_quantum; /* Roundrobin scheduling quantum in ticks. */
17a9f566 80int ncpus;
90100055 81int ncpus2, ncpus2_shift, ncpus2_mask;
b45759e1 82int ncpus_fit, ncpus_fit_mask;
e43a034f 83int safepri;
dbcd0c9b 84int tsleep_now_works;
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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);
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120#ifdef SMP
121static void tsleep_wakeup(struct thread *td);
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{
08f2f1bb
SS
206 struct lwp *lp;
207
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208 crit_enter();
209 p->p_swtime++;
c7e98b2f
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210 FOREACH_LWP_IN_PROC(lp, p) {
211 if (lp->lwp_stat == LSSLEEP)
212 lp->lwp_slptime++;
4b5f931b 213
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214 /*
215 * Only recalculate processes that are active or have slept
216 * less then 2 seconds. The schedulers understand this.
217 */
218 if (lp->lwp_slptime <= 1) {
219 p->p_usched->recalculate(lp);
220 } else {
221 lp->lwp_pctcpu = (lp->lwp_pctcpu * ccpu) >> FSHIFT;
222 }
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223 }
224 crit_exit();
225 return(0);
226}
a46fac56 227
8fa76237 228/*
84204577 229 * Resource checks. XXX break out since ksignal/killproc can block,
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230 * limiting us to one process killed per second. There is probably
231 * a better way.
232 */
233static int
234schedcpu_resource(struct proc *p, void *data __unused)
235{
236 u_int64_t ttime;
08f2f1bb 237 struct lwp *lp;
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238
239 crit_enter();
240 if (p->p_stat == SIDL ||
416d05d7 241 p->p_stat == SZOMB ||
c7e98b2f 242 p->p_limit == NULL
8fa76237 243 ) {
e43a034f 244 crit_exit();
8fa76237 245 return(0);
984263bc 246 }
344ad853 247
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248 ttime = 0;
249 FOREACH_LWP_IN_PROC(lp, p) {
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250 /*
251 * We may have caught an lp in the middle of being
252 * created, lwp_thread can be NULL.
253 */
254 if (lp->lwp_thread) {
255 ttime += lp->lwp_thread->td_sticks;
256 ttime += lp->lwp_thread->td_uticks;
257 }
c7e98b2f 258 }
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259
260 switch(plimit_testcpulimit(p->p_limit, ttime)) {
261 case PLIMIT_TESTCPU_KILL:
262 killproc(p, "exceeded maximum CPU limit");
263 break;
264 case PLIMIT_TESTCPU_XCPU:
265 if ((p->p_flag & P_XCPU) == 0) {
266 p->p_flag |= P_XCPU;
84204577 267 ksignal(p, SIGXCPU);
344ad853 268 }
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269 break;
270 default:
c0b8a06d 271 break;
344ad853 272 }
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273 crit_exit();
274 return(0);
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275}
276
277/*
dcc99b62
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278 * This is only used by ps. Generate a cpu percentage use over
279 * a period of one second.
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280 *
281 * MPSAFE
984263bc 282 */
dcc99b62 283void
553ea3c8 284updatepcpu(struct lwp *lp, int cpticks, int ttlticks)
984263bc 285{
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MD
286 fixpt_t acc;
287 int remticks;
288
289 acc = (cpticks << FSHIFT) / ttlticks;
290 if (ttlticks >= ESTCPUFREQ) {
553ea3c8 291 lp->lwp_pctcpu = acc;
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292 } else {
293 remticks = ESTCPUFREQ - ttlticks;
553ea3c8 294 lp->lwp_pctcpu = (acc * ttlticks + lp->lwp_pctcpu * remticks) /
dcc99b62 295 ESTCPUFREQ;
a46fac56 296 }
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297}
298
299/*
8aa3430c
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300 * tsleep/wakeup hash table parameters. Try to find the sweet spot for
301 * like addresses being slept on.
984263bc 302 */
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303#define TABLESIZE 1024
304#define LOOKUP(x) (((intptr_t)(x) >> 6) & (TABLESIZE - 1))
984263bc 305
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306static cpumask_t slpque_cpumasks[TABLESIZE];
307
984263bc 308/*
a46fac56 309 * General scheduler initialization. We force a reschedule 25 times
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310 * a second by default. Note that cpu0 is initialized in early boot and
311 * cannot make any high level calls.
312 *
313 * Each cpu has its own sleep queue.
984263bc 314 */
984263bc 315void
fc17ad60 316sleep_gdinit(globaldata_t gd)
984263bc 317{
fc17ad60 318 static struct tslpque slpque_cpu0[TABLESIZE];
9c1fad94 319 int i;
984263bc 320
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321 if (gd->gd_cpuid == 0) {
322 sched_quantum = (hz + 24) / 25;
323 hogticks = 2 * sched_quantum;
324
325 gd->gd_tsleep_hash = slpque_cpu0;
326 } else {
77652cad 327 gd->gd_tsleep_hash = kmalloc(sizeof(slpque_cpu0),
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328 M_TSLEEP, M_WAITOK | M_ZERO);
329 }
330 for (i = 0; i < TABLESIZE; ++i)
331 TAILQ_INIT(&gd->gd_tsleep_hash[i]);
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332}
333
334/*
ae8e83e6
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335 * This is a dandy function that allows us to interlock tsleep/wakeup
336 * operations with unspecified upper level locks, such as lockmgr locks,
337 * simply by holding a critical section. The sequence is:
338 *
339 * (acquire upper level lock)
340 * tsleep_interlock(blah)
341 * (release upper level lock)
342 * tsleep(blah, ...)
343 *
344 * Basically this functions queues us on the tsleep queue without actually
345 * descheduling us. When tsleep() is later called with PINTERLOCK it
346 * assumes the thread was already queued, otherwise it queues it there.
347 *
348 * Thus it is possible to receive the wakeup prior to going to sleep and
349 * the race conditions are covered.
350 */
351static __inline void
5decebc7 352_tsleep_interlock(globaldata_t gd, const volatile void *ident, int flags)
ae8e83e6
MD
353{
354 thread_t td = gd->gd_curthread;
355 int id;
356
357 crit_enter_quick(td);
358 if (td->td_flags & TDF_TSLEEPQ) {
359 id = LOOKUP(td->td_wchan);
360 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
361 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL)
362 atomic_clear_int(&slpque_cpumasks[id], gd->gd_cpumask);
363 } else {
364 td->td_flags |= TDF_TSLEEPQ;
365 }
366 id = LOOKUP(ident);
367 TAILQ_INSERT_TAIL(&gd->gd_tsleep_hash[id], td, td_sleepq);
368 atomic_set_int(&slpque_cpumasks[id], gd->gd_cpumask);
369 td->td_wchan = ident;
370 td->td_wdomain = flags & PDOMAIN_MASK;
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371 crit_exit_quick(td);
372}
373
374void
5decebc7 375tsleep_interlock(const volatile void *ident, int flags)
ae8e83e6
MD
376{
377 _tsleep_interlock(mycpu, ident, flags);
378}
379
380/*
381 * Remove thread from sleepq. Must be called with a critical section held.
382 */
383static __inline void
384_tsleep_remove(thread_t td)
385{
386 globaldata_t gd = mycpu;
387 int id;
388
389 KKASSERT(td->td_gd == gd);
390 if (td->td_flags & TDF_TSLEEPQ) {
391 td->td_flags &= ~TDF_TSLEEPQ;
392 id = LOOKUP(td->td_wchan);
393 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
394 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL)
395 atomic_clear_int(&slpque_cpumasks[id], gd->gd_cpumask);
396 td->td_wchan = NULL;
397 td->td_wdomain = 0;
398 }
399}
400
401void
402tsleep_remove(thread_t td)
403{
404 _tsleep_remove(td);
405}
406
407/*
408 * This function removes a thread from the tsleep queue and schedules
409 * it. This function may act asynchronously. The target thread may be
410 * sleeping on a different cpu.
411 *
412 * This function mus be called while in a critical section but if the
413 * target thread is sleeping on a different cpu we cannot safely probe
414 * td_flags.
415 */
416static __inline
417void
418_tsleep_wakeup(struct thread *td)
419{
c4e34360 420#ifdef SMP
ae8e83e6
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421 globaldata_t gd = mycpu;
422
ae8e83e6
MD
423 if (td->td_gd != gd) {
424 lwkt_send_ipiq(td->td_gd, (ipifunc1_t)tsleep_wakeup, td);
425 return;
426 }
427#endif
428 _tsleep_remove(td);
429 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
430 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
431 lwkt_schedule(td);
432 }
433}
434
ce4b5045 435#ifdef SMP
ae8e83e6
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436static
437void
438tsleep_wakeup(struct thread *td)
439{
440 _tsleep_wakeup(td);
441}
ce4b5045 442#endif
ae8e83e6
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443
444
445/*
984263bc
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446 * General sleep call. Suspends the current process until a wakeup is
447 * performed on the specified identifier. The process will then be made
448 * runnable with the specified priority. Sleeps at most timo/hz seconds
377d4740 449 * (0 means no timeout). If flags includes PCATCH flag, signals are checked
984263bc
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450 * before and after sleeping, else signals are not checked. Returns 0 if
451 * awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a
452 * signal needs to be delivered, ERESTART is returned if the current system
453 * call should be restarted if possible, and EINTR is returned if the system
454 * call should be interrupted by the signal (return EINTR).
26a0694b 455 *
0a3f9b47
MD
456 * Note that if we are a process, we release_curproc() before messing with
457 * the LWKT scheduler.
a46fac56
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458 *
459 * During autoconfiguration or after a panic, a sleep will simply
460 * lower the priority briefly to allow interrupts, then return.
984263bc
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461 */
462int
5decebc7 463tsleep(const volatile void *ident, int flags, const char *wmesg, int timo)
984263bc 464{
dadab5e9 465 struct thread *td = curthread;
08f2f1bb 466 struct lwp *lp = td->td_lwp;
0cfcada1 467 struct proc *p = td->td_proc; /* may be NULL */
fc17ad60 468 globaldata_t gd;
344ad853
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469 int sig;
470 int catch;
471 int id;
472 int error;
e43a034f 473 int oldpri;
076fecef 474 struct callout thandle;
984263bc 475
0cfcada1
MD
476 /*
477 * NOTE: removed KTRPOINT, it could cause races due to blocking
478 * even in stable. Just scrap it for now.
479 */
dbcd0c9b 480 if (tsleep_now_works == 0 || panicstr) {
984263bc 481 /*
dbcd0c9b
MD
482 * After a panic, or before we actually have an operational
483 * softclock, just give interrupts a chance, then just return;
484 *
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485 * don't run any other procs or panic below,
486 * in case this is the idle process and already asleep.
487 */
e43a034f
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488 splz();
489 oldpri = td->td_pri & TDPRI_MASK;
490 lwkt_setpri_self(safepri);
491 lwkt_switch();
492 lwkt_setpri_self(oldpri);
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493 return (0);
494 }
8aa3430c 495 logtsleep2(tsleep_beg, ident);
fc17ad60
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496 gd = td->td_gd;
497 KKASSERT(td != &gd->gd_idlethread); /* you must be kidding! */
344ad853
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498
499 /*
500 * NOTE: all of this occurs on the current cpu, including any
501 * callout-based wakeups, so a critical section is a sufficient
502 * interlock.
503 *
504 * The entire sequence through to where we actually sleep must
505 * run without breaking the critical section.
506 */
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507 catch = flags & PCATCH;
508 error = 0;
509 sig = 0;
510
37af14fe 511 crit_enter_quick(td);
344ad853 512
0cfcada1 513 KASSERT(ident != NULL, ("tsleep: no ident"));
7278a846
SS
514 KASSERT(lp == NULL ||
515 lp->lwp_stat == LSRUN || /* Obvious */
516 lp->lwp_stat == LSSTOP, /* Set in tstop */
517 ("tsleep %p %s %d",
518 ident, wmesg, lp->lwp_stat));
0cfcada1 519
344ad853
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520 /*
521 * Setup for the current process (if this is a process).
522 */
08f2f1bb 523 if (lp) {
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 /*
7c1212ec
MD
537 * Early termination if PCATCH was set and a
538 * mailbox signal was possibly delivered prior to
539 * the system call even being made, in order to
540 * allow the user to interlock without having to
541 * make additional system calls.
542 */
543 if (p->p_flag & P_MAILBOX)
544 goto resume;
545
546 /*
84204577 547 * Causes ksignal to wake us up when.
344ad853 548 */
9a379a4a 549 lp->lwp_flag |= LWP_SINTR;
344ad853 550 }
4ecd8190 551 }
344ad853 552
4ecd8190
MD
553 /*
554 * We interlock the sleep queue if the caller has not already done
555 * it for us.
556 */
557 if ((flags & PINTERLOCKED) == 0) {
558 id = LOOKUP(ident);
559 _tsleep_interlock(gd, ident, flags);
560 }
561
562 /*
563 *
564 * If no interlock was set we do an integrated interlock here.
565 * Make sure the current process has been untangled from
566 * the userland scheduler and initialize slptime to start
567 * counting. We must interlock the sleep queue before doing
568 * this to avoid wakeup/process-ipi races which can occur under
569 * heavy loads.
570 */
571 if (lp) {
08f2f1bb
SS
572 p->p_usched->release_curproc(lp);
573 lp->lwp_slptime = 0;
0a3f9b47 574 }
fc17ad60
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575
576 /*
d9345d3a
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577 * If the interlocked flag is set but our cpu bit in the slpqueue
578 * is no longer set, then a wakeup was processed inbetween the
4ecd8190
MD
579 * tsleep_interlock() (ours or the callers), and here. This can
580 * occur under numerous circumstances including when we release the
581 * current process.
d9345d3a 582 *
4ecd8190
MD
583 * Extreme loads can cause the sending of an IPI (e.g. wakeup()'s)
584 * to process incoming IPIs, thus draining incoming wakeups.
d9345d3a 585 */
4ecd8190
MD
586 if ((td->td_flags & TDF_TSLEEPQ) == 0) {
587 logtsleep2(ilockfail, ident);
588 goto resume;
d9345d3a 589 }
4ecd8190
MD
590
591 /*
592 * scheduling is blocked while in a critical section. Coincide
593 * the descheduled-by-tsleep flag with the descheduling of the
594 * lwkt.
595 */
37af14fe 596 lwkt_deschedule_self(td);
ae8e83e6 597 td->td_flags |= TDF_TSLEEP_DESCHEDULED;
344ad853 598 td->td_wmesg = wmesg;
344ad853
MD
599
600 /*
601 * Setup the timeout, if any
602 */
076fecef
MD
603 if (timo) {
604 callout_init(&thandle);
605 callout_reset(&thandle, timo, endtsleep, td);
606 }
344ad853 607
984263bc 608 /*
344ad853 609 * Beddy bye bye.
984263bc 610 */
08f2f1bb 611 if (lp) {
26a0694b 612 /*
52eedfb5 613 * Ok, we are sleeping. Place us in the SSLEEP state.
26a0694b 614 */
9388413d 615 KKASSERT((lp->lwp_flag & LWP_ONRUNQ) == 0);
7278a846
SS
616 /*
617 * tstop() sets LSSTOP, so don't fiddle with that.
618 */
619 if (lp->lwp_stat != LSSTOP)
620 lp->lwp_stat = LSSLEEP;
08f2f1bb 621 lp->lwp_ru.ru_nvcsw++;
344ad853 622 lwkt_switch();
ab554892
MD
623
624 /*
164b8401 625 * And when we are woken up, put us back in LSRUN. If we
ab554892
MD
626 * slept for over a second, recalculate our estcpu.
627 */
164b8401 628 lp->lwp_stat = LSRUN;
08f2f1bb
SS
629 if (lp->lwp_slptime)
630 p->p_usched->recalculate(lp);
631 lp->lwp_slptime = 0;
0cfcada1
MD
632 } else {
633 lwkt_switch();
634 }
344ad853 635
fc17ad60
MD
636 /*
637 * Make sure we haven't switched cpus while we were asleep. It's
344ad853 638 * not supposed to happen. Cleanup our temporary flags.
fc17ad60
MD
639 */
640 KKASSERT(gd == td->td_gd);
344ad853
MD
641
642 /*
643 * Cleanup the timeout.
644 */
645 if (timo) {
646 if (td->td_flags & TDF_TIMEOUT) {
647 td->td_flags &= ~TDF_TIMEOUT;
a40da8f0 648 error = EWOULDBLOCK;
344ad853
MD
649 } else {
650 callout_stop(&thandle);
651 }
0cfcada1 652 }
344ad853
MD
653
654 /*
ae8e83e6
MD
655 * Make sure we have been removed from the sleepq. This should
656 * have been done for us already.
344ad853 657 */
ae8e83e6 658 _tsleep_remove(td);
344ad853 659 td->td_wmesg = NULL;
ae8e83e6
MD
660 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
661 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
662 kprintf("td %p (%s) unexpectedly rescheduled\n",
663 td, td->td_comm);
664 }
344ad853
MD
665
666 /*
7c1212ec
MD
667 * Figure out the correct error return. If interrupted by a
668 * signal we want to return EINTR or ERESTART.
669 *
670 * If P_MAILBOX is set no automatic system call restart occurs
671 * and we return EINTR. P_MAILBOX is meant to be used as an
672 * interlock, the user must poll it prior to any system call
673 * that it wishes to interlock a mailbox signal against since
674 * the flag is cleared on *any* system call that sleeps.
344ad853
MD
675 */
676resume:
0cfcada1 677 if (p) {
7c1212ec
MD
678 if (catch && error == 0) {
679 if ((p->p_flag & P_MAILBOX) && sig == 0) {
344ad853 680 error = EINTR;
08f2f1bb 681 } else if (sig != 0 || (sig = CURSIG(lp))) {
7c1212ec
MD
682 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
683 error = EINTR;
684 else
685 error = ERESTART;
686 }
984263bc 687 }
9a379a4a
SS
688 lp->lwp_flag &= ~(LWP_BREAKTSLEEP | LWP_SINTR);
689 p->p_flag &= ~P_MAILBOX;
984263bc 690 }
8aa3430c 691 logtsleep1(tsleep_end);
344ad853
MD
692 crit_exit_quick(td);
693 return (error);
984263bc
MD
694}
695
984263bc 696/*
bf765287 697 * Interlocked spinlock sleep. An exclusively held spinlock must
e590ee86 698 * be passed to ssleep(). The function will atomically release the
bf765287
MD
699 * spinlock and tsleep on the ident, then reacquire the spinlock and
700 * return.
701 *
702 * This routine is fairly important along the critical path, so optimize it
703 * heavily.
704 */
705int
5decebc7 706ssleep(const volatile void *ident, struct spinlock *spin, int flags,
bf765287
MD
707 const char *wmesg, int timo)
708{
709 globaldata_t gd = mycpu;
710 int error;
16523a43 711
ae8e83e6 712 _tsleep_interlock(gd, ident, flags);
bf765287 713 spin_unlock_wr_quick(gd, spin);
ef48be0d 714 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
bf765287 715 spin_lock_wr_quick(gd, spin);
bf765287
MD
716
717 return (error);
16523a43
MD
718}
719
bed060de 720int
5decebc7
MD
721lksleep(const volatile void *ident, struct lock *lock, int flags,
722 const char *wmesg, int timo)
bed060de
AH
723{
724 globaldata_t gd = mycpu;
725 int error;
726
727 _tsleep_interlock(gd, ident, flags);
728 lockmgr(lock, LK_RELEASE);
729 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
730 lockmgr(lock, LK_EXCLUSIVE);
731
732 return (error);
733}
734
16523a43 735/*
7f6220a9
MD
736 * Interlocked mutex sleep. An exclusively held mutex must be passed
737 * to mtxsleep(). The function will atomically release the mutex
738 * and tsleep on the ident, then reacquire the mutex and return.
739 */
740int
5decebc7 741mtxsleep(const volatile void *ident, struct mtx *mtx, int flags,
7f6220a9
MD
742 const char *wmesg, int timo)
743{
744 globaldata_t gd = mycpu;
745 int error;
746
747 _tsleep_interlock(gd, ident, flags);
748 mtx_unlock(mtx);
749 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
750 mtx_lock_ex_quick(mtx, wmesg);
751
752 return (error);
753}
754
755/*
362e59be 756 * Interlocked serializer sleep. An exclusively held serializer must
ed3f6624 757 * be passed to zsleep(). The function will atomically release
362e59be
SZ
758 * the serializer and tsleep on the ident, then reacquire the serializer
759 * and return.
760 */
761int
5decebc7 762zsleep(const volatile void *ident, struct lwkt_serialize *slz, int flags,
ed3f6624 763 const char *wmesg, int timo)
362e59be 764{
ae8e83e6 765 globaldata_t gd = mycpu;
362e59be
SZ
766 int ret;
767
768 ASSERT_SERIALIZED(slz);
769
ae8e83e6 770 _tsleep_interlock(gd, ident, flags);
362e59be 771 lwkt_serialize_exit(slz);
ef48be0d 772 ret = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
362e59be 773 lwkt_serialize_enter(slz);
362e59be
SZ
774
775 return ret;
776}
777
778/*
a22c590e
MD
779 * Directly block on the LWKT thread by descheduling it. This
780 * is much faster then tsleep(), but the only legal way to wake
781 * us up is to directly schedule the thread.
782 *
783 * Setting TDF_SINTR will cause new signals to directly schedule us.
784 *
ae8e83e6 785 * This routine must be called while in a critical section.
a22c590e
MD
786 */
787int
788lwkt_sleep(const char *wmesg, int flags)
789{
790 thread_t td = curthread;
791 int sig;
792
793 if ((flags & PCATCH) == 0 || td->td_lwp == NULL) {
794 td->td_flags |= TDF_BLOCKED;
795 td->td_wmesg = wmesg;
796 lwkt_deschedule_self(td);
797 lwkt_switch();
798 td->td_wmesg = NULL;
799 td->td_flags &= ~TDF_BLOCKED;
800 return(0);
801 }
802 if ((sig = CURSIG(td->td_lwp)) != 0) {
803 if (SIGISMEMBER(td->td_proc->p_sigacts->ps_sigintr, sig))
804 return(EINTR);
805 else
806 return(ERESTART);
807
808 }
809 td->td_flags |= TDF_BLOCKED | TDF_SINTR;
810 td->td_wmesg = wmesg;
811 lwkt_deschedule_self(td);
812 lwkt_switch();
813 td->td_flags &= ~(TDF_BLOCKED | TDF_SINTR);
814 td->td_wmesg = NULL;
815 return(0);
816}
817
818/*
344ad853 819 * Implement the timeout for tsleep.
fc17ad60 820 *
9a379a4a 821 * We set LWP_BREAKTSLEEP to indicate that an event has occured, but
344ad853
MD
822 * we only call setrunnable if the process is not stopped.
823 *
824 * This type of callout timeout is scheduled on the same cpu the process
825 * is sleeping on. Also, at the moment, the MP lock is held.
984263bc
MD
826 */
827static void
0cfcada1 828endtsleep(void *arg)
984263bc 829{
0cfcada1 830 thread_t td = arg;
9a379a4a 831 struct lwp *lp;
984263bc 832
344ad853 833 ASSERT_MP_LOCK_HELD(curthread);
37af14fe 834 crit_enter();
344ad853
MD
835
836 /*
837 * cpu interlock. Thread flags are only manipulated on
838 * the cpu owning the thread. proc flags are only manipulated
839 * by the older of the MP lock. We have both.
840 */
ae8e83e6 841 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
0cfcada1 842 td->td_flags |= TDF_TIMEOUT;
344ad853 843
9a379a4a
SS
844 if ((lp = td->td_lwp) != NULL) {
845 lp->lwp_flag |= LWP_BREAKTSLEEP;
846 if (lp->lwp_proc->p_stat != SSTOP)
847 setrunnable(lp);
0cfcada1 848 } else {
ae8e83e6 849 _tsleep_wakeup(td);
0cfcada1 850 }
984263bc 851 }
37af14fe 852 crit_exit();
984263bc
MD
853}
854
984263bc 855/*
8fb8bca6 856 * Make all processes sleeping on the specified identifier runnable.
fc17ad60
MD
857 * count may be zero or one only.
858 *
859 * The domain encodes the sleep/wakeup domain AND the first cpu to check
860 * (which is always the current cpu). As we iterate across cpus
344ad853
MD
861 *
862 * This call may run without the MP lock held. We can only manipulate thread
863 * state on the cpu owning the thread. We CANNOT manipulate process state
864 * at all.
5decebc7
MD
865 *
866 * _wakeup() can be passed to an IPI so we can't use (const volatile
867 * void *ident).
8fb8bca6
EN
868 */
869static void
fc17ad60 870_wakeup(void *ident, int domain)
8fb8bca6 871{
fc17ad60 872 struct tslpque *qp;
0cfcada1
MD
873 struct thread *td;
874 struct thread *ntd;
fc17ad60 875 globaldata_t gd;
fc17ad60
MD
876#ifdef SMP
877 cpumask_t mask;
fc17ad60
MD
878#endif
879 int id;
984263bc 880
37af14fe 881 crit_enter();
8aa3430c 882 logtsleep2(wakeup_beg, ident);
fc17ad60
MD
883 gd = mycpu;
884 id = LOOKUP(ident);
885 qp = &gd->gd_tsleep_hash[id];
984263bc 886restart:
0cfcada1 887 for (td = TAILQ_FIRST(qp); td != NULL; td = ntd) {
ae8e83e6 888 ntd = TAILQ_NEXT(td, td_sleepq);
fc17ad60
MD
889 if (td->td_wchan == ident &&
890 td->td_wdomain == (domain & PDOMAIN_MASK)
891 ) {
ae8e83e6
MD
892 KKASSERT(td->td_gd == gd);
893 _tsleep_remove(td);
894 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
895 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
896 lwkt_schedule(td);
897 if (domain & PWAKEUP_ONE)
898 goto done;
fc17ad60 899 }
0cfcada1 900 goto restart;
984263bc
MD
901 }
902 }
fc17ad60
MD
903
904#ifdef SMP
905 /*
906 * We finished checking the current cpu but there still may be
907 * more work to do. Either wakeup_one was requested and no matching
908 * thread was found, or a normal wakeup was requested and we have
909 * to continue checking cpus.
910 *
fc17ad60
MD
911 * It should be noted that this scheme is actually less expensive then
912 * the old scheme when waking up multiple threads, since we send
913 * only one IPI message per target candidate which may then schedule
914 * multiple threads. Before we could have wound up sending an IPI
915 * message for each thread on the target cpu (!= current cpu) that
916 * needed to be woken up.
917 *
918 * NOTE: Wakeups occuring on remote cpus are asynchronous. This
919 * should be ok since we are passing idents in the IPI rather then
920 * thread pointers.
921 */
1f4f6e0b
MD
922 if ((domain & PWAKEUP_MYCPU) == 0 &&
923 (mask = slpque_cpumasks[id] & gd->gd_other_cpus) != 0) {
924 lwkt_send_ipiq2_mask(mask, _wakeup, ident,
925 domain | PWAKEUP_MYCPU);
fc17ad60
MD
926 }
927#endif
928done:
8aa3430c 929 logtsleep1(wakeup_end);
37af14fe 930 crit_exit();
984263bc
MD
931}
932
b336a9b1
MD
933/*
934 * Wakeup all threads tsleep()ing on the specified ident, on all cpus
935 */
984263bc 936void
5decebc7 937wakeup(const volatile void *ident)
984263bc 938{
5decebc7 939 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid));
0cfcada1 940}
984263bc 941
b336a9b1
MD
942/*
943 * Wakeup one thread tsleep()ing on the specified ident, on any cpu.
944 */
0cfcada1 945void
5decebc7 946wakeup_one(const volatile void *ident)
0cfcada1 947{
fc17ad60 948 /* XXX potentially round-robin the first responding cpu */
5decebc7 949 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid) | PWAKEUP_ONE);
da5fb9ef
MD
950}
951
b336a9b1
MD
952/*
953 * Wakeup threads tsleep()ing on the specified ident on the current cpu
954 * only.
955 */
956void
5decebc7 957wakeup_mycpu(const volatile void *ident)
b336a9b1 958{
5decebc7 959 _wakeup(__DEALL(ident), PWAKEUP_MYCPU);
b336a9b1
MD
960}
961
962/*
963 * Wakeup one thread tsleep()ing on the specified ident on the current cpu
964 * only.
965 */
966void
5decebc7 967wakeup_mycpu_one(const volatile void *ident)
b336a9b1
MD
968{
969 /* XXX potentially round-robin the first responding cpu */
5decebc7 970 _wakeup(__DEALL(ident), PWAKEUP_MYCPU|PWAKEUP_ONE);
b336a9b1
MD
971}
972
973/*
974 * Wakeup all thread tsleep()ing on the specified ident on the specified cpu
975 * only.
976 */
977void
5decebc7 978wakeup_oncpu(globaldata_t gd, const volatile void *ident)
b336a9b1 979{
1699d292 980#ifdef SMP
b336a9b1 981 if (gd == mycpu) {
5decebc7 982 _wakeup(__DEALL(ident), PWAKEUP_MYCPU);
b336a9b1 983 } else {
5decebc7 984 lwkt_send_ipiq2(gd, _wakeup, __DEALL(ident), PWAKEUP_MYCPU);
b336a9b1 985 }
1699d292 986#else
8e44b950 987 _wakeup(__DEALL(ident), PWAKEUP_MYCPU);
1699d292 988#endif
b336a9b1
MD
989}
990
991/*
992 * Wakeup one thread tsleep()ing on the specified ident on the specified cpu
993 * only.
994 */
995void
5decebc7 996wakeup_oncpu_one(globaldata_t gd, const volatile void *ident)
b336a9b1 997{
1699d292 998#ifdef SMP
b336a9b1 999 if (gd == mycpu) {
5decebc7 1000 _wakeup(__DEALL(ident), PWAKEUP_MYCPU | PWAKEUP_ONE);
b336a9b1 1001 } else {
5decebc7
MD
1002 lwkt_send_ipiq2(gd, _wakeup, __DEALL(ident),
1003 PWAKEUP_MYCPU | PWAKEUP_ONE);
b336a9b1 1004 }
1699d292 1005#else
8e44b950 1006 _wakeup(__DEALL(ident), PWAKEUP_MYCPU | PWAKEUP_ONE);
1699d292 1007#endif
b336a9b1
MD
1008}
1009
1010/*
1011 * Wakeup all threads waiting on the specified ident that slept using
1012 * the specified domain, on all cpus.
1013 */
da5fb9ef 1014void
5decebc7 1015wakeup_domain(const volatile void *ident, int domain)
da5fb9ef 1016{
5decebc7 1017 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(domain, mycpu->gd_cpuid));
da5fb9ef
MD
1018}
1019
b336a9b1
MD
1020/*
1021 * Wakeup one thread waiting on the specified ident that slept using
1022 * the specified domain, on any cpu.
1023 */
da5fb9ef 1024void
5decebc7 1025wakeup_domain_one(const volatile void *ident, int domain)
da5fb9ef 1026{
fc17ad60 1027 /* XXX potentially round-robin the first responding cpu */
5decebc7
MD
1028 _wakeup(__DEALL(ident),
1029 PWAKEUP_ENCODE(domain, mycpu->gd_cpuid) | PWAKEUP_ONE);
984263bc
MD
1030}
1031
1032/*
344ad853
MD
1033 * setrunnable()
1034 *
1035 * Make a process runnable. The MP lock must be held on call. This only
1036 * has an effect if we are in SSLEEP. We only break out of the
9a379a4a 1037 * tsleep if LWP_BREAKTSLEEP is set, otherwise we just fix-up the state.
37af14fe 1038 *
344ad853
MD
1039 * NOTE: With the MP lock held we can only safely manipulate the process
1040 * structure. We cannot safely manipulate the thread structure.
984263bc
MD
1041 */
1042void
9a379a4a 1043setrunnable(struct lwp *lp)
984263bc 1044{
344ad853
MD
1045 crit_enter();
1046 ASSERT_MP_LOCK_HELD(curthread);
2daf83b0
SS
1047 if (lp->lwp_stat == LSSTOP)
1048 lp->lwp_stat = LSSLEEP;
1049 if (lp->lwp_stat == LSSLEEP && (lp->lwp_flag & LWP_BREAKTSLEEP))
ae8e83e6 1050 _tsleep_wakeup(lp->lwp_thread);
344ad853 1051 crit_exit();
984263bc
MD
1052}
1053
1054/*
164b8401
SS
1055 * The process is stopped due to some condition, usually because p_stat is
1056 * set to SSTOP, but also possibly due to being traced.
fc17ad60 1057 *
164b8401 1058 * NOTE! If the caller sets SSTOP, the caller must also clear P_WAITED
344ad853
MD
1059 * because the parent may check the child's status before the child actually
1060 * gets to this routine.
1061 *
9a379a4a 1062 * This routine is called with the current lwp only, typically just
344ad853
MD
1063 * before returning to userland.
1064 *
9a379a4a 1065 * Setting LWP_BREAKTSLEEP before entering the tsleep will cause a passive
344ad853 1066 * SIGCONT to break out of the tsleep.
984263bc
MD
1067 */
1068void
9a379a4a 1069tstop(void)
984263bc 1070{
9a379a4a 1071 struct lwp *lp = curthread->td_lwp;
7278a846 1072 struct proc *p = lp->lwp_proc;
9a379a4a 1073
7278a846 1074 crit_enter();
f33e8653
SS
1075 /*
1076 * If LWP_WSTOP is set, we were sleeping
1077 * while our process was stopped. At this point
1078 * we were already counted as stopped.
1079 */
1080 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1081 /*
1082 * If we're the last thread to stop, signal
1083 * our parent.
1084 */
1085 p->p_nstopped++;
1086 lp->lwp_flag |= LWP_WSTOP;
ea59a697 1087 wakeup(&p->p_nstopped);
f33e8653
SS
1088 if (p->p_nstopped == p->p_nthreads) {
1089 p->p_flag &= ~P_WAITED;
1090 wakeup(p->p_pptr);
1091 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1092 ksignal(p->p_pptr, SIGCHLD);
1093 }
1094 }
ea59a697
SS
1095 while (p->p_stat == SSTOP) {
1096 lp->lwp_flag |= LWP_BREAKTSLEEP;
1097 lp->lwp_stat = LSSTOP;
1098 tsleep(p, 0, "stop", 0);
1099 }
7278a846 1100 p->p_nstopped--;
a5ff9d37 1101 lp->lwp_flag &= ~LWP_WSTOP;
7278a846 1102 crit_exit();
26a0694b
MD
1103}
1104
1105/*
a77ac49d
MD
1106 * Yield / synchronous reschedule. This is a bit tricky because the trap
1107 * code might have set a lazy release on the switch function. Setting
1108 * P_PASSIVE_ACQ will ensure that the lazy release executes when we call
1109 * switch, and that we are given a greater chance of affinity with our
1110 * current cpu.
1111 *
1112 * We call lwkt_setpri_self() to rotate our thread to the end of the lwkt
1113 * run queue. lwkt_switch() will also execute any assigned passive release
1114 * (which usually calls release_curproc()), allowing a same/higher priority
1115 * process to be designated as the current process.
1116 *
1117 * While it is possible for a lower priority process to be designated,
1118 * it's call to lwkt_maybe_switch() in acquire_curproc() will likely
1119 * round-robin back to us and we will be able to re-acquire the current
1120 * process designation.
3919ced0
MD
1121 *
1122 * MPSAFE
a77ac49d
MD
1123 */
1124void
1125uio_yield(void)
1126{
1127 struct thread *td = curthread;
1128 struct proc *p = td->td_proc;
1129
1130 lwkt_setpri_self(td->td_pri & TDPRI_MASK);
1131 if (p) {
1132 p->p_flag |= P_PASSIVE_ACQ;
1133 lwkt_switch();
1134 p->p_flag &= ~P_PASSIVE_ACQ;
1135 } else {
1136 lwkt_switch();
1137 }
1138}
1139
1140/*
984263bc
MD
1141 * Compute a tenex style load average of a quantity on
1142 * 1, 5 and 15 minute intervals.
1143 */
c7e98b2f 1144static int loadav_count_runnable(struct lwp *p, void *data);
8fa76237 1145
984263bc
MD
1146static void
1147loadav(void *arg)
1148{
984263bc 1149 struct loadavg *avg;
8fa76237 1150 int i, nrun;
984263bc 1151
984263bc 1152 nrun = 0;
c7e98b2f 1153 alllwp_scan(loadav_count_runnable, &nrun);
8fa76237
MD
1154 avg = &averunnable;
1155 for (i = 0; i < 3; i++) {
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1156 avg->ldavg[i] = (cexp[i] * avg->ldavg[i] +
1157 nrun * FSCALE * (FSCALE - cexp[i])) >> FSHIFT;
8fa76237 1158 }
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1159
1160 /*
1161 * Schedule the next update to occur after 5 seconds, but add a
1162 * random variation to avoid synchronisation with processes that
1163 * run at regular intervals.
1164 */
cddfb7bb 1165 callout_reset(&loadav_callout, hz * 4 + (int)(krandom() % (hz * 2 + 1)),
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1166 loadav, NULL);
1167}
1168
1169static int
c7e98b2f 1170loadav_count_runnable(struct lwp *lp, void *data)
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1171{
1172 int *nrunp = data;
1173 thread_t td;
1174
164b8401
SS
1175 switch (lp->lwp_stat) {
1176 case LSRUN:
08f2f1bb 1177 if ((td = lp->lwp_thread) == NULL)
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1178 break;
1179 if (td->td_flags & TDF_BLOCKED)
1180 break;
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1181 ++*nrunp;
1182 break;
1183 default:
1184 break;
1185 }
1186 return(0);
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1187}
1188
1189/* ARGSUSED */
1190static void
6656cd91 1191sched_setup(void *dummy)
984263bc 1192{
984263bc 1193 callout_init(&loadav_callout);
35f9d051 1194 callout_init(&schedcpu_callout);
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1195
1196 /* Kick off timeout driven events by calling first time. */
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1197 schedcpu(NULL);
1198 loadav(NULL);
1199}
1200