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34 * @(#)kern_synch.c 8.9 (Berkeley) 5/19/95
35 * $FreeBSD: src/sys/kern/kern_synch.c,v 1.87.2.6 2002/10/13 07:29:53 kbyanc Exp $
38 #include "opt_ktrace.h"
40 #include <sys/param.h>
41 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/signalvar.h>
45 #include <sys/resourcevar.h>
46 #include <sys/vmmeter.h>
47 #include <sys/sysctl.h>
51 #include <sys/ktrace.h>
53 #include <sys/xwait.h>
55 #include <sys/serialize.h>
57 #include <sys/signal2.h>
58 #include <sys/thread2.h>
59 #include <sys/spinlock2.h>
60 #include <sys/mutex2.h>
62 #include <machine/cpu.h>
63 #include <machine/smp.h>
65 TAILQ_HEAD(tslpque, thread);
67 static void sched_setup (void *dummy);
68 SYSINIT(sched_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, sched_setup, NULL)
73 int sched_quantum; /* Roundrobin scheduling quantum in ticks. */
75 int ncpus2, ncpus2_shift, ncpus2_mask; /* note: mask not cpumask_t */
76 int ncpus_fit, ncpus_fit_mask; /* note: mask not cpumask_t */
79 int tsleep_crypto_dump = 0;
81 static struct callout loadav_callout;
82 static struct callout schedcpu_callout;
83 MALLOC_DEFINE(M_TSLEEP, "tslpque", "tsleep queues");
85 #define __DEALL(ident) __DEQUALIFY(void *, ident)
87 #if !defined(KTR_TSLEEP)
88 #define KTR_TSLEEP KTR_ALL
90 KTR_INFO_MASTER(tsleep);
91 KTR_INFO(KTR_TSLEEP, tsleep, tsleep_beg, 0, "tsleep enter %p", const volatile void *ident);
92 KTR_INFO(KTR_TSLEEP, tsleep, tsleep_end, 1, "tsleep exit");
93 KTR_INFO(KTR_TSLEEP, tsleep, wakeup_beg, 2, "wakeup enter %p", const volatile void *ident);
94 KTR_INFO(KTR_TSLEEP, tsleep, wakeup_end, 3, "wakeup exit");
95 KTR_INFO(KTR_TSLEEP, tsleep, ilockfail, 4, "interlock failed %p", const volatile void *ident);
97 #define logtsleep1(name) KTR_LOG(tsleep_ ## name)
98 #define logtsleep2(name, val) KTR_LOG(tsleep_ ## name, val)
100 struct loadavg averunnable =
101 { {0, 0, 0}, FSCALE }; /* load average, of runnable procs */
103 * Constants for averages over 1, 5, and 15 minutes
104 * when sampling at 5 second intervals.
106 static fixpt_t cexp[3] = {
107 0.9200444146293232 * FSCALE, /* exp(-1/12) */
108 0.9834714538216174 * FSCALE, /* exp(-1/60) */
109 0.9944598480048967 * FSCALE, /* exp(-1/180) */
112 static void endtsleep (void *);
113 static void loadav (void *arg);
114 static void schedcpu (void *arg);
117 * Adjust the scheduler quantum. The quantum is specified in microseconds.
118 * Note that 'tick' is in microseconds per tick.
121 sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
125 new_val = sched_quantum * ustick;
126 error = sysctl_handle_int(oidp, &new_val, 0, req);
127 if (error != 0 || req->newptr == NULL)
129 if (new_val < ustick)
131 sched_quantum = new_val / ustick;
132 hogticks = 2 * sched_quantum;
136 SYSCTL_PROC(_kern, OID_AUTO, quantum, CTLTYPE_INT|CTLFLAG_RW,
137 0, sizeof sched_quantum, sysctl_kern_quantum, "I", "");
139 static int pctcpu_decay = 10;
140 SYSCTL_INT(_kern, OID_AUTO, pctcpu_decay, CTLFLAG_RW, &pctcpu_decay, 0, "");
143 * kernel uses `FSCALE', userland (SHOULD) use kern.fscale
145 int fscale __unused = FSCALE; /* exported to systat */
146 SYSCTL_INT(_kern, OID_AUTO, fscale, CTLFLAG_RD, 0, FSCALE, "");
149 * Recompute process priorities, once a second.
151 * Since the userland schedulers are typically event oriented, if the
152 * estcpu calculation at wakeup() time is not sufficient to make a
153 * process runnable relative to other processes in the system we have
154 * a 1-second recalc to help out.
156 * This code also allows us to store sysclock_t data in the process structure
157 * without fear of an overrun, since sysclock_t are guarenteed to hold
158 * several seconds worth of count.
160 * WARNING! callouts can preempt normal threads. However, they will not
161 * preempt a thread holding a spinlock so we *can* safely use spinlocks.
163 static int schedcpu_stats(struct proc *p, void *data __unused);
164 static int schedcpu_resource(struct proc *p, void *data __unused);
169 allproc_scan(schedcpu_stats, NULL);
170 allproc_scan(schedcpu_resource, NULL);
171 wakeup((caddr_t)&lbolt);
172 wakeup(lbolt_syncer);
173 callout_reset(&schedcpu_callout, hz, schedcpu, NULL);
177 * General process statistics once a second
180 schedcpu_stats(struct proc *p, void *data __unused)
185 * Threads may not be completely set up if process in SIDL state.
187 if (p->p_stat == SIDL)
191 if (lwkt_trytoken(&p->p_token) == FALSE) {
197 FOREACH_LWP_IN_PROC(lp, p) {
198 if (lp->lwp_stat == LSSLEEP) {
200 if (lp->lwp_slptime == 1)
201 p->p_usched->uload_update(lp);
205 * Only recalculate processes that are active or have slept
206 * less then 2 seconds. The schedulers understand this.
207 * Otherwise decay by 50% per second.
209 if (lp->lwp_slptime <= 1) {
210 p->p_usched->recalculate(lp);
214 decay = pctcpu_decay;
220 lp->lwp_pctcpu = (lp->lwp_pctcpu * (decay - 1)) / decay;
223 lwkt_reltoken(&p->p_token);
230 * Resource checks. XXX break out since ksignal/killproc can block,
231 * limiting us to one process killed per second. There is probably
235 schedcpu_resource(struct proc *p, void *data __unused)
240 if (p->p_stat == SIDL)
244 if (lwkt_trytoken(&p->p_token) == FALSE) {
249 if (p->p_stat == SZOMB || p->p_limit == NULL) {
250 lwkt_reltoken(&p->p_token);
256 FOREACH_LWP_IN_PROC(lp, p) {
258 * We may have caught an lp in the middle of being
259 * created, lwp_thread can be NULL.
261 if (lp->lwp_thread) {
262 ttime += lp->lwp_thread->td_sticks;
263 ttime += lp->lwp_thread->td_uticks;
267 switch(plimit_testcpulimit(p->p_limit, ttime)) {
268 case PLIMIT_TESTCPU_KILL:
269 killproc(p, "exceeded maximum CPU limit");
271 case PLIMIT_TESTCPU_XCPU:
272 if ((p->p_flags & P_XCPU) == 0) {
273 p->p_flags |= P_XCPU;
280 lwkt_reltoken(&p->p_token);
287 * This is only used by ps. Generate a cpu percentage use over
288 * a period of one second.
291 updatepcpu(struct lwp *lp, int cpticks, int ttlticks)
296 acc = (cpticks << FSHIFT) / ttlticks;
297 if (ttlticks >= ESTCPUFREQ) {
298 lp->lwp_pctcpu = acc;
300 remticks = ESTCPUFREQ - ttlticks;
301 lp->lwp_pctcpu = (acc * ttlticks + lp->lwp_pctcpu * remticks) /
307 * tsleep/wakeup hash table parameters. Try to find the sweet spot for
308 * like addresses being slept on.
310 #define TABLESIZE 4001
311 #define LOOKUP(x) (((u_int)(uintptr_t)(x)) % TABLESIZE)
313 static cpumask_t slpque_cpumasks[TABLESIZE];
316 * General scheduler initialization. We force a reschedule 25 times
317 * a second by default. Note that cpu0 is initialized in early boot and
318 * cannot make any high level calls.
320 * Each cpu has its own sleep queue.
323 sleep_gdinit(globaldata_t gd)
325 static struct tslpque slpque_cpu0[TABLESIZE];
328 if (gd->gd_cpuid == 0) {
329 sched_quantum = (hz + 24) / 25;
330 hogticks = 2 * sched_quantum;
332 gd->gd_tsleep_hash = slpque_cpu0;
334 gd->gd_tsleep_hash = kmalloc(sizeof(slpque_cpu0),
335 M_TSLEEP, M_WAITOK | M_ZERO);
337 for (i = 0; i < TABLESIZE; ++i)
338 TAILQ_INIT(&gd->gd_tsleep_hash[i]);
342 * This is a dandy function that allows us to interlock tsleep/wakeup
343 * operations with unspecified upper level locks, such as lockmgr locks,
344 * simply by holding a critical section. The sequence is:
346 * (acquire upper level lock)
347 * tsleep_interlock(blah)
348 * (release upper level lock)
351 * Basically this functions queues us on the tsleep queue without actually
352 * descheduling us. When tsleep() is later called with PINTERLOCK it
353 * assumes the thread was already queued, otherwise it queues it there.
355 * Thus it is possible to receive the wakeup prior to going to sleep and
356 * the race conditions are covered.
359 _tsleep_interlock(globaldata_t gd, const volatile void *ident, int flags)
361 thread_t td = gd->gd_curthread;
364 crit_enter_quick(td);
365 if (td->td_flags & TDF_TSLEEPQ) {
366 id = LOOKUP(td->td_wchan);
367 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
368 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL) {
369 ATOMIC_CPUMASK_NANDBIT(slpque_cpumasks[id],
373 td->td_flags |= TDF_TSLEEPQ;
376 TAILQ_INSERT_TAIL(&gd->gd_tsleep_hash[id], td, td_sleepq);
377 ATOMIC_CPUMASK_ORBIT(slpque_cpumasks[id], gd->gd_cpuid);
378 td->td_wchan = ident;
379 td->td_wdomain = flags & PDOMAIN_MASK;
384 tsleep_interlock(const volatile void *ident, int flags)
386 _tsleep_interlock(mycpu, ident, flags);
390 * Remove thread from sleepq. Must be called with a critical section held.
391 * The thread must not be migrating.
394 _tsleep_remove(thread_t td)
396 globaldata_t gd = mycpu;
399 KKASSERT(td->td_gd == gd && IN_CRITICAL_SECT(td));
400 KKASSERT((td->td_flags & TDF_MIGRATING) == 0);
401 if (td->td_flags & TDF_TSLEEPQ) {
402 td->td_flags &= ~TDF_TSLEEPQ;
403 id = LOOKUP(td->td_wchan);
404 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
405 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL) {
406 ATOMIC_CPUMASK_NANDBIT(slpque_cpumasks[id],
415 tsleep_remove(thread_t td)
421 * General sleep call. Suspends the current process until a wakeup is
422 * performed on the specified identifier. The process will then be made
423 * runnable with the specified priority. Sleeps at most timo/hz seconds
424 * (0 means no timeout). If flags includes PCATCH flag, signals are checked
425 * before and after sleeping, else signals are not checked. Returns 0 if
426 * awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a
427 * signal needs to be delivered, ERESTART is returned if the current system
428 * call should be restarted if possible, and EINTR is returned if the system
429 * call should be interrupted by the signal (return EINTR).
431 * Note that if we are a process, we release_curproc() before messing with
432 * the LWKT scheduler.
434 * During autoconfiguration or after a panic, a sleep will simply
435 * lower the priority briefly to allow interrupts, then return.
437 * WARNING! This code can't block (short of switching away), or bad things
438 * will happen. No getting tokens, no blocking locks, etc.
441 tsleep(const volatile void *ident, int flags, const char *wmesg, int timo)
443 struct thread *td = curthread;
444 struct lwp *lp = td->td_lwp;
445 struct proc *p = td->td_proc; /* may be NULL */
451 struct callout thandle;
454 * Currently a severe hack. Make sure any delayed wakeups
455 * are flushed before we sleep or we might deadlock on whatever
456 * event we are sleeping on.
458 if (td->td_flags & TDF_DELAYED_WAKEUP)
459 wakeup_end_delayed();
462 * NOTE: removed KTRPOINT, it could cause races due to blocking
463 * even in stable. Just scrap it for now.
465 if (!tsleep_crypto_dump && (tsleep_now_works == 0 || panicstr)) {
467 * After a panic, or before we actually have an operational
468 * softclock, just give interrupts a chance, then just return;
470 * don't run any other procs or panic below,
471 * in case this is the idle process and already asleep.
475 lwkt_setpri_self(safepri);
477 lwkt_setpri_self(oldpri);
480 logtsleep2(tsleep_beg, ident);
482 KKASSERT(td != &gd->gd_idlethread); /* you must be kidding! */
483 td->td_wakefromcpu = -1; /* overwritten by _wakeup */
486 * NOTE: all of this occurs on the current cpu, including any
487 * callout-based wakeups, so a critical section is a sufficient
490 * The entire sequence through to where we actually sleep must
491 * run without breaking the critical section.
493 catch = flags & PCATCH;
497 crit_enter_quick(td);
499 KASSERT(ident != NULL, ("tsleep: no ident"));
500 KASSERT(lp == NULL ||
501 lp->lwp_stat == LSRUN || /* Obvious */
502 lp->lwp_stat == LSSTOP, /* Set in tstop */
504 ident, wmesg, lp->lwp_stat));
507 * We interlock the sleep queue if the caller has not already done
508 * it for us. This must be done before we potentially acquire any
509 * tokens or we can loose the wakeup.
511 if ((flags & PINTERLOCKED) == 0) {
512 _tsleep_interlock(gd, ident, flags);
516 * Setup for the current process (if this is a process). We must
517 * interlock with lwp_token to avoid remote wakeup races via
521 lwkt_gettoken(&lp->lwp_token);
524 * Early termination if PCATCH was set and a
525 * signal is pending, interlocked with the
528 * Early termination only occurs when tsleep() is
529 * entered while in a normal LSRUN state.
531 if ((sig = CURSIG(lp)) != 0)
535 * Causes ksignal to wake us up if a signal is
536 * received (interlocked with p->p_token).
538 lp->lwp_flags |= LWP_SINTR;
545 * Make sure the current process has been untangled from
546 * the userland scheduler and initialize slptime to start
549 * NOTE: td->td_wakefromcpu is pre-set by the release function
550 * for the dfly scheduler, and then adjusted by _wakeup()
553 p->p_usched->release_curproc(lp);
558 * If the interlocked flag is set but our cpu bit in the slpqueue
559 * is no longer set, then a wakeup was processed inbetween the
560 * tsleep_interlock() (ours or the callers), and here. This can
561 * occur under numerous circumstances including when we release the
564 * Extreme loads can cause the sending of an IPI (e.g. wakeup()'s)
565 * to process incoming IPIs, thus draining incoming wakeups.
567 if ((td->td_flags & TDF_TSLEEPQ) == 0) {
568 logtsleep2(ilockfail, ident);
573 * scheduling is blocked while in a critical section. Coincide
574 * the descheduled-by-tsleep flag with the descheduling of the
577 * The timer callout is localized on our cpu and interlocked by
578 * our critical section.
580 lwkt_deschedule_self(td);
581 td->td_flags |= TDF_TSLEEP_DESCHEDULED;
582 td->td_wmesg = wmesg;
585 * Setup the timeout, if any. The timeout is only operable while
586 * the thread is flagged descheduled.
588 KKASSERT((td->td_flags & TDF_TIMEOUT) == 0);
590 callout_init_mp(&thandle);
591 callout_reset(&thandle, timo, endtsleep, td);
599 * Ok, we are sleeping. Place us in the SSLEEP state.
601 KKASSERT((lp->lwp_mpflags & LWP_MP_ONRUNQ) == 0);
604 * tstop() sets LSSTOP, so don't fiddle with that.
606 if (lp->lwp_stat != LSSTOP)
607 lp->lwp_stat = LSSLEEP;
608 lp->lwp_ru.ru_nvcsw++;
609 p->p_usched->uload_update(lp);
613 * And when we are woken up, put us back in LSRUN. If we
614 * slept for over a second, recalculate our estcpu.
616 lp->lwp_stat = LSRUN;
617 if (lp->lwp_slptime) {
618 p->p_usched->uload_update(lp);
619 p->p_usched->recalculate(lp);
627 * Make sure we haven't switched cpus while we were asleep. It's
628 * not supposed to happen. Cleanup our temporary flags.
630 KKASSERT(gd == td->td_gd);
633 * Cleanup the timeout. If the timeout has already occured thandle
634 * has already been stopped, otherwise stop thandle. If the timeout
635 * is running (the callout thread must be blocked trying to get
636 * lwp_token) then wait for us to get scheduled.
639 while (td->td_flags & TDF_TIMEOUT_RUNNING) {
640 lwkt_deschedule_self(td);
641 td->td_wmesg = "tsrace";
643 kprintf("td %p %s: timeout race\n", td, td->td_comm);
645 if (td->td_flags & TDF_TIMEOUT) {
646 td->td_flags &= ~TDF_TIMEOUT;
649 /* does not block when on same cpu */
650 callout_stop(&thandle);
653 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
656 * Make sure we have been removed from the sleepq. In most
657 * cases this will have been done for us already but it is
658 * possible for a scheduling IPI to be in-flight from a
659 * previous tsleep/tsleep_interlock() or due to a straight-out
660 * call to lwkt_schedule() (in the case of an interrupt thread),
661 * causing a spurious wakeup.
667 * Figure out the correct error return. If interrupted by a
668 * signal we want to return EINTR or ERESTART.
672 if (catch && error == 0) {
673 if (sig != 0 || (sig = CURSIG(lp))) {
674 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
680 lp->lwp_flags &= ~LWP_SINTR;
681 lwkt_reltoken(&lp->lwp_token);
683 logtsleep1(tsleep_end);
689 * Interlocked spinlock sleep. An exclusively held spinlock must
690 * be passed to ssleep(). The function will atomically release the
691 * spinlock and tsleep on the ident, then reacquire the spinlock and
694 * This routine is fairly important along the critical path, so optimize it
698 ssleep(const volatile void *ident, struct spinlock *spin, int flags,
699 const char *wmesg, int timo)
701 globaldata_t gd = mycpu;
704 _tsleep_interlock(gd, ident, flags);
705 spin_unlock_quick(gd, spin);
706 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
707 _spin_lock_quick(gd, spin, wmesg);
713 lksleep(const volatile void *ident, struct lock *lock, int flags,
714 const char *wmesg, int timo)
716 globaldata_t gd = mycpu;
719 _tsleep_interlock(gd, ident, flags);
720 lockmgr(lock, LK_RELEASE);
721 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
722 lockmgr(lock, LK_EXCLUSIVE);
728 * Interlocked mutex sleep. An exclusively held mutex must be passed
729 * to mtxsleep(). The function will atomically release the mutex
730 * and tsleep on the ident, then reacquire the mutex and return.
733 mtxsleep(const volatile void *ident, struct mtx *mtx, int flags,
734 const char *wmesg, int timo)
736 globaldata_t gd = mycpu;
739 _tsleep_interlock(gd, ident, flags);
741 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
742 mtx_lock_ex_quick(mtx, wmesg);
748 * Interlocked serializer sleep. An exclusively held serializer must
749 * be passed to zsleep(). The function will atomically release
750 * the serializer and tsleep on the ident, then reacquire the serializer
754 zsleep(const volatile void *ident, struct lwkt_serialize *slz, int flags,
755 const char *wmesg, int timo)
757 globaldata_t gd = mycpu;
760 ASSERT_SERIALIZED(slz);
762 _tsleep_interlock(gd, ident, flags);
763 lwkt_serialize_exit(slz);
764 ret = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
765 lwkt_serialize_enter(slz);
771 * Directly block on the LWKT thread by descheduling it. This
772 * is much faster then tsleep(), but the only legal way to wake
773 * us up is to directly schedule the thread.
775 * Setting TDF_SINTR will cause new signals to directly schedule us.
777 * This routine must be called while in a critical section.
780 lwkt_sleep(const char *wmesg, int flags)
782 thread_t td = curthread;
785 if ((flags & PCATCH) == 0 || td->td_lwp == NULL) {
786 td->td_flags |= TDF_BLOCKED;
787 td->td_wmesg = wmesg;
788 lwkt_deschedule_self(td);
791 td->td_flags &= ~TDF_BLOCKED;
794 if ((sig = CURSIG(td->td_lwp)) != 0) {
795 if (SIGISMEMBER(td->td_proc->p_sigacts->ps_sigintr, sig))
801 td->td_flags |= TDF_BLOCKED | TDF_SINTR;
802 td->td_wmesg = wmesg;
803 lwkt_deschedule_self(td);
805 td->td_flags &= ~(TDF_BLOCKED | TDF_SINTR);
811 * Implement the timeout for tsleep.
813 * This type of callout timeout is scheduled on the same cpu the process
814 * is sleeping on. Also, at the moment, the MP lock is held.
823 * We are going to have to get the lwp_token, which means we might
824 * block. This can race a tsleep getting woken up by other means
825 * so set TDF_TIMEOUT_RUNNING to force the tsleep to wait for our
826 * processing to complete (sorry tsleep!).
828 * We can safely set td_flags because td MUST be on the same cpu
831 KKASSERT(td->td_gd == mycpu);
833 td->td_flags |= TDF_TIMEOUT_RUNNING | TDF_TIMEOUT;
836 * This can block but TDF_TIMEOUT_RUNNING will prevent the thread
837 * from exiting the tsleep on us. The flag is interlocked by virtue
838 * of lp being on the same cpu as we are.
840 if ((lp = td->td_lwp) != NULL)
841 lwkt_gettoken(&lp->lwp_token);
843 KKASSERT(td->td_flags & TDF_TSLEEP_DESCHEDULED);
847 * callout timer should never be set in tstop() because
848 * it passes a timeout of 0.
850 KKASSERT(lp->lwp_stat != LSSTOP);
852 lwkt_reltoken(&lp->lwp_token);
857 KKASSERT(td->td_gd == mycpu);
858 td->td_flags &= ~TDF_TIMEOUT_RUNNING;
863 * Make all processes sleeping on the specified identifier runnable.
864 * count may be zero or one only.
866 * The domain encodes the sleep/wakeup domain, flags, plus the originating
869 * This call may run without the MP lock held. We can only manipulate thread
870 * state on the cpu owning the thread. We CANNOT manipulate process state
873 * _wakeup() can be passed to an IPI so we can't use (const volatile
877 _wakeup(void *ident, int domain)
887 logtsleep2(wakeup_beg, ident);
890 qp = &gd->gd_tsleep_hash[id];
892 for (td = TAILQ_FIRST(qp); td != NULL; td = ntd) {
893 ntd = TAILQ_NEXT(td, td_sleepq);
894 if (td->td_wchan == ident &&
895 td->td_wdomain == (domain & PDOMAIN_MASK)
897 KKASSERT(td->td_gd == gd);
899 td->td_wakefromcpu = PWAKEUP_DECODE(domain);
900 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
902 if (domain & PWAKEUP_ONE)
910 * We finished checking the current cpu but there still may be
911 * more work to do. Either wakeup_one was requested and no matching
912 * thread was found, or a normal wakeup was requested and we have
913 * to continue checking cpus.
915 * It should be noted that this scheme is actually less expensive then
916 * the old scheme when waking up multiple threads, since we send
917 * only one IPI message per target candidate which may then schedule
918 * multiple threads. Before we could have wound up sending an IPI
919 * message for each thread on the target cpu (!= current cpu) that
920 * needed to be woken up.
922 * NOTE: Wakeups occuring on remote cpus are asynchronous. This
923 * should be ok since we are passing idents in the IPI rather then
926 if ((domain & PWAKEUP_MYCPU) == 0) {
927 mask = slpque_cpumasks[id];
928 CPUMASK_ANDMASK(mask, gd->gd_other_cpus);
929 if (CPUMASK_TESTNZERO(mask)) {
930 lwkt_send_ipiq2_mask(mask, _wakeup, ident,
931 domain | PWAKEUP_MYCPU);
935 logtsleep1(wakeup_end);
940 * Wakeup all threads tsleep()ing on the specified ident, on all cpus
943 wakeup(const volatile void *ident)
945 globaldata_t gd = mycpu;
946 thread_t td = gd->gd_curthread;
948 if (td && (td->td_flags & TDF_DELAYED_WAKEUP)) {
950 * If we are in a delayed wakeup section, record up to two wakeups in
951 * a per-CPU queue and issue them when we block or exit the delayed
954 if (atomic_cmpset_ptr(&gd->gd_delayed_wakeup[0], NULL, ident))
956 if (atomic_cmpset_ptr(&gd->gd_delayed_wakeup[1], NULL, ident))
959 ident = atomic_swap_ptr(__DEQUALIFY(volatile void **, &gd->gd_delayed_wakeup[1]),
961 ident = atomic_swap_ptr(__DEQUALIFY(volatile void **, &gd->gd_delayed_wakeup[0]),
965 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, gd->gd_cpuid));
969 * Wakeup one thread tsleep()ing on the specified ident, on any cpu.
972 wakeup_one(const volatile void *ident)
974 /* XXX potentially round-robin the first responding cpu */
975 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid) |
980 * Wakeup threads tsleep()ing on the specified ident on the current cpu
984 wakeup_mycpu(const volatile void *ident)
986 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid) |
991 * Wakeup one thread tsleep()ing on the specified ident on the current cpu
995 wakeup_mycpu_one(const volatile void *ident)
997 /* XXX potentially round-robin the first responding cpu */
998 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid) |
999 PWAKEUP_MYCPU | PWAKEUP_ONE);
1003 * Wakeup all thread tsleep()ing on the specified ident on the specified cpu
1007 wakeup_oncpu(globaldata_t gd, const volatile void *ident)
1009 globaldata_t mygd = mycpu;
1011 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mygd->gd_cpuid) |
1014 lwkt_send_ipiq2(gd, _wakeup, __DEALL(ident),
1015 PWAKEUP_ENCODE(0, mygd->gd_cpuid) |
1021 * Wakeup one thread tsleep()ing on the specified ident on the specified cpu
1025 wakeup_oncpu_one(globaldata_t gd, const volatile void *ident)
1027 globaldata_t mygd = mycpu;
1029 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mygd->gd_cpuid) |
1030 PWAKEUP_MYCPU | PWAKEUP_ONE);
1032 lwkt_send_ipiq2(gd, _wakeup, __DEALL(ident),
1033 PWAKEUP_ENCODE(0, mygd->gd_cpuid) |
1034 PWAKEUP_MYCPU | PWAKEUP_ONE);
1039 * Wakeup all threads waiting on the specified ident that slept using
1040 * the specified domain, on all cpus.
1043 wakeup_domain(const volatile void *ident, int domain)
1045 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(domain, mycpu->gd_cpuid));
1049 * Wakeup one thread waiting on the specified ident that slept using
1050 * the specified domain, on any cpu.
1053 wakeup_domain_one(const volatile void *ident, int domain)
1055 /* XXX potentially round-robin the first responding cpu */
1056 _wakeup(__DEALL(ident),
1057 PWAKEUP_ENCODE(domain, mycpu->gd_cpuid) | PWAKEUP_ONE);
1061 wakeup_start_delayed(void)
1063 globaldata_t gd = mycpu;
1066 gd->gd_curthread->td_flags |= TDF_DELAYED_WAKEUP;
1071 wakeup_end_delayed(void)
1073 globaldata_t gd = mycpu;
1075 if (gd->gd_curthread->td_flags & TDF_DELAYED_WAKEUP) {
1077 gd->gd_curthread->td_flags &= ~TDF_DELAYED_WAKEUP;
1078 if (gd->gd_delayed_wakeup[0] || gd->gd_delayed_wakeup[1]) {
1079 if (gd->gd_delayed_wakeup[0]) {
1080 wakeup(gd->gd_delayed_wakeup[0]);
1081 gd->gd_delayed_wakeup[0] = NULL;
1083 if (gd->gd_delayed_wakeup[1]) {
1084 wakeup(gd->gd_delayed_wakeup[1]);
1085 gd->gd_delayed_wakeup[1] = NULL;
1095 * Make a process runnable. lp->lwp_token must be held on call and this
1096 * function must be called from the cpu owning lp.
1098 * This only has an effect if we are in LSSTOP or LSSLEEP.
1101 setrunnable(struct lwp *lp)
1103 thread_t td = lp->lwp_thread;
1105 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_token);
1106 KKASSERT(td->td_gd == mycpu);
1108 if (lp->lwp_stat == LSSTOP)
1109 lp->lwp_stat = LSSLEEP;
1110 if (lp->lwp_stat == LSSLEEP) {
1113 } else if (td->td_flags & TDF_SINTR) {
1120 * The process is stopped due to some condition, usually because p_stat is
1121 * set to SSTOP, but also possibly due to being traced.
1123 * Caller must hold p->p_token
1125 * NOTE! If the caller sets SSTOP, the caller must also clear P_WAITED
1126 * because the parent may check the child's status before the child actually
1127 * gets to this routine.
1129 * This routine is called with the current lwp only, typically just
1130 * before returning to userland if the process state is detected as
1131 * possibly being in a stopped state.
1136 struct lwp *lp = curthread->td_lwp;
1137 struct proc *p = lp->lwp_proc;
1140 lwkt_gettoken(&lp->lwp_token);
1144 * If LWP_MP_WSTOP is set, we were sleeping
1145 * while our process was stopped. At this point
1146 * we were already counted as stopped.
1148 if ((lp->lwp_mpflags & LWP_MP_WSTOP) == 0) {
1150 * If we're the last thread to stop, signal
1154 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WSTOP);
1155 wakeup(&p->p_nstopped);
1156 if (p->p_nstopped == p->p_nthreads) {
1158 * Token required to interlock kern_wait()
1162 lwkt_gettoken(&q->p_token);
1163 p->p_flags &= ~P_WAITED;
1165 if ((q->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1166 ksignal(q, SIGCHLD);
1167 lwkt_reltoken(&q->p_token);
1171 while (p->p_stat == SSTOP) {
1172 lp->lwp_stat = LSSTOP;
1173 tsleep(p, 0, "stop", 0);
1176 atomic_clear_int(&lp->lwp_mpflags, LWP_MP_WSTOP);
1178 lwkt_reltoken(&lp->lwp_token);
1182 * Compute a tenex style load average of a quantity on
1183 * 1, 5 and 15 minute intervals.
1185 static int loadav_count_runnable(struct lwp *p, void *data);
1190 struct loadavg *avg;
1194 alllwp_scan(loadav_count_runnable, &nrun);
1196 for (i = 0; i < 3; i++) {
1197 avg->ldavg[i] = (cexp[i] * avg->ldavg[i] +
1198 nrun * FSCALE * (FSCALE - cexp[i])) >> FSHIFT;
1202 * Schedule the next update to occur after 5 seconds, but add a
1203 * random variation to avoid synchronisation with processes that
1204 * run at regular intervals.
1206 callout_reset(&loadav_callout, hz * 4 + (int)(krandom() % (hz * 2 + 1)),
1211 loadav_count_runnable(struct lwp *lp, void *data)
1216 switch (lp->lwp_stat) {
1218 if ((td = lp->lwp_thread) == NULL)
1220 if (td->td_flags & TDF_BLOCKED)
1233 sched_setup(void *dummy)
1235 callout_init_mp(&loadav_callout);
1236 callout_init_mp(&schedcpu_callout);
1238 /* Kick off timeout driven events by calling first time. */