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38 * @(#)kern_synch.c 8.9 (Berkeley) 5/19/95
39 * $FreeBSD: src/sys/kern/kern_synch.c,v 1.87.2.6 2002/10/13 07:29:53 kbyanc Exp $
40 * $DragonFly: src/sys/kern/kern_synch.c,v 1.91 2008/09/09 04:06:13 dillon Exp $
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/signalvar.h>
50 #include <sys/signal2.h>
51 #include <sys/resourcevar.h>
52 #include <sys/vmmeter.h>
53 #include <sys/sysctl.h>
57 #include <sys/ktrace.h>
59 #include <sys/xwait.h>
62 #include <sys/thread2.h>
63 #include <sys/spinlock2.h>
64 #include <sys/serialize.h>
66 #include <machine/cpu.h>
67 #include <machine/smp.h>
69 TAILQ_HEAD(tslpque, thread);
71 static void sched_setup (void *dummy);
72 SYSINIT(sched_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, sched_setup, NULL)
77 int sched_quantum; /* Roundrobin scheduling quantum in ticks. */
79 int ncpus2, ncpus2_shift, ncpus2_mask;
80 int ncpus_fit, ncpus_fit_mask;
84 static struct callout loadav_callout;
85 static struct callout schedcpu_callout;
86 MALLOC_DEFINE(M_TSLEEP, "tslpque", "tsleep queues");
88 #if !defined(KTR_TSLEEP)
89 #define KTR_TSLEEP KTR_ALL
91 KTR_INFO_MASTER(tsleep);
92 KTR_INFO(KTR_TSLEEP, tsleep, tsleep_beg, 0, "tsleep enter %p", sizeof(void *));
93 KTR_INFO(KTR_TSLEEP, tsleep, tsleep_end, 1, "tsleep exit", 0);
94 KTR_INFO(KTR_TSLEEP, tsleep, wakeup_beg, 2, "wakeup enter %p", sizeof(void *));
95 KTR_INFO(KTR_TSLEEP, tsleep, wakeup_end, 3, "wakeup exit", 0);
96 KTR_INFO(KTR_TSLEEP, tsleep, ilockfail, 4, "interlock failed %p", sizeof(void *));
98 #define logtsleep1(name) KTR_LOG(tsleep_ ## name)
99 #define logtsleep2(name, val) KTR_LOG(tsleep_ ## name, val)
101 struct loadavg averunnable =
102 { {0, 0, 0}, FSCALE }; /* load average, of runnable procs */
104 * Constants for averages over 1, 5, and 15 minutes
105 * when sampling at 5 second intervals.
107 static fixpt_t cexp[3] = {
108 0.9200444146293232 * FSCALE, /* exp(-1/12) */
109 0.9834714538216174 * FSCALE, /* exp(-1/60) */
110 0.9944598480048967 * FSCALE, /* exp(-1/180) */
113 static void endtsleep (void *);
114 static void tsleep_wakeup(struct thread *td);
115 static void loadav (void *arg);
116 static void schedcpu (void *arg);
119 * Adjust the scheduler quantum. The quantum is specified in microseconds.
120 * Note that 'tick' is in microseconds per tick.
123 sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
127 new_val = sched_quantum * tick;
128 error = sysctl_handle_int(oidp, &new_val, 0, req);
129 if (error != 0 || req->newptr == NULL)
133 sched_quantum = new_val / tick;
134 hogticks = 2 * sched_quantum;
138 SYSCTL_PROC(_kern, OID_AUTO, quantum, CTLTYPE_INT|CTLFLAG_RW,
139 0, sizeof sched_quantum, sysctl_kern_quantum, "I", "");
142 * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the
143 * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below
144 * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT).
146 * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used:
147 * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits).
149 * If you don't want to bother with the faster/more-accurate formula, you
150 * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate
151 * (more general) method of calculating the %age of CPU used by a process.
153 * decay 95% of `lwp_pctcpu' in 60 seconds; see CCPU_SHIFT before changing
155 #define CCPU_SHIFT 11
157 static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
158 SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
161 * kernel uses `FSCALE', userland (SHOULD) use kern.fscale
163 int fscale __unused = FSCALE; /* exported to systat */
164 SYSCTL_INT(_kern, OID_AUTO, fscale, CTLFLAG_RD, 0, FSCALE, "");
167 * Recompute process priorities, once a second.
169 * Since the userland schedulers are typically event oriented, if the
170 * estcpu calculation at wakeup() time is not sufficient to make a
171 * process runnable relative to other processes in the system we have
172 * a 1-second recalc to help out.
174 * This code also allows us to store sysclock_t data in the process structure
175 * without fear of an overrun, since sysclock_t are guarenteed to hold
176 * several seconds worth of count.
178 * WARNING! callouts can preempt normal threads. However, they will not
179 * preempt a thread holding a spinlock so we *can* safely use spinlocks.
181 static int schedcpu_stats(struct proc *p, void *data __unused);
182 static int schedcpu_resource(struct proc *p, void *data __unused);
187 allproc_scan(schedcpu_stats, NULL);
188 allproc_scan(schedcpu_resource, NULL);
189 wakeup((caddr_t)&lbolt);
190 wakeup((caddr_t)&lbolt_syncer);
191 callout_reset(&schedcpu_callout, hz, schedcpu, NULL);
195 * General process statistics once a second
198 schedcpu_stats(struct proc *p, void *data __unused)
204 FOREACH_LWP_IN_PROC(lp, p) {
205 if (lp->lwp_stat == LSSLEEP)
209 * Only recalculate processes that are active or have slept
210 * less then 2 seconds. The schedulers understand this.
212 if (lp->lwp_slptime <= 1) {
213 p->p_usched->recalculate(lp);
215 lp->lwp_pctcpu = (lp->lwp_pctcpu * ccpu) >> FSHIFT;
223 * Resource checks. XXX break out since ksignal/killproc can block,
224 * limiting us to one process killed per second. There is probably
228 schedcpu_resource(struct proc *p, void *data __unused)
234 if (p->p_stat == SIDL ||
235 p->p_stat == SZOMB ||
243 FOREACH_LWP_IN_PROC(lp, p) {
245 * We may have caught an lp in the middle of being
246 * created, lwp_thread can be NULL.
248 if (lp->lwp_thread) {
249 ttime += lp->lwp_thread->td_sticks;
250 ttime += lp->lwp_thread->td_uticks;
254 switch(plimit_testcpulimit(p->p_limit, ttime)) {
255 case PLIMIT_TESTCPU_KILL:
256 killproc(p, "exceeded maximum CPU limit");
258 case PLIMIT_TESTCPU_XCPU:
259 if ((p->p_flag & P_XCPU) == 0) {
272 * This is only used by ps. Generate a cpu percentage use over
273 * a period of one second.
278 updatepcpu(struct lwp *lp, int cpticks, int ttlticks)
283 acc = (cpticks << FSHIFT) / ttlticks;
284 if (ttlticks >= ESTCPUFREQ) {
285 lp->lwp_pctcpu = acc;
287 remticks = ESTCPUFREQ - ttlticks;
288 lp->lwp_pctcpu = (acc * ttlticks + lp->lwp_pctcpu * remticks) /
294 * tsleep/wakeup hash table parameters. Try to find the sweet spot for
295 * like addresses being slept on.
297 #define TABLESIZE 1024
298 #define LOOKUP(x) (((intptr_t)(x) >> 6) & (TABLESIZE - 1))
300 static cpumask_t slpque_cpumasks[TABLESIZE];
303 * General scheduler initialization. We force a reschedule 25 times
304 * a second by default. Note that cpu0 is initialized in early boot and
305 * cannot make any high level calls.
307 * Each cpu has its own sleep queue.
310 sleep_gdinit(globaldata_t gd)
312 static struct tslpque slpque_cpu0[TABLESIZE];
315 if (gd->gd_cpuid == 0) {
316 sched_quantum = (hz + 24) / 25;
317 hogticks = 2 * sched_quantum;
319 gd->gd_tsleep_hash = slpque_cpu0;
321 gd->gd_tsleep_hash = kmalloc(sizeof(slpque_cpu0),
322 M_TSLEEP, M_WAITOK | M_ZERO);
324 for (i = 0; i < TABLESIZE; ++i)
325 TAILQ_INIT(&gd->gd_tsleep_hash[i]);
329 * This is a dandy function that allows us to interlock tsleep/wakeup
330 * operations with unspecified upper level locks, such as lockmgr locks,
331 * simply by holding a critical section. The sequence is:
333 * (acquire upper level lock)
334 * tsleep_interlock(blah)
335 * (release upper level lock)
338 * Basically this functions queues us on the tsleep queue without actually
339 * descheduling us. When tsleep() is later called with PINTERLOCK it
340 * assumes the thread was already queued, otherwise it queues it there.
342 * Thus it is possible to receive the wakeup prior to going to sleep and
343 * the race conditions are covered.
346 _tsleep_interlock(globaldata_t gd, void *ident, int flags)
348 thread_t td = gd->gd_curthread;
351 crit_enter_quick(td);
352 if (td->td_flags & TDF_TSLEEPQ) {
353 id = LOOKUP(td->td_wchan);
354 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
355 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL)
356 atomic_clear_int(&slpque_cpumasks[id], gd->gd_cpumask);
358 td->td_flags |= TDF_TSLEEPQ;
361 TAILQ_INSERT_TAIL(&gd->gd_tsleep_hash[id], td, td_sleepq);
362 atomic_set_int(&slpque_cpumasks[id], gd->gd_cpumask);
363 td->td_wchan = ident;
364 td->td_wdomain = flags & PDOMAIN_MASK;
365 atomic_set_int(&slpque_cpumasks[id], gd->gd_cpumask);
370 tsleep_interlock(void *ident, int flags)
372 _tsleep_interlock(mycpu, ident, flags);
376 * Remove thread from sleepq. Must be called with a critical section held.
379 _tsleep_remove(thread_t td)
381 globaldata_t gd = mycpu;
384 KKASSERT(td->td_gd == gd);
385 if (td->td_flags & TDF_TSLEEPQ) {
386 td->td_flags &= ~TDF_TSLEEPQ;
387 id = LOOKUP(td->td_wchan);
388 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
389 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL)
390 atomic_clear_int(&slpque_cpumasks[id], gd->gd_cpumask);
397 tsleep_remove(thread_t td)
403 * This function removes a thread from the tsleep queue and schedules
404 * it. This function may act asynchronously. The target thread may be
405 * sleeping on a different cpu.
407 * This function mus be called while in a critical section but if the
408 * target thread is sleeping on a different cpu we cannot safely probe
413 _tsleep_wakeup(struct thread *td)
415 globaldata_t gd = mycpu;
418 if (td->td_gd != gd) {
419 lwkt_send_ipiq(td->td_gd, (ipifunc1_t)tsleep_wakeup, td);
424 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
425 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
432 tsleep_wakeup(struct thread *td)
439 * General sleep call. Suspends the current process until a wakeup is
440 * performed on the specified identifier. The process will then be made
441 * runnable with the specified priority. Sleeps at most timo/hz seconds
442 * (0 means no timeout). If flags includes PCATCH flag, signals are checked
443 * before and after sleeping, else signals are not checked. Returns 0 if
444 * awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a
445 * signal needs to be delivered, ERESTART is returned if the current system
446 * call should be restarted if possible, and EINTR is returned if the system
447 * call should be interrupted by the signal (return EINTR).
449 * Note that if we are a process, we release_curproc() before messing with
450 * the LWKT scheduler.
452 * During autoconfiguration or after a panic, a sleep will simply
453 * lower the priority briefly to allow interrupts, then return.
456 tsleep(void *ident, int flags, const char *wmesg, int timo)
458 struct thread *td = curthread;
459 struct lwp *lp = td->td_lwp;
460 struct proc *p = td->td_proc; /* may be NULL */
467 struct callout thandle;
470 * NOTE: removed KTRPOINT, it could cause races due to blocking
471 * even in stable. Just scrap it for now.
473 if (tsleep_now_works == 0 || panicstr) {
475 * After a panic, or before we actually have an operational
476 * softclock, just give interrupts a chance, then just return;
478 * don't run any other procs or panic below,
479 * in case this is the idle process and already asleep.
482 oldpri = td->td_pri & TDPRI_MASK;
483 lwkt_setpri_self(safepri);
485 lwkt_setpri_self(oldpri);
488 logtsleep2(tsleep_beg, ident);
490 KKASSERT(td != &gd->gd_idlethread); /* you must be kidding! */
493 * NOTE: all of this occurs on the current cpu, including any
494 * callout-based wakeups, so a critical section is a sufficient
497 * The entire sequence through to where we actually sleep must
498 * run without breaking the critical section.
500 catch = flags & PCATCH;
504 crit_enter_quick(td);
506 KASSERT(ident != NULL, ("tsleep: no ident"));
507 KASSERT(lp == NULL ||
508 lp->lwp_stat == LSRUN || /* Obvious */
509 lp->lwp_stat == LSSTOP, /* Set in tstop */
511 ident, wmesg, lp->lwp_stat));
514 * Setup for the current process (if this is a process).
519 * Early termination if PCATCH was set and a
520 * signal is pending, interlocked with the
523 * Early termination only occurs when tsleep() is
524 * entered while in a normal LSRUN state.
526 if ((sig = CURSIG(lp)) != 0)
530 * Early termination if PCATCH was set and a
531 * mailbox signal was possibly delivered prior to
532 * the system call even being made, in order to
533 * allow the user to interlock without having to
534 * make additional system calls.
536 if (p->p_flag & P_MAILBOX)
540 * Causes ksignal to wake us up when.
542 lp->lwp_flag |= LWP_SINTR;
546 * Make sure the current process has been untangled from
547 * the userland scheduler and initialize slptime to start
550 p->p_usched->release_curproc(lp);
555 * If the interlocked flag is set but our cpu bit in the slpqueue
556 * is no longer set, then a wakeup was processed inbetween the
557 * tsleep_interlock() and here. This can occur under extreme loads
558 * if the IPIQ fills up and gets processed synchronously by, say,
559 * a wakeup() or other IPI sent inbetween the interlock and here.
561 * Even the usched->release function just above can muff it up.
563 if (flags & PINTERLOCKED) {
564 if ((td->td_flags & TDF_TSLEEPQ) == 0) {
565 logtsleep2(ilockfail, ident);
570 _tsleep_interlock(gd, ident, flags);
572 lwkt_deschedule_self(td);
573 td->td_flags |= TDF_TSLEEP_DESCHEDULED;
574 td->td_wmesg = wmesg;
577 * Setup the timeout, if any
580 callout_init(&thandle);
581 callout_reset(&thandle, timo, endtsleep, td);
589 * Ok, we are sleeping. Place us in the SSLEEP state.
591 KKASSERT((lp->lwp_flag & LWP_ONRUNQ) == 0);
593 * tstop() sets LSSTOP, so don't fiddle with that.
595 if (lp->lwp_stat != LSSTOP)
596 lp->lwp_stat = LSSLEEP;
597 lp->lwp_ru.ru_nvcsw++;
601 * And when we are woken up, put us back in LSRUN. If we
602 * slept for over a second, recalculate our estcpu.
604 lp->lwp_stat = LSRUN;
606 p->p_usched->recalculate(lp);
613 * Make sure we haven't switched cpus while we were asleep. It's
614 * not supposed to happen. Cleanup our temporary flags.
616 KKASSERT(gd == td->td_gd);
619 * Cleanup the timeout.
622 if (td->td_flags & TDF_TIMEOUT) {
623 td->td_flags &= ~TDF_TIMEOUT;
626 callout_stop(&thandle);
631 * Make sure we have been removed from the sleepq. This should
632 * have been done for us already.
636 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
637 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
638 kprintf("td %p (%s) unexpectedly rescheduled\n",
643 * Figure out the correct error return. If interrupted by a
644 * signal we want to return EINTR or ERESTART.
646 * If P_MAILBOX is set no automatic system call restart occurs
647 * and we return EINTR. P_MAILBOX is meant to be used as an
648 * interlock, the user must poll it prior to any system call
649 * that it wishes to interlock a mailbox signal against since
650 * the flag is cleared on *any* system call that sleeps.
654 if (catch && error == 0) {
655 if ((p->p_flag & P_MAILBOX) && sig == 0) {
657 } else if (sig != 0 || (sig = CURSIG(lp))) {
658 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
664 lp->lwp_flag &= ~(LWP_BREAKTSLEEP | LWP_SINTR);
665 p->p_flag &= ~P_MAILBOX;
667 logtsleep1(tsleep_end);
673 * Interlocked spinlock sleep. An exclusively held spinlock must
674 * be passed to msleep(). The function will atomically release the
675 * spinlock and tsleep on the ident, then reacquire the spinlock and
678 * This routine is fairly important along the critical path, so optimize it
682 msleep(void *ident, struct spinlock *spin, int flags,
683 const char *wmesg, int timo)
685 globaldata_t gd = mycpu;
688 _tsleep_interlock(gd, ident, flags);
689 spin_unlock_wr_quick(gd, spin);
690 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
691 spin_lock_wr_quick(gd, spin);
697 * Interlocked serializer sleep. An exclusively held serializer must
698 * be passed to serialize_sleep(). The function will atomically release
699 * the serializer and tsleep on the ident, then reacquire the serializer
703 serialize_sleep(void *ident, struct lwkt_serialize *slz, int flags,
704 const char *wmesg, int timo)
706 globaldata_t gd = mycpu;
709 ASSERT_SERIALIZED(slz);
711 _tsleep_interlock(gd, ident, flags);
712 lwkt_serialize_exit(slz);
713 ret = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
714 lwkt_serialize_enter(slz);
720 * Directly block on the LWKT thread by descheduling it. This
721 * is much faster then tsleep(), but the only legal way to wake
722 * us up is to directly schedule the thread.
724 * Setting TDF_SINTR will cause new signals to directly schedule us.
726 * This routine must be called while in a critical section.
729 lwkt_sleep(const char *wmesg, int flags)
731 thread_t td = curthread;
734 if ((flags & PCATCH) == 0 || td->td_lwp == NULL) {
735 td->td_flags |= TDF_BLOCKED;
736 td->td_wmesg = wmesg;
737 lwkt_deschedule_self(td);
740 td->td_flags &= ~TDF_BLOCKED;
743 if ((sig = CURSIG(td->td_lwp)) != 0) {
744 if (SIGISMEMBER(td->td_proc->p_sigacts->ps_sigintr, sig))
750 td->td_flags |= TDF_BLOCKED | TDF_SINTR;
751 td->td_wmesg = wmesg;
752 lwkt_deschedule_self(td);
754 td->td_flags &= ~(TDF_BLOCKED | TDF_SINTR);
760 * Implement the timeout for tsleep.
762 * We set LWP_BREAKTSLEEP to indicate that an event has occured, but
763 * we only call setrunnable if the process is not stopped.
765 * This type of callout timeout is scheduled on the same cpu the process
766 * is sleeping on. Also, at the moment, the MP lock is held.
774 ASSERT_MP_LOCK_HELD(curthread);
778 * cpu interlock. Thread flags are only manipulated on
779 * the cpu owning the thread. proc flags are only manipulated
780 * by the older of the MP lock. We have both.
782 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
783 td->td_flags |= TDF_TIMEOUT;
785 if ((lp = td->td_lwp) != NULL) {
786 lp->lwp_flag |= LWP_BREAKTSLEEP;
787 if (lp->lwp_proc->p_stat != SSTOP)
797 * Make all processes sleeping on the specified identifier runnable.
798 * count may be zero or one only.
800 * The domain encodes the sleep/wakeup domain AND the first cpu to check
801 * (which is always the current cpu). As we iterate across cpus
803 * This call may run without the MP lock held. We can only manipulate thread
804 * state on the cpu owning the thread. We CANNOT manipulate process state
808 _wakeup(void *ident, int domain)
820 logtsleep2(wakeup_beg, ident);
823 qp = &gd->gd_tsleep_hash[id];
825 for (td = TAILQ_FIRST(qp); td != NULL; td = ntd) {
826 ntd = TAILQ_NEXT(td, td_sleepq);
827 if (td->td_wchan == ident &&
828 td->td_wdomain == (domain & PDOMAIN_MASK)
830 KKASSERT(td->td_gd == gd);
832 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
833 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
835 if (domain & PWAKEUP_ONE)
844 * We finished checking the current cpu but there still may be
845 * more work to do. Either wakeup_one was requested and no matching
846 * thread was found, or a normal wakeup was requested and we have
847 * to continue checking cpus.
849 * It should be noted that this scheme is actually less expensive then
850 * the old scheme when waking up multiple threads, since we send
851 * only one IPI message per target candidate which may then schedule
852 * multiple threads. Before we could have wound up sending an IPI
853 * message for each thread on the target cpu (!= current cpu) that
854 * needed to be woken up.
856 * NOTE: Wakeups occuring on remote cpus are asynchronous. This
857 * should be ok since we are passing idents in the IPI rather then
860 if ((domain & PWAKEUP_MYCPU) == 0 &&
861 (mask = slpque_cpumasks[id] & gd->gd_other_cpus) != 0) {
862 lwkt_send_ipiq2_mask(mask, _wakeup, ident,
863 domain | PWAKEUP_MYCPU);
867 logtsleep1(wakeup_end);
872 * Wakeup all threads tsleep()ing on the specified ident, on all cpus
877 _wakeup(ident, PWAKEUP_ENCODE(0, mycpu->gd_cpuid));
881 * Wakeup one thread tsleep()ing on the specified ident, on any cpu.
884 wakeup_one(void *ident)
886 /* XXX potentially round-robin the first responding cpu */
887 _wakeup(ident, PWAKEUP_ENCODE(0, mycpu->gd_cpuid) | PWAKEUP_ONE);
891 * Wakeup threads tsleep()ing on the specified ident on the current cpu
895 wakeup_mycpu(void *ident)
897 _wakeup(ident, PWAKEUP_MYCPU);
901 * Wakeup one thread tsleep()ing on the specified ident on the current cpu
905 wakeup_mycpu_one(void *ident)
907 /* XXX potentially round-robin the first responding cpu */
908 _wakeup(ident, PWAKEUP_MYCPU|PWAKEUP_ONE);
912 * Wakeup all thread tsleep()ing on the specified ident on the specified cpu
916 wakeup_oncpu(globaldata_t gd, void *ident)
920 _wakeup(ident, PWAKEUP_MYCPU);
922 lwkt_send_ipiq2(gd, _wakeup, ident, PWAKEUP_MYCPU);
925 _wakeup(ident, PWAKEUP_MYCPU);
930 * Wakeup one thread tsleep()ing on the specified ident on the specified cpu
934 wakeup_oncpu_one(globaldata_t gd, void *ident)
938 _wakeup(ident, PWAKEUP_MYCPU | PWAKEUP_ONE);
940 lwkt_send_ipiq2(gd, _wakeup, ident, PWAKEUP_MYCPU | PWAKEUP_ONE);
943 _wakeup(ident, PWAKEUP_MYCPU | PWAKEUP_ONE);
948 * Wakeup all threads waiting on the specified ident that slept using
949 * the specified domain, on all cpus.
952 wakeup_domain(void *ident, int domain)
954 _wakeup(ident, PWAKEUP_ENCODE(domain, mycpu->gd_cpuid));
958 * Wakeup one thread waiting on the specified ident that slept using
959 * the specified domain, on any cpu.
962 wakeup_domain_one(void *ident, int domain)
964 /* XXX potentially round-robin the first responding cpu */
965 _wakeup(ident, PWAKEUP_ENCODE(domain, mycpu->gd_cpuid) | PWAKEUP_ONE);
971 * Make a process runnable. The MP lock must be held on call. This only
972 * has an effect if we are in SSLEEP. We only break out of the
973 * tsleep if LWP_BREAKTSLEEP is set, otherwise we just fix-up the state.
975 * NOTE: With the MP lock held we can only safely manipulate the process
976 * structure. We cannot safely manipulate the thread structure.
979 setrunnable(struct lwp *lp)
982 ASSERT_MP_LOCK_HELD(curthread);
983 if (lp->lwp_stat == LSSTOP)
984 lp->lwp_stat = LSSLEEP;
985 if (lp->lwp_stat == LSSLEEP && (lp->lwp_flag & LWP_BREAKTSLEEP))
986 _tsleep_wakeup(lp->lwp_thread);
991 * The process is stopped due to some condition, usually because p_stat is
992 * set to SSTOP, but also possibly due to being traced.
994 * NOTE! If the caller sets SSTOP, the caller must also clear P_WAITED
995 * because the parent may check the child's status before the child actually
996 * gets to this routine.
998 * This routine is called with the current lwp only, typically just
999 * before returning to userland.
1001 * Setting LWP_BREAKTSLEEP before entering the tsleep will cause a passive
1002 * SIGCONT to break out of the tsleep.
1007 struct lwp *lp = curthread->td_lwp;
1008 struct proc *p = lp->lwp_proc;
1012 * If LWP_WSTOP is set, we were sleeping
1013 * while our process was stopped. At this point
1014 * we were already counted as stopped.
1016 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1018 * If we're the last thread to stop, signal
1022 lp->lwp_flag |= LWP_WSTOP;
1023 wakeup(&p->p_nstopped);
1024 if (p->p_nstopped == p->p_nthreads) {
1025 p->p_flag &= ~P_WAITED;
1027 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1028 ksignal(p->p_pptr, SIGCHLD);
1031 while (p->p_stat == SSTOP) {
1032 lp->lwp_flag |= LWP_BREAKTSLEEP;
1033 lp->lwp_stat = LSSTOP;
1034 tsleep(p, 0, "stop", 0);
1037 lp->lwp_flag &= ~LWP_WSTOP;
1042 * Yield / synchronous reschedule. This is a bit tricky because the trap
1043 * code might have set a lazy release on the switch function. Setting
1044 * P_PASSIVE_ACQ will ensure that the lazy release executes when we call
1045 * switch, and that we are given a greater chance of affinity with our
1048 * We call lwkt_setpri_self() to rotate our thread to the end of the lwkt
1049 * run queue. lwkt_switch() will also execute any assigned passive release
1050 * (which usually calls release_curproc()), allowing a same/higher priority
1051 * process to be designated as the current process.
1053 * While it is possible for a lower priority process to be designated,
1054 * it's call to lwkt_maybe_switch() in acquire_curproc() will likely
1055 * round-robin back to us and we will be able to re-acquire the current
1056 * process designation.
1061 struct thread *td = curthread;
1062 struct proc *p = td->td_proc;
1064 lwkt_setpri_self(td->td_pri & TDPRI_MASK);
1066 p->p_flag |= P_PASSIVE_ACQ;
1068 p->p_flag &= ~P_PASSIVE_ACQ;
1075 * Compute a tenex style load average of a quantity on
1076 * 1, 5 and 15 minute intervals.
1078 static int loadav_count_runnable(struct lwp *p, void *data);
1083 struct loadavg *avg;
1087 alllwp_scan(loadav_count_runnable, &nrun);
1089 for (i = 0; i < 3; i++) {
1090 avg->ldavg[i] = (cexp[i] * avg->ldavg[i] +
1091 nrun * FSCALE * (FSCALE - cexp[i])) >> FSHIFT;
1095 * Schedule the next update to occur after 5 seconds, but add a
1096 * random variation to avoid synchronisation with processes that
1097 * run at regular intervals.
1099 callout_reset(&loadav_callout, hz * 4 + (int)(krandom() % (hz * 2 + 1)),
1104 loadav_count_runnable(struct lwp *lp, void *data)
1109 switch (lp->lwp_stat) {
1111 if ((td = lp->lwp_thread) == NULL)
1113 if (td->td_flags & TDF_BLOCKED)
1125 sched_setup(void *dummy)
1127 callout_init(&loadav_callout);
1128 callout_init(&schedcpu_callout);
1130 /* Kick off timeout driven events by calling first time. */