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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/resourcevar.h>
51 #include <sys/vmmeter.h>
52 #include <sys/sysctl.h>
56 #include <sys/ktrace.h>
58 #include <sys/xwait.h>
60 #include <sys/serialize.h>
62 #include <sys/signal2.h>
63 #include <sys/thread2.h>
64 #include <sys/spinlock2.h>
65 #include <sys/mutex2.h>
67 #include <machine/cpu.h>
68 #include <machine/smp.h>
70 TAILQ_HEAD(tslpque, thread);
72 static void sched_setup (void *dummy);
73 SYSINIT(sched_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, sched_setup, NULL)
78 int sched_quantum; /* Roundrobin scheduling quantum in ticks. */
80 int ncpus2, ncpus2_shift, ncpus2_mask; /* note: mask not cpumask_t */
81 int ncpus_fit, ncpus_fit_mask; /* note: mask not cpumask_t */
84 int tsleep_crypto_dump = 0;
86 static struct callout loadav_callout;
87 static struct callout schedcpu_callout;
88 MALLOC_DEFINE(M_TSLEEP, "tslpque", "tsleep queues");
90 #define __DEALL(ident) __DEQUALIFY(void *, ident)
92 #if !defined(KTR_TSLEEP)
93 #define KTR_TSLEEP KTR_ALL
95 KTR_INFO_MASTER(tsleep);
96 KTR_INFO(KTR_TSLEEP, tsleep, tsleep_beg, 0, "tsleep enter %p", const volatile void *ident);
97 KTR_INFO(KTR_TSLEEP, tsleep, tsleep_end, 1, "tsleep exit");
98 KTR_INFO(KTR_TSLEEP, tsleep, wakeup_beg, 2, "wakeup enter %p", const volatile void *ident);
99 KTR_INFO(KTR_TSLEEP, tsleep, wakeup_end, 3, "wakeup exit");
100 KTR_INFO(KTR_TSLEEP, tsleep, ilockfail, 4, "interlock failed %p", const volatile void *ident);
102 #define logtsleep1(name) KTR_LOG(tsleep_ ## name)
103 #define logtsleep2(name, val) KTR_LOG(tsleep_ ## name, val)
105 struct loadavg averunnable =
106 { {0, 0, 0}, FSCALE }; /* load average, of runnable procs */
108 * Constants for averages over 1, 5, and 15 minutes
109 * when sampling at 5 second intervals.
111 static 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) */
117 static void endtsleep (void *);
118 static void loadav (void *arg);
119 static void schedcpu (void *arg);
122 * Adjust the scheduler quantum. The quantum is specified in microseconds.
123 * Note that 'tick' is in microseconds per tick.
126 sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
130 new_val = sched_quantum * ustick;
131 error = sysctl_handle_int(oidp, &new_val, 0, req);
132 if (error != 0 || req->newptr == NULL)
134 if (new_val < ustick)
136 sched_quantum = new_val / ustick;
137 hogticks = 2 * sched_quantum;
141 SYSCTL_PROC(_kern, OID_AUTO, quantum, CTLTYPE_INT|CTLFLAG_RW,
142 0, sizeof sched_quantum, sysctl_kern_quantum, "I", "");
145 * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the
146 * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below
147 * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT).
149 * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used:
150 * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits).
152 * If you don't want to bother with the faster/more-accurate formula, you
153 * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate
154 * (more general) method of calculating the %age of CPU used by a process.
156 * decay 95% of `lwp_pctcpu' in 60 seconds; see CCPU_SHIFT before changing
158 #define CCPU_SHIFT 11
160 static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
161 SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
164 * kernel uses `FSCALE', userland (SHOULD) use kern.fscale
166 int fscale __unused = FSCALE; /* exported to systat */
167 SYSCTL_INT(_kern, OID_AUTO, fscale, CTLFLAG_RD, 0, FSCALE, "");
170 * Recompute process priorities, once a second.
172 * Since the userland schedulers are typically event oriented, if the
173 * estcpu calculation at wakeup() time is not sufficient to make a
174 * process runnable relative to other processes in the system we have
175 * a 1-second recalc to help out.
177 * This code also allows us to store sysclock_t data in the process structure
178 * without fear of an overrun, since sysclock_t are guarenteed to hold
179 * several seconds worth of count.
181 * WARNING! callouts can preempt normal threads. However, they will not
182 * preempt a thread holding a spinlock so we *can* safely use spinlocks.
184 static int schedcpu_stats(struct proc *p, void *data __unused);
185 static int schedcpu_resource(struct proc *p, void *data __unused);
190 allproc_scan(schedcpu_stats, NULL);
191 allproc_scan(schedcpu_resource, NULL);
192 wakeup((caddr_t)&lbolt);
193 wakeup(lbolt_syncer);
194 callout_reset(&schedcpu_callout, hz, schedcpu, NULL);
198 * General process statistics once a second
201 schedcpu_stats(struct proc *p, void *data __unused)
206 * Threads may not be completely set up if process in SIDL state.
208 if (p->p_stat == SIDL)
212 if (lwkt_trytoken(&p->p_token) == FALSE) {
218 FOREACH_LWP_IN_PROC(lp, p) {
219 if (lp->lwp_stat == LSSLEEP)
223 * Only recalculate processes that are active or have slept
224 * less then 2 seconds. The schedulers understand this.
226 if (lp->lwp_slptime <= 1) {
227 p->p_usched->recalculate(lp);
229 lp->lwp_pctcpu = (lp->lwp_pctcpu * ccpu) >> FSHIFT;
232 lwkt_reltoken(&p->p_token);
239 * Resource checks. XXX break out since ksignal/killproc can block,
240 * limiting us to one process killed per second. There is probably
244 schedcpu_resource(struct proc *p, void *data __unused)
249 if (p->p_stat == SIDL)
253 if (lwkt_trytoken(&p->p_token) == FALSE) {
258 if (p->p_stat == SZOMB || p->p_limit == NULL) {
259 lwkt_reltoken(&p->p_token);
265 FOREACH_LWP_IN_PROC(lp, p) {
267 * We may have caught an lp in the middle of being
268 * created, lwp_thread can be NULL.
270 if (lp->lwp_thread) {
271 ttime += lp->lwp_thread->td_sticks;
272 ttime += lp->lwp_thread->td_uticks;
276 switch(plimit_testcpulimit(p->p_limit, ttime)) {
277 case PLIMIT_TESTCPU_KILL:
278 killproc(p, "exceeded maximum CPU limit");
280 case PLIMIT_TESTCPU_XCPU:
281 if ((p->p_flags & P_XCPU) == 0) {
282 p->p_flags |= P_XCPU;
289 lwkt_reltoken(&p->p_token);
296 * This is only used by ps. Generate a cpu percentage use over
297 * a period of one second.
302 updatepcpu(struct lwp *lp, int cpticks, int ttlticks)
307 acc = (cpticks << FSHIFT) / ttlticks;
308 if (ttlticks >= ESTCPUFREQ) {
309 lp->lwp_pctcpu = acc;
311 remticks = ESTCPUFREQ - ttlticks;
312 lp->lwp_pctcpu = (acc * ttlticks + lp->lwp_pctcpu * remticks) /
318 * tsleep/wakeup hash table parameters. Try to find the sweet spot for
319 * like addresses being slept on.
321 #define TABLESIZE 4001
322 #define LOOKUP(x) (((u_int)(uintptr_t)(x)) % TABLESIZE)
324 static cpumask_t slpque_cpumasks[TABLESIZE];
327 * General scheduler initialization. We force a reschedule 25 times
328 * a second by default. Note that cpu0 is initialized in early boot and
329 * cannot make any high level calls.
331 * Each cpu has its own sleep queue.
334 sleep_gdinit(globaldata_t gd)
336 static struct tslpque slpque_cpu0[TABLESIZE];
339 if (gd->gd_cpuid == 0) {
340 sched_quantum = (hz + 24) / 25;
341 hogticks = 2 * sched_quantum;
343 gd->gd_tsleep_hash = slpque_cpu0;
345 gd->gd_tsleep_hash = kmalloc(sizeof(slpque_cpu0),
346 M_TSLEEP, M_WAITOK | M_ZERO);
348 for (i = 0; i < TABLESIZE; ++i)
349 TAILQ_INIT(&gd->gd_tsleep_hash[i]);
353 * This is a dandy function that allows us to interlock tsleep/wakeup
354 * operations with unspecified upper level locks, such as lockmgr locks,
355 * simply by holding a critical section. The sequence is:
357 * (acquire upper level lock)
358 * tsleep_interlock(blah)
359 * (release upper level lock)
362 * Basically this functions queues us on the tsleep queue without actually
363 * descheduling us. When tsleep() is later called with PINTERLOCK it
364 * assumes the thread was already queued, otherwise it queues it there.
366 * Thus it is possible to receive the wakeup prior to going to sleep and
367 * the race conditions are covered.
370 _tsleep_interlock(globaldata_t gd, const volatile void *ident, int flags)
372 thread_t td = gd->gd_curthread;
375 crit_enter_quick(td);
376 if (td->td_flags & TDF_TSLEEPQ) {
377 id = LOOKUP(td->td_wchan);
378 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
379 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL) {
380 atomic_clear_cpumask(&slpque_cpumasks[id],
384 td->td_flags |= TDF_TSLEEPQ;
387 TAILQ_INSERT_TAIL(&gd->gd_tsleep_hash[id], td, td_sleepq);
388 atomic_set_cpumask(&slpque_cpumasks[id], gd->gd_cpumask);
389 td->td_wchan = ident;
390 td->td_wdomain = flags & PDOMAIN_MASK;
395 tsleep_interlock(const volatile void *ident, int flags)
397 _tsleep_interlock(mycpu, ident, flags);
401 * Remove thread from sleepq. Must be called with a critical section held.
402 * The thread must not be migrating.
405 _tsleep_remove(thread_t td)
407 globaldata_t gd = mycpu;
410 KKASSERT(td->td_gd == gd && IN_CRITICAL_SECT(td));
411 KKASSERT((td->td_flags & TDF_MIGRATING) == 0);
412 if (td->td_flags & TDF_TSLEEPQ) {
413 td->td_flags &= ~TDF_TSLEEPQ;
414 id = LOOKUP(td->td_wchan);
415 TAILQ_REMOVE(&gd->gd_tsleep_hash[id], td, td_sleepq);
416 if (TAILQ_FIRST(&gd->gd_tsleep_hash[id]) == NULL)
417 atomic_clear_cpumask(&slpque_cpumasks[id], gd->gd_cpumask);
424 tsleep_remove(thread_t td)
430 * General sleep call. Suspends the current process until a wakeup is
431 * performed on the specified identifier. The process will then be made
432 * runnable with the specified priority. Sleeps at most timo/hz seconds
433 * (0 means no timeout). If flags includes PCATCH flag, signals are checked
434 * before and after sleeping, else signals are not checked. Returns 0 if
435 * awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a
436 * signal needs to be delivered, ERESTART is returned if the current system
437 * call should be restarted if possible, and EINTR is returned if the system
438 * call should be interrupted by the signal (return EINTR).
440 * Note that if we are a process, we release_curproc() before messing with
441 * the LWKT scheduler.
443 * During autoconfiguration or after a panic, a sleep will simply
444 * lower the priority briefly to allow interrupts, then return.
446 * WARNING! This code can't block (short of switching away), or bad things
447 * will happen. No getting tokens, no blocking locks, etc.
450 tsleep(const volatile void *ident, int flags, const char *wmesg, int timo)
452 struct thread *td = curthread;
453 struct lwp *lp = td->td_lwp;
454 struct proc *p = td->td_proc; /* may be NULL */
460 struct callout thandle;
463 * NOTE: removed KTRPOINT, it could cause races due to blocking
464 * even in stable. Just scrap it for now.
466 if (!tsleep_crypto_dump && (tsleep_now_works == 0 || panicstr)) {
468 * After a panic, or before we actually have an operational
469 * softclock, just give interrupts a chance, then just return;
471 * don't run any other procs or panic below,
472 * in case this is the idle process and already asleep.
476 lwkt_setpri_self(safepri);
478 lwkt_setpri_self(oldpri);
481 logtsleep2(tsleep_beg, ident);
483 KKASSERT(td != &gd->gd_idlethread); /* you must be kidding! */
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
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() (ours or the callers), and here. This can
558 * occur under numerous circumstances including when we release the
561 * Extreme loads can cause the sending of an IPI (e.g. wakeup()'s)
562 * to process incoming IPIs, thus draining incoming wakeups.
564 if ((td->td_flags & TDF_TSLEEPQ) == 0) {
565 logtsleep2(ilockfail, ident);
570 * scheduling is blocked while in a critical section. Coincide
571 * the descheduled-by-tsleep flag with the descheduling of the
574 * The timer callout is localized on our cpu and interlocked by
575 * our critical section.
577 lwkt_deschedule_self(td);
578 td->td_flags |= TDF_TSLEEP_DESCHEDULED;
579 td->td_wmesg = wmesg;
582 * Setup the timeout, if any. The timeout is only operable while
583 * the thread is flagged descheduled.
585 KKASSERT((td->td_flags & TDF_TIMEOUT) == 0);
587 callout_init_mp(&thandle);
588 callout_reset(&thandle, timo, endtsleep, td);
596 * Ok, we are sleeping. Place us in the SSLEEP state.
598 KKASSERT((lp->lwp_mpflags & LWP_MP_ONRUNQ) == 0);
600 * tstop() sets LSSTOP, so don't fiddle with that.
602 if (lp->lwp_stat != LSSTOP)
603 lp->lwp_stat = LSSLEEP;
604 lp->lwp_ru.ru_nvcsw++;
608 * And when we are woken up, put us back in LSRUN. If we
609 * slept for over a second, recalculate our estcpu.
611 lp->lwp_stat = LSRUN;
613 p->p_usched->recalculate(lp);
620 * Make sure we haven't switched cpus while we were asleep. It's
621 * not supposed to happen. Cleanup our temporary flags.
623 KKASSERT(gd == td->td_gd);
626 * Cleanup the timeout. If the timeout has already occured thandle
627 * has already been stopped, otherwise stop thandle. If the timeout
628 * is running (the callout thread must be blocked trying to get
629 * lwp_token) then wait for us to get scheduled.
632 while (td->td_flags & TDF_TIMEOUT_RUNNING) {
633 lwkt_deschedule_self(td);
634 td->td_wmesg = "tsrace";
636 kprintf("td %p %s: timeout race\n", td, td->td_comm);
638 if (td->td_flags & TDF_TIMEOUT) {
639 td->td_flags &= ~TDF_TIMEOUT;
642 /* does not block when on same cpu */
643 callout_stop(&thandle);
646 td->td_flags &= ~TDF_TSLEEP_DESCHEDULED;
649 * Make sure we have been removed from the sleepq. In most
650 * cases this will have been done for us already but it is
651 * possible for a scheduling IPI to be in-flight from a
652 * previous tsleep/tsleep_interlock() or due to a straight-out
653 * call to lwkt_schedule() (in the case of an interrupt thread),
654 * causing a spurious wakeup.
660 * Figure out the correct error return. If interrupted by a
661 * signal we want to return EINTR or ERESTART.
665 if (catch && error == 0) {
666 if (sig != 0 || (sig = CURSIG(lp))) {
667 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
673 lp->lwp_flags &= ~LWP_SINTR;
674 lwkt_reltoken(&lp->lwp_token);
676 logtsleep1(tsleep_end);
682 * Interlocked spinlock sleep. An exclusively held spinlock must
683 * be passed to ssleep(). The function will atomically release the
684 * spinlock and tsleep on the ident, then reacquire the spinlock and
687 * This routine is fairly important along the critical path, so optimize it
691 ssleep(const volatile void *ident, struct spinlock *spin, int flags,
692 const char *wmesg, int timo)
694 globaldata_t gd = mycpu;
697 _tsleep_interlock(gd, ident, flags);
698 spin_unlock_quick(gd, spin);
699 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
700 spin_lock_quick(gd, spin);
706 lksleep(const volatile void *ident, struct lock *lock, int flags,
707 const char *wmesg, int timo)
709 globaldata_t gd = mycpu;
712 _tsleep_interlock(gd, ident, flags);
713 lockmgr(lock, LK_RELEASE);
714 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
715 lockmgr(lock, LK_EXCLUSIVE);
721 * Interlocked mutex sleep. An exclusively held mutex must be passed
722 * to mtxsleep(). The function will atomically release the mutex
723 * and tsleep on the ident, then reacquire the mutex and return.
726 mtxsleep(const volatile void *ident, struct mtx *mtx, int flags,
727 const char *wmesg, int timo)
729 globaldata_t gd = mycpu;
732 _tsleep_interlock(gd, ident, flags);
734 error = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
735 mtx_lock_ex_quick(mtx, wmesg);
741 * Interlocked serializer sleep. An exclusively held serializer must
742 * be passed to zsleep(). The function will atomically release
743 * the serializer and tsleep on the ident, then reacquire the serializer
747 zsleep(const volatile void *ident, struct lwkt_serialize *slz, int flags,
748 const char *wmesg, int timo)
750 globaldata_t gd = mycpu;
753 ASSERT_SERIALIZED(slz);
755 _tsleep_interlock(gd, ident, flags);
756 lwkt_serialize_exit(slz);
757 ret = tsleep(ident, flags | PINTERLOCKED, wmesg, timo);
758 lwkt_serialize_enter(slz);
764 * Directly block on the LWKT thread by descheduling it. This
765 * is much faster then tsleep(), but the only legal way to wake
766 * us up is to directly schedule the thread.
768 * Setting TDF_SINTR will cause new signals to directly schedule us.
770 * This routine must be called while in a critical section.
773 lwkt_sleep(const char *wmesg, int flags)
775 thread_t td = curthread;
778 if ((flags & PCATCH) == 0 || td->td_lwp == NULL) {
779 td->td_flags |= TDF_BLOCKED;
780 td->td_wmesg = wmesg;
781 lwkt_deschedule_self(td);
784 td->td_flags &= ~TDF_BLOCKED;
787 if ((sig = CURSIG(td->td_lwp)) != 0) {
788 if (SIGISMEMBER(td->td_proc->p_sigacts->ps_sigintr, sig))
794 td->td_flags |= TDF_BLOCKED | TDF_SINTR;
795 td->td_wmesg = wmesg;
796 lwkt_deschedule_self(td);
798 td->td_flags &= ~(TDF_BLOCKED | TDF_SINTR);
804 * Implement the timeout for tsleep.
806 * This type of callout timeout is scheduled on the same cpu the process
807 * is sleeping on. Also, at the moment, the MP lock is held.
816 * We are going to have to get the lwp_token, which means we might
817 * block. This can race a tsleep getting woken up by other means
818 * so set TDF_TIMEOUT_RUNNING to force the tsleep to wait for our
819 * processing to complete (sorry tsleep!).
821 * We can safely set td_flags because td MUST be on the same cpu
824 KKASSERT(td->td_gd == mycpu);
826 td->td_flags |= TDF_TIMEOUT_RUNNING | TDF_TIMEOUT;
829 * This can block but TDF_TIMEOUT_RUNNING will prevent the thread
830 * from exiting the tsleep on us. The flag is interlocked by virtue
831 * of lp being on the same cpu as we are.
833 if ((lp = td->td_lwp) != NULL)
834 lwkt_gettoken(&lp->lwp_token);
836 KKASSERT(td->td_flags & TDF_TSLEEP_DESCHEDULED);
839 if (lp->lwp_proc->p_stat != SSTOP)
841 lwkt_reltoken(&lp->lwp_token);
846 KKASSERT(td->td_gd == mycpu);
847 td->td_flags &= ~TDF_TIMEOUT_RUNNING;
852 * Make all processes sleeping on the specified identifier runnable.
853 * count may be zero or one only.
855 * The domain encodes the sleep/wakeup domain AND the first cpu to check
856 * (which is always the current cpu). As we iterate across cpus
858 * This call may run without the MP lock held. We can only manipulate thread
859 * state on the cpu owning the thread. We CANNOT manipulate process state
862 * _wakeup() can be passed to an IPI so we can't use (const volatile
866 _wakeup(void *ident, int domain)
878 logtsleep2(wakeup_beg, ident);
881 qp = &gd->gd_tsleep_hash[id];
883 for (td = TAILQ_FIRST(qp); td != NULL; td = ntd) {
884 ntd = TAILQ_NEXT(td, td_sleepq);
885 if (td->td_wchan == ident &&
886 td->td_wdomain == (domain & PDOMAIN_MASK)
888 KKASSERT(td->td_gd == gd);
890 if (td->td_flags & TDF_TSLEEP_DESCHEDULED) {
892 if (domain & PWAKEUP_ONE)
901 * We finished checking the current cpu but there still may be
902 * more work to do. Either wakeup_one was requested and no matching
903 * thread was found, or a normal wakeup was requested and we have
904 * to continue checking cpus.
906 * It should be noted that this scheme is actually less expensive then
907 * the old scheme when waking up multiple threads, since we send
908 * only one IPI message per target candidate which may then schedule
909 * multiple threads. Before we could have wound up sending an IPI
910 * message for each thread on the target cpu (!= current cpu) that
911 * needed to be woken up.
913 * NOTE: Wakeups occuring on remote cpus are asynchronous. This
914 * should be ok since we are passing idents in the IPI rather then
917 if ((domain & PWAKEUP_MYCPU) == 0 &&
918 (mask = slpque_cpumasks[id] & gd->gd_other_cpus) != 0) {
919 lwkt_send_ipiq2_mask(mask, _wakeup, ident,
920 domain | PWAKEUP_MYCPU);
924 logtsleep1(wakeup_end);
929 * Wakeup all threads tsleep()ing on the specified ident, on all cpus
932 wakeup(const volatile void *ident)
934 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid));
938 * Wakeup one thread tsleep()ing on the specified ident, on any cpu.
941 wakeup_one(const volatile void *ident)
943 /* XXX potentially round-robin the first responding cpu */
944 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(0, mycpu->gd_cpuid) | PWAKEUP_ONE);
948 * Wakeup threads tsleep()ing on the specified ident on the current cpu
952 wakeup_mycpu(const volatile void *ident)
954 _wakeup(__DEALL(ident), PWAKEUP_MYCPU);
958 * Wakeup one thread tsleep()ing on the specified ident on the current cpu
962 wakeup_mycpu_one(const volatile void *ident)
964 /* XXX potentially round-robin the first responding cpu */
965 _wakeup(__DEALL(ident), PWAKEUP_MYCPU|PWAKEUP_ONE);
969 * Wakeup all thread tsleep()ing on the specified ident on the specified cpu
973 wakeup_oncpu(globaldata_t gd, const volatile void *ident)
977 _wakeup(__DEALL(ident), PWAKEUP_MYCPU);
979 lwkt_send_ipiq2(gd, _wakeup, __DEALL(ident), PWAKEUP_MYCPU);
982 _wakeup(__DEALL(ident), PWAKEUP_MYCPU);
987 * Wakeup one thread tsleep()ing on the specified ident on the specified cpu
991 wakeup_oncpu_one(globaldata_t gd, const volatile void *ident)
995 _wakeup(__DEALL(ident), PWAKEUP_MYCPU | PWAKEUP_ONE);
997 lwkt_send_ipiq2(gd, _wakeup, __DEALL(ident),
998 PWAKEUP_MYCPU | PWAKEUP_ONE);
1001 _wakeup(__DEALL(ident), PWAKEUP_MYCPU | PWAKEUP_ONE);
1006 * Wakeup all threads waiting on the specified ident that slept using
1007 * the specified domain, on all cpus.
1010 wakeup_domain(const volatile void *ident, int domain)
1012 _wakeup(__DEALL(ident), PWAKEUP_ENCODE(domain, mycpu->gd_cpuid));
1016 * Wakeup one thread waiting on the specified ident that slept using
1017 * the specified domain, on any cpu.
1020 wakeup_domain_one(const volatile void *ident, int domain)
1022 /* XXX potentially round-robin the first responding cpu */
1023 _wakeup(__DEALL(ident),
1024 PWAKEUP_ENCODE(domain, mycpu->gd_cpuid) | PWAKEUP_ONE);
1030 * Make a process runnable. lp->lwp_token must be held on call and this
1031 * function must be called from the cpu owning lp.
1033 * This only has an effect if we are in LSSTOP or LSSLEEP.
1036 setrunnable(struct lwp *lp)
1038 thread_t td = lp->lwp_thread;
1040 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_token);
1041 KKASSERT(td->td_gd == mycpu);
1043 if (lp->lwp_stat == LSSTOP)
1044 lp->lwp_stat = LSSLEEP;
1045 if (lp->lwp_stat == LSSLEEP) {
1048 } else if (td->td_flags & TDF_SINTR) {
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.
1058 * Caller must hold p->p_token
1060 * NOTE! If the caller sets SSTOP, the caller must also clear P_WAITED
1061 * because the parent may check the child's status before the child actually
1062 * gets to this routine.
1064 * This routine is called with the current lwp only, typically just
1065 * before returning to userland if the process state is detected as
1066 * possibly being in a stopped state.
1071 struct lwp *lp = curthread->td_lwp;
1072 struct proc *p = lp->lwp_proc;
1075 lwkt_gettoken(&lp->lwp_token);
1079 * If LWP_MP_WSTOP is set, we were sleeping
1080 * while our process was stopped. At this point
1081 * we were already counted as stopped.
1083 if ((lp->lwp_mpflags & LWP_MP_WSTOP) == 0) {
1085 * If we're the last thread to stop, signal
1089 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WSTOP);
1090 wakeup(&p->p_nstopped);
1091 if (p->p_nstopped == p->p_nthreads) {
1093 * Token required to interlock kern_wait()
1097 lwkt_gettoken(&q->p_token);
1098 p->p_flags &= ~P_WAITED;
1100 if ((q->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1101 ksignal(q, SIGCHLD);
1102 lwkt_reltoken(&q->p_token);
1106 while (p->p_stat == SSTOP) {
1107 lp->lwp_stat = LSSTOP;
1108 tsleep(p, 0, "stop", 0);
1111 atomic_clear_int(&lp->lwp_mpflags, LWP_MP_WSTOP);
1113 lwkt_reltoken(&lp->lwp_token);
1117 * Compute a tenex style load average of a quantity on
1118 * 1, 5 and 15 minute intervals.
1120 static int loadav_count_runnable(struct lwp *p, void *data);
1125 struct loadavg *avg;
1129 alllwp_scan(loadav_count_runnable, &nrun);
1131 for (i = 0; i < 3; i++) {
1132 avg->ldavg[i] = (cexp[i] * avg->ldavg[i] +
1133 nrun * FSCALE * (FSCALE - cexp[i])) >> FSHIFT;
1137 * Schedule the next update to occur after 5 seconds, but add a
1138 * random variation to avoid synchronisation with processes that
1139 * run at regular intervals.
1141 callout_reset(&loadav_callout, hz * 4 + (int)(krandom() % (hz * 2 + 1)),
1146 loadav_count_runnable(struct lwp *lp, void *data)
1151 switch (lp->lwp_stat) {
1153 if ((td = lp->lwp_thread) == NULL)
1155 if (td->td_flags & TDF_BLOCKED)
1168 sched_setup(void *dummy)
1170 callout_init_mp(&loadav_callout);
1171 callout_init_mp(&schedcpu_callout);
1173 /* Kick off timeout driven events by calling first time. */