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34 * From: @(#)kern_clock.c 8.5 (Berkeley) 1/21/94
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
40 #include "opt_kdtrace.h"
42 #include <sys/param.h>
43 #include <sys/systm.h>
45 #include <sys/callout.h>
46 #include <sys/condvar.h>
47 #include <sys/interrupt.h>
48 #include <sys/kernel.h>
51 #include <sys/malloc.h>
52 #include <sys/mutex.h>
55 #include <sys/sleepqueue.h>
56 #include <sys/sysctl.h>
60 #include <machine/cpu.h>
63 SDT_PROVIDER_DEFINE(callout_execute);
64 SDT_PROBE_DEFINE(callout_execute, kernel, , callout_start, callout-start);
65 SDT_PROBE_ARGTYPE(callout_execute, kernel, , callout_start, 0,
67 SDT_PROBE_DEFINE(callout_execute, kernel, , callout_end, callout-end);
68 SDT_PROBE_ARGTYPE(callout_execute, kernel, , callout_end, 0,
72 SYSCTL_INT(_debug, OID_AUTO, to_avg_depth, CTLFLAG_RD, &avg_depth, 0,
73 "Average number of items examined per softclock call. Units = 1/1000");
74 static int avg_gcalls;
75 SYSCTL_INT(_debug, OID_AUTO, to_avg_gcalls, CTLFLAG_RD, &avg_gcalls, 0,
76 "Average number of Giant callouts made per softclock call. Units = 1/1000");
77 static int avg_lockcalls;
78 SYSCTL_INT(_debug, OID_AUTO, to_avg_lockcalls, CTLFLAG_RD, &avg_lockcalls, 0,
79 "Average number of lock callouts made per softclock call. Units = 1/1000");
80 static int avg_mpcalls;
81 SYSCTL_INT(_debug, OID_AUTO, to_avg_mpcalls, CTLFLAG_RD, &avg_mpcalls, 0,
82 "Average number of MP callouts made per softclock call. Units = 1/1000");
85 * allocate more timeout table slots when table overflows.
87 int callwheelsize, callwheelbits, callwheelmask;
90 * The callout cpu migration entity represents informations necessary for
91 * describing the migrating callout to the new callout cpu.
92 * The cached informations are very important for deferring migration when
93 * the migrating callout is already running.
97 void (*ce_migration_func)(void *);
98 void *ce_migration_arg;
100 int ce_migration_ticks;
105 * There is one struct callout_cpu per cpu, holding all relevant
106 * state for the callout processing thread on the individual CPU.
108 * cc_ticks is incremented once per tick in callout_cpu().
109 * It tracks the global 'ticks' but in a way that the individual
110 * threads should not worry about races in the order in which
111 * hardclock() and hardclock_cpu() run on the various CPUs.
112 * cc_softclock is advanced in callout_cpu() to point to the
113 * first entry in cc_callwheel that may need handling. In turn,
114 * a softclock() is scheduled so it can serve the various entries i
115 * such that cc_softclock <= i <= cc_ticks .
116 * XXX maybe cc_softclock and cc_ticks should be volatile ?
118 * cc_ticks is also used in callout_reset_cpu() to determine
119 * when the callout should be served.
122 struct cc_mig_ent cc_migrating_entity;
124 struct callout *cc_callout;
125 struct callout_tailq *cc_callwheel;
126 struct callout_list cc_callfree;
127 struct callout *cc_next;
128 struct callout *cc_curr;
137 #define cc_migration_func cc_migrating_entity.ce_migration_func
138 #define cc_migration_arg cc_migrating_entity.ce_migration_arg
139 #define cc_migration_cpu cc_migrating_entity.ce_migration_cpu
140 #define cc_migration_ticks cc_migrating_entity.ce_migration_ticks
142 struct callout_cpu cc_cpu[MAXCPU];
143 #define CPUBLOCK MAXCPU
144 #define CC_CPU(cpu) (&cc_cpu[(cpu)])
145 #define CC_SELF() CC_CPU(PCPU_GET(cpuid))
147 struct callout_cpu cc_cpu;
148 #define CC_CPU(cpu) &cc_cpu
149 #define CC_SELF() &cc_cpu
151 #define CC_LOCK(cc) mtx_lock_spin(&(cc)->cc_lock)
152 #define CC_UNLOCK(cc) mtx_unlock_spin(&(cc)->cc_lock)
153 #define CC_LOCK_ASSERT(cc) mtx_assert(&(cc)->cc_lock, MA_OWNED)
155 static int timeout_cpu;
157 MALLOC_DEFINE(M_CALLOUT, "callout", "Callout datastructures");
161 * cc_curr - If a callout is in progress, it is curr_callout.
162 * If curr_callout is non-NULL, threads waiting in
163 * callout_drain() will be woken up as soon as the
164 * relevant callout completes.
165 * cc_cancel - Changing to 1 with both callout_lock and c_lock held
166 * guarantees that the current callout will not run.
167 * The softclock() function sets this to 0 before it
168 * drops callout_lock to acquire c_lock, and it calls
169 * the handler only if curr_cancelled is still 0 after
170 * c_lock is successfully acquired.
171 * cc_waiting - If a thread is waiting in callout_drain(), then
172 * callout_wait is nonzero. Set only when
173 * curr_callout is non-NULL.
177 * Resets the migration entity tied to a specific callout cpu.
180 cc_cme_cleanup(struct callout_cpu *cc)
184 cc->cc_migration_cpu = CPUBLOCK;
185 cc->cc_migration_ticks = 0;
186 cc->cc_migration_func = NULL;
187 cc->cc_migration_arg = NULL;
192 * Checks if migration is requested by a specific callout cpu.
195 cc_cme_migrating(struct callout_cpu *cc)
199 return (cc->cc_migration_cpu != CPUBLOCK);
206 * kern_timeout_callwheel_alloc() - kernel low level callwheel initialization
208 * This code is called very early in the kernel initialization sequence,
209 * and may be called more then once.
212 kern_timeout_callwheel_alloc(caddr_t v)
214 struct callout_cpu *cc;
216 timeout_cpu = PCPU_GET(cpuid);
217 cc = CC_CPU(timeout_cpu);
219 * Calculate callout wheel size
221 for (callwheelsize = 1, callwheelbits = 0;
222 callwheelsize < ncallout;
223 callwheelsize <<= 1, ++callwheelbits)
225 callwheelmask = callwheelsize - 1;
227 cc->cc_callout = (struct callout *)v;
228 v = (caddr_t)(cc->cc_callout + ncallout);
229 cc->cc_callwheel = (struct callout_tailq *)v;
230 v = (caddr_t)(cc->cc_callwheel + callwheelsize);
235 callout_cpu_init(struct callout_cpu *cc)
240 mtx_init(&cc->cc_lock, "callout", NULL, MTX_SPIN | MTX_RECURSE);
241 SLIST_INIT(&cc->cc_callfree);
242 for (i = 0; i < callwheelsize; i++) {
243 TAILQ_INIT(&cc->cc_callwheel[i]);
246 if (cc->cc_callout == NULL)
248 for (i = 0; i < ncallout; i++) {
249 c = &cc->cc_callout[i];
251 c->c_flags = CALLOUT_LOCAL_ALLOC;
252 SLIST_INSERT_HEAD(&cc->cc_callfree, c, c_links.sle);
258 * Switches the cpu tied to a specific callout.
259 * The function expects a locked incoming callout cpu and returns with
260 * locked outcoming callout cpu.
262 static struct callout_cpu *
263 callout_cpu_switch(struct callout *c, struct callout_cpu *cc, int new_cpu)
265 struct callout_cpu *new_cc;
267 MPASS(c != NULL && cc != NULL);
271 * Avoid interrupts and preemption firing after the callout cpu
272 * is blocked in order to avoid deadlocks as the new thread
273 * may be willing to acquire the callout cpu lock.
278 new_cc = CC_CPU(new_cpu);
287 * kern_timeout_callwheel_init() - initialize previously reserved callwheel
290 * This code is called just once, after the space reserved for the
291 * callout wheel has been finalized.
294 kern_timeout_callwheel_init(void)
296 callout_cpu_init(CC_CPU(timeout_cpu));
300 * Start standard softclock thread.
305 start_softclock(void *dummy)
307 struct callout_cpu *cc;
312 cc = CC_CPU(timeout_cpu);
313 if (swi_add(&clk_intr_event, "clock", softclock, cc, SWI_CLOCK,
314 INTR_MPSAFE, &softclock_ih))
315 panic("died while creating standard software ithreads");
316 cc->cc_cookie = softclock_ih;
319 if (cpu == timeout_cpu)
322 if (swi_add(NULL, "clock", softclock, cc, SWI_CLOCK,
323 INTR_MPSAFE, &cc->cc_cookie))
324 panic("died while creating standard software ithreads");
325 cc->cc_callout = NULL; /* Only cpu0 handles timeout(). */
326 cc->cc_callwheel = malloc(
327 sizeof(struct callout_tailq) * callwheelsize, M_CALLOUT,
329 callout_cpu_init(cc);
334 SYSINIT(start_softclock, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softclock, NULL);
339 struct callout_cpu *cc;
344 * Process callouts at a very low cpu priority, so we don't keep the
345 * relatively high clock interrupt priority any longer than necessary.
349 mtx_lock_spin_flags(&cc->cc_lock, MTX_QUIET);
351 for (; (cc->cc_softticks - cc->cc_ticks) <= 0; cc->cc_softticks++) {
352 bucket = cc->cc_softticks & callwheelmask;
353 if (!TAILQ_EMPTY(&cc->cc_callwheel[bucket])) {
358 mtx_unlock_spin_flags(&cc->cc_lock, MTX_QUIET);
360 * swi_sched acquires the thread lock, so we don't want to call it
361 * with cc_lock held; incorrect locking order.
364 swi_sched(cc->cc_cookie, 0);
367 static struct callout_cpu *
368 callout_lock(struct callout *c)
370 struct callout_cpu *cc;
376 if (cpu == CPUBLOCK) {
377 while (c->c_cpu == CPUBLOCK)
392 callout_cc_add(struct callout *c, struct callout_cpu *cc, int to_ticks,
393 void (*func)(void *), void *arg, int cpu)
401 c->c_flags |= (CALLOUT_ACTIVE | CALLOUT_PENDING);
403 c->c_time = cc->cc_ticks + to_ticks;
404 TAILQ_INSERT_TAIL(&cc->cc_callwheel[c->c_time & callwheelmask],
409 callout_cc_del(struct callout *c, struct callout_cpu *cc)
412 if (cc->cc_next == c)
413 cc->cc_next = TAILQ_NEXT(c, c_links.tqe);
414 if (c->c_flags & CALLOUT_LOCAL_ALLOC) {
416 SLIST_INSERT_HEAD(&cc->cc_callfree, c, c_links.sle);
420 static struct callout *
421 softclock_call_cc(struct callout *c, struct callout_cpu *cc, int *mpcalls,
422 int *lockcalls, int *gcalls)
424 void (*c_func)(void *);
426 struct lock_class *class;
427 struct lock_object *c_lock;
428 int c_flags, sharedlock;
430 struct callout_cpu *new_cc;
431 void (*new_func)(void *);
433 int new_cpu, new_ticks;
436 struct bintime bt1, bt2;
438 static uint64_t maxdt = 36893488147419102LL; /* 2 msec */
439 static timeout_t *lastfunc;
442 cc->cc_next = TAILQ_NEXT(c, c_links.tqe);
443 class = (c->c_lock != NULL) ? LOCK_CLASS(c->c_lock) : NULL;
444 sharedlock = (c->c_flags & CALLOUT_SHAREDLOCK) ? 0 : 1;
448 c_flags = c->c_flags;
449 if (c->c_flags & CALLOUT_LOCAL_ALLOC)
450 c->c_flags = CALLOUT_LOCAL_ALLOC;
452 c->c_flags &= ~CALLOUT_PENDING;
456 if (c_lock != NULL) {
457 class->lc_lock(c_lock, sharedlock);
459 * The callout may have been cancelled
460 * while we switched locks.
463 class->lc_unlock(c_lock);
466 /* The callout cannot be stopped now. */
469 if (c_lock == &Giant.lock_object) {
471 CTR3(KTR_CALLOUT, "callout %p func %p arg %p",
475 CTR3(KTR_CALLOUT, "callout lock %p func %p arg %p",
480 CTR3(KTR_CALLOUT, "callout mpsafe %p func %p arg %p",
486 THREAD_NO_SLEEPING();
487 SDT_PROBE(callout_execute, kernel, , callout_start, c, 0, 0, 0, 0);
489 SDT_PROBE(callout_execute, kernel, , callout_end, c, 0, 0, 0, 0);
490 THREAD_SLEEPING_OK();
493 bintime_sub(&bt2, &bt1);
494 if (bt2.frac > maxdt) {
495 if (lastfunc != c_func || bt2.frac > maxdt * 2) {
496 bintime2timespec(&bt2, &ts2);
498 "Expensive timeout(9) function: %p(%p) %jd.%09ld s\n",
499 c_func, c_arg, (intmax_t)ts2.tv_sec, ts2.tv_nsec);
505 CTR1(KTR_CALLOUT, "callout %p finished", c);
506 if ((c_flags & CALLOUT_RETURNUNLOCKED) == 0)
507 class->lc_unlock(c_lock);
511 * If the current callout is locally allocated (from
512 * timeout(9)) then put it on the freelist.
514 * Note: we need to check the cached copy of c_flags because
515 * if it was not local, then it's not safe to deref the
518 if (c_flags & CALLOUT_LOCAL_ALLOC) {
519 KASSERT(c->c_flags == CALLOUT_LOCAL_ALLOC,
520 ("corrupted callout"));
522 SLIST_INSERT_HEAD(&cc->cc_callfree, c, c_links.sle);
525 if (cc->cc_waiting) {
527 * There is someone waiting for the
528 * callout to complete.
529 * If the callout was scheduled for
530 * migration just cancel it.
532 if (cc_cme_migrating(cc))
536 wakeup(&cc->cc_waiting);
538 } else if (cc_cme_migrating(cc)) {
541 * If the callout was scheduled for
542 * migration just perform it now.
544 new_cpu = cc->cc_migration_cpu;
545 new_ticks = cc->cc_migration_ticks;
546 new_func = cc->cc_migration_func;
547 new_arg = cc->cc_migration_arg;
551 * Handle deferred callout stops
553 if ((c->c_flags & CALLOUT_DFRMIGRATION) == 0) {
555 "deferred cancelled %p func %p arg %p",
556 c, new_func, new_arg);
557 callout_cc_del(c, cc);
561 c->c_flags &= ~CALLOUT_DFRMIGRATION;
564 * It should be assert here that the
565 * callout is not destroyed but that
568 new_cc = callout_cpu_switch(c, cc, new_cpu);
569 callout_cc_add(c, new_cc, new_ticks, new_func, new_arg,
574 panic("migration should not happen");
580 return (cc->cc_next);
584 * The callout mechanism is based on the work of Adam M. Costello and
585 * George Varghese, published in a technical report entitled "Redesigning
586 * the BSD Callout and Timer Facilities" and modified slightly for inclusion
587 * in FreeBSD by Justin T. Gibbs. The original work on the data structures
588 * used in this implementation was published by G. Varghese and T. Lauck in
589 * the paper "Hashed and Hierarchical Timing Wheels: Data Structures for
590 * the Efficient Implementation of a Timer Facility" in the Proceedings of
591 * the 11th ACM Annual Symposium on Operating Systems Principles,
592 * Austin, Texas Nov 1987.
596 * Software (low priority) clock interrupt.
597 * Run periodic events from timeout queue.
602 struct callout_cpu *cc;
604 struct callout_tailq *bucket;
606 int steps; /* #steps since we last allowed interrupts */
612 #ifndef MAX_SOFTCLOCK_STEPS
613 #define MAX_SOFTCLOCK_STEPS 100 /* Maximum allowed value of steps. */
614 #endif /* MAX_SOFTCLOCK_STEPS */
621 cc = (struct callout_cpu *)arg;
623 while (cc->cc_softticks - 1 != cc->cc_ticks) {
625 * cc_softticks may be modified by hard clock, so cache
626 * it while we work on a given bucket.
628 curticks = cc->cc_softticks;
630 bucket = &cc->cc_callwheel[curticks & callwheelmask];
631 c = TAILQ_FIRST(bucket);
634 if (c->c_time != curticks) {
635 c = TAILQ_NEXT(c, c_links.tqe);
637 if (steps >= MAX_SOFTCLOCK_STEPS) {
639 /* Give interrupts a chance. */
647 TAILQ_REMOVE(bucket, c, c_links.tqe);
648 c = softclock_call_cc(c, cc, &mpcalls,
649 &lockcalls, &gcalls);
654 avg_depth += (depth * 1000 - avg_depth) >> 8;
655 avg_mpcalls += (mpcalls * 1000 - avg_mpcalls) >> 8;
656 avg_lockcalls += (lockcalls * 1000 - avg_lockcalls) >> 8;
657 avg_gcalls += (gcalls * 1000 - avg_gcalls) >> 8;
664 * Execute a function after a specified length of time.
667 * Cancel previous timeout function call.
669 * callout_handle_init --
670 * Initialize a handle so that using it with untimeout is benign.
672 * See AT&T BCI Driver Reference Manual for specification. This
673 * implementation differs from that one in that although an
674 * identification value is returned from timeout, the original
675 * arguments to timeout as well as the identifier are used to
676 * identify entries for untimeout.
678 struct callout_handle
679 timeout(ftn, arg, to_ticks)
684 struct callout_cpu *cc;
686 struct callout_handle handle;
688 cc = CC_CPU(timeout_cpu);
690 /* Fill in the next free callout structure. */
691 new = SLIST_FIRST(&cc->cc_callfree);
693 /* XXX Attempt to malloc first */
694 panic("timeout table full");
695 SLIST_REMOVE_HEAD(&cc->cc_callfree, c_links.sle);
696 callout_reset(new, to_ticks, ftn, arg);
697 handle.callout = new;
704 untimeout(ftn, arg, handle)
707 struct callout_handle handle;
709 struct callout_cpu *cc;
712 * Check for a handle that was initialized
713 * by callout_handle_init, but never used
714 * for a real timeout.
716 if (handle.callout == NULL)
719 cc = callout_lock(handle.callout);
720 if (handle.callout->c_func == ftn && handle.callout->c_arg == arg)
721 callout_stop(handle.callout);
726 callout_handle_init(struct callout_handle *handle)
728 handle->callout = NULL;
732 * New interface; clients allocate their own callout structures.
734 * callout_reset() - establish or change a timeout
735 * callout_stop() - disestablish a timeout
736 * callout_init() - initialize a callout structure so that it can
737 * safely be passed to callout_reset() and callout_stop()
739 * <sys/callout.h> defines three convenience macros:
741 * callout_active() - returns truth if callout has not been stopped,
742 * drained, or deactivated since the last time the callout was
744 * callout_pending() - returns truth if callout is still waiting for timeout
745 * callout_deactivate() - marks the callout as having been serviced
748 callout_reset_on(struct callout *c, int to_ticks, void (*ftn)(void *),
751 struct callout_cpu *cc;
755 * Don't allow migration of pre-allocated callouts lest they
758 if (c->c_flags & CALLOUT_LOCAL_ALLOC)
760 cc = callout_lock(c);
761 if (cc->cc_curr == c) {
763 * We're being asked to reschedule a callout which is
764 * currently in progress. If there is a lock then we
765 * can cancel the callout if it has not really started.
767 if (c->c_lock != NULL && !cc->cc_cancel)
768 cancelled = cc->cc_cancel = 1;
769 if (cc->cc_waiting) {
771 * Someone has called callout_drain to kill this
772 * callout. Don't reschedule.
774 CTR4(KTR_CALLOUT, "%s %p func %p arg %p",
775 cancelled ? "cancelled" : "failed to cancel",
776 c, c->c_func, c->c_arg);
781 if (c->c_flags & CALLOUT_PENDING) {
782 if (cc->cc_next == c) {
783 cc->cc_next = TAILQ_NEXT(c, c_links.tqe);
785 TAILQ_REMOVE(&cc->cc_callwheel[c->c_time & callwheelmask], c,
789 c->c_flags &= ~(CALLOUT_ACTIVE | CALLOUT_PENDING);
794 * If the callout must migrate try to perform it immediately.
795 * If the callout is currently running, just defer the migration
796 * to a more appropriate moment.
798 if (c->c_cpu != cpu) {
799 if (cc->cc_curr == c) {
800 cc->cc_migration_cpu = cpu;
801 cc->cc_migration_ticks = to_ticks;
802 cc->cc_migration_func = ftn;
803 cc->cc_migration_arg = arg;
804 c->c_flags |= CALLOUT_DFRMIGRATION;
806 "migration of %p func %p arg %p in %d to %u deferred",
807 c, c->c_func, c->c_arg, to_ticks, cpu);
811 cc = callout_cpu_switch(c, cc, cpu);
815 callout_cc_add(c, cc, to_ticks, ftn, arg, cpu);
816 CTR5(KTR_CALLOUT, "%sscheduled %p func %p arg %p in %d",
817 cancelled ? "re" : "", c, c->c_func, c->c_arg, to_ticks);
824 * Common idioms that can be optimized in the future.
827 callout_schedule_on(struct callout *c, int to_ticks, int cpu)
829 return callout_reset_on(c, to_ticks, c->c_func, c->c_arg, cpu);
833 callout_schedule(struct callout *c, int to_ticks)
835 return callout_reset_on(c, to_ticks, c->c_func, c->c_arg, c->c_cpu);
839 _callout_stop_safe(c, safe)
843 struct callout_cpu *cc, *old_cc;
844 struct lock_class *class;
845 int use_lock, sq_locked;
848 * Some old subsystems don't hold Giant while running a callout_stop(),
849 * so just discard this check for the moment.
851 if (!safe && c->c_lock != NULL) {
852 if (c->c_lock == &Giant.lock_object)
853 use_lock = mtx_owned(&Giant);
856 class = LOCK_CLASS(c->c_lock);
857 class->lc_assert(c->c_lock, LA_XLOCKED);
865 cc = callout_lock(c);
868 * If the callout was migrating while the callout cpu lock was
869 * dropped, just drop the sleepqueue lock and check the states
872 if (sq_locked != 0 && cc != old_cc) {
875 sleepq_release(&old_cc->cc_waiting);
880 panic("migration should not happen");
885 * If the callout isn't pending, it's not on the queue, so
886 * don't attempt to remove it from the queue. We can try to
887 * stop it by other means however.
889 if (!(c->c_flags & CALLOUT_PENDING)) {
890 c->c_flags &= ~CALLOUT_ACTIVE;
893 * If it wasn't on the queue and it isn't the current
894 * callout, then we can't stop it, so just bail.
896 if (cc->cc_curr != c) {
897 CTR3(KTR_CALLOUT, "failed to stop %p func %p arg %p",
898 c, c->c_func, c->c_arg);
901 sleepq_release(&cc->cc_waiting);
907 * The current callout is running (or just
908 * about to run) and blocking is allowed, so
909 * just wait for the current invocation to
912 while (cc->cc_curr == c) {
915 * Use direct calls to sleepqueue interface
916 * instead of cv/msleep in order to avoid
917 * a LOR between cc_lock and sleepqueue
918 * chain spinlocks. This piece of code
919 * emulates a msleep_spin() call actually.
921 * If we already have the sleepqueue chain
922 * locked, then we can safely block. If we
923 * don't already have it locked, however,
924 * we have to drop the cc_lock to lock
925 * it. This opens several races, so we
926 * restart at the beginning once we have
927 * both locks. If nothing has changed, then
928 * we will end up back here with sq_locked
933 sleepq_lock(&cc->cc_waiting);
940 * Migration could be cancelled here, but
941 * as long as it is still not sure when it
942 * will be packed up, just let softclock()
948 sleepq_add(&cc->cc_waiting,
949 &cc->cc_lock.lock_object, "codrain",
951 sleepq_wait(&cc->cc_waiting, 0);
955 /* Reacquire locks previously released. */
959 } else if (use_lock && !cc->cc_cancel) {
961 * The current callout is waiting for its
962 * lock which we hold. Cancel the callout
963 * and return. After our caller drops the
964 * lock, the callout will be skipped in
968 CTR3(KTR_CALLOUT, "cancelled %p func %p arg %p",
969 c, c->c_func, c->c_arg);
970 KASSERT(!cc_cme_migrating(cc),
971 ("callout wrongly scheduled for migration"));
973 KASSERT(!sq_locked, ("sleepqueue chain locked"));
975 } else if ((c->c_flags & CALLOUT_DFRMIGRATION) != 0) {
976 c->c_flags &= ~CALLOUT_DFRMIGRATION;
977 CTR3(KTR_CALLOUT, "postponing stop %p func %p arg %p",
978 c, c->c_func, c->c_arg);
982 CTR3(KTR_CALLOUT, "failed to stop %p func %p arg %p",
983 c, c->c_func, c->c_arg);
985 KASSERT(!sq_locked, ("sleepqueue chain still locked"));
989 sleepq_release(&cc->cc_waiting);
991 c->c_flags &= ~(CALLOUT_ACTIVE | CALLOUT_PENDING);
993 CTR3(KTR_CALLOUT, "cancelled %p func %p arg %p",
994 c, c->c_func, c->c_arg);
995 TAILQ_REMOVE(&cc->cc_callwheel[c->c_time & callwheelmask], c,
997 callout_cc_del(c, cc);
1004 callout_init(c, mpsafe)
1008 bzero(c, sizeof *c);
1011 c->c_flags = CALLOUT_RETURNUNLOCKED;
1013 c->c_lock = &Giant.lock_object;
1016 c->c_cpu = timeout_cpu;
1020 _callout_init_lock(c, lock, flags)
1022 struct lock_object *lock;
1025 bzero(c, sizeof *c);
1027 KASSERT((flags & ~(CALLOUT_RETURNUNLOCKED | CALLOUT_SHAREDLOCK)) == 0,
1028 ("callout_init_lock: bad flags %d", flags));
1029 KASSERT(lock != NULL || (flags & CALLOUT_RETURNUNLOCKED) == 0,
1030 ("callout_init_lock: CALLOUT_RETURNUNLOCKED with no lock"));
1031 KASSERT(lock == NULL || !(LOCK_CLASS(lock)->lc_flags &
1032 (LC_SPINLOCK | LC_SLEEPABLE)), ("%s: invalid lock class",
1034 c->c_flags = flags & (CALLOUT_RETURNUNLOCKED | CALLOUT_SHAREDLOCK);
1035 c->c_cpu = timeout_cpu;
1038 #ifdef APM_FIXUP_CALLTODO
1040 * Adjust the kernel calltodo timeout list. This routine is used after
1041 * an APM resume to recalculate the calltodo timer list values with the
1042 * number of hz's we have been sleeping. The next hardclock() will detect
1043 * that there are fired timers and run softclock() to execute them.
1045 * Please note, I have not done an exhaustive analysis of what code this
1046 * might break. I am motivated to have my select()'s and alarm()'s that
1047 * have expired during suspend firing upon resume so that the applications
1048 * which set the timer can do the maintanence the timer was for as close
1049 * as possible to the originally intended time. Testing this code for a
1050 * week showed that resuming from a suspend resulted in 22 to 25 timers
1051 * firing, which seemed independant on whether the suspend was 2 hours or
1052 * 2 days. Your milage may vary. - Ken Key <key@cs.utk.edu>
1055 adjust_timeout_calltodo(time_change)
1056 struct timeval *time_change;
1058 register struct callout *p;
1059 unsigned long delta_ticks;
1062 * How many ticks were we asleep?
1063 * (stolen from tvtohz()).
1066 /* Don't do anything */
1067 if (time_change->tv_sec < 0)
1069 else if (time_change->tv_sec <= LONG_MAX / 1000000)
1070 delta_ticks = (time_change->tv_sec * 1000000 +
1071 time_change->tv_usec + (tick - 1)) / tick + 1;
1072 else if (time_change->tv_sec <= LONG_MAX / hz)
1073 delta_ticks = time_change->tv_sec * hz +
1074 (time_change->tv_usec + (tick - 1)) / tick + 1;
1076 delta_ticks = LONG_MAX;
1078 if (delta_ticks > INT_MAX)
1079 delta_ticks = INT_MAX;
1082 * Now rip through the timer calltodo list looking for timers
1086 /* don't collide with softclock() */
1088 for (p = calltodo.c_next; p != NULL; p = p->c_next) {
1089 p->c_time -= delta_ticks;
1091 /* Break if the timer had more time on it than delta_ticks */
1095 /* take back the ticks the timer didn't use (p->c_time <= 0) */
1096 delta_ticks = -p->c_time;
1102 #endif /* APM_FIXUP_CALLTODO */