X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/1c79356b52d46aa6b508fb032f5ae709b1f2897b..39236c6e673c41db228275375ab7fdb0f837b292:/osfmk/kern/timer_call.c diff --git a/osfmk/kern/timer_call.c b/osfmk/kern/timer_call.c index e1e4bb649..a382c8607 100644 --- a/osfmk/kern/timer_call.c +++ b/osfmk/kern/timer_call.c @@ -1,323 +1,1481 @@ /* - * Copyright (c) 1993-1995, 1999-2000 Apple Computer, Inc. - * All rights reserved. + * Copyright (c) 1993-2008 Apple Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * The contents of this file constitute Original Code as defined in and - * are subject to the Apple Public Source License Version 1.1 (the - * "License"). You may not use this file except in compliance with the - * License. Please obtain a copy of the License at - * http://www.apple.com/publicsource and read it before using this file. + * This file contains Original Code and/or Modifications of Original Code + * as defined in and that are subject to the Apple Public Source License + * Version 2.0 (the 'License'). You may not use this file except in + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * unlawful or unlicensed copies of an Apple operating system, or to + * circumvent, violate, or enable the circumvention or violation of, any + * terms of an Apple operating system software license agreement. * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this file. + * + * The Original Code and all software distributed under the License are + * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the - * License for the specific language governing rights and limitations - * under the License. + * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * Please see the License for the specific language governing rights and + * limitations under the License. * - * @APPLE_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * Timer interrupt callout module. - * - * HISTORY - * - * 20 December 2000 (debo) - * Created. */ #include #include - +#include #include +#include #include +#include -decl_simple_lock_data(static,timer_call_lock) +#include -static -queue_head_t - delayed_call_queues[NCPUS]; +#if CONFIG_DTRACE +#include +#endif -static struct { - int pending_num, - pending_hiwat; - int delayed_num, - delayed_hiwat; -} timer_calls; -static boolean_t - timer_call_initialized = FALSE; +#if DEBUG +#define TIMER_ASSERT 1 +#endif -static void -timer_call_interrupt( - AbsoluteTime timestamp); +//#define TIMER_ASSERT 1 +//#define TIMER_DBG 1 -#define qe(x) ((queue_entry_t)(x)) -#define TC(x) ((timer_call_t)(x)) +#if TIMER_DBG +#define DBG(x...) kprintf("DBG: " x); +#else +#define DBG(x...) +#endif -void -timer_call_initialize(void) -{ - spl_t s; - int i; +#if TIMER_TRACE +#define TIMER_KDEBUG_TRACE KERNEL_DEBUG_CONSTANT_IST +#else +#define TIMER_KDEBUG_TRACE(x...) +#endif - if (timer_call_initialized) - panic("timer_call_initialize"); - simple_lock_init(&timer_call_lock, ETAP_MISC_TIMER); +lck_grp_t timer_call_lck_grp; +lck_attr_t timer_call_lck_attr; +lck_grp_attr_t timer_call_lck_grp_attr; - s = splclock(); - simple_lock(&timer_call_lock); +lck_grp_t timer_longterm_lck_grp; +lck_attr_t timer_longterm_lck_attr; +lck_grp_attr_t timer_longterm_lck_grp_attr; - for (i = 0; i < NCPUS; i++) - queue_init(&delayed_call_queues[i]); - clock_set_timer_func((clock_timer_func_t)timer_call_interrupt); +#define timer_queue_lock_spin(queue) \ + lck_mtx_lock_spin_always(&queue->lock_data) - timer_call_initialized = TRUE; +#define timer_queue_unlock(queue) \ + lck_mtx_unlock_always(&queue->lock_data) - simple_unlock(&timer_call_lock); - splx(s); + +#define QUEUE(x) ((queue_t)(x)) +#define MPQUEUE(x) ((mpqueue_head_t *)(x)) +#define TIMER_CALL(x) ((timer_call_t)(x)) + +/* + * The longterm timer object is a global structure holding all timers + * beyond the short-term, local timer queue threshold. The boot processor + * is responsible for moving each timer to its local timer queue + * if and when that timer becomes due within the threshold. + */ +#define TIMER_LONGTERM_NONE EndOfAllTime +#if defined(__x86_64__) +#define TIMER_LONGTERM_THRESHOLD (1ULL * NSEC_PER_SEC) +#else +#define TIMER_LONGTERM_THRESHOLD TIMER_LONGTERM_NONE +#endif + +typedef struct { + uint64_t interval; /* longterm timer interval */ + uint64_t margin; /* fudge factor (10% of interval */ + uint64_t deadline; /* first/soonest longterm deadline */ + uint64_t preempted; /* sooner timer has pre-empted */ + timer_call_t call; /* first/soonest longterm timer call */ + uint64_t deadline_set; /* next timer set */ + timer_call_data_t timer; /* timer used by threshold management */ + /* Stats: */ + uint64_t scans; /* num threshold timer scans */ + uint64_t preempts; /* num threshold reductions */ + uint64_t latency; /* average threshold latency */ + uint64_t latency_min; /* minimum threshold latency */ + uint64_t latency_max; /* maximum threshold latency */ +} threshold_t; + +typedef struct { + mpqueue_head_t queue; /* longterm timer list */ + uint64_t enqueues; /* num timers queued */ + uint64_t dequeues; /* num timers dequeued */ + uint64_t escalates; /* num timers becoming shortterm */ + uint64_t scan_time; /* last time the list was scanned */ + threshold_t threshold; /* longterm timer threshold */ +} timer_longterm_t; + +timer_longterm_t timer_longterm; + +static mpqueue_head_t *timer_longterm_queue = NULL; + +static void timer_longterm_init(void); +static void timer_longterm_callout( + timer_call_param_t p0, + timer_call_param_t p1); +extern void timer_longterm_scan( + timer_longterm_t *tlp, + uint64_t now); +static void timer_longterm_update( + timer_longterm_t *tlp); +static void timer_longterm_update_locked( + timer_longterm_t *tlp); +static mpqueue_head_t * timer_longterm_enqueue_unlocked( + timer_call_t call, + uint64_t now, + uint64_t deadline, + mpqueue_head_t ** old_queue); +static void timer_longterm_dequeued_locked( + timer_call_t call); + +uint64_t past_deadline_timers; +uint64_t past_deadline_deltas; +uint64_t past_deadline_longest; +uint64_t past_deadline_shortest = ~0ULL; +enum {PAST_DEADLINE_TIMER_ADJUSTMENT_NS = 10 * 1000}; + +uint64_t past_deadline_timer_adjustment; + +static boolean_t timer_call_enter_internal(timer_call_t call, timer_call_param_t param1, uint64_t deadline, uint64_t leeway, uint32_t flags, boolean_t ratelimited); +boolean_t mach_timer_coalescing_enabled = TRUE; + +mpqueue_head_t *timer_call_enqueue_deadline_unlocked( + timer_call_t call, + mpqueue_head_t *queue, + uint64_t deadline); + +mpqueue_head_t *timer_call_dequeue_unlocked( + timer_call_t call); + + +void +timer_call_init(void) +{ + lck_attr_setdefault(&timer_call_lck_attr); + lck_grp_attr_setdefault(&timer_call_lck_grp_attr); + lck_grp_init(&timer_call_lck_grp, "timer_call", &timer_call_lck_grp_attr); + nanotime_to_absolutetime(0, PAST_DEADLINE_TIMER_ADJUSTMENT_NS, &past_deadline_timer_adjustment); + + timer_longterm_init(); +} + + +void +timer_call_queue_init(mpqueue_head_t *queue) +{ + DBG("timer_call_queue_init(%p)\n", queue); + mpqueue_init(queue, &timer_call_lck_grp, &timer_call_lck_attr); } + void timer_call_setup( timer_call_t call, timer_call_func_t func, timer_call_param_t param0) { - call_entry_setup(call, func, param0); + DBG("timer_call_setup(%p,%p,%p)\n", call, func, param0); + call_entry_setup(CE(call), func, param0); + simple_lock_init(&(call)->lock, 0); + call->async_dequeue = FALSE; } -static __inline__ -void -_delayed_call_enqueue( - queue_t queue, - timer_call_t call) +/* + * Timer call entry locking model + * ============================== + * + * Timer call entries are linked on per-cpu timer queues which are protected + * by the queue lock and the call entry lock. The locking protocol is: + * + * 0) The canonical locking order is timer call entry followed by queue. + * + * 1) With only the entry lock held, entry.queue is valid: + * 1a) NULL: the entry is not queued, or + * 1b) non-NULL: this queue must be locked before the entry is modified. + * After locking the queue, the call.async_dequeue flag must be checked: + * 1c) TRUE: the entry was removed from the queue by another thread + * and we must NULL the entry.queue and reset this flag, or + * 1d) FALSE: (ie. queued), the entry can be manipulated. + * + * 2) If a queue lock is obtained first, the queue is stable: + * 2a) If a try-lock of a queued entry succeeds, the call can be operated on + * and dequeued. + * 2b) If a try-lock fails, it indicates that another thread is attempting + * to change the entry and move it to a different position in this queue + * or to different queue. The entry can be dequeued but it should not be + * operated upon since it is being changed. Furthermore, we don't null + * the entry.queue pointer (protected by the entry lock we don't own). + * Instead, we set the async_dequeue flag -- see (1c). + * 2c) Same as 2b but occurring when a longterm timer is matured. + */ + +/* + * Inlines timer_call_entry_dequeue() and timer_call_entry_enqueue_deadline() + * cast between pointer types (mpqueue_head_t *) and (queue_t) so that + * we can use the call_entry_dequeue() and call_entry_enqueue_deadline() + * methods to operate on timer_call structs as if they are call_entry structs. + * These structures are identical except for their queue head pointer fields. + * + * In the debug case, we assert that the timer call locking protocol + * is being obeyed. + */ +#if TIMER_ASSERT +static __inline__ mpqueue_head_t * +timer_call_entry_dequeue( + timer_call_t entry) { - timer_call_t current; + mpqueue_head_t *old_queue = MPQUEUE(CE(entry)->queue); + + if (!hw_lock_held((hw_lock_t)&entry->lock)) + panic("_call_entry_dequeue() " + "entry %p is not locked\n", entry); + /* + * XXX The queue lock is actually a mutex in spin mode + * but there's no way to test for it being held + * so we pretend it's a spinlock! + */ + if (!hw_lock_held((hw_lock_t)&old_queue->lock_data)) + panic("_call_entry_dequeue() " + "queue %p is not locked\n", old_queue); + + call_entry_dequeue(CE(entry)); + old_queue->count--; + + return (old_queue); +} - current = TC(queue_first(queue)); +static __inline__ mpqueue_head_t * +timer_call_entry_enqueue_deadline( + timer_call_t entry, + mpqueue_head_t *queue, + uint64_t deadline) +{ + mpqueue_head_t *old_queue = MPQUEUE(CE(entry)->queue); + + if (!hw_lock_held((hw_lock_t)&entry->lock)) + panic("_call_entry_enqueue_deadline() " + "entry %p is not locked\n", entry); + /* XXX More lock pretense: */ + if (!hw_lock_held((hw_lock_t)&queue->lock_data)) + panic("_call_entry_enqueue_deadline() " + "queue %p is not locked\n", queue); + if (old_queue != NULL && old_queue != queue) + panic("_call_entry_enqueue_deadline() " + "old_queue %p != queue", old_queue); + + call_entry_enqueue_deadline(CE(entry), QUEUE(queue), deadline); + +/* For efficiency, track the earliest soft deadline on the queue, so that + * fuzzy decisions can be made without lock acquisitions. + */ + queue->earliest_soft_deadline = ((timer_call_t)queue_first(&queue->head))->soft_deadline; - while (TRUE) { - if ( queue_end(queue, qe(current)) || - CMP_ABSOLUTETIME(&call->deadline, - ¤t->deadline) < 0 ) { - current = TC(queue_prev(qe(current))); - break; - } + if (old_queue) + old_queue->count--; + queue->count++; - current = TC(queue_next(qe(current))); - } + return (old_queue); +} - insque(qe(call), qe(current)); - if (++timer_calls.delayed_num > timer_calls.delayed_hiwat) - timer_calls.delayed_hiwat = timer_calls.delayed_num; +#else + +static __inline__ mpqueue_head_t * +timer_call_entry_dequeue( + timer_call_t entry) +{ + mpqueue_head_t *old_queue = MPQUEUE(CE(entry)->queue); - call->state = DELAYED; + call_entry_dequeue(CE(entry)); + old_queue->count--; + + return old_queue; } -static __inline__ -void -_delayed_call_dequeue( - timer_call_t call) +static __inline__ mpqueue_head_t * +timer_call_entry_enqueue_deadline( + timer_call_t entry, + mpqueue_head_t *queue, + uint64_t deadline) { - (void)remque(qe(call)); - timer_calls.delayed_num--; + mpqueue_head_t *old_queue = MPQUEUE(CE(entry)->queue); + + call_entry_enqueue_deadline(CE(entry), QUEUE(queue), deadline); - call->state = IDLE; + /* For efficiency, track the earliest soft deadline on the queue, + * so that fuzzy decisions can be made without lock acquisitions. + */ + queue->earliest_soft_deadline = ((timer_call_t)queue_first(&queue->head))->soft_deadline; + + if (old_queue) + old_queue->count--; + queue->count++; + + return old_queue; } -static __inline__ -void -_pending_call_enqueue( - queue_t queue, - timer_call_t call) +#endif + +static __inline__ void +timer_call_entry_enqueue_tail( + timer_call_t entry, + mpqueue_head_t *queue) { - enqueue_tail(queue, qe(call)); - if (++timer_calls.pending_num > timer_calls.pending_hiwat) - timer_calls.pending_hiwat = timer_calls.pending_num; + call_entry_enqueue_tail(CE(entry), QUEUE(queue)); + queue->count++; + return; +} - call->state = PENDING; +/* + * Remove timer entry from its queue but don't change the queue pointer + * and set the async_dequeue flag. This is locking case 2b. + */ +static __inline__ void +timer_call_entry_dequeue_async( + timer_call_t entry) +{ + mpqueue_head_t *old_queue = MPQUEUE(CE(entry)->queue); + if (old_queue) { + old_queue->count--; + (void) remque(qe(entry)); + entry->async_dequeue = TRUE; + } + return; } -static __inline__ -void -_pending_call_dequeue( - timer_call_t call) +#if TIMER_ASSERT +unsigned timer_call_enqueue_deadline_unlocked_async1; +unsigned timer_call_enqueue_deadline_unlocked_async2; +#endif +/* + * Assumes call_entry and queues unlocked, interrupts disabled. + */ +__inline__ mpqueue_head_t * +timer_call_enqueue_deadline_unlocked( + timer_call_t call, + mpqueue_head_t *queue, + uint64_t deadline) { - (void)remque(qe(call)); - timer_calls.pending_num--; + call_entry_t entry = CE(call); + mpqueue_head_t *old_queue; + + DBG("timer_call_enqueue_deadline_unlocked(%p,%p,)\n", call, queue); + + simple_lock(&call->lock); + old_queue = MPQUEUE(entry->queue); + if (old_queue != NULL) { + timer_queue_lock_spin(old_queue); + if (call->async_dequeue) { + /* collision (1c): timer already dequeued, clear flag */ +#if TIMER_ASSERT + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_ASYNC_DEQ | DBG_FUNC_NONE, + call, + call->async_dequeue, + CE(call)->queue, + 0x1c, 0); + timer_call_enqueue_deadline_unlocked_async1++; +#endif + call->async_dequeue = FALSE; + entry->queue = NULL; + } else if (old_queue != queue) { + timer_call_entry_dequeue(call); +#if TIMER_ASSERT + timer_call_enqueue_deadline_unlocked_async2++; +#endif + } + if (old_queue == timer_longterm_queue) + timer_longterm_dequeued_locked(call); + if (old_queue != queue) { + timer_queue_unlock(old_queue); + timer_queue_lock_spin(queue); + } + } else { + timer_queue_lock_spin(queue); + } - call->state = IDLE; + timer_call_entry_enqueue_deadline(call, queue, deadline); + timer_queue_unlock(queue); + simple_unlock(&call->lock); + + return (old_queue); } -static __inline__ -void -_set_delayed_call_timer( - timer_call_t call) +#if TIMER_ASSERT +unsigned timer_call_dequeue_unlocked_async1; +unsigned timer_call_dequeue_unlocked_async2; +#endif +mpqueue_head_t * +timer_call_dequeue_unlocked( + timer_call_t call) { - clock_set_timer_deadline(call->deadline); + call_entry_t entry = CE(call); + mpqueue_head_t *old_queue; + + DBG("timer_call_dequeue_unlocked(%p)\n", call); + + simple_lock(&call->lock); + old_queue = MPQUEUE(entry->queue); +#if TIMER_ASSERT + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_ASYNC_DEQ | DBG_FUNC_NONE, + call, + call->async_dequeue, + CE(call)->queue, + 0, 0); +#endif + if (old_queue != NULL) { + timer_queue_lock_spin(old_queue); + if (call->async_dequeue) { + /* collision (1c): timer already dequeued, clear flag */ +#if TIMER_ASSERT + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_ASYNC_DEQ | DBG_FUNC_NONE, + call, + call->async_dequeue, + CE(call)->queue, + 0x1c, 0); + timer_call_dequeue_unlocked_async1++; +#endif + call->async_dequeue = FALSE; + entry->queue = NULL; + } else { + timer_call_entry_dequeue(call); + } + if (old_queue == timer_longterm_queue) + timer_longterm_dequeued_locked(call); + timer_queue_unlock(old_queue); + } + simple_unlock(&call->lock); + return (old_queue); } -boolean_t -timer_call_enter( - timer_call_t call, - AbsoluteTime deadline) +static boolean_t +timer_call_enter_internal( + timer_call_t call, + timer_call_param_t param1, + uint64_t deadline, + uint64_t leeway, + uint32_t flags, + boolean_t ratelimited) { - boolean_t result = TRUE; - queue_t delayed; + mpqueue_head_t *queue = NULL; + mpqueue_head_t *old_queue; spl_t s; + uint64_t slop; + uint32_t urgency; s = splclock(); - simple_lock(&timer_call_lock); - if (call->state == PENDING) - _pending_call_dequeue(call); - else if (call->state == DELAYED) - _delayed_call_dequeue(call); - else if (call->state == IDLE) - result = FALSE; + call->soft_deadline = deadline; + call->flags = flags; + + uint64_t ctime = mach_absolute_time(); + + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_ENTER | DBG_FUNC_START, + call, + param1, deadline, flags, 0); + + urgency = (flags & TIMER_CALL_URGENCY_MASK); + + boolean_t slop_ratelimited = FALSE; + slop = timer_call_slop(deadline, ctime, urgency, current_thread(), &slop_ratelimited); + + if ((flags & TIMER_CALL_LEEWAY) != 0 && leeway > slop) + slop = leeway; + + if (UINT64_MAX - deadline <= slop) { + deadline = UINT64_MAX; + } else { + deadline += slop; + } + + if (__improbable(deadline < ctime)) { + uint64_t delta = (ctime - deadline); - call->param1 = 0; - call->deadline = deadline; + past_deadline_timers++; + past_deadline_deltas += delta; + if (delta > past_deadline_longest) + past_deadline_longest = deadline; + if (delta < past_deadline_shortest) + past_deadline_shortest = delta; - delayed = &delayed_call_queues[cpu_number()]; + deadline = ctime + past_deadline_timer_adjustment; + call->soft_deadline = deadline; + } + + /* Bit 0 of the "soft" deadline indicates that + * this particular timer call requires rate-limiting + * behaviour. Maintain the invariant deadline >= soft_deadline by + * setting bit 0 of "deadline". + */ + + deadline |= 1; + if (ratelimited || slop_ratelimited) { + call->soft_deadline |= 1ULL; + } else { + call->soft_deadline &= ~0x1ULL; + } + + call->ttd = call->soft_deadline - ctime; - _delayed_call_enqueue(delayed, call); +#if CONFIG_DTRACE + DTRACE_TMR7(callout__create, timer_call_func_t, CE(call)->func, + timer_call_param_t, CE(call)->param0, uint32_t, call->flags, + (deadline - call->soft_deadline), + (call->ttd >> 32), (unsigned) (call->ttd & 0xFFFFFFFF), call); +#endif + + if (!ratelimited && !slop_ratelimited) { + queue = timer_longterm_enqueue_unlocked(call, ctime, deadline, &old_queue); + } + + if (queue == NULL) { + queue = timer_queue_assign(deadline); + old_queue = timer_call_enqueue_deadline_unlocked(call, queue, deadline); + } - if (queue_first(delayed) == qe(call)) - _set_delayed_call_timer(call); + CE(call)->param1 = param1; +#if TIMER_TRACE + CE(call)->entry_time = ctime; +#endif + + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_ENTER | DBG_FUNC_END, + call, + (old_queue != NULL), call->soft_deadline, queue->count, 0); - simple_unlock(&timer_call_lock); splx(s); - return (result); + return (old_queue != NULL); +} + +/* + * timer_call_*() + * return boolean indicating whether the call was previously queued. + */ +boolean_t +timer_call_enter( + timer_call_t call, + uint64_t deadline, + uint32_t flags) +{ + return timer_call_enter_internal(call, NULL, deadline, 0, flags, FALSE); } boolean_t timer_call_enter1( - timer_call_t call, - timer_call_param_t param1, - AbsoluteTime deadline) + timer_call_t call, + timer_call_param_t param1, + uint64_t deadline, + uint32_t flags) +{ + return timer_call_enter_internal(call, param1, deadline, 0, flags, FALSE); +} + +boolean_t +timer_call_enter_with_leeway( + timer_call_t call, + timer_call_param_t param1, + uint64_t deadline, + uint64_t leeway, + uint32_t flags, + boolean_t ratelimited) { - boolean_t result = TRUE; - queue_t delayed; + return timer_call_enter_internal(call, param1, deadline, leeway, flags, ratelimited); +} + +boolean_t +timer_call_cancel( + timer_call_t call) +{ + mpqueue_head_t *old_queue; spl_t s; s = splclock(); - simple_lock(&timer_call_lock); - if (call->state == PENDING) - _pending_call_dequeue(call); - else if (call->state == DELAYED) - _delayed_call_dequeue(call); - else if (call->state == IDLE) - result = FALSE; + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_CANCEL | DBG_FUNC_START, + call, + CE(call)->deadline, call->soft_deadline, call->flags, 0); + + old_queue = timer_call_dequeue_unlocked(call); + + if (old_queue != NULL) { + timer_queue_lock_spin(old_queue); + if (!queue_empty(&old_queue->head)) { + timer_queue_cancel(old_queue, CE(call)->deadline, CE(queue_first(&old_queue->head))->deadline); + old_queue->earliest_soft_deadline = ((timer_call_t)queue_first(&old_queue->head))->soft_deadline; + } + else { + timer_queue_cancel(old_queue, CE(call)->deadline, UINT64_MAX); + old_queue->earliest_soft_deadline = UINT64_MAX; + } + timer_queue_unlock(old_queue); + } + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_CANCEL | DBG_FUNC_END, + call, + old_queue, + CE(call)->deadline - mach_absolute_time(), + CE(call)->deadline - CE(call)->entry_time, 0); + splx(s); + +#if CONFIG_DTRACE + DTRACE_TMR6(callout__cancel, timer_call_func_t, CE(call)->func, + timer_call_param_t, CE(call)->param0, uint32_t, call->flags, 0, + (call->ttd >> 32), (unsigned) (call->ttd & 0xFFFFFFFF)); +#endif - call->param1 = param1; - call->deadline = deadline; + return (old_queue != NULL); +} - delayed = &delayed_call_queues[cpu_number()]; +uint32_t timer_queue_shutdown_lock_skips; +void +timer_queue_shutdown( + mpqueue_head_t *queue) +{ + timer_call_t call; + mpqueue_head_t *new_queue; + spl_t s; - _delayed_call_enqueue(delayed, call); + DBG("timer_queue_shutdown(%p)\n", queue); - if (queue_first(delayed) == qe(call)) - _set_delayed_call_timer(call); + s = splclock(); + + /* Note comma operator in while expression re-locking each iteration */ + while (timer_queue_lock_spin(queue), !queue_empty(&queue->head)) { + call = TIMER_CALL(queue_first(&queue->head)); + if (!simple_lock_try(&call->lock)) { + /* + * case (2b) lock order inversion, dequeue and skip + * Don't change the call_entry queue back-pointer + * but set the async_dequeue field. + */ + timer_queue_shutdown_lock_skips++; + timer_call_entry_dequeue_async(call); +#if TIMER_ASSERT + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_ASYNC_DEQ | DBG_FUNC_NONE, + call, + call->async_dequeue, + CE(call)->queue, + 0x2b, 0); +#endif + timer_queue_unlock(queue); + continue; + } + + /* remove entry from old queue */ + timer_call_entry_dequeue(call); + timer_queue_unlock(queue); + + /* and queue it on new */ + new_queue = timer_queue_assign(CE(call)->deadline); + timer_queue_lock_spin(new_queue); + timer_call_entry_enqueue_deadline( + call, new_queue, CE(call)->deadline); + timer_queue_unlock(new_queue); + + simple_unlock(&call->lock); + } - simple_unlock(&timer_call_lock); + timer_queue_unlock(queue); splx(s); +} + +uint32_t timer_queue_expire_lock_skips; +uint64_t +timer_queue_expire_with_options( + mpqueue_head_t *queue, + uint64_t deadline, + boolean_t rescan) +{ + timer_call_t call = NULL; + uint32_t tc_iterations = 0; + DBG("timer_queue_expire(%p,)\n", queue); + + uint64_t cur_deadline = deadline; + timer_queue_lock_spin(queue); + + while (!queue_empty(&queue->head)) { + /* Upon processing one or more timer calls, refresh the + * deadline to account for time elapsed in the callout + */ + if (++tc_iterations > 1) + cur_deadline = mach_absolute_time(); + + if (call == NULL) + call = TIMER_CALL(queue_first(&queue->head)); + + if (call->soft_deadline <= cur_deadline) { + timer_call_func_t func; + timer_call_param_t param0, param1; + + TCOAL_DEBUG(0xDDDD0000, queue->earliest_soft_deadline, call->soft_deadline, 0, 0, 0); + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_EXPIRE | DBG_FUNC_NONE, + call, + call->soft_deadline, + CE(call)->deadline, + CE(call)->entry_time, 0); + + /* Bit 0 of the "soft" deadline indicates that + * this particular timer call is rate-limited + * and hence shouldn't be processed before its + * hard deadline. + */ + if ((call->soft_deadline & 0x1) && + (CE(call)->deadline > cur_deadline)) { + if (rescan == FALSE) + break; + } + + if (!simple_lock_try(&call->lock)) { + /* case (2b) lock inversion, dequeue and skip */ + timer_queue_expire_lock_skips++; + timer_call_entry_dequeue_async(call); + call = NULL; + continue; + } + + timer_call_entry_dequeue(call); + + func = CE(call)->func; + param0 = CE(call)->param0; + param1 = CE(call)->param1; + + simple_unlock(&call->lock); + timer_queue_unlock(queue); + + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_CALLOUT | DBG_FUNC_START, + call, VM_KERNEL_UNSLIDE(func), param0, param1, 0); + +#if CONFIG_DTRACE + DTRACE_TMR7(callout__start, timer_call_func_t, func, + timer_call_param_t, param0, unsigned, call->flags, + 0, (call->ttd >> 32), + (unsigned) (call->ttd & 0xFFFFFFFF), call); +#endif + /* Maintain time-to-deadline in per-processor data + * structure for thread wakeup deadline statistics. + */ + uint64_t *ttdp = &(PROCESSOR_DATA(current_processor(), timer_call_ttd)); + *ttdp = call->ttd; + (*func)(param0, param1); + *ttdp = 0; +#if CONFIG_DTRACE + DTRACE_TMR4(callout__end, timer_call_func_t, func, + param0, param1, call); +#endif + + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_CALLOUT | DBG_FUNC_END, + call, VM_KERNEL_UNSLIDE(func), param0, param1, 0); + call = NULL; + timer_queue_lock_spin(queue); + } else { + if (__probable(rescan == FALSE)) { + break; + } else { + int64_t skew = CE(call)->deadline - call->soft_deadline; + assert(CE(call)->deadline >= call->soft_deadline); + + /* DRK: On a latency quality-of-service level change, + * re-sort potentially rate-limited timers. The platform + * layer determines which timers require + * this. In the absence of the per-callout + * synchronization requirement, a global resort could + * be more efficient. The re-sort effectively + * annuls all timer adjustments, i.e. the "soft + * deadline" is the sort key. + */ + + if (timer_resort_threshold(skew)) { + if (__probable(simple_lock_try(&call->lock))) { + timer_call_entry_dequeue(call); + timer_call_entry_enqueue_deadline(call, queue, call->soft_deadline); + simple_unlock(&call->lock); + call = NULL; + } + } + if (call) { + call = TIMER_CALL(queue_next(qe(call))); + if (queue_end(&queue->head, qe(call))) + break; + } + } + } + } + + if (!queue_empty(&queue->head)) { + call = TIMER_CALL(queue_first(&queue->head)); + cur_deadline = CE(call)->deadline; + queue->earliest_soft_deadline = call->soft_deadline; + } else { + queue->earliest_soft_deadline = cur_deadline = UINT64_MAX; + } + + timer_queue_unlock(queue); - return (result); + return (cur_deadline); } -boolean_t -timer_call_cancel( - timer_call_t call) +uint64_t +timer_queue_expire( + mpqueue_head_t *queue, + uint64_t deadline) { - boolean_t result = TRUE; - spl_t s; + return timer_queue_expire_with_options(queue, deadline, FALSE); +} + +extern int serverperfmode; +uint32_t timer_queue_migrate_lock_skips; +/* + * timer_queue_migrate() is called by timer_queue_migrate_cpu() + * to move timer requests from the local processor (queue_from) + * to a target processor's (queue_to). + */ +int +timer_queue_migrate(mpqueue_head_t *queue_from, mpqueue_head_t *queue_to) +{ + timer_call_t call; + timer_call_t head_to; + int timers_migrated = 0; + + DBG("timer_queue_migrate(%p,%p)\n", queue_from, queue_to); + + assert(!ml_get_interrupts_enabled()); + assert(queue_from != queue_to); + + if (serverperfmode) { + /* + * if we're running a high end server + * avoid migrations... they add latency + * and don't save us power under typical + * server workloads + */ + return -4; + } + + /* + * Take both local (from) and target (to) timer queue locks while + * moving the timers from the local queue to the target processor. + * We assume that the target is always the boot processor. + * But only move if all of the following is true: + * - the target queue is non-empty + * - the local queue is non-empty + * - the local queue's first deadline is later than the target's + * - the local queue contains no non-migrateable "local" call + * so that we need not have the target resync. + */ + + timer_queue_lock_spin(queue_to); + + head_to = TIMER_CALL(queue_first(&queue_to->head)); + if (queue_empty(&queue_to->head)) { + timers_migrated = -1; + goto abort1; + } + + timer_queue_lock_spin(queue_from); + + if (queue_empty(&queue_from->head)) { + timers_migrated = -2; + goto abort2; + } + + call = TIMER_CALL(queue_first(&queue_from->head)); + if (CE(call)->deadline < CE(head_to)->deadline) { + timers_migrated = 0; + goto abort2; + } + + /* perform scan for non-migratable timers */ + do { + if (call->flags & TIMER_CALL_LOCAL) { + timers_migrated = -3; + goto abort2; + } + call = TIMER_CALL(queue_next(qe(call))); + } while (!queue_end(&queue_from->head, qe(call))); + + /* migration loop itself -- both queues are locked */ + while (!queue_empty(&queue_from->head)) { + call = TIMER_CALL(queue_first(&queue_from->head)); + if (!simple_lock_try(&call->lock)) { + /* case (2b) lock order inversion, dequeue only */ +#ifdef TIMER_ASSERT + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_ASYNC_DEQ | DBG_FUNC_NONE, + call, + CE(call)->queue, + call->lock.interlock.lock_data, + 0x2b, 0); +#endif + timer_queue_migrate_lock_skips++; + timer_call_entry_dequeue_async(call); + continue; + } + timer_call_entry_dequeue(call); + timer_call_entry_enqueue_deadline( + call, queue_to, CE(call)->deadline); + timers_migrated++; + simple_unlock(&call->lock); + } + queue_from->earliest_soft_deadline = UINT64_MAX; +abort2: + timer_queue_unlock(queue_from); +abort1: + timer_queue_unlock(queue_to); + + return timers_migrated; +} + +void +timer_queue_trace_cpu(int ncpu) +{ + timer_call_nosync_cpu( + ncpu, + (void(*)())timer_queue_trace, + (void*) timer_queue_cpu(ncpu)); +} + +void +timer_queue_trace( + mpqueue_head_t *queue) +{ + timer_call_t call; + spl_t s; + + if (!kdebug_enable) + return; s = splclock(); - simple_lock(&timer_call_lock); + timer_queue_lock_spin(queue); + + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_QUEUE | DBG_FUNC_START, + queue->count, mach_absolute_time(), 0, 0, 0); + + if (!queue_empty(&queue->head)) { + call = TIMER_CALL(queue_first(&queue->head)); + do { + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_QUEUE | DBG_FUNC_NONE, + call->soft_deadline, + CE(call)->deadline, + CE(call)->entry_time, + CE(call)->func, + 0); + call = TIMER_CALL(queue_next(qe(call))); + } while (!queue_end(&queue->head, qe(call))); + } - if (call->state == PENDING) - _pending_call_dequeue(call); - else if (call->state == DELAYED) - _delayed_call_dequeue(call); - else - result = FALSE; + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_QUEUE | DBG_FUNC_END, + queue->count, mach_absolute_time(), 0, 0, 0); - simple_unlock(&timer_call_lock); + timer_queue_unlock(queue); splx(s); +} + +void +timer_longterm_dequeued_locked(timer_call_t call) +{ + timer_longterm_t *tlp = &timer_longterm; - return (result); + tlp->dequeues++; + if (call == tlp->threshold.call) + tlp->threshold.call = NULL; } -boolean_t -timer_call_is_delayed( - timer_call_t call, - AbsoluteTime *deadline) +/* + * Place a timer call in the longterm list + * and adjust the next timer callout deadline if the new timer is first. + */ +mpqueue_head_t * +timer_longterm_enqueue_unlocked(timer_call_t call, + uint64_t now, + uint64_t deadline, + mpqueue_head_t **old_queue) { - boolean_t result = FALSE; - spl_t s; + timer_longterm_t *tlp = &timer_longterm; + boolean_t update_required = FALSE; + uint64_t longterm_threshold; + + longterm_threshold = now + tlp->threshold.interval; + + /* + * Return NULL without doing anything if: + * - this timer is local, or + * - the longterm mechanism is disabled, or + * - this deadline is too short. + */ + if (__probable((call->flags & TIMER_CALL_LOCAL) != 0 || + (tlp->threshold.interval == TIMER_LONGTERM_NONE) || + (deadline <= longterm_threshold))) + return NULL; + + /* + * Remove timer from its current queue, if any. + */ + *old_queue = timer_call_dequeue_unlocked(call); + + /* + * Lock the longterm queue, queue timer and determine + * whether an update is necessary. + */ + assert(!ml_get_interrupts_enabled()); + simple_lock(&call->lock); + timer_queue_lock_spin(timer_longterm_queue); + timer_call_entry_enqueue_tail(call, timer_longterm_queue); + CE(call)->deadline = deadline; + + tlp->enqueues++; + + /* + * We'll need to update the currently set threshold timer + * if the new deadline is sooner and no sooner update is in flight. + */ + if (deadline < tlp->threshold.deadline && + deadline < tlp->threshold.preempted) { + tlp->threshold.preempted = deadline; + tlp->threshold.call = call; + update_required = TRUE; + } + timer_queue_unlock(timer_longterm_queue); + simple_unlock(&call->lock); + + if (update_required) { + timer_call_nosync_cpu( + master_cpu, + (void (*)(void *)) timer_longterm_update, + (void *)tlp); + } - s = splclock(); - simple_lock(&timer_call_lock); + return timer_longterm_queue; +} - if (call->state == DELAYED) { - if (deadline != NULL) - *deadline = call->deadline; - result = TRUE; +/* + * Scan for timers below the longterm threshold. + * Move these to the local timer queue (of the boot processor on which the + * calling thread is running). + * Both the local (boot) queue and the longterm queue are locked. + * The scan is similar to the timer migrate sequence but is performed by + * successively examining each timer on the longterm queue: + * - if within the short-term threshold + * - enter on the local queue (unless being deleted), + * - otherwise: + * - if sooner, deadline becomes the next threshold deadline. + */ +void +timer_longterm_scan(timer_longterm_t *tlp, + uint64_t now) +{ + queue_entry_t qe; + timer_call_t call; + uint64_t threshold; + uint64_t deadline; + mpqueue_head_t *timer_master_queue; + + assert(!ml_get_interrupts_enabled()); + assert(cpu_number() == master_cpu); + + if (tlp->threshold.interval != TIMER_LONGTERM_NONE) + threshold = now + tlp->threshold.interval; + else + threshold = TIMER_LONGTERM_NONE; + + tlp->threshold.deadline = TIMER_LONGTERM_NONE; + tlp->threshold.call = NULL; + + if (queue_empty(&timer_longterm_queue->head)) + return; + + timer_master_queue = timer_queue_cpu(master_cpu); + timer_queue_lock_spin(timer_master_queue); + + qe = queue_first(&timer_longterm_queue->head); + while (!queue_end(&timer_longterm_queue->head, qe)) { + call = TIMER_CALL(qe); + deadline = call->soft_deadline; + qe = queue_next(qe); + if (!simple_lock_try(&call->lock)) { + /* case (2c) lock order inversion, dequeue only */ +#ifdef TIMER_ASSERT + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_ASYNC_DEQ | DBG_FUNC_NONE, + call, + CE(call)->queue, + call->lock.interlock.lock_data, + 0x2c, 0); +#endif + timer_call_entry_dequeue_async(call); + continue; + } + if (deadline < threshold) { + /* + * This timer needs moving (escalating) + * to the local (boot) processor's queue. + */ +#ifdef TIMER_ASSERT + if (deadline < now) + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_OVERDUE | DBG_FUNC_NONE, + call, + deadline, + now, + threshold, + 0); +#endif + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_ESCALATE | DBG_FUNC_NONE, + call, + CE(call)->deadline, + CE(call)->entry_time, + CE(call)->func, + 0); + tlp->escalates++; + timer_call_entry_dequeue(call); + timer_call_entry_enqueue_deadline( + call, timer_master_queue, CE(call)->deadline); + /* + * A side-effect of the following call is to update + * the actual hardware deadline if required. + */ + (void) timer_queue_assign(deadline); + } else { + if (deadline < tlp->threshold.deadline) { + tlp->threshold.deadline = deadline; + tlp->threshold.call = call; + } + } + simple_unlock(&call->lock); } - simple_unlock(&timer_call_lock); - splx(s); + timer_queue_unlock(timer_master_queue); +} - return (result); +void +timer_longterm_callout(timer_call_param_t p0, __unused timer_call_param_t p1) +{ + timer_longterm_t *tlp = (timer_longterm_t *) p0; + + timer_longterm_update(tlp); } -static void -timer_call_interrupt( - AbsoluteTime timestamp) +timer_longterm_update_locked(timer_longterm_t *tlp) { - timer_call_t call; - queue_t delayed = &delayed_call_queues[cpu_number()]; + uint64_t latency; + + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_UPDATE | DBG_FUNC_START, + &tlp->queue, + tlp->threshold.deadline, + tlp->threshold.preempted, + tlp->queue.count, 0); + + tlp->scan_time = mach_absolute_time(); + if (tlp->threshold.preempted != TIMER_LONGTERM_NONE) { + tlp->threshold.preempts++; + tlp->threshold.deadline = tlp->threshold.preempted; + tlp->threshold.preempted = TIMER_LONGTERM_NONE; + /* + * Note: in the unlikely event that a pre-empted timer has + * itself been cancelled, we'll simply re-scan later at the + * time of the preempted/cancelled timer. + */ + } else { + tlp->threshold.scans++; + + /* + * Maintain a moving average of our wakeup latency. + * Clamp latency to 0 and ignore above threshold interval. + */ + if (tlp->scan_time > tlp->threshold.deadline_set) + latency = tlp->scan_time - tlp->threshold.deadline_set; + else + latency = 0; + if (latency < tlp->threshold.interval) { + tlp->threshold.latency_min = + MIN(tlp->threshold.latency_min, latency); + tlp->threshold.latency_max = + MAX(tlp->threshold.latency_max, latency); + tlp->threshold.latency = + (tlp->threshold.latency*99 + latency) / 100; + } - simple_lock(&timer_call_lock); + timer_longterm_scan(tlp, tlp->scan_time); + } - call = TC(queue_first(delayed)); + tlp->threshold.deadline_set = tlp->threshold.deadline; + /* The next deadline timer to be set is adjusted */ + if (tlp->threshold.deadline != TIMER_LONGTERM_NONE) { + tlp->threshold.deadline_set -= tlp->threshold.margin; + tlp->threshold.deadline_set -= tlp->threshold.latency; + } - while (!queue_end(delayed, qe(call))) { - if (CMP_ABSOLUTETIME(&call->deadline, ×tamp) <= 0) { - timer_call_func_t func; - timer_call_param_t param0, param1; + TIMER_KDEBUG_TRACE(KDEBUG_TRACE, + DECR_TIMER_UPDATE | DBG_FUNC_END, + &tlp->queue, + tlp->threshold.deadline, + tlp->threshold.scans, + tlp->queue.count, 0); +} - _delayed_call_dequeue(call); +void +timer_longterm_update(timer_longterm_t *tlp) +{ + spl_t s = splclock(); - func = call->func; - param0 = call->param0; - param1 = call->param1; + timer_queue_lock_spin(timer_longterm_queue); - simple_unlock(&timer_call_lock); + if (cpu_number() != master_cpu) + panic("timer_longterm_update_master() on non-boot cpu"); - (*func)(param0, param1); + timer_longterm_update_locked(tlp); + + if (tlp->threshold.deadline != TIMER_LONGTERM_NONE) + timer_call_enter( + &tlp->threshold.timer, + tlp->threshold.deadline_set, + TIMER_CALL_LOCAL | TIMER_CALL_SYS_CRITICAL); + + timer_queue_unlock(timer_longterm_queue); + splx(s); +} + +void +timer_longterm_init(void) +{ + uint32_t longterm; + timer_longterm_t *tlp = &timer_longterm; + + DBG("timer_longterm_init() tlp: %p, queue: %p\n", tlp, &tlp->queue); + + /* + * Set the longterm timer threshold. + * Defaults to TIMER_LONGTERM_THRESHOLD; overridden longterm boot-arg + */ + tlp->threshold.interval = TIMER_LONGTERM_THRESHOLD; + if (PE_parse_boot_argn("longterm", &longterm, sizeof (longterm))) { + tlp->threshold.interval = (longterm == 0) ? + TIMER_LONGTERM_NONE : + longterm * NSEC_PER_MSEC; + } + if (tlp->threshold.interval != TIMER_LONGTERM_NONE) { + printf("Longterm timer threshold: %llu ms\n", + tlp->threshold.interval / NSEC_PER_MSEC); + kprintf("Longterm timer threshold: %llu ms\n", + tlp->threshold.interval / NSEC_PER_MSEC); + nanoseconds_to_absolutetime(tlp->threshold.interval, + &tlp->threshold.interval); + tlp->threshold.margin = tlp->threshold.interval / 10; + tlp->threshold.latency_min = EndOfAllTime; + tlp->threshold.latency_max = 0; + } + + tlp->threshold.preempted = TIMER_LONGTERM_NONE; + tlp->threshold.deadline = TIMER_LONGTERM_NONE; + + lck_attr_setdefault(&timer_longterm_lck_attr); + lck_grp_attr_setdefault(&timer_longterm_lck_grp_attr); + lck_grp_init(&timer_longterm_lck_grp, + "timer_longterm", &timer_longterm_lck_grp_attr); + mpqueue_init(&tlp->queue, + &timer_longterm_lck_grp, &timer_longterm_lck_attr); + + timer_call_setup(&tlp->threshold.timer, + timer_longterm_callout, (timer_call_param_t) tlp); + + timer_longterm_queue = &tlp->queue; +} - simple_lock(&timer_call_lock); +enum { + THRESHOLD, QCOUNT, + ENQUEUES, DEQUEUES, ESCALATES, SCANS, PREEMPTS, + LATENCY, LATENCY_MIN, LATENCY_MAX +}; +uint64_t +timer_sysctl_get(int oid) +{ + timer_longterm_t *tlp = &timer_longterm; + + switch (oid) { + case THRESHOLD: + return (tlp->threshold.interval == TIMER_LONGTERM_NONE) ? + 0 : tlp->threshold.interval / NSEC_PER_MSEC; + case QCOUNT: + return tlp->queue.count; + case ENQUEUES: + return tlp->enqueues; + case DEQUEUES: + return tlp->dequeues; + case ESCALATES: + return tlp->escalates; + case SCANS: + return tlp->threshold.scans; + case PREEMPTS: + return tlp->threshold.preempts; + case LATENCY: + return tlp->threshold.latency; + case LATENCY_MIN: + return tlp->threshold.latency_min; + case LATENCY_MAX: + return tlp->threshold.latency_max; + default: + return 0; + } +} + +/* + * timer_master_scan() is the inverse of timer_longterm_scan() + * since it un-escalates timers to the longterm queue. + */ +static void +timer_master_scan(timer_longterm_t *tlp, + uint64_t now) +{ + queue_entry_t qe; + timer_call_t call; + uint64_t threshold; + uint64_t deadline; + mpqueue_head_t *timer_master_queue; + + if (tlp->threshold.interval != TIMER_LONGTERM_NONE) + threshold = now + tlp->threshold.interval; + else + threshold = TIMER_LONGTERM_NONE; + + timer_master_queue = timer_queue_cpu(master_cpu); + timer_queue_lock_spin(timer_master_queue); + + qe = queue_first(&timer_master_queue->head); + while (!queue_end(&timer_master_queue->head, qe)) { + call = TIMER_CALL(qe); + deadline = CE(call)->deadline; + qe = queue_next(qe); + if ((call->flags & TIMER_CALL_LOCAL) != 0) + continue; + if (!simple_lock_try(&call->lock)) { + /* case (2c) lock order inversion, dequeue only */ + timer_call_entry_dequeue_async(call); + continue; } + if (deadline > threshold) { + /* move from master to longterm */ + timer_call_entry_dequeue(call); + timer_call_entry_enqueue_tail(call, timer_longterm_queue); + if (deadline < tlp->threshold.deadline) { + tlp->threshold.deadline = deadline; + tlp->threshold.call = call; + } + } + simple_unlock(&call->lock); + } + timer_queue_unlock(timer_master_queue); +} + +static void +timer_sysctl_set_threshold(uint64_t value) +{ + timer_longterm_t *tlp = &timer_longterm; + spl_t s = splclock(); + boolean_t threshold_increase; + + timer_queue_lock_spin(timer_longterm_queue); + + timer_call_cancel(&tlp->threshold.timer); + + /* + * Set the new threshold and note whther it's increasing. + */ + if (value == 0) { + tlp->threshold.interval = TIMER_LONGTERM_NONE; + threshold_increase = TRUE; + timer_call_cancel(&tlp->threshold.timer); + } else { + uint64_t old_interval = tlp->threshold.interval; + tlp->threshold.interval = value * NSEC_PER_MSEC; + nanoseconds_to_absolutetime(tlp->threshold.interval, + &tlp->threshold.interval); + tlp->threshold.margin = tlp->threshold.interval / 10; + if (old_interval == TIMER_LONGTERM_NONE) + threshold_increase = FALSE; else - break; + threshold_increase = (tlp->threshold.interval > old_interval); + } - call = TC(queue_first(delayed)); + if (threshold_increase /* or removal */) { + /* Escalate timers from the longterm queue */ + timer_longterm_scan(tlp, mach_absolute_time()); + } else /* decrease or addition */ { + /* + * We scan the local/master queue for timers now longterm. + * To be strictly correct, we should scan all processor queues + * but timer migration results in most timers gravitating to the + * master processor in any case. + */ + timer_master_scan(tlp, mach_absolute_time()); } - if (!queue_end(delayed, qe(call))) - _set_delayed_call_timer(call); + /* Set new timer accordingly */ + tlp->threshold.deadline_set = tlp->threshold.deadline; + if (tlp->threshold.deadline != TIMER_LONGTERM_NONE) { + tlp->threshold.deadline_set -= tlp->threshold.margin; + tlp->threshold.deadline_set -= tlp->threshold.latency; + timer_call_enter( + &tlp->threshold.timer, + tlp->threshold.deadline_set, + TIMER_CALL_LOCAL | TIMER_CALL_SYS_CRITICAL); + } - simple_unlock(&timer_call_lock); + /* Reset stats */ + tlp->enqueues = 0; + tlp->dequeues = 0; + tlp->escalates = 0; + tlp->threshold.scans = 0; + tlp->threshold.preempts = 0; + tlp->threshold.latency = 0; + tlp->threshold.latency_min = EndOfAllTime; + tlp->threshold.latency_max = 0; + + timer_queue_unlock(timer_longterm_queue); + splx(s); +} + +int +timer_sysctl_set(int oid, uint64_t value) +{ + switch (oid) { + case THRESHOLD: + timer_call_cpu( + master_cpu, + (void (*)(void *)) timer_sysctl_set_threshold, + (void *) value); + return KERN_SUCCESS; + default: + return KERN_INVALID_ARGUMENT; + } }