/*
- * 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 <mach/mach_types.h>
#include <kern/clock.h>
-
+#include <kern/processor.h>
+#include <kern/etimer.h>
#include <kern/timer_call.h>
+#include <kern/timer_queue.h>
#include <kern/call_entry.h>
-decl_simple_lock_data(static,timer_call_lock)
+#include <sys/kdebug.h>
-static
-queue_head_t
- delayed_call_queues[NCPUS];
+#if CONFIG_DTRACE && (DEVELOPMENT || DEBUG )
+#include <mach/sdt.h>
+#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;
+lck_grp_t timer_call_lck_grp;
+lck_attr_t timer_call_lck_attr;
+lck_grp_attr_t timer_call_lck_grp_attr;
- if (timer_call_initialized)
- panic("timer_call_initialize");
- simple_lock_init(&timer_call_lock, ETAP_MISC_TIMER);
+#define timer_call_lock_spin(queue) \
+ lck_mtx_lock_spin_always(&queue->lock_data)
- s = splclock();
- simple_lock(&timer_call_lock);
+#define timer_call_unlock(queue) \
+ lck_mtx_unlock_always(&queue->lock_data)
- for (i = 0; i < NCPUS; i++)
- queue_init(&delayed_call_queues[i]);
- clock_set_timer_func((clock_timer_func_t)timer_call_interrupt);
+#define QUEUE(x) ((queue_t)(x))
+#define MPQUEUE(x) ((mpqueue_head_t *)(x))
+#define TIMER_CALL(x) ((timer_call_t)(x))
- timer_call_initialized = TRUE;
+static boolean_t timer_call_enter_internal(timer_call_t call, timer_call_param_t param1, uint64_t deadline, uint32_t flags);
+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);
- simple_unlock(&timer_call_lock);
- splx(s);
-}
void
-timer_call_setup(
- timer_call_t call,
- timer_call_func_t func,
- timer_call_param_t param0)
+timer_call_initialize(void)
{
- call_entry_setup(call, func, param0);
+ 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);
}
-static __inline__
+
void
-_delayed_call_enqueue(
- queue_t queue,
- timer_call_t call)
+timer_call_initialize_queue(mpqueue_head_t *queue)
{
- timer_call_t current;
-
- current = TC(queue_first(queue));
+ DBG("timer_call_initialize_queue(%p)\n", queue);
+ mpqueue_init(queue, &timer_call_lck_grp, &timer_call_lck_attr);
+}
- while (TRUE) {
- if ( queue_end(queue, qe(current)) ||
- CMP_ABSOLUTETIME(&call->deadline,
- ¤t->deadline) < 0 ) {
- current = TC(queue_prev(qe(current)));
- break;
- }
- current = TC(queue_next(qe(current)));
- }
+void
+timer_call_setup(
+ timer_call_t call,
+ timer_call_func_t func,
+ timer_call_param_t 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;
+}
- insque(qe(call), qe(current));
- if (++timer_calls.delayed_num > timer_calls.delayed_hiwat)
- timer_calls.delayed_hiwat = timer_calls.delayed_num;
+/*
+ * 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).
+ */
- call->state = DELAYED;
+/*
+ * 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)
+{
+ 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));
+
+ 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--;
-
- call->state = IDLE;
+ 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);
+
+ return (old_queue);
}
-static __inline__
-void
-_pending_call_enqueue(
- queue_t queue,
- timer_call_t call)
+#else
+
+static __inline__ mpqueue_head_t *
+timer_call_entry_dequeue(
+ timer_call_t entry)
{
- enqueue_tail(queue, qe(call));
- if (++timer_calls.pending_num > timer_calls.pending_hiwat)
- timer_calls.pending_hiwat = timer_calls.pending_num;
+ return MPQUEUE(call_entry_dequeue(CE(entry)));
+}
- call->state = PENDING;
+static __inline__ mpqueue_head_t *
+timer_call_entry_enqueue_deadline(
+ timer_call_t entry,
+ mpqueue_head_t *queue,
+ uint64_t deadline)
+{
+ return MPQUEUE(call_entry_enqueue_deadline(CE(entry),
+ QUEUE(queue), deadline));
}
-static __inline__
-void
-_pending_call_dequeue(
- timer_call_t call)
+#endif
+
+#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_call_lock_spin(old_queue);
+ if (call->async_dequeue) {
+ /* collision (1c): null queue pointer and reset flag */
+ call->async_dequeue = FALSE;
+ entry->queue = NULL;
+#if TIMER_ASSERT
+ timer_call_enqueue_deadline_unlocked_async1++;
+#endif
+ } else if (old_queue != queue) {
+ (void)remque(qe(entry));
+ entry->queue = NULL;
+#if TIMER_ASSERT
+ timer_call_enqueue_deadline_unlocked_async2++;
+#endif
+ }
+ if (old_queue != queue) {
+ timer_call_unlock(old_queue);
+ timer_call_lock_spin(queue);
+ }
+ } else {
+ timer_call_lock_spin(queue);
+ }
- call->state = IDLE;
+ timer_call_entry_enqueue_deadline(call, queue, deadline);
+ timer_call_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 (old_queue != NULL) {
+ timer_call_lock_spin(old_queue);
+ if (call->async_dequeue) {
+ /* collision (1c): null queue pointer and reset flag */
+ call->async_dequeue = FALSE;
+#if TIMER_ASSERT
+ timer_call_dequeue_unlocked_async1++;
+#endif
+ } else {
+ (void)remque(qe(entry));
+#if TIMER_ASSERT
+ timer_call_dequeue_unlocked_async2++;
+#endif
+ }
+ entry->queue = NULL;
+ timer_call_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,
+ uint32_t flags)
{
- boolean_t result = TRUE;
- queue_t delayed;
+ mpqueue_head_t *queue;
+ mpqueue_head_t *old_queue;
spl_t s;
+ uint64_t slop = 0;
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;
- call->param1 = 0;
- call->deadline = deadline;
+ if ((flags & TIMER_CALL_CRITICAL) == 0 &&
+ mach_timer_coalescing_enabled) {
+ slop = timer_call_slop(deadline);
+ deadline += slop;
+ }
- delayed = &delayed_call_queues[cpu_number()];
+ queue = timer_queue_assign(deadline);
- _delayed_call_enqueue(delayed, call);
+ 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;
- simple_unlock(&timer_call_lock);
splx(s);
- return (result);
+ return (old_queue != NULL);
}
boolean_t
-timer_call_enter1(
- timer_call_t call,
- timer_call_param_t param1,
- AbsoluteTime deadline)
+timer_call_enter(
+ timer_call_t call,
+ uint64_t deadline,
+ uint32_t flags)
{
- boolean_t result = TRUE;
- queue_t delayed;
- 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;
-
- call->param1 = param1;
- call->deadline = deadline;
-
- delayed = &delayed_call_queues[cpu_number()];
-
- _delayed_call_enqueue(delayed, call);
-
- if (queue_first(delayed) == qe(call))
- _set_delayed_call_timer(call);
-
- simple_unlock(&timer_call_lock);
- splx(s);
+ return timer_call_enter_internal(call, NULL, deadline, flags);
+}
- return (result);
+boolean_t
+timer_call_enter1(
+ timer_call_t call,
+ timer_call_param_t param1,
+ uint64_t deadline,
+ uint32_t flags)
+{
+ return timer_call_enter_internal(call, param1, deadline, flags);
}
boolean_t
timer_call_cancel(
- timer_call_t call)
+ timer_call_t call)
{
- boolean_t result = TRUE;
+ 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
- result = FALSE;
+ old_queue = timer_call_dequeue_unlocked(call);
- simple_unlock(&timer_call_lock);
+ if (old_queue != NULL) {
+ timer_call_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);
+ else
+ timer_queue_cancel(old_queue, CE(call)->deadline, UINT64_MAX);
+ timer_call_unlock(old_queue);
+ }
splx(s);
- return (result);
+ return (old_queue != NULL);
}
-boolean_t
-timer_call_is_delayed(
- timer_call_t call,
- AbsoluteTime *deadline)
+uint32_t timer_queue_shutdown_lock_skips;
+void
+timer_queue_shutdown(
+ mpqueue_head_t *queue)
{
- boolean_t result = FALSE;
+ timer_call_t call;
+ mpqueue_head_t *new_queue;
spl_t s;
+ DBG("timer_queue_shutdown(%p)\n", queue);
+
s = splclock();
- simple_lock(&timer_call_lock);
- if (call->state == DELAYED) {
- if (deadline != NULL)
- *deadline = call->deadline;
- result = TRUE;
+ /* Note comma operator in while expression re-locking each iteration */
+ while (timer_call_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++;
+ (void) remque(qe(call));
+ call->async_dequeue = TRUE;
+ timer_call_unlock(queue);
+ continue;
+ }
+
+ /* remove entry from old queue */
+ timer_call_entry_dequeue(call);
+ timer_call_unlock(queue);
+
+ /* and queue it on new */
+ new_queue = timer_queue_assign(CE(call)->deadline);
+ timer_call_lock_spin(new_queue);
+ timer_call_entry_enqueue_deadline(
+ call, new_queue, CE(call)->deadline);
+ timer_call_unlock(new_queue);
+
+ simple_unlock(&call->lock);
}
- simple_unlock(&timer_call_lock);
+ timer_call_unlock(queue);
splx(s);
-
- return (result);
}
-static
-void
-timer_call_interrupt(
- AbsoluteTime timestamp)
+uint32_t timer_queue_expire_lock_skips;
+uint64_t
+timer_queue_expire(
+ mpqueue_head_t *queue,
+ uint64_t deadline)
{
- timer_call_t call;
- queue_t delayed = &delayed_call_queues[cpu_number()];
+ timer_call_t call;
+
+ DBG("timer_queue_expire(%p,)\n", queue);
- simple_lock(&timer_call_lock);
+ timer_call_lock_spin(queue);
- call = TC(queue_first(delayed));
+ while (!queue_empty(&queue->head)) {
+ call = TIMER_CALL(queue_first(&queue->head));
- while (!queue_end(delayed, qe(call))) {
- if (CMP_ABSOLUTETIME(&call->deadline, ×tamp) <= 0) {
+ if (call->soft_deadline <= deadline) {
timer_call_func_t func;
timer_call_param_t param0, param1;
- _delayed_call_dequeue(call);
+ if (!simple_lock_try(&call->lock)) {
+ /* case (2b) lock inversion, dequeue and skip */
+ timer_queue_expire_lock_skips++;
+ (void) remque(qe(call));
+ call->async_dequeue = TRUE;
+ continue;
+ }
- func = call->func;
- param0 = call->param0;
- param1 = call->param1;
+ timer_call_entry_dequeue(call);
- simple_unlock(&timer_call_lock);
+ func = CE(call)->func;
+ param0 = CE(call)->param0;
+ param1 = CE(call)->param1;
+
+ simple_unlock(&call->lock);
+ timer_call_unlock(queue);
+
+ KERNEL_DEBUG_CONSTANT(DECR_TIMER_CALLOUT | DBG_FUNC_START,
+ func,
+ param0,
+ param1, 0, 0);
+
+#if CONFIG_DTRACE && (DEVELOPMENT || DEBUG )
+ DTRACE_TMR3(callout__start, timer_call_func_t, func,
+ timer_call_param_t, param0,
+ timer_call_param_t, param1);
+#endif
(*func)(param0, param1);
- simple_lock(&timer_call_lock);
+#if CONFIG_DTRACE && (DEVELOPMENT || DEBUG )
+ DTRACE_TMR3(callout__end, timer_call_func_t, func,
+ timer_call_param_t, param0,
+ timer_call_param_t, param1);
+#endif
+
+ KERNEL_DEBUG_CONSTANT(DECR_TIMER_CALLOUT | DBG_FUNC_END,
+ func,
+ param0,
+ param1, 0, 0);
+
+ timer_call_lock_spin(queue);
}
else
break;
+ }
+
+ if (!queue_empty(&queue->head))
+ deadline = CE(call)->deadline;
+ else
+ deadline = UINT64_MAX;
+
+ timer_call_unlock(queue);
+
+ return (deadline);
+}
- call = TC(queue_first(delayed));
+
+extern int serverperfmode;
+uint32_t timer_queue_migrate_lock_skips;
+/*
+ * timer_queue_migrate() is called by etimer_queue_migrate()
+ * 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_call_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_call_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 */
+ timer_queue_migrate_lock_skips++;
+ (void) remque(qe(call));
+ call->async_dequeue = TRUE;
+ continue;
+ }
+ timer_call_entry_dequeue(call);
+ timer_call_entry_enqueue_deadline(
+ call, queue_to, CE(call)->deadline);
+ timers_migrated++;
+ simple_unlock(&call->lock);
}
- if (!queue_end(delayed, qe(call)))
- _set_delayed_call_timer(call);
+abort2:
+ timer_call_unlock(queue_from);
+abort1:
+ timer_call_unlock(queue_to);
- simple_unlock(&timer_call_lock);
+ return timers_migrated;
}
projects / apple / xnu.git / blobdiff