#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>
+#include <kern/thread.h>
#include <sys/kdebug.h>
#define DBG(x...)
#endif
+#if TIMER_TRACE
+#define TIMER_KDEBUG_TRACE KERNEL_DEBUG_CONSTANT_IST
+#else
+#define TIMER_KDEBUG_TRACE(x...)
+#endif
+
+
lck_grp_t timer_call_lck_grp;
lck_attr_t timer_call_lck_attr;
lck_grp_attr_t timer_call_lck_grp_attr;
+lck_grp_t timer_longterm_lck_grp;
+lck_attr_t timer_longterm_lck_attr;
+lck_grp_attr_t timer_longterm_lck_grp_attr;
+
-#define timer_call_lock_spin(queue) \
+#define timer_queue_lock_spin(queue) \
lck_mtx_lock_spin_always(&queue->lock_data)
-#define timer_call_unlock(queue) \
+#define timer_queue_unlock(queue) \
lck_mtx_unlock_always(&queue->lock_data)
#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_timer_adjustment;
-static boolean_t timer_call_enter_internal(timer_call_t call, timer_call_param_t param1, uint64_t deadline, uint32_t flags);
+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(
void
-timer_call_initialize(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_initialize_queue(mpqueue_head_t *queue)
+timer_call_queue_init(mpqueue_head_t *queue)
{
- DBG("timer_call_initialize_queue(%p)\n", queue);
+ DBG("timer_call_queue_init(%p)\n", queue);
mpqueue_init(queue, &timer_call_lck_grp, &timer_call_lck_attr);
}
* 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.
*/
/*
"queue %p is not locked\n", old_queue);
call_entry_dequeue(CE(entry));
+ old_queue->count--;
return (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;
+
+ if (old_queue)
+ old_queue->count--;
+ queue->count++;
+
return (old_queue);
}
timer_call_entry_dequeue(
timer_call_t entry)
{
- return MPQUEUE(call_entry_dequeue(CE(entry)));
+ mpqueue_head_t *old_queue = MPQUEUE(CE(entry)->queue);
+
+ call_entry_dequeue(CE(entry));
+ old_queue->count--;
+
+ return old_queue;
}
static __inline__ mpqueue_head_t *
mpqueue_head_t *queue,
uint64_t deadline)
{
- return MPQUEUE(call_entry_enqueue_deadline(CE(entry),
- QUEUE(queue), deadline));
+ mpqueue_head_t *old_queue = MPQUEUE(CE(entry)->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;
+
+ if (old_queue)
+ old_queue->count--;
+ queue->count++;
+
+ return old_queue;
}
#endif
+static __inline__ void
+timer_call_entry_enqueue_tail(
+ timer_call_t entry,
+ mpqueue_head_t *queue)
+{
+ call_entry_enqueue_tail(CE(entry), QUEUE(queue));
+ queue->count++;
+ return;
+}
+
+/*
+ * 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;
+}
+
#if TIMER_ASSERT
unsigned timer_call_enqueue_deadline_unlocked_async1;
unsigned timer_call_enqueue_deadline_unlocked_async2;
simple_lock(&call->lock);
old_queue = MPQUEUE(entry->queue);
if (old_queue != NULL) {
- timer_call_lock_spin(old_queue);
+ timer_queue_lock_spin(old_queue);
if (call->async_dequeue) {
- /* collision (1c): null queue pointer and reset flag */
- call->async_dequeue = FALSE;
- entry->queue = NULL;
+ /* 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
- } else if (old_queue != queue) {
- (void)remque(qe(entry));
+ 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_call_unlock(old_queue);
- timer_call_lock_spin(queue);
+ timer_queue_unlock(old_queue);
+ timer_queue_lock_spin(queue);
}
} else {
- timer_call_lock_spin(queue);
+ timer_queue_lock_spin(queue);
}
timer_call_entry_enqueue_deadline(call, queue, deadline);
- timer_call_unlock(queue);
+ timer_queue_unlock(queue);
simple_unlock(&call->lock);
return (old_queue);
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_call_lock_spin(old_queue);
+ timer_queue_lock_spin(old_queue);
if (call->async_dequeue) {
- /* collision (1c): null queue pointer and reset flag */
- call->async_dequeue = FALSE;
+ /* 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 {
- (void)remque(qe(entry));
-#if TIMER_ASSERT
- timer_call_dequeue_unlocked_async2++;
-#endif
+ timer_call_entry_dequeue(call);
}
- entry->queue = NULL;
- timer_call_unlock(old_queue);
+ if (old_queue == timer_longterm_queue)
+ timer_longterm_dequeued_locked(call);
+ timer_queue_unlock(old_queue);
}
simple_unlock(&call->lock);
return (old_queue);
timer_call_t call,
timer_call_param_t param1,
uint64_t deadline,
- uint32_t flags)
+ uint64_t leeway,
+ uint32_t flags,
+ boolean_t ratelimited)
{
- mpqueue_head_t *queue;
+ mpqueue_head_t *queue = NULL;
mpqueue_head_t *old_queue;
spl_t s;
- uint64_t slop = 0;
+ uint64_t slop;
+ uint32_t urgency;
s = splclock();
call->soft_deadline = deadline;
call->flags = flags;
- if ((flags & TIMER_CALL_CRITICAL) == 0 &&
- mach_timer_coalescing_enabled) {
- slop = timer_call_slop(deadline);
+ 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 defined(__i386__) || defined(__x86_64__)
- uint64_t ctime = mach_absolute_time();
if (__improbable(deadline < ctime)) {
uint64_t delta = (ctime - deadline);
deadline = ctime + past_deadline_timer_adjustment;
call->soft_deadline = deadline;
}
-#endif
+
+ /* 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;
#if CONFIG_DTRACE
- DTRACE_TMR6(callout__create, timer_call_func_t, CE(call)->func,
+ 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->ttd >> 32), (unsigned) (call->ttd & 0xFFFFFFFF), call);
#endif
- queue = timer_queue_assign(deadline);
+ if (!ratelimited && !slop_ratelimited) {
+ queue = timer_longterm_enqueue_unlocked(call, ctime, deadline, &old_queue);
+ }
- old_queue = timer_call_enqueue_deadline_unlocked(call, queue, deadline);
+ if (queue == NULL) {
+ queue = timer_queue_assign(deadline);
+ old_queue = timer_call_enqueue_deadline_unlocked(call, queue, deadline);
+ }
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);
splx(s);
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, flags);
+ return timer_call_enter_internal(call, NULL, deadline, 0, flags, FALSE);
}
boolean_t
uint64_t deadline,
uint32_t flags)
{
- return timer_call_enter_internal(call, param1, deadline, 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)
+{
+ return timer_call_enter_internal(call, param1, deadline, leeway, flags, ratelimited);
}
boolean_t
s = splclock();
+ 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_call_lock_spin(old_queue);
- if (!queue_empty(&old_queue->head))
+ 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);
- else
+ 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);
- timer_call_unlock(old_queue);
+ 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
s = splclock();
/* Note comma operator in while expression re-locking each iteration */
- while (timer_call_lock_spin(queue), !queue_empty(&queue->head)) {
+ while (timer_queue_lock_spin(queue), !queue_empty(&queue->head)) {
call = TIMER_CALL(queue_first(&queue->head));
if (!simple_lock_try(&call->lock)) {
/*
* but set the async_dequeue field.
*/
timer_queue_shutdown_lock_skips++;
- (void) remque(qe(call));
- call->async_dequeue = TRUE;
- timer_call_unlock(queue);
+ 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_call_unlock(queue);
+ timer_queue_unlock(queue);
/* and queue it on new */
new_queue = timer_queue_assign(CE(call)->deadline);
- timer_call_lock_spin(new_queue);
+ timer_queue_lock_spin(new_queue);
timer_call_entry_enqueue_deadline(
call, new_queue, CE(call)->deadline);
- timer_call_unlock(new_queue);
+ timer_queue_unlock(new_queue);
simple_unlock(&call->lock);
}
- timer_call_unlock(queue);
+ timer_queue_unlock(queue);
splx(s);
}
uint32_t timer_queue_expire_lock_skips;
uint64_t
-timer_queue_expire(
+timer_queue_expire_with_options(
mpqueue_head_t *queue,
- uint64_t deadline)
+ uint64_t deadline,
+ boolean_t rescan)
{
- timer_call_t call;
-
+ timer_call_t call = NULL;
+ uint32_t tc_iterations = 0;
DBG("timer_queue_expire(%p,)\n", queue);
- timer_call_lock_spin(queue);
+ uint64_t cur_deadline = deadline;
+ timer_queue_lock_spin(queue);
while (!queue_empty(&queue->head)) {
- call = TIMER_CALL(queue_first(&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 <= deadline) {
+ 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++;
- (void) remque(qe(call));
- call->async_dequeue = TRUE;
+ timer_call_entry_dequeue_async(call);
+ call = NULL;
continue;
}
param1 = CE(call)->param1;
simple_unlock(&call->lock);
- timer_call_unlock(queue);
+ timer_queue_unlock(queue);
- KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ TIMER_KDEBUG_TRACE(KDEBUG_TRACE,
DECR_TIMER_CALLOUT | DBG_FUNC_START,
- VM_KERNEL_UNSLIDE(func), param0, param1, 0, 0);
+ call, VM_KERNEL_UNSLIDE(func), param0, param1, 0);
#if CONFIG_DTRACE
- DTRACE_TMR6(callout__start, timer_call_func_t, func,
+ 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));
+ (unsigned) (call->ttd & 0xFFFFFFFF), call);
#endif
-
/* Maintain time-to-deadline in per-processor data
* structure for thread wakeup deadline statistics.
*/
*ttdp = call->ttd;
(*func)(param0, param1);
*ttdp = 0;
-
#if CONFIG_DTRACE
- DTRACE_TMR3(callout__end, timer_call_func_t, func,
- timer_call_param_t, param0, timer_call_param_t,
- param1);
+ DTRACE_TMR4(callout__end, timer_call_func_t, func,
+ param0, param1, call);
#endif
- KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ TIMER_KDEBUG_TRACE(KDEBUG_TRACE,
DECR_TIMER_CALLOUT | DBG_FUNC_END,
- VM_KERNEL_UNSLIDE(func), param0, param1, 0, 0);
-
- timer_call_lock_spin(queue);
+ 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;
+ }
+ }
}
- else
- break;
}
- if (!queue_empty(&queue->head))
- deadline = CE(call)->deadline;
- else
- deadline = UINT64_MAX;
+ 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_call_unlock(queue);
+ timer_queue_unlock(queue);
- return (deadline);
+ return (cur_deadline);
}
+uint64_t
+timer_queue_expire(
+ mpqueue_head_t *queue,
+ uint64_t deadline)
+{
+ 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 etimer_queue_migrate()
+ * 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).
*/
* so that we need not have the target resync.
*/
- timer_call_lock_spin(queue_to);
+ timer_queue_lock_spin(queue_to);
head_to = TIMER_CALL(queue_first(&queue_to->head));
if (queue_empty(&queue_to->head)) {
goto abort1;
}
- timer_call_lock_spin(queue_from);
+ timer_queue_lock_spin(queue_from);
if (queue_empty(&queue_from->head)) {
timers_migrated = -2;
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++;
- (void) remque(qe(call));
- call->async_dequeue = TRUE;
+ timer_call_entry_dequeue_async(call);
continue;
}
timer_call_entry_dequeue(call);
timers_migrated++;
simple_unlock(&call->lock);
}
-
+ queue_from->earliest_soft_deadline = UINT64_MAX;
abort2:
- timer_call_unlock(queue_from);
+ timer_queue_unlock(queue_from);
abort1:
- timer_call_unlock(queue_to);
+ 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();
+ 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)));
+ }
+
+ TIMER_KDEBUG_TRACE(KDEBUG_TRACE,
+ DECR_TIMER_QUEUE | DBG_FUNC_END,
+ queue->count, mach_absolute_time(), 0, 0, 0);
+
+ timer_queue_unlock(queue);
+ splx(s);
+}
+
+void
+timer_longterm_dequeued_locked(timer_call_t call)
+{
+ timer_longterm_t *tlp = &timer_longterm;
+
+ tlp->dequeues++;
+ if (call == tlp->threshold.call)
+ tlp->threshold.call = NULL;
+}
+
+/*
+ * 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)
+{
+ 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);
+ }
+
+ return timer_longterm_queue;
+}
+
+/*
+ * 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);
+ }
+
+ timer_queue_unlock(timer_master_queue);
+}
+
+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);
+}
+
+void
+timer_longterm_update_locked(timer_longterm_t *tlp)
+{
+ 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;
+ }
+
+ timer_longterm_scan(tlp, tlp->scan_time);
+ }
+
+ 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;
+ }
+
+ TIMER_KDEBUG_TRACE(KDEBUG_TRACE,
+ DECR_TIMER_UPDATE | DBG_FUNC_END,
+ &tlp->queue,
+ tlp->threshold.deadline,
+ tlp->threshold.scans,
+ tlp->queue.count, 0);
+}
+
+void
+timer_longterm_update(timer_longterm_t *tlp)
+{
+ spl_t s = splclock();
+
+ timer_queue_lock_spin(timer_longterm_queue);
+
+ if (cpu_number() != master_cpu)
+ panic("timer_longterm_update_master() on non-boot cpu");
+
+ 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;
+}
+
+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
+ threshold_increase = (tlp->threshold.interval > old_interval);
+ }
+
+ 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());
+ }
+
+ /* 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);
+ }
+
+ /* 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;
+ }
+}
projects / apple / xnu.git / blobdiff