/*
- * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2009 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
#include <kern/host.h>
#include <kern/mach_param.h>
#include <kern/sched.h>
+#include <sys/kdebug.h>
#include <kern/spl.h>
#include <kern/thread.h>
#include <kern/processor.h>
thread_lock(thread);
+ /*
+ * We've run up until our quantum expiration, and will (potentially)
+ * continue without re-entering the scheduler, so update this now.
+ */
+ thread->last_run_time = processor->quantum_end;
+
/*
* Check for fail-safe trip.
*/
- if (!(thread->sched_mode & (TH_MODE_TIMESHARE|TH_MODE_PROMOTED))) {
- uint64_t new_computation;
+ if ((thread->sched_mode == TH_MODE_REALTIME || thread->sched_mode == TH_MODE_FIXED) &&
+ !(thread->sched_flags & TH_SFLAG_PROMOTED) &&
+ !(thread->options & TH_OPT_SYSTEM_CRITICAL)) {
+ uint64_t new_computation;
- new_computation = processor->quantum_end;
- new_computation -= thread->computation_epoch;
- if (new_computation + thread->computation_metered >
- max_unsafe_computation) {
+ new_computation = processor->quantum_end - thread->computation_epoch;
+ new_computation += thread->computation_metered;
+ if (new_computation > max_unsafe_computation) {
- if (thread->sched_mode & TH_MODE_REALTIME) {
- thread->priority = DEPRESSPRI;
+ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_FAILSAFE)|DBG_FUNC_NONE,
+ (uintptr_t)thread->sched_pri, (uintptr_t)thread->sched_mode, 0, 0, 0);
- thread->safe_mode |= TH_MODE_REALTIME;
- thread->sched_mode &= ~TH_MODE_REALTIME;
+ if (thread->sched_mode == TH_MODE_REALTIME) {
+ thread->priority = DEPRESSPRI;
+ }
+
+ thread->saved_mode = thread->sched_mode;
+
+ if (SCHED(supports_timeshare_mode)) {
+ sched_share_incr();
+ thread->sched_mode = TH_MODE_TIMESHARE;
+ } else {
+ /* XXX handle fixed->fixed case */
+ thread->sched_mode = TH_MODE_FIXED;
}
- sched_share_incr();
-
- thread->safe_release = sched_tick + sched_safe_duration;
- thread->sched_mode |= (TH_MODE_FAILSAFE|TH_MODE_TIMESHARE);
+ thread->safe_release = processor->quantum_end + sched_safe_duration;
+ thread->sched_flags |= TH_SFLAG_FAILSAFE;
}
}
/*
* Recompute scheduled priority if appropriate.
*/
- if (thread->sched_stamp != sched_tick)
- update_priority(thread);
+ if (SCHED(can_update_priority)(thread))
+ SCHED(update_priority)(thread);
else
- if (thread->sched_mode & TH_MODE_TIMESHARE) {
- register uint32_t delta;
-
- thread_timer_delta(thread, delta);
-
- /*
- * Accumulate timesharing usage only
- * during contention for processor
- * resources.
- */
- if (thread->pri_shift < INT8_MAX)
- thread->sched_usage += delta;
-
- thread->cpu_delta += delta;
-
- /*
- * Adjust the scheduled priority if
- * the thread has not been promoted
- * and is not depressed.
- */
- if ( !(thread->sched_mode & TH_MODE_PROMOTED) &&
- !(thread->sched_mode & TH_MODE_ISDEPRESSED) )
- compute_my_priority(thread);
- }
+ SCHED(lightweight_update_priority)(thread);
+ SCHED(quantum_expire)(thread);
+
processor->current_pri = thread->sched_pri;
+ processor->current_thmode = thread->sched_mode;
/*
* This quantum is up, give this thread another.
processor->timeslice--;
thread_quantum_init(thread);
+ thread->last_quantum_refill_time = processor->quantum_end;
+
processor->quantum_end += thread->current_quantum;
timer_call_enter1(&processor->quantum_timer,
- thread, processor->quantum_end);
+ thread, processor->quantum_end, 0);
/*
* Context switch check.
pset_lock(pset);
pset_pri_hint(pset, processor, processor->current_pri);
- pset_count_hint(pset, processor, processor->runq.count);
+ pset_count_hint(pset, processor, SCHED(processor_runq_count)(processor));
pset_unlock(pset);
}
thread_unlock(thread);
}
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+void
+sched_traditional_quantum_expire(thread_t thread __unused)
+{
+ /*
+ * No special behavior when a timeshare, fixed, or realtime thread
+ * uses up its entire quantum
+ */
+}
+
+void
+lightweight_update_priority(thread_t thread)
+{
+ if (thread->sched_mode == TH_MODE_TIMESHARE) {
+ register uint32_t delta;
+
+ thread_timer_delta(thread, delta);
+
+ /*
+ * Accumulate timesharing usage only
+ * during contention for processor
+ * resources.
+ */
+ if (thread->pri_shift < INT8_MAX)
+ thread->sched_usage += delta;
+
+ thread->cpu_delta += delta;
+
+ /*
+ * Adjust the scheduled priority if
+ * the thread has not been promoted
+ * and is not depressed.
+ */
+ if ( !(thread->sched_flags & TH_SFLAG_PROMOTED) &&
+ !(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) )
+ compute_my_priority(thread);
+ }
+}
+
/*
* Define shifts for simulating (5/8) ** n
*
*
* Calculate the timesharing priority based upon usage and load.
*/
+#ifdef CONFIG_EMBEDDED
+
+#define do_priority_computation(thread, pri) \
+ MACRO_BEGIN \
+ (pri) = (thread)->priority /* start with base priority */ \
+ - ((thread)->sched_usage >> (thread)->pri_shift); \
+ if ((pri) < MAXPRI_THROTTLE) { \
+ if ((thread)->task->max_priority > MAXPRI_THROTTLE) \
+ (pri) = MAXPRI_THROTTLE; \
+ else \
+ if ((pri) < MINPRI_USER) \
+ (pri) = MINPRI_USER; \
+ } else \
+ if ((pri) > MAXPRI_KERNEL) \
+ (pri) = MAXPRI_KERNEL; \
+ MACRO_END
+
+#else
+
#define do_priority_computation(thread, pri) \
MACRO_BEGIN \
(pri) = (thread)->priority /* start with base priority */ \
(pri) = MAXPRI_KERNEL; \
MACRO_END
+#endif /* defined(CONFIG_SCHED_TRADITIONAL) */
+
+#endif
+
/*
* set_priority:
*
register int priority)
{
thread->priority = priority;
- compute_priority(thread, FALSE);
+ SCHED(compute_priority)(thread, FALSE);
}
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
/*
* compute_priority:
*
{
register int priority;
- if ( !(thread->sched_mode & TH_MODE_PROMOTED) &&
- (!(thread->sched_mode & TH_MODE_ISDEPRESSED) ||
+ if ( !(thread->sched_flags & TH_SFLAG_PROMOTED) &&
+ (!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) ||
override_depress ) ) {
- if (thread->sched_mode & TH_MODE_TIMESHARE)
+ if (thread->sched_mode == TH_MODE_TIMESHARE)
do_priority_computation(thread, priority);
else
priority = thread->priority;
thread->sched_pri = priority;
}
+/*
+ * can_update_priority
+ *
+ * Make sure we don't do re-dispatches more frequently than a scheduler tick.
+ *
+ * Called with the thread locked.
+ */
+boolean_t
+can_update_priority(
+ thread_t thread)
+{
+ if (sched_tick == thread->sched_stamp)
+ return (FALSE);
+ else
+ return (TRUE);
+}
+
/*
* update_priority
*
/*
* Check for fail-safe release.
*/
- if ( (thread->sched_mode & TH_MODE_FAILSAFE) &&
- thread->sched_stamp >= thread->safe_release ) {
- if (!(thread->safe_mode & TH_MODE_TIMESHARE)) {
- if (thread->safe_mode & TH_MODE_REALTIME) {
+ if ( (thread->sched_flags & TH_SFLAG_FAILSAFE) &&
+ mach_absolute_time() >= thread->safe_release ) {
+ if (thread->saved_mode != TH_MODE_TIMESHARE) {
+ if (thread->saved_mode == TH_MODE_REALTIME) {
thread->priority = BASEPRI_RTQUEUES;
-
- thread->sched_mode |= TH_MODE_REALTIME;
}
- thread->sched_mode &= ~TH_MODE_TIMESHARE;
+ thread->sched_mode = thread->saved_mode;
+ thread->saved_mode = TH_MODE_NONE;
if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN)
sched_share_decr();
- if (!(thread->sched_mode & TH_MODE_ISDEPRESSED))
+ if (!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK))
set_sched_pri(thread, thread->priority);
}
- thread->safe_mode = 0;
- thread->sched_mode &= ~TH_MODE_FAILSAFE;
+ thread->sched_flags &= ~TH_SFLAG_FAILSAFE;
}
/*
* Recompute scheduled priority if appropriate.
*/
- if ( (thread->sched_mode & TH_MODE_TIMESHARE) &&
- !(thread->sched_mode & TH_MODE_PROMOTED) &&
- !(thread->sched_mode & TH_MODE_ISDEPRESSED) ) {
+ if ( (thread->sched_mode == TH_MODE_TIMESHARE) &&
+ !(thread->sched_flags & TH_SFLAG_PROMOTED) &&
+ !(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) ) {
register int new_pri;
do_priority_computation(thread, new_pri);
if (new_pri != thread->sched_pri) {
- boolean_t removed = run_queue_remove(thread);
+ boolean_t removed = thread_run_queue_remove(thread);
thread->sched_pri = new_pri;
if (removed)
thread_setrun(thread, SCHED_TAILQ);
}
}
+
+ return;
}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */
projects / apple / xnu.git / blobdiff