/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_LICENSE_OSREFERENCE_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 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.
- *
- * @APPLE_LICENSE_HEADER_END@
+ * 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.
+ *
+ * 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, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
*/
/*
* @OSF_COPYRIGHT@
* Clock primitives.
*/
-#include <cpus.h>
-
#include <mach/boolean.h>
#include <mach/kern_return.h>
#include <mach/machine.h>
#include <kern/thread.h>
#include <kern/processor.h>
#include <machine/machparam.h>
-#include <kern/sf.h>
-#include <kern/mk_sp.h> /*** ??? fix so this can be removed ***/
-/*** ??? Should this file be MK SP-specific? Or is it more general purpose? ***/
-
-
/*
- * USAGE_THRESHOLD is the amount by which usage must change to
- * cause a priority shift that moves a thread between run queues.
- */
-
-#ifdef PRI_SHIFT_2
-#if PRI_SHIFT_2 > 0
-#define USAGE_THRESHOLD (((1 << PRI_SHIFT) + (1 << PRI_SHIFT_2)) << (2 + SCHED_SHIFT))
-#else /* PRI_SHIFT_2 > 0 */
-#define USAGE_THRESHOLD (((1 << PRI_SHIFT) - (1 << -(PRI_SHIFT_2))) << (2 + SCHED_SHIFT))
-#endif /* PRI_SHIFT_2 > 0 */
-#else /* PRI_SHIFT_2 */
-#define USAGE_THRESHOLD (1 << (PRI_SHIFT + 2 + SCHED_SHIFT))
-#endif /* PRI_SHIFT_2 */
-
-/*
- * thread_quantum_update:
+ * thread_quantum_expire:
*
* Recalculate the quantum and priority for a thread.
- * The number of ticks that has elapsed since we were last called
- * is passed as "nticks."
*/
void
-thread_quantum_update(
- register int mycpu,
- register thread_t thread,
- int nticks,
- int state)
+thread_quantum_expire(
+ timer_call_param_t p0,
+ timer_call_param_t p1)
{
- register int quantum;
- register processor_t myprocessor;
- register processor_set_t pset;
+ register processor_t myprocessor = p0;
+ register thread_t thread = p1;
spl_t s;
- myprocessor = cpu_to_processor(mycpu);
- pset = myprocessor->processor_set;
+ s = splsched();
+ thread_lock(thread);
/*
- * Account for thread's utilization of these ticks.
- * This assumes that there is *always* a current thread.
- * When the processor is idle, it should be the idle thread.
+ * Check for fail-safe trip.
*/
+ if (!(thread->sched_mode & TH_MODE_TIMESHARE)) {
+ uint64_t new_computation;
- /*
- * Update set_quantum and calculate the current quantum.
- */
- pset->set_quantum = pset->machine_quantum[
- (pset->runq.count > pset->processor_count) ?
- pset->processor_count : pset->runq.count];
+ new_computation = myprocessor->quantum_end;
+ new_computation -= thread->computation_epoch;
+ if (new_computation + thread->computation_metered >
+ max_unsafe_computation) {
- if (myprocessor->runq.count != 0)
- quantum = min_quantum;
- else
- quantum = pset->set_quantum;
+ if (thread->sched_mode & TH_MODE_REALTIME) {
+ thread->priority = DEPRESSPRI;
+
+ thread->safe_mode |= TH_MODE_REALTIME;
+ thread->sched_mode &= ~TH_MODE_REALTIME;
+ }
+
+ pset_share_incr(thread->processor_set);
+
+ thread->safe_release = sched_tick + sched_safe_duration;
+ thread->sched_mode |= (TH_MODE_FAILSAFE|TH_MODE_TIMESHARE);
+ thread->sched_mode &= ~TH_MODE_PREEMPT;
+ }
+ }
/*
- * Now recompute the priority of the thread if appropriate.
+ * Recompute scheduled priority if appropriate.
*/
+ if (thread->sched_stamp != sched_tick)
+ update_priority(thread);
+ else
+ if (thread->sched_mode & TH_MODE_TIMESHARE) {
+ register uint32_t delta;
- {
- s = splsched();
- thread_lock(thread);
+ thread_timer_delta(thread, delta);
- if (!(thread->policy & (POLICY_TIMESHARE|POLICY_RR|POLICY_FIFO))) {
- thread_unlock(thread);
- splx(s);
- return;
- }
+ /*
+ * Accumulate timesharing usage only
+ * during contention for processor
+ * resources.
+ */
+ if (thread->pri_shift < INT8_MAX)
+ thread->sched_usage += delta;
- if (thread->state&TH_IDLE) {
- /* Don't try to time-slice idle threads */
- myprocessor->first_quantum = TRUE;
- if (thread->sched_stamp != sched_tick)
- update_priority(thread);
- thread_unlock(thread);
- splx(s);
- ast_check();
- return;
- }
+ thread->cpu_delta += delta;
- myprocessor->quantum -= nticks;
/*
- * Runtime quantum adjustment. Use quantum_adj_index
- * to avoid synchronizing quantum expirations.
+ * Adjust the scheduled priority if
+ * the thread has not been promoted
+ * and is not depressed.
*/
- if ( quantum != myprocessor->last_quantum &&
- pset->processor_count > 1 ) {
- myprocessor->last_quantum = quantum;
- simple_lock(&pset->quantum_adj_lock);
- quantum = min_quantum + (pset->quantum_adj_index *
- (quantum - min_quantum)) /
- (pset->processor_count - 1);
- if (++(pset->quantum_adj_index) >= pset->processor_count)
- pset->quantum_adj_index = 0;
- simple_unlock(&pset->quantum_adj_lock);
- }
- if (myprocessor->quantum <= 0) {
- if (thread->sched_stamp != sched_tick)
- update_priority(thread);
- else
- if ( thread->policy == POLICY_TIMESHARE &&
- thread->depress_priority < 0 ) {
- thread_timer_delta(thread);
- thread->sched_usage += thread->sched_delta;
- thread->sched_delta = 0;
- compute_my_priority(thread);
- }
+ if ( !(thread->sched_mode & TH_MODE_PROMOTED) &&
+ !(thread->sched_mode & TH_MODE_ISDEPRESSED) )
+ compute_my_priority(thread);
+ }
+
+ /*
+ * This quantum is up, give this thread another.
+ */
+ if (first_timeslice(myprocessor))
+ myprocessor->timeslice--;
+
+ thread_quantum_init(thread);
+ myprocessor->quantum_end += thread->current_quantum;
+ timer_call_enter1(&myprocessor->quantum_timer,
+ thread, myprocessor->quantum_end);
+
+ thread_unlock(thread);
+
+ /*
+ * Check for and schedule ast if needed.
+ */
+ ast_check(myprocessor);
+
+ splx(s);
+}
+
+/*
+ * Define shifts for simulating (5/8) ** n
+ *
+ * Shift structures for holding update shifts. Actual computation
+ * is usage = (usage >> shift1) +/- (usage >> abs(shift2)) where the
+ * +/- is determined by the sign of shift 2.
+ */
+struct shift_data {
+ int shift1;
+ int shift2;
+};
+
+#define SCHED_DECAY_TICKS 32
+static struct shift_data sched_decay_shifts[SCHED_DECAY_TICKS] = {
+ {1,1},{1,3},{1,-3},{2,-7},{3,5},{3,-5},{4,-8},{5,7},
+ {5,-7},{6,-10},{7,10},{7,-9},{8,-11},{9,12},{9,-11},{10,-13},
+ {11,14},{11,-13},{12,-15},{13,17},{13,-15},{14,-17},{15,19},{16,18},
+ {16,-19},{17,22},{18,20},{18,-20},{19,26},{20,22},{20,-22},{21,-27}
+};
+
+/*
+ * do_priority_computation:
+ *
+ * Calculate the timesharing priority based upon usage and load.
+ */
+#define do_priority_computation(thread, pri) \
+ MACRO_BEGIN \
+ (pri) = (thread)->priority /* start with base priority */ \
+ - ((thread)->sched_usage >> (thread)->pri_shift); \
+ if ((pri) < MINPRI_USER) \
+ (pri) = MINPRI_USER; \
+ else \
+ if ((pri) > MAXPRI_KERNEL) \
+ (pri) = MAXPRI_KERNEL; \
+ MACRO_END
+
+/*
+ * set_priority:
+ *
+ * Set the base priority of the thread
+ * and reset its scheduled priority.
+ *
+ * Called with the thread locked.
+ */
+void
+set_priority(
+ register thread_t thread,
+ register int priority)
+{
+ thread->priority = priority;
+ compute_priority(thread, FALSE);
+}
+
+/*
+ * compute_priority:
+ *
+ * Reset the scheduled priority of the thread
+ * according to its base priority if the
+ * thread has not been promoted or depressed.
+ *
+ * Called with the thread locked.
+ */
+void
+compute_priority(
+ register thread_t thread,
+ boolean_t override_depress)
+{
+ register int priority;
+
+ if ( !(thread->sched_mode & TH_MODE_PROMOTED) &&
+ (!(thread->sched_mode & TH_MODE_ISDEPRESSED) ||
+ override_depress ) ) {
+ if (thread->sched_mode & TH_MODE_TIMESHARE)
+ do_priority_computation(thread, priority);
+ else
+ priority = thread->priority;
+
+ set_sched_pri(thread, priority);
+ }
+}
+
+/*
+ * compute_my_priority:
+ *
+ * Reset the scheduled priority for
+ * a timesharing thread.
+ *
+ * Only for use on the current thread
+ * if timesharing and not depressed.
+ *
+ * Called with the thread locked.
+ */
+void
+compute_my_priority(
+ register thread_t thread)
+{
+ register int priority;
+
+ do_priority_computation(thread, priority);
+ assert(thread->runq == RUN_QUEUE_NULL);
+ thread->sched_pri = priority;
+}
+
+/*
+ * update_priority
+ *
+ * Perform housekeeping operations driven by scheduler tick.
+ *
+ * Called with the thread locked.
+ */
+void
+update_priority(
+ register thread_t thread)
+{
+ register unsigned ticks;
+ register uint32_t delta;
+
+ ticks = sched_tick - thread->sched_stamp;
+ assert(ticks != 0);
+ thread->sched_stamp += ticks;
+ thread->pri_shift = thread->processor_set->pri_shift;
+
+ /*
+ * Gather cpu usage data.
+ */
+ thread_timer_delta(thread, delta);
+ if (ticks < SCHED_DECAY_TICKS) {
+ register struct shift_data *shiftp;
- /*
- * This quantum is up, give this thread another.
- */
- myprocessor->first_quantum = FALSE;
- if (thread->policy == POLICY_TIMESHARE)
- myprocessor->quantum += quantum;
- else
- myprocessor->quantum += min_quantum;
- }
/*
- * Recompute priority if appropriate.
+ * Accumulate timesharing usage only
+ * during contention for processor
+ * resources.
*/
+ if (thread->pri_shift < INT8_MAX)
+ thread->sched_usage += delta;
+
+ thread->cpu_usage += delta + thread->cpu_delta;
+ thread->cpu_delta = 0;
+
+ shiftp = &sched_decay_shifts[ticks];
+ if (shiftp->shift2 > 0) {
+ thread->cpu_usage =
+ (thread->cpu_usage >> shiftp->shift1) +
+ (thread->cpu_usage >> shiftp->shift2);
+ thread->sched_usage =
+ (thread->sched_usage >> shiftp->shift1) +
+ (thread->sched_usage >> shiftp->shift2);
+ }
else {
- if (thread->sched_stamp != sched_tick)
- update_priority(thread);
- else
- if ( thread->policy == POLICY_TIMESHARE &&
- thread->depress_priority < 0 ) {
- thread_timer_delta(thread);
- if (thread->sched_delta >= USAGE_THRESHOLD) {
- thread->sched_usage += thread->sched_delta;
- thread->sched_delta = 0;
- compute_my_priority(thread);
- }
+ thread->cpu_usage =
+ (thread->cpu_usage >> shiftp->shift1) -
+ (thread->cpu_usage >> -(shiftp->shift2));
+ thread->sched_usage =
+ (thread->sched_usage >> shiftp->shift1) -
+ (thread->sched_usage >> -(shiftp->shift2));
+ }
+ }
+ else {
+ thread->cpu_usage = thread->cpu_delta = 0;
+ thread->sched_usage = 0;
+ }
+
+ /*
+ * 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) {
+ thread->priority = BASEPRI_RTQUEUES;
+
+ thread->sched_mode |= TH_MODE_REALTIME;
}
+
+ thread->sched_mode &= ~TH_MODE_TIMESHARE;
+
+ if (thread->state & TH_RUN)
+ pset_share_decr(thread->processor_set);
+
+ if (!(thread->sched_mode & TH_MODE_ISDEPRESSED))
+ set_sched_pri(thread, thread->priority);
}
- thread_unlock(thread);
- splx(s);
+ thread->safe_mode = 0;
+ thread->sched_mode &= ~TH_MODE_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) ) {
+ register int new_pri;
- /*
- * Check for and schedule ast if needed.
- */
- ast_check();
+ do_priority_computation(thread, new_pri);
+ if (new_pri != thread->sched_pri) {
+ run_queue_t runq;
+
+ runq = run_queue_remove(thread);
+ thread->sched_pri = new_pri;
+ if (runq != RUN_QUEUE_NULL)
+ thread_setrun(thread, SCHED_TAILQ);
+ }
}
}
projects / apple / xnu.git / blobdiff