[apple/xnu.git] / osfmk / kern / sched_proto.c

/*
 * Copyright (c) 2009 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * 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_OSREFERENCE_LICENSE_HEADER_END@
 */

#include <mach/mach_types.h>
#include <mach/machine.h>
#include <mach/policy.h>
#include <mach/sync_policy.h>
#include <mach/thread_act.h>

#include <machine/machine_routines.h>
#include <machine/sched_param.h>
#include <machine/machine_cpu.h>

#include <kern/kern_types.h>
#include <kern/clock.h>
#include <kern/counters.h>
#include <kern/cpu_number.h>
#include <kern/cpu_data.h>
#include <kern/debug.h>
#include <kern/macro_help.h>
#include <kern/machine.h>
#include <kern/misc_protos.h>
#include <kern/processor.h>
#include <kern/queue.h>
#include <kern/sched.h>
#include <kern/sched_prim.h>
#include <kern/syscall_subr.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/wait_queue.h>

#include <vm/pmap.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>

#include <mach/sdt.h>

#include <sys/kdebug.h>

static void
sched_proto_init(void);

static void
sched_proto_timebase_init(void);

static void
sched_proto_processor_init(processor_t processor);

static void
sched_proto_pset_init(processor_set_t pset);

static void
sched_proto_maintenance_continuation(void);

static thread_t
sched_proto_choose_thread(processor_t		processor,
							 int				priority,
							 ast_t				reason);

static thread_t
sched_proto_steal_thread(processor_set_t		pset);

static void
sched_proto_compute_priority(thread_t	thread,
							 boolean_t			override_depress);

static processor_t
sched_proto_choose_processor(	processor_set_t		pset,
								processor_t			processor,
								thread_t			thread);


static boolean_t
sched_proto_processor_enqueue(
							 processor_t			processor,
							 thread_t			thread,
							 integer_t			options);

static void
sched_proto_processor_queue_shutdown(
									 processor_t			processor);

static boolean_t
sched_proto_processor_queue_remove(
						    processor_t			processor,
							thread_t		thread);

static boolean_t
sched_proto_processor_queue_empty(processor_t		processor);

static boolean_t
sched_proto_processor_queue_has_priority(processor_t		processor,
										 int				priority,
										 boolean_t		gte);

static boolean_t
sched_proto_priority_is_urgent(int priority);

static ast_t
sched_proto_processor_csw_check(processor_t processor);

static uint32_t
sched_proto_initial_quantum_size(thread_t thread);

static sched_mode_t
sched_proto_initial_thread_sched_mode(task_t parent_task);

static boolean_t
sched_proto_can_update_priority(thread_t	thread);

static void
sched_proto_update_priority(thread_t	thread);

static void
sched_proto_lightweight_update_priority(thread_t	thread);

static void
sched_proto_quantum_expire(thread_t	thread);

static boolean_t
sched_proto_should_current_thread_rechoose_processor(processor_t			processor);

static int
sched_proto_processor_runq_count(processor_t   processor);

static uint64_t
sched_proto_processor_runq_stats_count_sum(processor_t   processor);

static int
sched_proto_processor_bound_count(processor_t   processor);

static void
sched_proto_thread_update_scan(void);


const struct sched_dispatch_table sched_proto_dispatch = {
	.init                                           = sched_proto_init,
	.timebase_init                                  = sched_proto_timebase_init,
	.processor_init                                 = sched_proto_processor_init,
	.pset_init                                      = sched_proto_pset_init,
	.maintenance_continuation                       = sched_proto_maintenance_continuation,
	.choose_thread                                  = sched_proto_choose_thread,
	.steal_thread                                   = sched_proto_steal_thread,
	.compute_priority                               = sched_proto_compute_priority,
	.choose_processor                               = sched_proto_choose_processor,
	.processor_enqueue                              = sched_proto_processor_enqueue,
	.processor_queue_shutdown                       = sched_proto_processor_queue_shutdown,
	.processor_queue_remove                         = sched_proto_processor_queue_remove,
	.processor_queue_empty                          = sched_proto_processor_queue_empty,
	.priority_is_urgent                             = sched_proto_priority_is_urgent,
	.processor_csw_check                            = sched_proto_processor_csw_check,
	.processor_queue_has_priority                   = sched_proto_processor_queue_has_priority,
	.initial_quantum_size                           = sched_proto_initial_quantum_size,
	.initial_thread_sched_mode                      = sched_proto_initial_thread_sched_mode,
	.can_update_priority                            = sched_proto_can_update_priority,
	.update_priority                                = sched_proto_update_priority,
	.lightweight_update_priority                    = sched_proto_lightweight_update_priority,
	.quantum_expire                                 = sched_proto_quantum_expire,
	.should_current_thread_rechoose_processor       = sched_proto_should_current_thread_rechoose_processor,
	.processor_runq_count                           = sched_proto_processor_runq_count,
	.processor_runq_stats_count_sum                 = sched_proto_processor_runq_stats_count_sum,
	.fairshare_init                                 = sched_traditional_fairshare_init,
	.fairshare_runq_count                           = sched_traditional_fairshare_runq_count,
	.fairshare_runq_stats_count_sum                 = sched_traditional_fairshare_runq_stats_count_sum,
	.fairshare_enqueue                              = sched_traditional_fairshare_enqueue,
	.fairshare_dequeue                              = sched_traditional_fairshare_dequeue,
	.fairshare_queue_remove                         = sched_traditional_fairshare_queue_remove,
	.processor_bound_count                          = sched_proto_processor_bound_count,
	.thread_update_scan                             = sched_proto_thread_update_scan,
	.direct_dispatch_to_idle_processors             = TRUE,
};

static struct run_queue	*global_runq;
static struct run_queue	global_runq_storage;

#define GLOBAL_RUNQ		((processor_t)-2)
decl_simple_lock_data(static,global_runq_lock);

extern int	max_unsafe_quanta;

static uint32_t proto_quantum_us;
static uint32_t proto_quantum;

static uint32_t	runqueue_generation;

static processor_t proto_processor;

static uint64_t			sched_proto_tick_deadline;
static uint32_t			sched_proto_tick;

static void
sched_proto_init(void)
{
	proto_quantum_us = 10*1000;
	
	printf("standard proto timeslicing quantum is %d us\n", proto_quantum_us);

	simple_lock_init(&global_runq_lock, 0);
	global_runq = &global_runq_storage;
	run_queue_init(global_runq);
	runqueue_generation = 0;
	
	proto_processor = master_processor;
}

static void
sched_proto_timebase_init(void)
{
	uint64_t	abstime;

	/* standard timeslicing quantum */
	clock_interval_to_absolutetime_interval(
											proto_quantum_us, NSEC_PER_USEC, &abstime);
	assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
	proto_quantum = (uint32_t)abstime;
	
	thread_depress_time = 1 * proto_quantum;
	default_timeshare_computation = proto_quantum / 2;
	default_timeshare_constraint = proto_quantum;
	
	max_unsafe_computation = max_unsafe_quanta * proto_quantum;
	sched_safe_duration = 2 * max_unsafe_quanta * proto_quantum;

}

static void
sched_proto_processor_init(processor_t processor __unused)
{
	/* No per-processor state */
}

static void
sched_proto_pset_init(processor_set_t pset __unused)
{
}

static void
sched_proto_maintenance_continuation(void)
{
	uint64_t			abstime = mach_absolute_time();
	
	sched_proto_tick++;
	
	/* Every 8 seconds, switch to another processor */
	if ((sched_proto_tick & 0x7) == 0) {
		processor_t new_processor;
		
		new_processor = proto_processor->processor_list;
		if (new_processor == PROCESSOR_NULL)
			proto_processor = master_processor;
		else
			proto_processor = new_processor;
	}
		
	
	/*
	 *  Compute various averages.
	 */
	compute_averages(1);
	
	if (sched_proto_tick_deadline == 0)
		sched_proto_tick_deadline = abstime;
	
	clock_deadline_for_periodic_event(sched_one_second_interval, abstime,
						&sched_proto_tick_deadline);
	
	assert_wait_deadline((event_t)sched_proto_maintenance_continuation, THREAD_UNINT, sched_proto_tick_deadline);
	thread_block((thread_continue_t)sched_proto_maintenance_continuation);
	/*NOTREACHED*/
}

static thread_t
sched_proto_choose_thread(processor_t		processor,
						  int				priority,
						  ast_t				reason __unused)
{
	run_queue_t		rq = global_runq;
	queue_t			queue;
	int				pri, count;
	thread_t		thread;
	
	
	simple_lock(&global_runq_lock);
	
	queue = rq->queues + rq->highq;
	pri = rq->highq;
	count = rq->count;
	
	/*
	 * Since we don't depress priorities, a high priority thread
	 * may get selected over and over again. Put a runqueue
	 * generation number in the thread structure so that we
	 * can ensure that we've cycled through all runnable tasks
	 * before coming back to a high priority thread. This isn't
	 * perfect, especially if the number of runnable threads always
	 * stays high, but is a workable approximation
	 */
	 
	while (count > 0 && pri >= priority) {
		thread = (thread_t)queue_first(queue);
		while (!queue_end(queue, (queue_entry_t)thread)) {
			if ((thread->bound_processor == PROCESSOR_NULL ||
				thread->bound_processor == processor) &&
				runqueue_generation != thread->runqueue_generation) {
				remqueue((queue_entry_t)thread);
				
				thread->runq = PROCESSOR_NULL;
				thread->runqueue_generation = runqueue_generation;
				SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
				rq->count--;
				if (queue_empty(queue)) {
					if (pri != IDLEPRI)
						clrbit(MAXPRI - pri, rq->bitmap);
					rq->highq = MAXPRI - ffsbit(rq->bitmap);
				}
				
				simple_unlock(&global_runq_lock);
				return (thread);
			}
			count--;
			
			thread = (thread_t)queue_next((queue_entry_t)thread);
		}
		
		queue--; pri--;
	}
	
	runqueue_generation++;
	
	simple_unlock(&global_runq_lock);
	return (THREAD_NULL);
}

static thread_t
sched_proto_steal_thread(processor_set_t		pset)
{
	pset_unlock(pset);
	
	return (THREAD_NULL);
	
}

static void
sched_proto_compute_priority(thread_t	thread,
							 boolean_t			override_depress __unused)
{
	set_sched_pri(thread, thread->priority);
}

static processor_t
sched_proto_choose_processor(	processor_set_t		pset,
							 processor_t			processor,
							 thread_t			thread __unused)
{
	processor = proto_processor;
	
	/*
	 *	Check that the correct processor set is
	 *	returned locked.
	 */
	if (pset != processor->processor_set) {
		pset_unlock(pset);
		
		pset = processor->processor_set;
		pset_lock(pset);
	}
	
	return (processor);
}

static boolean_t
sched_proto_processor_enqueue(
							 processor_t			processor __unused,
							 thread_t			thread,
							 integer_t			options)
{
	run_queue_t		rq = global_runq;
	boolean_t		result;
	
	simple_lock(&global_runq_lock);
	result = run_queue_enqueue(rq, thread, options);
	thread->runq = GLOBAL_RUNQ;
	simple_unlock(&global_runq_lock);
	
	return (result);
}

static void
sched_proto_processor_queue_shutdown(
									 processor_t			processor)
{
	/* With a global runqueue, just stop choosing this processor */
	(void)processor;
}

static boolean_t
sched_proto_processor_queue_remove(
								processor_t			processor,
								thread_t		thread)
{
	void *			rqlock;
	run_queue_t		rq;
	
	rqlock = &global_runq_lock;
	rq = global_runq;
	
	simple_lock(rqlock);
	if (processor == thread->runq) {
		/*
		 *	Thread is on a run queue and we have a lock on
		 *	that run queue.
		 */
		remqueue((queue_entry_t)thread);
		SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
		rq->count--;
		if (SCHED(priority_is_urgent)(thread->sched_pri)) {
			rq->urgency--; assert(rq->urgency >= 0);
		}
		
		if (queue_empty(rq->queues + thread->sched_pri)) {
			/* update run queue status */
			if (thread->sched_pri != IDLEPRI)
				clrbit(MAXPRI - thread->sched_pri, rq->bitmap);
			rq->highq = MAXPRI - ffsbit(rq->bitmap);
		}
		
		thread->runq = PROCESSOR_NULL;
	}
	else {
		/*
		 *	The thread left the run queue before we could
		 * 	lock the run queue.
		 */
		assert(thread->runq == PROCESSOR_NULL);
		processor = PROCESSOR_NULL;
	}
	
	simple_unlock(rqlock);
	
	return (processor != PROCESSOR_NULL);
}

static boolean_t
sched_proto_processor_queue_empty(processor_t		processor __unused)
{
	boolean_t result;
	
	result = (global_runq->count == 0);
	
	return result;
}

static boolean_t
sched_proto_processor_queue_has_priority(processor_t		processor __unused,
										 int				priority,
										 boolean_t		gte)
{
	boolean_t result;
	
	simple_lock(&global_runq_lock);

	if (gte)
		result = global_runq->highq >= priority;
	else
		result = global_runq->highq >= priority;

	simple_unlock(&global_runq_lock);
	
	return result;
}

/* Implement sched_preempt_pri in code */
static boolean_t
sched_proto_priority_is_urgent(int priority)
{
	if (priority <= BASEPRI_FOREGROUND)
		return FALSE;
	
	if (priority < MINPRI_KERNEL)
		return TRUE;

	if (priority >= BASEPRI_PREEMPT)
		return TRUE;
	
	return FALSE;
}

static ast_t
sched_proto_processor_csw_check(processor_t processor __unused)
{
	run_queue_t		runq;
	int				count, urgency;
	
	runq = global_runq;
	count = runq->count;
	urgency = runq->urgency;
	
	if (count > 0) {
		if (urgency > 0)
			return (AST_PREEMPT | AST_URGENT);
		
		return AST_PREEMPT;
	}
	
	return AST_NONE;
}

static uint32_t
sched_proto_initial_quantum_size(thread_t thread __unused)
{
	return proto_quantum;
}

static sched_mode_t
sched_proto_initial_thread_sched_mode(task_t parent_task)
{
	if (parent_task == kernel_task)
		return TH_MODE_FIXED;
	else
		return TH_MODE_TIMESHARE;	
}

static boolean_t
sched_proto_can_update_priority(thread_t	thread __unused)
{
	return FALSE;
}

static void
sched_proto_update_priority(thread_t	thread __unused)
{
	
}

static void
sched_proto_lightweight_update_priority(thread_t	thread __unused)
{
	
}

static void
sched_proto_quantum_expire(thread_t	thread __unused)
{
	
}

static boolean_t
sched_proto_should_current_thread_rechoose_processor(processor_t			processor)
{
	return (proto_processor != processor);
}

static int
sched_proto_processor_runq_count(processor_t   processor)
{
	if (master_processor == processor) {
		return global_runq->count;
	} else {
		return 0;
	}	
}

static uint64_t
sched_proto_processor_runq_stats_count_sum(processor_t   processor)
{
	if (master_processor == processor) {
		return global_runq->runq_stats.count_sum;
	} else {
		return 0ULL;
	}
}

static int
sched_proto_processor_bound_count(__unused processor_t   processor)
{
	return 0;
}

static void
sched_proto_thread_update_scan(void)
{
	
}
Commit	Line	Data
6d2010ae A	1	/*
	2	* Copyright (c) 2009 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28
	29	#include <mach/mach_types.h>
	30	#include <mach/machine.h>
	31	#include <mach/policy.h>
	32	#include <mach/sync_policy.h>
	33	#include <mach/thread_act.h>
	34
	35	#include <machine/machine_routines.h>
	36	#include <machine/sched_param.h>
	37	#include <machine/machine_cpu.h>
	38
	39	#include <kern/kern_types.h>
	40	#include <kern/clock.h>
	41	#include <kern/counters.h>
	42	#include <kern/cpu_number.h>
	43	#include <kern/cpu_data.h>
	44	#include <kern/debug.h>
6d2010ae A	45	#include <kern/macro_help.h>
	46	#include <kern/machine.h>
	47	#include <kern/misc_protos.h>
	48	#include <kern/processor.h>
	49	#include <kern/queue.h>
	50	#include <kern/sched.h>
	51	#include <kern/sched_prim.h>
	52	#include <kern/syscall_subr.h>
	53	#include <kern/task.h>
	54	#include <kern/thread.h>
	55	#include <kern/wait_queue.h>
	56
	57	#include <vm/pmap.h>
	58	#include <vm/vm_kern.h>
	59	#include <vm/vm_map.h>
	60
	61	#include <mach/sdt.h>
	62
	63	#include <sys/kdebug.h>
	64
	65	static void
	66	sched_proto_init(void);
	67
	68	static void
	69	sched_proto_timebase_init(void);
	70
	71	static void
	72	sched_proto_processor_init(processor_t processor);
	73
	74	static void
	75	sched_proto_pset_init(processor_set_t pset);
	76
	77	static void
	78	sched_proto_maintenance_continuation(void);
	79
	80	static thread_t
	81	sched_proto_choose_thread(processor_t processor,
fe8ab488 A	82	int priority,
fe8ab488 A	83	ast_t reason);
6d2010ae A	84
	85	static thread_t
	86	sched_proto_steal_thread(processor_set_t pset);
	87
	88	static void
	89	sched_proto_compute_priority(thread_t thread,
	90	boolean_t override_depress);
	91
	92	static processor_t
	93	sched_proto_choose_processor( processor_set_t pset,
	94	processor_t processor,
	95	thread_t thread);
	96
	97
	98	static boolean_t
	99	sched_proto_processor_enqueue(
	100	processor_t processor,
	101	thread_t thread,
	102	integer_t options);
	103
	104	static void
	105	sched_proto_processor_queue_shutdown(
	106	processor_t processor);
	107
	108	static boolean_t
	109	sched_proto_processor_queue_remove(
	110	processor_t processor,
	111	thread_t thread);
	112
	113	static boolean_t
	114	sched_proto_processor_queue_empty(processor_t processor);
	115
	116	static boolean_t
	117	sched_proto_processor_queue_has_priority(processor_t processor,
	118	int priority,
	119	boolean_t gte);
	120
	121	static boolean_t
	122	sched_proto_priority_is_urgent(int priority);
	123
	124	static ast_t
	125	sched_proto_processor_csw_check(processor_t processor);
	126
	127	static uint32_t
	128	sched_proto_initial_quantum_size(thread_t thread);
	129
	130	static sched_mode_t
	131	sched_proto_initial_thread_sched_mode(task_t parent_task);
	132
6d2010ae A	133	static boolean_t
	134	sched_proto_can_update_priority(thread_t thread);
	135
	136	static void
	137	sched_proto_update_priority(thread_t thread);
	138
	139	static void
	140	sched_proto_lightweight_update_priority(thread_t thread);
	141
	142	static void
	143	sched_proto_quantum_expire(thread_t thread);
	144
	145	static boolean_t
	146	sched_proto_should_current_thread_rechoose_processor(processor_t processor);
	147
	148	static int
	149	sched_proto_processor_runq_count(processor_t processor);
	150
	151	static uint64_t
	152	sched_proto_processor_runq_stats_count_sum(processor_t processor);
	153
fe8ab488 A	154	static int
	155	sched_proto_processor_bound_count(processor_t processor);
	156
	157	static void
	158	sched_proto_thread_update_scan(void);
	159
	160
6d2010ae	161	const struct sched_dispatch_table sched_proto_dispatch = {
fe8ab488 A	162	.init = sched_proto_init,
	163	.timebase_init = sched_proto_timebase_init,
	164	.processor_init = sched_proto_processor_init,
	165	.pset_init = sched_proto_pset_init,
	166	.maintenance_continuation = sched_proto_maintenance_continuation,
	167	.choose_thread = sched_proto_choose_thread,
	168	.steal_thread = sched_proto_steal_thread,
	169	.compute_priority = sched_proto_compute_priority,
	170	.choose_processor = sched_proto_choose_processor,
	171	.processor_enqueue = sched_proto_processor_enqueue,
	172	.processor_queue_shutdown = sched_proto_processor_queue_shutdown,
	173	.processor_queue_remove = sched_proto_processor_queue_remove,
	174	.processor_queue_empty = sched_proto_processor_queue_empty,
	175	.priority_is_urgent = sched_proto_priority_is_urgent,
	176	.processor_csw_check = sched_proto_processor_csw_check,
	177	.processor_queue_has_priority = sched_proto_processor_queue_has_priority,
	178	.initial_quantum_size = sched_proto_initial_quantum_size,
	179	.initial_thread_sched_mode = sched_proto_initial_thread_sched_mode,
	180	.can_update_priority = sched_proto_can_update_priority,
	181	.update_priority = sched_proto_update_priority,
	182	.lightweight_update_priority = sched_proto_lightweight_update_priority,
	183	.quantum_expire = sched_proto_quantum_expire,
	184	.should_current_thread_rechoose_processor = sched_proto_should_current_thread_rechoose_processor,
	185	.processor_runq_count = sched_proto_processor_runq_count,
	186	.processor_runq_stats_count_sum = sched_proto_processor_runq_stats_count_sum,
	187	.fairshare_init = sched_traditional_fairshare_init,
	188	.fairshare_runq_count = sched_traditional_fairshare_runq_count,
	189	.fairshare_runq_stats_count_sum = sched_traditional_fairshare_runq_stats_count_sum,
	190	.fairshare_enqueue = sched_traditional_fairshare_enqueue,
	191	.fairshare_dequeue = sched_traditional_fairshare_dequeue,
	192	.fairshare_queue_remove = sched_traditional_fairshare_queue_remove,
	193	.processor_bound_count = sched_proto_processor_bound_count,
	194	.thread_update_scan = sched_proto_thread_update_scan,
	195	.direct_dispatch_to_idle_processors = TRUE,
6d2010ae A	196	};
	197
	198	static struct run_queue *global_runq;
	199	static struct run_queue global_runq_storage;
	200
	201	#define GLOBAL_RUNQ ((processor_t)-2)
	202	decl_simple_lock_data(static,global_runq_lock);
	203
	204	extern int max_unsafe_quanta;
	205
	206	static uint32_t proto_quantum_us;
	207	static uint32_t proto_quantum;
	208
	209	static uint32_t runqueue_generation;
	210
	211	static processor_t proto_processor;
	212
	213	static uint64_t sched_proto_tick_deadline;
	214	static uint32_t sched_proto_tick;
	215
	216	static void
	217	sched_proto_init(void)
	218	{
	219	proto_quantum_us = 10*1000;
	220
	221	printf("standard proto timeslicing quantum is %d us\n", proto_quantum_us);
	222
	223	simple_lock_init(&global_runq_lock, 0);
	224	global_runq = &global_runq_storage;
	225	run_queue_init(global_runq);
	226	runqueue_generation = 0;
	227
	228	proto_processor = master_processor;
	229	}
	230
	231	static void
	232	sched_proto_timebase_init(void)
	233	{
	234	uint64_t abstime;
	235
	236	/* standard timeslicing quantum */
	237	clock_interval_to_absolutetime_interval(
	238	proto_quantum_us, NSEC_PER_USEC, &abstime);
	239	assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
	240	proto_quantum = (uint32_t)abstime;
	241
	242	thread_depress_time = 1 * proto_quantum;
	243	default_timeshare_computation = proto_quantum / 2;
	244	default_timeshare_constraint = proto_quantum;
	245
	246	max_unsafe_computation = max_unsafe_quanta * proto_quantum;
	247	sched_safe_duration = 2 * max_unsafe_quanta * proto_quantum;
	248
	249	}
	250
	251	static void
	252	sched_proto_processor_init(processor_t processor __unused)
	253	{
	254	/* No per-processor state */
	255	}
	256
	257	static void
	258	sched_proto_pset_init(processor_set_t pset __unused)
	259	{
260	}
261
262	static void
263	sched_proto_maintenance_continuation(void)
264	{
265	uint64_t abstime = mach_absolute_time();
266
267	sched_proto_tick++;
268
269	/* Every 8 seconds, switch to another processor */
270	if ((sched_proto_tick & 0x7) == 0) {
271	processor_t new_processor;
272
273	new_processor = proto_processor->processor_list;
274	if (new_processor == PROCESSOR_NULL)
275	proto_processor = master_processor;
276	else
277	proto_processor = new_processor;
278	}
279
280
281	/*
282	* Compute various averages.
283	*/
39236c6e	284	compute_averages(1);
6d2010ae A	285
	286	if (sched_proto_tick_deadline == 0)
	287	sched_proto_tick_deadline = abstime;
	288
	289	clock_deadline_for_periodic_event(sched_one_second_interval, abstime,
	290	&sched_proto_tick_deadline);
	291
	292	assert_wait_deadline((event_t)sched_proto_maintenance_continuation, THREAD_UNINT, sched_proto_tick_deadline);
	293	thread_block((thread_continue_t)sched_proto_maintenance_continuation);
	294	/NOTREACHED/
	295	}
	296
	297	static thread_t
	298	sched_proto_choose_thread(processor_t processor,
fe8ab488 A	299	int priority,
fe8ab488 A	300	ast_t reason __unused)
6d2010ae A	301	{
	302	run_queue_t rq = global_runq;
	303	queue_t queue;
	304	int pri, count;
	305	thread_t thread;
	306
	307
	308	simple_lock(&global_runq_lock);
	309
	310	queue = rq->queues + rq->highq;
	311	pri = rq->highq;
	312	count = rq->count;
	313
	314	/*
	315	* Since we don't depress priorities, a high priority thread
	316	* may get selected over and over again. Put a runqueue
	317	* generation number in the thread structure so that we
	318	* can ensure that we've cycled through all runnable tasks
	319	* before coming back to a high priority thread. This isn't
	320	* perfect, especially if the number of runnable threads always
	321	* stays high, but is a workable approximation
	322	*/
	323
	324	while (count > 0 && pri >= priority) {
	325	thread = (thread_t)queue_first(queue);
	326	while (!queue_end(queue, (queue_entry_t)thread)) {
	327	if ((thread->bound_processor == PROCESSOR_NULL \|\|
	328	thread->bound_processor == processor) &&
	329	runqueue_generation != thread->runqueue_generation) {
	330	remqueue((queue_entry_t)thread);
	331
	332	thread->runq = PROCESSOR_NULL;
	333	thread->runqueue_generation = runqueue_generation;
	334	SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
	335	rq->count--;
	336	if (queue_empty(queue)) {
	337	if (pri != IDLEPRI)
	338	clrbit(MAXPRI - pri, rq->bitmap);
	339	rq->highq = MAXPRI - ffsbit(rq->bitmap);
	340	}
	341
	342	simple_unlock(&global_runq_lock);
	343	return (thread);
	344	}
	345	count--;
	346
	347	thread = (thread_t)queue_next((queue_entry_t)thread);
	348	}
	349
	350	queue--; pri--;
	351	}
	352
	353	runqueue_generation++;
	354
	355	simple_unlock(&global_runq_lock);
	356	return (THREAD_NULL);
	357	}
	358
	359	static thread_t
	360	sched_proto_steal_thread(processor_set_t pset)
	361	{
	362	pset_unlock(pset);
	363
	364	return (THREAD_NULL);
365
366	}
367
368	static void
369	sched_proto_compute_priority(thread_t thread,
370	boolean_t override_depress __unused)
371	{
372	set_sched_pri(thread, thread->priority);
373	}
374
375	static processor_t
376	sched_proto_choose_processor( processor_set_t pset,
377	processor_t processor,
378	thread_t thread __unused)
379	{
380	processor = proto_processor;
381
382	/*
383	* Check that the correct processor set is
384	* returned locked.
385	*/
386	if (pset != processor->processor_set) {
387	pset_unlock(pset);
388
389	pset = processor->processor_set;
390	pset_lock(pset);
391	}
392
393	return (processor);
394	}
395
396	static boolean_t
397	sched_proto_processor_enqueue(
398	processor_t processor __unused,
399	thread_t thread,
400	integer_t options)
401	{
402	run_queue_t rq = global_runq;
403	boolean_t result;
404
405	simple_lock(&global_runq_lock);
406	result = run_queue_enqueue(rq, thread, options);
407	thread->runq = GLOBAL_RUNQ;
408	simple_unlock(&global_runq_lock);
409
410	return (result);
411	}
412
413	static void
414	sched_proto_processor_queue_shutdown(
415	processor_t processor)
416	{
417	/* With a global runqueue, just stop choosing this processor */
418	(void)processor;
419	}
420
421	static boolean_t
422	sched_proto_processor_queue_remove(
423	processor_t processor,
424	thread_t thread)
425	{
426	void * rqlock;
427	run_queue_t rq;
428
429	rqlock = &global_runq_lock;
430	rq = global_runq;
431
432	simple_lock(rqlock);
433	if (processor == thread->runq) {
434	/*
435	* Thread is on a run queue and we have a lock on
436	* that run queue.
437	*/
438	remqueue((queue_entry_t)thread);
439	SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
440	rq->count--;
441	if (SCHED(priority_is_urgent)(thread->sched_pri)) {
442	rq->urgency--; assert(rq->urgency >= 0);
443	}
444
445	if (queue_empty(rq->queues + thread->sched_pri)) {
446	/* update run queue status */
447	if (thread->sched_pri != IDLEPRI)
448	clrbit(MAXPRI - thread->sched_pri, rq->bitmap);
449	rq->highq = MAXPRI - ffsbit(rq->bitmap);
450	}
451
452	thread->runq = PROCESSOR_NULL;
453	}
454	else {
455	/*
456	* The thread left the run queue before we could
457	* lock the run queue.
458	*/
459	assert(thread->runq == PROCESSOR_NULL);
460	processor = PROCESSOR_NULL;
461	}
462
463	simple_unlock(rqlock);
464
465	return (processor != PROCESSOR_NULL);
466	}
467
468	static boolean_t
469	sched_proto_processor_queue_empty(processor_t processor __unused)
470	{
471	boolean_t result;
472
473	result = (global_runq->count == 0);
474
475	return result;
476	}
477
478	static boolean_t
479	sched_proto_processor_queue_has_priority(processor_t processor __unused,
480	int priority,
481	boolean_t gte)
482	{
483	boolean_t result;
484
485	simple_lock(&global_runq_lock);
486
487	if (gte)
488	result = global_runq->highq >= priority;
489	else
490	result = global_runq->highq >= priority;
491
492	simple_unlock(&global_runq_lock);
493
494	return result;
495	}
496
497	/* Implement sched_preempt_pri in code */
498	static boolean_t
499	sched_proto_priority_is_urgent(int priority)
500	{
501	if (priority <= BASEPRI_FOREGROUND)
502	return FALSE;
503
504	if (priority < MINPRI_KERNEL)
505	return TRUE;
506
507	if (priority >= BASEPRI_PREEMPT)
508	return TRUE;
509
510	return FALSE;
511	}
512
513	static ast_t
514	sched_proto_processor_csw_check(processor_t processor __unused)
515	{
516	run_queue_t runq;
517	int count, urgency;
518
519	runq = global_runq;
520	count = runq->count;
521	urgency = runq->urgency;
522
523	if (count > 0) {
524	if (urgency > 0)
525	return (AST_PREEMPT \| AST_URGENT);
526
527	return AST_PREEMPT;
528	}
529
530	return AST_NONE;
531	}
532
533	static uint32_t
534	sched_proto_initial_quantum_size(thread_t thread __unused)
535	{
536	return proto_quantum;
537	}
538
539	static sched_mode_t
540	sched_proto_initial_thread_sched_mode(task_t parent_task)
541	{
542	if (parent_task == kernel_task)
543	return TH_MODE_FIXED;
544	else
545	return TH_MODE_TIMESHARE;
546	}
547
6d2010ae A	548	static boolean_t
	549	sched_proto_can_update_priority(thread_t thread __unused)
	550	{
	551	return FALSE;
	552	}
	553
	554	static void
	555	sched_proto_update_priority(thread_t thread __unused)
	556	{
	557
	558	}
	559
	560	static void
	561	sched_proto_lightweight_update_priority(thread_t thread __unused)
	562	{
	563
	564	}
	565
	566	static void
	567	sched_proto_quantum_expire(thread_t thread __unused)
	568	{
	569
	570	}
	571
	572	static boolean_t
	573	sched_proto_should_current_thread_rechoose_processor(processor_t processor)
	574	{
	575	return (proto_processor != processor);
	576	}
	577
	578	static int
	579	sched_proto_processor_runq_count(processor_t processor)
	580	{
	581	if (master_processor == processor) {
	582	return global_runq->count;
	583	} else {
	584	return 0;
	585	}
	586	}
	587
	588	static uint64_t
	589	sched_proto_processor_runq_stats_count_sum(processor_t processor)
	590	{
	591	if (master_processor == processor) {
	592	return global_runq->runq_stats.count_sum;
	593	} else {
	594	return 0ULL;
	595	}
	596	}
	597
fe8ab488 A	598	static int
	599	sched_proto_processor_bound_count(__unused processor_t processor)
	600	{
	601	return 0;
	602	}
	603
	604	static void
	605	sched_proto_thread_update_scan(void)
	606	{
	607
	608	}
	609
	610
	611