[apple/xnu.git] / osfmk / kern / sched.h

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_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 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@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */
/*
 *	File:	sched.h
 *	Author:	Avadis Tevanian, Jr.
 *	Date:	1985
 *
 *	Header file for scheduler.
 *
 */

#ifndef	_KERN_SCHED_H_
#define _KERN_SCHED_H_

#include <simple_clock.h>
#include <stat_time.h>

#include <mach/policy.h>
#include <kern/kern_types.h>
#include <kern/queue.h>
#include <kern/lock.h>
#include <kern/macro_help.h>
#include <kern/timer_call.h>

#if	STAT_TIME

/*
 *	Statistical timing uses microseconds as timer units.
 */
#define PRI_SHIFT	(16 - SCHED_TICK_SHIFT)

#else	/* STAT_TIME */

/*
 *	Otherwise machine provides shift(s) based on time units it uses.
 */
#include <machine/sched_param.h>

#endif	/* STAT_TIME */

#define	NRQS		128				/* 128 run queues per cpu */
#define NRQBM		(NRQS / 32)		/* number of run queue bit maps */

#define MAXPRI		(NRQS-1)
#define MINPRI		IDLEPRI			/* lowest legal priority schedulable */
#define	IDLEPRI		0				/* idle thread priority */
#define DEPRESSPRI	MINPRI			/* depress priority */

/*
 *	High-level priority assignments
 *
 *************************************************************************
 * 127		Reserved (real-time)
 *				A
 *				+
 *			(32 levels)
 *				+
 *				V
 * 96		Reserved (real-time)
 * 95		Kernel mode only
 *				A
 *				+
 *			(16 levels)
 *				+
 *				V
 * 80		Kernel mode only
 * 79		System high priority
 *				A
 *				+
 *			(16 levels)
 *				+
 *				V
 * 64		System high priority
 * 63		Elevated priorities
 *				A
 *				+
 *			(12 levels)
 *				+
 *				V
 * 52		Elevated priorities
 * 51		Elevated priorities (incl. BSD +nice)
 *				A
 *				+
 *			(20 levels)
 *				+
 *				V
 * 32		Elevated priorities (incl. BSD +nice)
 * 31		Default (default base for threads)
 * 30		Lowered priorities (incl. BSD -nice)
 *				A
 *				+
 *			(20 levels)
 *				+
 *				V
 * 11		Lowered priorities (incl. BSD -nice)
 * 10		Lowered priorities (aged pri's)
 *				A
 *				+
 *			(11 levels)
 *				+
 *				V
 * 0		Lowered priorities (aged pri's / idle)
 *************************************************************************
 */

#define BASEPRI_REALTIME	(MAXPRI - (NRQS / 4) + 1)			/* 96 */

#define MAXPRI_STANDARD		(BASEPRI_REALTIME - 1)				/* 95 */

#define MAXPRI_KERNEL		MAXPRI_STANDARD						/* 95 */
#define BASEPRI_PREEMPT		(MAXPRI_KERNEL - 2)					/* 93 */
#define MINPRI_KERNEL		(MAXPRI_KERNEL - (NRQS / 8) + 1)	/* 80 */

#define MAXPRI_SYSTEM		(MINPRI_KERNEL - 1)					/* 79 */
#define MINPRI_SYSTEM		(MAXPRI_SYSTEM - (NRQS / 8) + 1)	/* 64 */

#define MAXPRI_USER			(MINPRI_SYSTEM - 1)					/* 63 */
#define BASEPRI_DEFAULT		(MAXPRI_USER - (NRQS / 4))			/* 31 */
#define MINPRI_USER			MINPRI								/*  0 */

#define MINPRI_STANDARD		MINPRI_USER							/*  0 */

/*
 *	Macro to check for invalid priorities.
 */
#define invalid_pri(pri) ((pri) < MINPRI || (pri) > MAXPRI)

struct run_queue {
	queue_head_t		queues[NRQS];		/* one for each priority */
	decl_simple_lock_data(,lock)			/* one lock for all queues */
	int					bitmap[NRQBM];		/* run queue bitmap array */
	int					highq;				/* highest runnable queue */
	int					count;				/* # of runnable threads */
};

typedef struct run_queue	*run_queue_t;
#define RUN_QUEUE_NULL		((run_queue_t) 0)

#define first_quantum(processor)	((processor)->slice_quanta > 0)

#define csw_needed(thread, processor) (										\
	((thread)->state & TH_SUSP)										||		\
	(first_quantum(processor)?												\
	 ((processor)->runq.highq > (thread)->sched_pri				||			\
	  (processor)->processor_set->runq.highq > (thread)->sched_pri) :		\
	 ((processor)->runq.highq >= (thread)->sched_pri			||			\
	  (processor)->processor_set->runq.highq >= (thread)->sched_pri))	)

/*
 *	Scheduler routines.
 */

/* Remove thread from its run queue */
extern run_queue_t	rem_runq(
						thread_t	thread);

/* Periodic computation of load factors */
extern void		compute_mach_factor(void);

/* Handle quantum expiration for an executing thread */
extern void		thread_quantum_expire(
					timer_call_param_t	processor,
					timer_call_param_t	thread);

extern uint32_t	std_quantum, min_std_quantum;
extern uint32_t	std_quantum_us;

extern uint32_t	max_rt_quantum, min_rt_quantum;

/*
 *	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 {
	int	shift1;
	int	shift2;
};

typedef	struct shift	*shift_t, shift_data_t;

/*
 *	Age usage (1 << SCHED_TICK_SHIFT) times per second.
 */

extern unsigned	sched_tick;

#define SCHED_TICK_SHIFT	3

#define SCHED_SCALE		128
#define SCHED_SHIFT		7

/*
 *	thread_timer_delta macro takes care of both thread timers.
 */

#define thread_timer_delta(thread)  						\
MACRO_BEGIN													\
	register unsigned	delta;								\
															\
	delta = 0;												\
	TIMER_DELTA((thread)->system_timer,						\
					(thread)->system_timer_save, delta);	\
	TIMER_DELTA((thread)->user_timer,						\
					(thread)->user_timer_save, delta);		\
	(thread)->cpu_delta += delta;							\
	(thread)->sched_delta += (delta * 						\
					(thread)->processor_set->sched_load);	\
MACRO_END

#if	SIMPLE_CLOCK
/*
 *	sched_usec is an exponential average of number of microseconds
 *	in a second for clock drift compensation.
 */

extern int	sched_usec;
#endif	/* SIMPLE_CLOCK */

#endif	/* _KERN_SCHED_H_ */
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* @OSF_COPYRIGHT@
	24	*/
	25	/*
	26	* Mach Operating System
	27	* Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
	28	* All Rights Reserved.
	29	*
	30	* Permission to use, copy, modify and distribute this software and its
	31	* documentation is hereby granted, provided that both the copyright
	32	* notice and this permission notice appear in all copies of the
	33	* software, derivative works or modified versions, and any portions
	34	* thereof, and that both notices appear in supporting documentation.
	35	*
	36	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	37	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	38	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
	39	*
	40	* Carnegie Mellon requests users of this software to return to
	41	*
	42	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	43	* School of Computer Science
	44	* Carnegie Mellon University
	45	* Pittsburgh PA 15213-3890
	46	*
	47	* any improvements or extensions that they make and grant Carnegie Mellon
	48	* the rights to redistribute these changes.
	49	*/
	50	/*
	51	*/
	52	/*
	53	* File: sched.h
	54	* Author: Avadis Tevanian, Jr.
	55	* Date: 1985
	56	*
	57	* Header file for scheduler.
	58	*
	59	*/
	60
	61	#ifndef _KERN_SCHED_H_
	62	#define _KERN_SCHED_H_
	63
1c79356b A	64	#include <simple_clock.h>
	65	#include <stat_time.h>
	66
	67	#include <mach/policy.h>
	68	#include <kern/kern_types.h>
	69	#include <kern/queue.h>
	70	#include <kern/lock.h>
	71	#include <kern/macro_help.h>
0b4e3aa0	72	#include <kern/timer_call.h>
1c79356b A	73
	74	#if STAT_TIME
	75
	76	/*
0b4e3aa0	77	* Statistical timing uses microseconds as timer units.
1c79356b A	78	*/
	79	#define PRI_SHIFT (16 - SCHED_TICK_SHIFT)
	80
	81	#else /* STAT_TIME */
	82
	83	/*
	84	* Otherwise machine provides shift(s) based on time units it uses.
	85	*/
	86	#include <machine/sched_param.h>
	87
	88	#endif /* STAT_TIME */
	89
	90	#define NRQS 128 /* 128 run queues per cpu */
	91	#define NRQBM (NRQS / 32) /* number of run queue bit maps */
	92
	93	#define MAXPRI (NRQS-1)
	94	#define MINPRI IDLEPRI /* lowest legal priority schedulable */
	95	#define IDLEPRI 0 /* idle thread priority */
	96	#define DEPRESSPRI MINPRI /* depress priority */
	97
	98	/*
	99	* High-level priority assignments
	100	*
	101	*************************************************************************
	102	* 127 Reserved (real-time)
	103	* A
	104	* +
	105	* (32 levels)
	106	* +
	107	* V
	108	* 96 Reserved (real-time)
	109	* 95 Kernel mode only
	110	* A
	111	* +
	112	* (16 levels)
	113	* +
	114	* V
	115	* 80 Kernel mode only
0b4e3aa0	116	* 79 System high priority
1c79356b A	117	* A
	118	* +
	119	* (16 levels)
	120	* +
	121	* V
0b4e3aa0	122	* 64 System high priority
1c79356b A	123	* 63 Elevated priorities
	124	* A
	125	* +
	126	* (12 levels)
	127	* +
	128	* V
	129	* 52 Elevated priorities
	130	* 51 Elevated priorities (incl. BSD +nice)
	131	* A
	132	* +
	133	* (20 levels)
	134	* +
	135	* V
	136	* 32 Elevated priorities (incl. BSD +nice)
	137	* 31 Default (default base for threads)
	138	* 30 Lowered priorities (incl. BSD -nice)
	139	* A
	140	* +
	141	* (20 levels)
	142	* +
	143	* V
	144	* 11 Lowered priorities (incl. BSD -nice)
	145	* 10 Lowered priorities (aged pri's)
	146	* A
	147	* +
	148	* (11 levels)
	149	* +
	150	* V
	151	* 0 Lowered priorities (aged pri's / idle)
	152	*************************************************************************
	153	*/
	154
	155	#define BASEPRI_REALTIME (MAXPRI - (NRQS / 4) + 1) /* 96 */
	156
	157	#define MAXPRI_STANDARD (BASEPRI_REALTIME - 1) /* 95 */
	158
0b4e3aa0 A	159	#define MAXPRI_KERNEL MAXPRI_STANDARD /* 95 */
	160	#define BASEPRI_PREEMPT (MAXPRI_KERNEL - 2) /* 93 */
	161	#define MINPRI_KERNEL (MAXPRI_KERNEL - (NRQS / 8) + 1) /* 80 */
1c79356b	162
0b4e3aa0 A	163	#define MAXPRI_SYSTEM (MINPRI_KERNEL - 1) /* 79 */
0b4e3aa0 A	164	#define MINPRI_SYSTEM (MAXPRI_SYSTEM - (NRQS / 8) + 1) /* 64 */
1c79356b	165
0b4e3aa0 A	166	#define MAXPRI_USER (MINPRI_SYSTEM - 1) /* 63 */
	167	#define BASEPRI_DEFAULT (MAXPRI_USER - (NRQS / 4)) /* 31 */
	168	#define MINPRI_USER MINPRI /* 0 */
1c79356b	169
0b4e3aa0	170	#define MINPRI_STANDARD MINPRI_USER /* 0 */
1c79356b A	171
	172	/*
	173	* Macro to check for invalid priorities.
	174	*/
	175	#define invalid_pri(pri) ((pri) < MINPRI \|\| (pri) > MAXPRI)
	176
	177	struct run_queue {
	178	queue_head_t queues[NRQS]; /* one for each priority */
	179	decl_simple_lock_data(,lock) /* one lock for all queues */
	180	int bitmap[NRQBM]; /* run queue bitmap array */
	181	int highq; /* highest runnable queue */
	182	int count; /* # of runnable threads */
	183	};
	184
	185	typedef struct run_queue *run_queue_t;
	186	#define RUN_QUEUE_NULL ((run_queue_t) 0)
	187
0b4e3aa0 A	188	#define first_quantum(processor) ((processor)->slice_quanta > 0)
0b4e3aa0 A	189
1c79356b A	190	#define csw_needed(thread, processor) ( \
1c79356b A	191	((thread)->state & TH_SUSP) \|\| \
0b4e3aa0	192	(first_quantum(processor)? \
1c79356b A	193	((processor)->runq.highq > (thread)->sched_pri \|\| \
	194	(processor)->processor_set->runq.highq > (thread)->sched_pri) : \
	195	((processor)->runq.highq >= (thread)->sched_pri \|\| \
	196	(processor)->processor_set->runq.highq >= (thread)->sched_pri)) )
	197
	198	/*
	199	* Scheduler routines.
	200	*/
	201
	202	/* Remove thread from its run queue */
	203	extern run_queue_t rem_runq(
0b4e3aa0	204	thread_t thread);
1c79356b	205
0b4e3aa0	206	/* Periodic computation of load factors */
1c79356b A	207	extern void compute_mach_factor(void);
1c79356b A	208
0b4e3aa0 A	209	/* Handle quantum expiration for an executing thread */
	210	extern void thread_quantum_expire(
	211	timer_call_param_t processor,
	212	timer_call_param_t thread);
	213
	214	extern uint32_t std_quantum, min_std_quantum;
	215	extern uint32_t std_quantum_us;
1c79356b	216
0b4e3aa0	217	extern uint32_t max_rt_quantum, min_rt_quantum;
1c79356b A	218
	219	/*
	220	* Shift structures for holding update shifts. Actual computation
	221	* is usage = (usage >> shift1) +/- (usage >> abs(shift2)) where the
	222	* +/- is determined by the sign of shift 2.
	223	*/
	224	struct shift {
	225	int shift1;
	226	int shift2;
	227	};
	228
	229	typedef struct shift *shift_t, shift_data_t;
	230
	231	/*
	232	* Age usage (1 << SCHED_TICK_SHIFT) times per second.
	233	*/
	234
	235	extern unsigned sched_tick;
	236
	237	#define SCHED_TICK_SHIFT 3
	238
	239	#define SCHED_SCALE 128
	240	#define SCHED_SHIFT 7
	241
	242	/*
	243	* thread_timer_delta macro takes care of both thread timers.
	244	*/
	245
	246	#define thread_timer_delta(thread) \
	247	MACRO_BEGIN \
	248	register unsigned delta; \
	249	\
	250	delta = 0; \
	251	TIMER_DELTA((thread)->system_timer, \
	252	(thread)->system_timer_save, delta); \
	253	TIMER_DELTA((thread)->user_timer, \
	254	(thread)->user_timer_save, delta); \
	255	(thread)->cpu_delta += delta; \
	256	(thread)->sched_delta += (delta * \
	257	(thread)->processor_set->sched_load); \
	258	MACRO_END
	259
	260	#if SIMPLE_CLOCK
	261	/*
	262	* sched_usec is an exponential average of number of microseconds
	263	* in a second for clock drift compensation.
	264	*/
	265
	266	extern int sched_usec;
	267	#endif /* SIMPLE_CLOCK */
	268
	269	#endif /* _KERN_SCHED_H_ */