osfmk/kern/sched.h

   1 /*
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  10  * may not be used to create, or enable the creation or redistribution of,
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  13  * terms of an Apple operating system software license agreement.
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  17  *
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  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56 /*
  57  */
  58 /*
  59  *      File:   sched.h
  60  *      Author: Avadis Tevanian, Jr.
  61  *      Date:   1985
  62  *
  63  *      Header file for scheduler.
  64  *
  65  */
  66
  67 #ifndef _KERN_SCHED_H_
  68 #define _KERN_SCHED_H_
  69
  70 #include <stat_time.h>
  71
  72 #include <mach/policy.h>
  73 #include <kern/kern_types.h>
  74 #include <kern/queue.h>
  75 #include <kern/lock.h>
  76 #include <kern/macro_help.h>
  77 #include <kern/timer_call.h>
  78 #include <kern/ast.h>
  79
  80 #define NRQS            128                             /* 128 levels per run queue */
  81 #define NRQBM           (NRQS / 32)             /* number of words per bit map */
  82
  83 #define MAXPRI          (NRQS-1)
  84 #define MINPRI          IDLEPRI                 /* lowest legal priority schedulable */
  85 #define IDLEPRI         0                               /* idle thread priority */
  86
  87 /*
  88  *      High-level priority assignments
  89  *
  90  *************************************************************************
  91  * 127          Reserved (real-time)
  92  *                              A
  93  *                              +
  94  *                      (32 levels)
  95  *                              +
  96  *                              V
  97  * 96           Reserved (real-time)
  98  * 95           Kernel mode only
  99  *                              A
 100  *                              +
 101  *                      (16 levels)
 102  *                              +
 103  *                              V
 104  * 80           Kernel mode only
 105  * 79           System high priority
 106  *                              A
 107  *                              +
 108  *                      (16 levels)
 109  *                              +
 110  *                              V
 111  * 64           System high priority
 112  * 63           Elevated priorities
 113  *                              A
 114  *                              +
 115  *                      (12 levels)
 116  *                              +
 117  *                              V
 118  * 52           Elevated priorities
 119  * 51           Elevated priorities (incl. BSD +nice)
 120  *                              A
 121  *                              +
 122  *                      (20 levels)
 123  *                              +
 124  *                              V
 125  * 32           Elevated priorities (incl. BSD +nice)
 126  * 31           Default (default base for threads)
 127  * 30           Lowered priorities (incl. BSD -nice)
 128  *                              A
 129  *                              +
 130  *                      (20 levels)
 131  *                              +
 132  *                              V
 133  * 11           Lowered priorities (incl. BSD -nice)
 134  * 10           Lowered priorities (aged pri's)
 135  *                              A
 136  *                              +
 137  *                      (11 levels)
 138  *                              +
 139  *                              V
 140  * 0            Lowered priorities (aged pri's / idle)
 141  *************************************************************************
 142  */
 143
 144 #define BASEPRI_RTQUEUES        (BASEPRI_REALTIME + 1)                          /* 97 */
 145 #define BASEPRI_REALTIME        (MAXPRI - (NRQS / 4) + 1)                       /* 96 */
 146
 147 #define MAXPRI_KERNEL           (BASEPRI_REALTIME - 1)                          /* 95 */
 148 #define BASEPRI_PREEMPT         (MAXPRI_KERNEL - 2)                                     /* 93 */
 149 #define BASEPRI_KERNEL          (MINPRI_KERNEL + 1)                                     /* 81 */
 150 #define MINPRI_KERNEL           (MAXPRI_KERNEL - (NRQS / 8) + 1)        /* 80 */
 151
 152 #define MAXPRI_RESERVED         (MINPRI_KERNEL - 1)                                     /* 79 */
 153 #define MINPRI_RESERVED         (MAXPRI_RESERVED - (NRQS / 8) + 1)      /* 64 */
 154
 155 #define MAXPRI_USER                     (MINPRI_RESERVED - 1)                           /* 63 */
 156 #define BASEPRI_CONTROL         (BASEPRI_DEFAULT + 17)                          /* 48 */
 157 #define BASEPRI_FOREGROUND      (BASEPRI_DEFAULT + 16)                          /* 47 */
 158 #define BASEPRI_BACKGROUND      (BASEPRI_DEFAULT + 15)                          /* 46 */
 159 #define BASEPRI_DEFAULT         (MAXPRI_USER - (NRQS / 4))                      /* 31 */
 160 #define MAXPRI_THROTTLE         (MINPRI + 4)                                            /*  4 */
 161 #define MINPRI_USER                     MINPRI                                                          /*  0 */
 162
 163 #ifdef CONFIG_EMBEDDED
 164 #define DEPRESSPRI      MAXPRI_THROTTLE
 165 #else
 166 #define DEPRESSPRI      MINPRI                  /* depress priority */
 167 #endif
 168
 169 /*
 170  *      Macro to check for invalid priorities.
 171  */
 172 #define invalid_pri(pri) ((pri) < MINPRI || (pri) > MAXPRI)
 173
 174 struct run_queue {
 175         int                                     highq;                          /* highest runnable queue */
 176         int                                     bitmap[NRQBM];          /* run queue bitmap array */
 177         int                                     count;                          /* # of threads total */
 178         int                                     urgency;                        /* level of preemption urgency */
 179         queue_head_t            queues[NRQS];           /* one for each priority */
 180 };
 181
 182 typedef struct run_queue        *run_queue_t;
 183 #define RUN_QUEUE_NULL          ((run_queue_t) 0)
 184
 185 #define first_timeslice(processor)              ((processor)->timeslice > 0)
 186
 187 #define thread_quantum_init(thread)                                                     \
 188 MACRO_BEGIN                                                                                                     \
 189         (thread)->current_quantum =                                                     \
 190                 ((thread)->sched_mode & TH_MODE_REALTIME)?                      \
 191                         (thread)->realtime.computation: std_quantum;    \
 192 MACRO_END
 193
 194 extern struct run_queue         rt_runq;
 195
 196 /*
 197  *      Scheduler routines.
 198  */
 199
 200 /* Remove thread from its run queue */
 201 extern boolean_t        run_queue_remove(
 202                                                 thread_t        thread);
 203
 204 /* Handle quantum expiration for an executing thread */
 205 extern void             thread_quantum_expire(
 206                                         timer_call_param_t      processor,
 207                                         timer_call_param_t      thread);
 208
 209 /* Context switch check for current processor */
 210 extern ast_t    csw_check(processor_t           processor);
 211
 212 extern uint32_t std_quantum, min_std_quantum;
 213 extern uint32_t std_quantum_us;
 214
 215 extern uint32_t max_rt_quantum, min_rt_quantum;
 216
 217 extern uint32_t sched_cswtime;
 218
 219 /*
 220  *      Age usage (1 << SCHED_TICK_SHIFT) times per second.
 221  */
 222 #define SCHED_TICK_SHIFT        3
 223
 224 extern unsigned         sched_tick;
 225 extern uint32_t         sched_tick_interval;
 226
 227 /* Periodic computation of various averages */
 228 extern void             compute_averages(void);
 229
 230 extern void             compute_averunnable(
 231                                         void                    *nrun);
 232
 233 extern void             compute_stack_target(
 234                                         void                    *arg);
 235
 236 extern void             compute_memory_pressure(
 237                                         void                    *arg);
 238
 239 /*
 240  *      Conversion factor from usage
 241  *      to priority.
 242  */
 243 extern uint32_t         sched_pri_shift;
 244 extern uint32_t         sched_fixed_shift;
 245 extern int8_t           sched_load_shifts[NRQS];
 246
 247 extern int32_t          sched_poll_yield_shift;
 248 extern uint32_t         sched_safe_duration;
 249
 250 extern uint32_t         sched_run_count, sched_share_count;
 251 extern uint32_t         sched_load_average, sched_mach_factor;
 252
 253 extern uint32_t         avenrun[3], mach_factor[3];
 254
 255 extern uint64_t         max_unsafe_computation;
 256 extern uint64_t         max_poll_computation;
 257
 258 #define sched_run_incr()                        \
 259 MACRO_BEGIN                                                                                                     \
 260         machine_run_count(hw_atomic_add(&sched_run_count, 1));  \
 261 MACRO_END
 262
 263 #define sched_run_decr()                        \
 264 MACRO_BEGIN                                                                                                     \
 265         machine_run_count(hw_atomic_sub(&sched_run_count, 1));  \
 266 MACRO_END
 267
 268 #define sched_share_incr()                      \
 269 MACRO_BEGIN                                                                                     \
 270         (void)hw_atomic_add(&sched_share_count, 1);             \
 271 MACRO_END
 272
 273 #define sched_share_decr()                      \
 274 MACRO_BEGIN                                                                                     \
 275         (void)hw_atomic_sub(&sched_share_count, 1);             \
 276 MACRO_END
 277
 278 /*
 279  *      thread_timer_delta macro takes care of both thread timers.
 280  */
 281 #define thread_timer_delta(thread, delta)                                       \
 282 MACRO_BEGIN                                                                                                     \
 283         (delta) = (typeof(delta))timer_delta(&(thread)->system_timer,                   \
 284                                                         &(thread)->system_timer_save);  \
 285         (delta) += (typeof(delta))timer_delta(&(thread)->user_timer,                    \
 286                                                         &(thread)->user_timer_save);    \
 287 MACRO_END
 288
 289 #endif  /* _KERN_SCHED_H_ */