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 <mach/policy.h>
  71 #include <kern/kern_types.h>
  72 #include <kern/queue.h>
  73 #include <kern/lock.h>
  74 #include <kern/macro_help.h>
  75 #include <kern/timer_call.h>
  76 #include <kern/ast.h>
  77
  78 #define NRQS            128                             /* 128 levels per run queue */
  79 #define NRQBM           (NRQS / 32)             /* number of words per bit map */
  80
  81 #define MAXPRI          (NRQS-1)
  82 #define MINPRI          IDLEPRI                 /* lowest legal priority schedulable */
  83 #define IDLEPRI         0                               /* idle thread priority */
  84
  85 /*
  86  *      High-level priority assignments
  87  *
  88  *************************************************************************
  89  * 127          Reserved (real-time)
  90  *                              A
  91  *                              +
  92  *                      (32 levels)
  93  *                              +
  94  *                              V
  95  * 96           Reserved (real-time)
  96  * 95           Kernel mode only
  97  *                              A
  98  *                              +
  99  *                      (16 levels)
 100  *                              +
 101  *                              V
 102  * 80           Kernel mode only
 103  * 79           System high priority
 104  *                              A
 105  *                              +
 106  *                      (16 levels)
 107  *                              +
 108  *                              V
 109  * 64           System high priority
 110  * 63           Elevated priorities
 111  *                              A
 112  *                              +
 113  *                      (12 levels)
 114  *                              +
 115  *                              V
 116  * 52           Elevated priorities
 117  * 51           Elevated priorities (incl. BSD +nice)
 118  *                              A
 119  *                              +
 120  *                      (20 levels)
 121  *                              +
 122  *                              V
 123  * 32           Elevated priorities (incl. BSD +nice)
 124  * 31           Default (default base for threads)
 125  * 30           Lowered priorities (incl. BSD -nice)
 126  *                              A
 127  *                              +
 128  *                      (20 levels)
 129  *                              +
 130  *                              V
 131  * 11           Lowered priorities (incl. BSD -nice)
 132  * 10           Lowered priorities (aged pri's)
 133  *                              A
 134  *                              +
 135  *                      (11 levels)
 136  *                              +
 137  *                              V
 138  * 0            Lowered priorities (aged pri's / idle)
 139  *************************************************************************
 140  */
 141
 142 #define BASEPRI_RTQUEUES        (BASEPRI_REALTIME + 1)                          /* 97 */
 143 #define BASEPRI_REALTIME        (MAXPRI - (NRQS / 4) + 1)                       /* 96 */
 144
 145 #define MAXPRI_KERNEL           (BASEPRI_REALTIME - 1)                          /* 95 */
 146 #define BASEPRI_PREEMPT         (MAXPRI_KERNEL - 2)                                     /* 93 */
 147 #define BASEPRI_KERNEL          (MINPRI_KERNEL + 1)                                     /* 81 */
 148 #define MINPRI_KERNEL           (MAXPRI_KERNEL - (NRQS / 8) + 1)        /* 80 */
 149
 150 #define MAXPRI_RESERVED         (MINPRI_KERNEL - 1)                                     /* 79 */
 151 #define BASEPRI_GRAPHICS        (MAXPRI_RESERVED - 3)                           /* 76 */
 152 #define MINPRI_RESERVED         (MAXPRI_RESERVED - (NRQS / 8) + 1)      /* 64 */
 153
 154 #define MAXPRI_USER                     (MINPRI_RESERVED - 1)                           /* 63 */
 155 #define BASEPRI_CONTROL         (BASEPRI_DEFAULT + 17)                          /* 48 */
 156 #define BASEPRI_FOREGROUND      (BASEPRI_DEFAULT + 16)                          /* 47 */
 157 #define BASEPRI_BACKGROUND      (BASEPRI_DEFAULT + 15)                          /* 46 */
 158 #define BASEPRI_DEFAULT         (MAXPRI_USER - (NRQS / 4))                      /* 31 */
 159 #define MAXPRI_SUPPRESSED       (BASEPRI_DEFAULT - 3)                           /* 28 */
 160 #define MAXPRI_THROTTLE         (MINPRI + 4)                                            /*  4 */
 161 #define MINPRI_USER                     MINPRI                                                          /*  0 */
 162
 163 #define DEPRESSPRI      MINPRI                  /* depress priority */
 164
 165 /* Type used for thread->sched_mode and saved_mode */
 166 typedef enum {
 167         TH_MODE_NONE = 0,                                       /* unassigned, usually for saved_mode only */
 168         TH_MODE_REALTIME,                                       /* time constraints supplied */
 169         TH_MODE_FIXED,                                          /* use fixed priorities, no decay */
 170         TH_MODE_TIMESHARE,                                      /* use timesharing algorithm */
 171         TH_MODE_FAIRSHARE                                       /* use fair-share scheduling */
 172 } sched_mode_t;
 173
 174 /*
 175  *      Macro to check for invalid priorities.
 176  */
 177 #define invalid_pri(pri) ((pri) < MINPRI || (pri) > MAXPRI)
 178
 179 struct runq_stats {
 180         uint64_t                                count_sum;
 181         uint64_t                                last_change_timestamp;
 182 };
 183
 184 #if defined(CONFIG_SCHED_TRADITIONAL) || defined(CONFIG_SCHED_PROTO) || defined(CONFIG_SCHED_FIXEDPRIORITY)
 185
 186 struct run_queue {
 187         int                                     highq;                          /* highest runnable queue */
 188         int                                     bitmap[NRQBM];          /* run queue bitmap array */
 189         int                                     count;                          /* # of threads total */
 190         int                                     urgency;                        /* level of preemption urgency */
 191         queue_head_t            queues[NRQS];           /* one for each priority */
 192
 193         struct runq_stats       runq_stats;
 194 };
 195
 196 #endif /* defined(CONFIG_SCHED_TRADITIONAL) || defined(CONFIG_SCHED_PROTO) || defined(CONFIG_SCHED_FIXEDPRIORITY) */
 197
 198 struct rt_queue {
 199         int                                     count;                          /* # of threads total */
 200         queue_head_t            queue;                          /* all runnable RT threads */
 201
 202         struct runq_stats       runq_stats;
 203 };
 204
 205 #if defined(CONFIG_SCHED_TRADITIONAL) || defined(CONFIG_SCHED_PROTO) || defined(CONFIG_SCHED_FIXEDPRIORITY)
 206 struct fairshare_queue {
 207         int                                     count;                          /* # of threads total */
 208         queue_head_t            queue;                          /* all runnable threads demoted to fairshare scheduling */
 209
 210         struct runq_stats       runq_stats;
 211 };
 212 #endif
 213
 214 #if defined(CONFIG_SCHED_GRRR_CORE)
 215
 216 /*
 217  * We map standard Mach priorities to an abstract scale that more properly
 218  * indicates how we want processor time allocated under contention.
 219  */
 220 typedef uint8_t grrr_proportional_priority_t;
 221 typedef uint8_t grrr_group_index_t;
 222
 223 #define NUM_GRRR_PROPORTIONAL_PRIORITIES        256
 224 #define MAX_GRRR_PROPORTIONAL_PRIORITY ((grrr_proportional_priority_t)255)
 225
 226 #if 0
 227 #define NUM_GRRR_GROUPS 8                                       /* log(256) */
 228 #endif
 229
 230 #define NUM_GRRR_GROUPS 64                                      /* 256/4 */
 231
 232 struct grrr_group {
 233         queue_chain_t                   priority_order;                         /* next greatest weight group */
 234         grrr_proportional_priority_t            minpriority;
 235         grrr_group_index_t              index;
 236
 237         queue_head_t                    clients;
 238         int                                             count;
 239         uint32_t                                weight;
 240 #if 0
 241         uint32_t                                deferred_removal_weight;
 242 #endif
 243         uint32_t                                work;
 244         thread_t                                current_client;
 245 };
 246
 247 struct grrr_run_queue {
 248         int                                     count;
 249         uint32_t                        last_rescale_tick;
 250         struct grrr_group       groups[NUM_GRRR_GROUPS];
 251         queue_head_t            sorted_group_list;
 252         uint32_t                        weight;
 253         grrr_group_t            current_group;
 254
 255         struct runq_stats   runq_stats;
 256 };
 257
 258 #endif /* defined(CONFIG_SCHED_GRRR_CORE) */
 259
 260 #define first_timeslice(processor)              ((processor)->timeslice > 0)
 261
 262 extern struct rt_queue          rt_runq;
 263
 264 /*
 265  *      Scheduler routines.
 266  */
 267
 268 /* Handle quantum expiration for an executing thread */
 269 extern void             thread_quantum_expire(
 270                                         timer_call_param_t      processor,
 271                                         timer_call_param_t      thread);
 272
 273 /* Context switch check for current processor */
 274 extern ast_t    csw_check(processor_t           processor);
 275
 276 #if defined(CONFIG_SCHED_TRADITIONAL)
 277 extern uint32_t std_quantum, min_std_quantum;
 278 extern uint32_t std_quantum_us;
 279 #endif
 280
 281 extern uint32_t thread_depress_time;
 282 extern uint32_t default_timeshare_computation;
 283 extern uint32_t default_timeshare_constraint;
 284
 285 extern uint32_t max_rt_quantum, min_rt_quantum;
 286
 287 extern int default_preemption_rate;
 288 extern int default_bg_preemption_rate;
 289
 290 #if defined(CONFIG_SCHED_TRADITIONAL)
 291
 292 /*
 293  *      Age usage  at approximately (1 << SCHED_TICK_SHIFT) times per second
 294  *      Aging may be deferred during periods where all processors are idle
 295  *      and cumulatively applied during periods of activity.
 296  */
 297 #define SCHED_TICK_SHIFT        3
 298 #define SCHED_TICK_MAX_DELTA    (8)
 299
 300 extern unsigned         sched_tick;
 301 extern uint32_t         sched_tick_interval;
 302
 303 #endif /* CONFIG_SCHED_TRADITIONAL */
 304
 305 extern uint64_t         sched_one_second_interval;
 306
 307 /* Periodic computation of various averages */
 308 extern void             compute_averages(uint64_t);
 309
 310 extern void             compute_averunnable(
 311                                         void                    *nrun);
 312
 313 extern void             compute_stack_target(
 314                                         void                    *arg);
 315
 316 extern void             compute_memory_pressure(
 317                                         void                    *arg);
 318
 319 extern void             compute_zone_gc_throttle(
 320                                         void                    *arg);
 321
 322 extern void             compute_pageout_gc_throttle(
 323                                         void                    *arg);
 324
 325 extern void             compute_pmap_gc_throttle(
 326                                         void                    *arg);
 327
 328 /*
 329  *      Conversion factor from usage
 330  *      to priority.
 331  */
 332 #if defined(CONFIG_SCHED_TRADITIONAL)
 333 extern uint32_t         sched_pri_shift;
 334 extern uint32_t         sched_background_pri_shift;
 335 extern uint32_t         sched_combined_fgbg_pri_shift;
 336 extern uint32_t         sched_fixed_shift;
 337 extern int8_t           sched_load_shifts[NRQS];
 338 extern uint32_t         sched_decay_usage_age_factor;
 339 extern uint32_t         sched_use_combined_fgbg_decay;
 340 void sched_traditional_consider_maintenance(uint64_t);
 341 #endif
 342
 343 extern int32_t          sched_poll_yield_shift;
 344 extern uint64_t         sched_safe_duration;
 345
 346 extern uint32_t         sched_run_count, sched_share_count, sched_background_count;
 347 extern uint32_t         sched_load_average, sched_mach_factor;
 348
 349 extern uint32_t         avenrun[3], mach_factor[3];
 350
 351 extern uint64_t         max_unsafe_computation;
 352 extern uint64_t         max_poll_computation;
 353
 354 #define sched_run_incr()                        \
 355 MACRO_BEGIN                                     \
 356          hw_atomic_add(&sched_run_count, 1);    \
 357 MACRO_END
 358
 359 #define sched_run_decr()                        \
 360 MACRO_BEGIN                                     \
 361         hw_atomic_sub(&sched_run_count, 1);     \
 362 MACRO_END
 363
 364 #define sched_share_incr()                      \
 365 MACRO_BEGIN                                                                                     \
 366         (void)hw_atomic_add(&sched_share_count, 1);             \
 367 MACRO_END
 368
 369 #define sched_share_decr()                      \
 370 MACRO_BEGIN                                                                                     \
 371         (void)hw_atomic_sub(&sched_share_count, 1);             \
 372 MACRO_END
 373
 374 #define sched_background_incr()                                          \
 375 MACRO_BEGIN                                                                                      \
 376         (void)hw_atomic_add(&sched_background_count, 1); \
 377 MACRO_END
 378
 379 #define sched_background_decr()                                          \
 380 MACRO_BEGIN                                                                                      \
 381         (void)hw_atomic_sub(&sched_background_count, 1); \
 382 MACRO_END
 383
 384 /*
 385  *      thread_timer_delta macro takes care of both thread timers.
 386  */
 387 #define thread_timer_delta(thread, delta)                                       \
 388 MACRO_BEGIN                                                                                                     \
 389         (delta) = (typeof(delta))timer_delta(&(thread)->system_timer,                   \
 390                                                         &(thread)->system_timer_save);  \
 391         (delta) += (typeof(delta))timer_delta(&(thread)->user_timer,                    \
 392                                                         &(thread)->user_timer_save);    \
 393 MACRO_END
 394
 395 #endif  /* _KERN_SCHED_H_ */