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/macro_help.h>
  74 #include <kern/timer_call.h>
  75 #include <kern/ast.h>
  76 #include <kern/kalloc.h>
  77 #include <kern/bits.h>
  78
  79 #define NRQS            128                             /* 128 levels per run queue */
  80
  81 #define MAXPRI          (NRQS-1)
  82 #define MINPRI          0                               /* lowest legal priority schedulable */
  83 #define IDLEPRI         MINPRI                          /* idle thread priority */
  84 #define NOPRI           -1
  85
  86 /*
  87  *      High-level priority assignments
  88  *
  89  *************************************************************************
  90  * 127          Reserved (real-time)
  91  *                              A
  92  *                              +
  93  *                      (32 levels)
  94  *                              +
  95  *                              V
  96  * 96           Reserved (real-time)
  97  * 95           Kernel mode only
  98  *                              A
  99  *                              +
 100  *                      (16 levels)
 101  *                              +
 102  *                              V
 103  * 80           Kernel mode only
 104  * 79           System high priority
 105  *                              A
 106  *                              +
 107  *                      (16 levels)
 108  *                              +
 109  *                              V
 110  * 64           System high priority
 111  * 63           Elevated priorities
 112  *                              A
 113  *                              +
 114  *                      (12 levels)
 115  *                              +
 116  *                              V
 117  * 52           Elevated priorities
 118  * 51           Elevated priorities (incl. BSD +nice)
 119  *                              A
 120  *                              +
 121  *                      (20 levels)
 122  *                              +
 123  *                              V
 124  * 32           Elevated priorities (incl. BSD +nice)
 125  * 31           Default (default base for threads)
 126  * 30           Lowered priorities (incl. BSD -nice)
 127  *                              A
 128  *                              +
 129  *                      (20 levels)
 130  *                              +
 131  *                              V
 132  * 11           Lowered priorities (incl. BSD -nice)
 133  * 10           Lowered priorities (aged pri's)
 134  *                              A
 135  *                              +
 136  *                      (11 levels)
 137  *                              +
 138  *                              V
 139  * 0            Lowered priorities (aged pri's / idle)
 140  *************************************************************************
 141  */
 142
 143 #define BASEPRI_RTQUEUES        (BASEPRI_REALTIME + 1)                          /* 97 */
 144 #define BASEPRI_REALTIME        (MAXPRI - (NRQS / 4) + 1)                       /* 96 */
 145
 146 #define MAXPRI_KERNEL           (BASEPRI_REALTIME - 1)                          /* 95 */
 147 #define BASEPRI_PREEMPT         (MAXPRI_KERNEL - 2)                             /* 93 */
 148 #define BASEPRI_KERNEL          (MINPRI_KERNEL + 1)                             /* 81 */
 149 #define MINPRI_KERNEL           (MAXPRI_KERNEL - (NRQS / 8) + 1)                /* 80 */
 150
 151 #define MAXPRI_RESERVED         (MINPRI_KERNEL - 1)                             /* 79 */
 152 #define BASEPRI_GRAPHICS        (MAXPRI_RESERVED - 3)                           /* 76 */
 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_USER_INITIATED  (BASEPRI_DEFAULT +  6)                          /* 37 */
 160 #define BASEPRI_DEFAULT         (MAXPRI_USER - (NRQS / 4))                      /* 31 */
 161 #define MAXPRI_SUPPRESSED       (BASEPRI_DEFAULT - 3)                           /* 28 */
 162 #define BASEPRI_UTILITY         (BASEPRI_DEFAULT - 11)                          /* 20 */
 163 #define MAXPRI_THROTTLE         (MINPRI + 4)                                    /*  4 */
 164 #define MINPRI_USER             MINPRI                                          /*  0 */
 165
 166 #define DEPRESSPRI              MINPRI                  /* depress priority */
 167 #define MAXPRI_PROMOTE          (MAXPRI_KERNEL)         /* ceiling for mutex promotion */
 168
 169 /* Type used for thread->sched_mode and saved_mode */
 170 typedef enum {
 171         TH_MODE_NONE = 0,                                       /* unassigned, usually for saved_mode only */
 172         TH_MODE_REALTIME,                                       /* time constraints supplied */
 173         TH_MODE_FIXED,                                          /* use fixed priorities, no decay */
 174         TH_MODE_TIMESHARE,                                      /* use timesharing algorithm */
 175 } sched_mode_t;
 176
 177 /* Buckets used for load calculation */
 178 typedef enum {
 179         TH_BUCKET_RUN = 0,      /* All runnable threads */
 180         TH_BUCKET_FIXPRI,       /* Fixed-priority */
 181         TH_BUCKET_SHARE_FG,     /* Timeshare thread above BASEPRI_UTILITY */
 182         TH_BUCKET_SHARE_UT,     /* Timeshare thread between BASEPRI_UTILITY and MAXPRI_THROTTLE */
 183         TH_BUCKET_SHARE_BG,     /* Timeshare thread between MAXPRI_THROTTLE and MINPRI */
 184         TH_BUCKET_MAX,
 185 } sched_bucket_t;
 186
 187 /*
 188  *      Macro to check for invalid priorities.
 189  */
 190 #define invalid_pri(pri) ((pri) < MINPRI || (pri) > MAXPRI)
 191
 192 struct runq_stats {
 193         uint64_t                                count_sum;
 194         uint64_t                                last_change_timestamp;
 195 };
 196
 197 #if defined(CONFIG_SCHED_TIMESHARE_CORE) || defined(CONFIG_SCHED_PROTO)
 198
 199 struct run_queue {
 200         int                                     highq;                          /* highest runnable queue */
 201         bitmap_t                                bitmap[BITMAP_LEN(NRQS)];       /* run queue bitmap array */
 202         int                                     count;                          /* # of threads total */
 203         int                                     urgency;                        /* level of preemption urgency */
 204         queue_head_t            queues[NRQS];           /* one for each priority */
 205
 206         struct runq_stats       runq_stats;
 207 };
 208
 209 inline static void
 210 rq_bitmap_set(bitmap_t *map, u_int n)
 211 {
 212         assert(n < NRQS);
 213         bitmap_set(map, n);
 214 }
 215
 216 inline static void
 217 rq_bitmap_clear(bitmap_t *map, u_int n)
 218 {
 219         assert(n < NRQS);
 220         bitmap_clear(map, n);
 221 }
 222
 223 #endif /* defined(CONFIG_SCHED_TIMESHARE_CORE) || defined(CONFIG_SCHED_PROTO) */
 224
 225 struct rt_queue {
 226         int                                     count;                          /* # of threads total */
 227         queue_head_t            queue;                          /* all runnable RT threads */
 228
 229         struct runq_stats       runq_stats;
 230 };
 231
 232 #if defined(CONFIG_SCHED_GRRR_CORE)
 233
 234 /*
 235  * We map standard Mach priorities to an abstract scale that more properly
 236  * indicates how we want processor time allocated under contention.
 237  */
 238 typedef uint8_t grrr_proportional_priority_t;
 239 typedef uint8_t grrr_group_index_t;
 240
 241 #define NUM_GRRR_PROPORTIONAL_PRIORITIES        256
 242 #define MAX_GRRR_PROPORTIONAL_PRIORITY ((grrr_proportional_priority_t)255)
 243
 244 #if 0
 245 #define NUM_GRRR_GROUPS 8                                       /* log(256) */
 246 #endif
 247
 248 #define NUM_GRRR_GROUPS 64                                      /* 256/4 */
 249
 250 struct grrr_group {
 251         queue_chain_t                   priority_order;                         /* next greatest weight group */
 252         grrr_proportional_priority_t            minpriority;
 253         grrr_group_index_t              index;
 254
 255         queue_head_t                    clients;
 256         int                                             count;
 257         uint32_t                                weight;
 258 #if 0
 259         uint32_t                                deferred_removal_weight;
 260 #endif
 261         uint32_t                                work;
 262         thread_t                                current_client;
 263 };
 264
 265 struct grrr_run_queue {
 266         int                                     count;
 267         uint32_t                        last_rescale_tick;
 268         struct grrr_group       groups[NUM_GRRR_GROUPS];
 269         queue_head_t            sorted_group_list;
 270         uint32_t                        weight;
 271         grrr_group_t            current_group;
 272
 273         struct runq_stats   runq_stats;
 274 };
 275
 276 #endif /* defined(CONFIG_SCHED_GRRR_CORE) */
 277
 278 extern struct rt_queue          rt_runq;
 279
 280 #if defined(CONFIG_SCHED_MULTIQ)
 281 sched_group_t   sched_group_create(void);
 282 void            sched_group_destroy(sched_group_t sched_group);
 283 #endif /* defined(CONFIG_SCHED_MULTIQ) */
 284
 285
 286
 287 /*
 288  *      Scheduler routines.
 289  */
 290
 291 /* Handle quantum expiration for an executing thread */
 292 extern void             thread_quantum_expire(
 293                                         timer_call_param_t      processor,
 294                                         timer_call_param_t      thread);
 295
 296 /* Context switch check for current processor */
 297 extern ast_t    csw_check(processor_t           processor,
 298                                                 ast_t                   check_reason);
 299
 300 #if defined(CONFIG_SCHED_TIMESHARE_CORE)
 301 extern uint32_t std_quantum, min_std_quantum;
 302 extern uint32_t std_quantum_us;
 303 #endif /* CONFIG_SCHED_TIMESHARE_CORE */
 304
 305 extern uint32_t thread_depress_time;
 306 extern uint32_t default_timeshare_computation;
 307 extern uint32_t default_timeshare_constraint;
 308
 309 extern uint32_t max_rt_quantum, min_rt_quantum;
 310
 311 extern int default_preemption_rate;
 312 extern int default_bg_preemption_rate;
 313
 314 #if defined(CONFIG_SCHED_TIMESHARE_CORE)
 315
 316 /*
 317  *      Age usage  at approximately (1 << SCHED_TICK_SHIFT) times per second
 318  *      Aging may be deferred during periods where all processors are idle
 319  *      and cumulatively applied during periods of activity.
 320  */
 321 #define SCHED_TICK_SHIFT        3
 322 #define SCHED_TICK_MAX_DELTA    (8)
 323
 324 extern unsigned         sched_tick;
 325 extern uint32_t         sched_tick_interval;
 326
 327 #endif /* CONFIG_SCHED_TIMESHARE_CORE */
 328
 329 extern uint64_t         sched_one_second_interval;
 330
 331 /* Periodic computation of various averages */
 332 extern void             compute_averages(uint64_t);
 333
 334 extern void             compute_averunnable(
 335                                         void                    *nrun);
 336
 337 extern void             compute_stack_target(
 338                                         void                    *arg);
 339
 340 extern void             compute_memory_pressure(
 341                                         void                    *arg);
 342
 343 extern void             compute_pageout_gc_throttle(
 344                                         void                    *arg);
 345
 346 extern void             compute_pmap_gc_throttle(
 347                                         void                    *arg);
 348
 349 /*
 350  *      Conversion factor from usage
 351  *      to priority.
 352  */
 353 #if defined(CONFIG_SCHED_TIMESHARE_CORE)
 354
 355 #define MAX_LOAD (NRQS - 1)
 356 extern uint32_t         sched_pri_shifts[TH_BUCKET_MAX];
 357 extern uint32_t         sched_fixed_shift;
 358 extern int8_t           sched_load_shifts[NRQS];
 359 extern uint32_t         sched_decay_usage_age_factor;
 360 void sched_timeshare_consider_maintenance(uint64_t ctime);
 361 #endif /* CONFIG_SCHED_TIMESHARE_CORE */
 362
 363 void sched_consider_recommended_cores(uint64_t ctime, thread_t thread);
 364
 365 extern int32_t          sched_poll_yield_shift;
 366 extern uint64_t         sched_safe_duration;
 367
 368 extern uint32_t         sched_load_average, sched_mach_factor;
 369
 370 extern uint32_t         avenrun[3], mach_factor[3];
 371
 372 extern uint64_t         max_unsafe_computation;
 373 extern uint64_t         max_poll_computation;
 374
 375 extern volatile uint32_t sched_run_buckets[TH_BUCKET_MAX];
 376
 377 extern uint32_t sched_run_incr(thread_t thread);
 378 extern uint32_t sched_run_decr(thread_t thread);
 379
 380 /*
 381  *      thread_timer_delta macro takes care of both thread timers.
 382  */
 383 #define thread_timer_delta(thread, delta)                                       \
 384 MACRO_BEGIN                                                                                                     \
 385         (delta) = (typeof(delta))timer_delta(&(thread)->system_timer,                   \
 386                                                         &(thread)->system_timer_save);  \
 387         (delta) += (typeof(delta))timer_delta(&(thread)->user_timer,                    \
 388                                                         &(thread)->user_timer_save);    \
 389 MACRO_END
 390
 391 #endif  /* _KERN_SCHED_H_ */