Changeset c7ceacf in mainline
- Timestamp:
- 2024-01-15T14:54:17Z (12 months ago)
- Branches:
- master
- Children:
- 5861b60
- Parents:
- 4760793 (diff), 151c050 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the(diff)links above to see all the changes relative to each parent. - Location:
- kernel/generic
- Files:
-
- 6 edited
-
include/proc/scheduler.h (modified) (2 diffs)
-
include/proc/thread.h (modified) (3 diffs)
-
src/main/main.c (modified) (2 diffs)
-
src/proc/scheduler.c (modified) (7 diffs)
-
src/proc/thread.c (modified) (9 diffs)
-
src/time/clock.c (modified) (1 diff)
Legend:
- Unmodified
- Added
- Removed
-
kernel/generic/include/proc/scheduler.h
r4760793 rc7ceacf 41 41 #include <atomic.h> 42 42 #include <adt/list.h> 43 #include <abi/proc/thread.h> 43 44 44 45 #define RQ_COUNT 16 … … 56 57 57 58 extern void scheduler_fpu_lazy_request(void); 58 extern void scheduler(void);59 extern void scheduler_locked(ipl_t);60 59 extern void kcpulb(void *arg); 61 60 62 61 extern void sched_print_list(void); 62 63 extern void scheduler_run(void) __attribute__((noreturn)); 64 extern void scheduler_enter(state_t); 63 65 64 66 /* -
kernel/generic/include/proc/thread.h
r4760793 rc7ceacf 113 113 */ 114 114 context_t saved_context; 115 ipl_t saved_ipl;116 115 117 116 /** … … 190 189 extern void thread_interrupt(thread_t *); 191 190 191 enum sleep_state { 192 SLEEP_INITIAL, 193 SLEEP_ASLEEP, 194 SLEEP_WOKE, 195 }; 196 192 197 typedef enum { 193 198 THREAD_OK, … … 238 243 extern errno_t thread_join_timeout(thread_t *, uint32_t, unsigned int); 239 244 245 extern void thread_yield(void); 246 240 247 extern void thread_print_list(bool); 241 248 extern thread_t *thread_find_by_id(thread_id_t); -
kernel/generic/src/main/main.c
r4760793 rc7ceacf 285 285 286 286 /* 287 * This call to scheduler () will return to kinit,287 * This call to scheduler_run() will return to kinit, 288 288 * starting the thread of kernel threads. 289 289 */ 290 scheduler ();290 scheduler_run(); 291 291 /* not reached */ 292 292 } … … 356 356 357 357 semaphore_up(&ap_completion_semaphore); 358 scheduler ();358 scheduler_run(); 359 359 /* not reached */ 360 360 } -
kernel/generic/src/proc/scheduler.c
r4760793 rc7ceacf 70 70 atomic_size_t nrdy; /**< Number of ready threads in the system. */ 71 71 72 /** Take actions before new thread runs.73 *74 * Perform actions that need to be75 * taken before the newly selected76 * thread is passed control.77 *78 * THREAD->lock is locked on entry79 *80 */81 static void before_thread_runs(void)82 {83 before_thread_runs_arch();84 85 #ifdef CONFIG_FPU_LAZY86 /*87 * The only concurrent modification possible for fpu_owner here is88 * another thread changing it from itself to NULL in its destructor.89 */90 thread_t *owner = atomic_load_explicit(&CPU->fpu_owner,91 memory_order_relaxed);92 93 if (THREAD == owner)94 fpu_enable();95 else96 fpu_disable();97 #elif defined CONFIG_FPU98 fpu_enable();99 if (THREAD->fpu_context_exists)100 fpu_context_restore(&THREAD->fpu_context);101 else {102 fpu_init();103 THREAD->fpu_context_exists = true;104 }105 #endif106 107 #ifdef CONFIG_UDEBUG108 if (THREAD->btrace) {109 istate_t *istate = THREAD->udebug.uspace_state;110 if (istate != NULL) {111 printf("Thread %" PRIu64 " stack trace:\n", THREAD->tid);112 stack_trace_istate(istate);113 }114 115 THREAD->btrace = false;116 }117 #endif118 }119 120 /** Take actions after THREAD had run.121 *122 * Perform actions that need to be123 * taken after the running thread124 * had been preempted by the scheduler.125 *126 * THREAD->lock is locked on entry127 *128 */129 static void after_thread_ran(void)130 {131 after_thread_ran_arch();132 }133 134 72 #ifdef CONFIG_FPU_LAZY 135 73 void scheduler_fpu_lazy_request(void) … … 207 145 list_remove(&thread->rq_link); 208 146 209 irq_spinlock_pass(&(CPU->rq[i].lock), &thread->lock); 210 211 thread->cpu = CPU; 212 thread->priority = i; /* Correct rq index */ 213 214 /* Time allocation in microseconds. */ 215 uint64_t time_to_run = (i + 1) * 10000; 216 217 /* This is safe because interrupts are disabled. */ 218 CPU_LOCAL->preempt_deadline = 219 CPU_LOCAL->current_clock_tick + us2ticks(time_to_run); 220 221 /* 222 * Clear the stolen flag so that it can be migrated 223 * when load balancing needs emerge. 224 */ 225 thread->stolen = false; 226 irq_spinlock_unlock(&thread->lock, false); 147 irq_spinlock_unlock(&(CPU->rq[i].lock), false); 227 148 228 149 *rq_index = i; … … 341 262 } 342 263 343 void scheduler(void) 344 { 345 ipl_t ipl = interrupts_disable(); 346 347 if (atomic_load(&haltstate)) 348 halt(); 349 350 if (THREAD) { 351 irq_spinlock_lock(&THREAD->lock, false); 352 } 353 354 scheduler_locked(ipl); 264 /** 265 * Do whatever needs to be done with current FPU state before we switch to 266 * another thread. 267 */ 268 static void fpu_cleanup(void) 269 { 270 #if (defined CONFIG_FPU) && (!defined CONFIG_FPU_LAZY) 271 fpu_context_save(&THREAD->fpu_context); 272 #endif 273 } 274 275 /** 276 * Set correct FPU state for this thread after switch from another thread. 277 */ 278 static void fpu_restore(void) 279 { 280 #ifdef CONFIG_FPU_LAZY 281 /* 282 * The only concurrent modification possible for fpu_owner here is 283 * another thread changing it from itself to NULL in its destructor. 284 */ 285 thread_t *owner = atomic_load_explicit(&CPU->fpu_owner, 286 memory_order_relaxed); 287 288 if (THREAD == owner) 289 fpu_enable(); 290 else 291 fpu_disable(); 292 293 #elif defined CONFIG_FPU 294 fpu_enable(); 295 if (THREAD->fpu_context_exists) 296 fpu_context_restore(&THREAD->fpu_context); 297 else { 298 fpu_init(); 299 THREAD->fpu_context_exists = true; 300 } 301 #endif 302 } 303 304 void scheduler_run(void) 305 { 306 assert(interrupts_disabled()); 307 assert(THREAD == NULL); 308 assert(CPU != NULL); 309 310 current_copy(CURRENT, (current_t *) CPU_LOCAL->stack); 311 312 context_t ctx; 313 context_save(&ctx); 314 context_set(&ctx, FADDR(scheduler_separated_stack), 315 (uintptr_t) CPU_LOCAL->stack, STACK_SIZE); 316 context_restore(&ctx); 317 318 unreachable(); 319 } 320 321 /** Things to do before we switch to THREAD context. 322 */ 323 static void prepare_to_run_thread(int rq_index) 324 { 325 relink_rq(rq_index); 326 327 switch_task(THREAD->task); 328 329 irq_spinlock_lock(&THREAD->lock, false); 330 THREAD->state = Running; 331 THREAD->cpu = CPU; 332 THREAD->priority = rq_index; /* Correct rq index */ 333 334 /* 335 * Clear the stolen flag so that it can be migrated 336 * when load balancing needs emerge. 337 */ 338 THREAD->stolen = false; 339 340 #ifdef SCHEDULER_VERBOSE 341 log(LF_OTHER, LVL_DEBUG, 342 "cpu%u: tid %" PRIu64 " (priority=%d, ticks=%" PRIu64 343 ", nrdy=%zu)", CPU->id, THREAD->tid, THREAD->priority, 344 THREAD->ticks, atomic_load(&CPU->nrdy)); 345 #endif 346 347 /* 348 * Some architectures provide late kernel PA2KA(identity) 349 * mapping in a page fault handler. However, the page fault 350 * handler uses the kernel stack of the running thread and 351 * therefore cannot be used to map it. The kernel stack, if 352 * necessary, is to be mapped in before_thread_runs(). This 353 * function must be executed before the switch to the new stack. 354 */ 355 before_thread_runs_arch(); 356 357 #ifdef CONFIG_UDEBUG 358 if (THREAD->btrace) { 359 istate_t *istate = THREAD->udebug.uspace_state; 360 if (istate != NULL) { 361 printf("Thread %" PRIu64 " stack trace:\n", THREAD->tid); 362 stack_trace_istate(istate); 363 } 364 365 THREAD->btrace = false; 366 } 367 #endif 368 369 fpu_restore(); 370 371 /* Time allocation in microseconds. */ 372 uint64_t time_to_run = (rq_index + 1) * 10000; 373 374 /* Set the time of next preemption. */ 375 CPU_LOCAL->preempt_deadline = 376 CPU_LOCAL->current_clock_tick + us2ticks(time_to_run); 377 378 /* Save current CPU cycle */ 379 THREAD->last_cycle = get_cycle(); 380 } 381 382 static void cleanup_after_thread(thread_t *thread, state_t out_state) 383 { 384 assert(CURRENT->mutex_locks == 0); 385 assert(interrupts_disabled()); 386 387 int expected; 388 389 switch (out_state) { 390 case Running: 391 thread_ready(thread); 392 break; 393 394 case Exiting: 395 waitq_close(&thread->join_wq); 396 397 /* 398 * Release the reference CPU has for the thread. 399 * If there are no other references (e.g. threads calling join), 400 * the thread structure is deallocated. 401 */ 402 thread_put(thread); 403 break; 404 405 case Sleeping: 406 expected = SLEEP_INITIAL; 407 408 /* Only set SLEEP_ASLEEP in sleep pad if it's still in initial state */ 409 if (!atomic_compare_exchange_strong_explicit(&thread->sleep_state, 410 &expected, SLEEP_ASLEEP, 411 memory_order_acq_rel, memory_order_acquire)) { 412 413 assert(expected == SLEEP_WOKE); 414 /* The thread has already been woken up, requeue immediately. */ 415 thread_ready(thread); 416 } 417 break; 418 419 default: 420 /* 421 * Entering state is unexpected. 422 */ 423 panic("tid%" PRIu64 ": unexpected state %s.", 424 thread->tid, thread_states[thread->state]); 425 break; 426 } 355 427 } 356 428 … … 362 434 * 363 435 */ 364 void scheduler_locked(ipl_t ipl) 365 { 436 void scheduler_enter(state_t new_state) 437 { 438 ipl_t ipl = interrupts_disable(); 439 366 440 assert(CPU != NULL); 367 368 if (THREAD) { 369 /* Update thread kernel accounting */ 370 THREAD->kcycles += get_cycle() - THREAD->last_cycle; 371 372 #if (defined CONFIG_FPU) && (!defined CONFIG_FPU_LAZY) 373 fpu_context_save(&THREAD->fpu_context); 374 #endif 375 if (!context_save(&THREAD->saved_context)) { 376 /* 377 * This is the place where threads leave scheduler(); 378 */ 379 380 /* Save current CPU cycle */ 381 THREAD->last_cycle = get_cycle(); 382 383 irq_spinlock_unlock(&THREAD->lock, false); 384 interrupts_restore(THREAD->saved_ipl); 385 386 return; 387 } 388 389 /* 390 * Interrupt priority level of preempted thread is recorded 391 * here to facilitate scheduler() invocations from 392 * interrupts_disable()'d code (e.g. waitq_sleep_timeout()). 393 * 394 */ 395 THREAD->saved_ipl = ipl; 441 assert(THREAD != NULL); 442 443 fpu_cleanup(); 444 445 irq_spinlock_lock(&THREAD->lock, false); 446 THREAD->state = new_state; 447 448 /* Update thread kernel accounting */ 449 THREAD->kcycles += get_cycle() - THREAD->last_cycle; 450 451 if (!context_save(&THREAD->saved_context)) { 452 /* 453 * This is the place where threads leave scheduler(); 454 */ 455 456 irq_spinlock_unlock(&THREAD->lock, false); 457 interrupts_restore(ipl); 458 return; 396 459 } 397 460 … … 439 502 assert(interrupts_disabled()); 440 503 504 if (atomic_load(&haltstate)) 505 halt(); 506 441 507 if (THREAD) { 442 /* Must be run after the switch to scheduler stack */ 443 after_thread_ran(); 444 445 switch (THREAD->state) { 446 case Running: 447 irq_spinlock_unlock(&THREAD->lock, false); 448 thread_ready(THREAD); 449 break; 450 451 case Exiting: 452 irq_spinlock_unlock(&THREAD->lock, false); 453 waitq_close(&THREAD->join_wq); 454 455 /* 456 * Release the reference CPU has for the thread. 457 * If there are no other references (e.g. threads calling join), 458 * the thread structure is deallocated. 459 */ 460 thread_put(THREAD); 461 break; 462 463 case Sleeping: 464 /* 465 * Prefer the thread after it's woken up. 466 */ 508 after_thread_ran_arch(); 509 510 state_t state = THREAD->state; 511 512 if (state == Sleeping) { 513 /* Prefer the thread after it's woken up. */ 467 514 THREAD->priority = -1; 468 irq_spinlock_unlock(&THREAD->lock, false);469 break;470 471 default:472 /*473 * Entering state is unexpected.474 */475 panic("tid%" PRIu64 ": unexpected state %s.",476 THREAD->tid, thread_states[THREAD->state]);477 break;478 515 } 516 517 irq_spinlock_unlock(&THREAD->lock, false); 518 519 cleanup_after_thread(THREAD, state); 479 520 480 521 THREAD = NULL; … … 484 525 THREAD = find_best_thread(&rq_index); 485 526 486 relink_rq(rq_index); 487 488 switch_task(THREAD->task); 489 490 irq_spinlock_lock(&THREAD->lock, false); 491 THREAD->state = Running; 492 493 #ifdef SCHEDULER_VERBOSE 494 log(LF_OTHER, LVL_DEBUG, 495 "cpu%u: tid %" PRIu64 " (priority=%d, ticks=%" PRIu64 496 ", nrdy=%zu)", CPU->id, THREAD->tid, THREAD->priority, 497 THREAD->ticks, atomic_load(&CPU->nrdy)); 498 #endif 499 500 /* 501 * Some architectures provide late kernel PA2KA(identity) 502 * mapping in a page fault handler. However, the page fault 503 * handler uses the kernel stack of the running thread and 504 * therefore cannot be used to map it. The kernel stack, if 505 * necessary, is to be mapped in before_thread_runs(). This 506 * function must be executed before the switch to the new stack. 507 */ 508 before_thread_runs(); 527 prepare_to_run_thread(rq_index); 509 528 510 529 /* … … 660 679 * 661 680 */ 662 scheduler();681 thread_yield(); 663 682 } else { 664 683 /* -
kernel/generic/src/proc/thread.c
r4760793 rc7ceacf 82 82 }; 83 83 84 enum sleep_state {85 SLEEP_INITIAL,86 SLEEP_ASLEEP,87 SLEEP_WOKE,88 };89 90 84 /** Lock protecting the @c threads ordered dictionary . 91 85 * … … 127 121 void (*f)(void *) = THREAD->thread_code; 128 122 void *arg = THREAD->thread_arg; 129 THREAD->last_cycle = get_cycle();130 123 131 124 /* This is where each thread wakes up after its creation */ … … 320 313 321 314 current_initialize((current_t *) thread->kstack); 322 323 ipl_t ipl = interrupts_disable();324 thread->saved_ipl = interrupts_read();325 interrupts_restore(ipl);326 315 327 316 str_cpy(thread->name, THREAD_NAME_BUFLEN, name); … … 525 514 } 526 515 527 irq_spinlock_lock(&THREAD->lock, true); 528 THREAD->state = Exiting; 529 irq_spinlock_unlock(&THREAD->lock, true); 530 531 scheduler(); 532 533 panic("should never be reached"); 516 scheduler_enter(Exiting); 517 unreachable(); 534 518 } 535 519 … … 579 563 } 580 564 581 static void thread_wait_internal(void)582 {583 assert(THREAD != NULL);584 585 ipl_t ipl = interrupts_disable();586 587 if (atomic_load(&haltstate))588 halt();589 590 /*591 * Lock here to prevent a race between entering the scheduler and another592 * thread rescheduling this thread.593 */594 irq_spinlock_lock(&THREAD->lock, false);595 596 int expected = SLEEP_INITIAL;597 598 /* Only set SLEEP_ASLEEP in sleep pad if it's still in initial state */599 if (atomic_compare_exchange_strong_explicit(&THREAD->sleep_state, &expected,600 SLEEP_ASLEEP, memory_order_acq_rel, memory_order_acquire)) {601 THREAD->state = Sleeping;602 scheduler_locked(ipl);603 } else {604 assert(expected == SLEEP_WOKE);605 /* Return immediately. */606 irq_spinlock_unlock(&THREAD->lock, false);607 interrupts_restore(ipl);608 }609 }610 611 565 static void thread_wait_timeout_callback(void *arg) 612 566 { … … 649 603 timeout_t timeout; 650 604 605 /* Extra check to avoid going to scheduler if we don't need to. */ 606 if (atomic_load_explicit(&THREAD->sleep_state, memory_order_acquire) != 607 SLEEP_INITIAL) 608 return THREAD_WAIT_SUCCESS; 609 651 610 if (deadline != DEADLINE_NEVER) { 652 /* Extra check to avoid setting up a deadline if we don't need to. */653 if (atomic_load_explicit(&THREAD->sleep_state, memory_order_acquire) !=654 SLEEP_INITIAL)655 return THREAD_WAIT_SUCCESS;656 657 611 timeout_initialize(&timeout); 658 612 timeout_register_deadline(&timeout, deadline, … … 660 614 } 661 615 662 thread_wait_internal();616 scheduler_enter(Sleeping); 663 617 664 618 if (deadline != DEADLINE_NEVER && !timeout_unregister(&timeout)) { … … 674 628 675 629 int state = atomic_exchange_explicit(&thread->sleep_state, SLEEP_WOKE, 676 memory_order_ release);630 memory_order_acq_rel); 677 631 678 632 if (state == SLEEP_ASLEEP) { … … 770 724 771 725 (void) waitq_sleep_timeout(&wq, usec); 726 } 727 728 /** Allow other threads to run. */ 729 void thread_yield(void) 730 { 731 assert(THREAD != NULL); 732 scheduler_enter(Running); 772 733 } 773 734 -
kernel/generic/src/time/clock.c
r4760793 rc7ceacf 187 187 if (THREAD) { 188 188 if (current_clock_tick >= CPU_LOCAL->preempt_deadline && PREEMPTION_ENABLED) { 189 scheduler();189 thread_yield(); 190 190 #ifdef CONFIG_UDEBUG 191 191 /*
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