X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/490019cf9519204c5fb36b2fba54ceb983bb6b72..d9a64523371fa019c4575bb400cbbc3a50ac9903:/osfmk/kern/priority.c diff --git a/osfmk/kern/priority.c b/osfmk/kern/priority.c index f50696079..40eb17242 100644 --- a/osfmk/kern/priority.c +++ b/osfmk/kern/priority.c @@ -81,6 +81,12 @@ #include /* for commpage_update_mach_approximate_time */ #endif +#if MONOTONIC +#include +#endif /* MONOTONIC */ + +static void sched_update_thread_bucket(thread_t thread); + /* * thread_quantum_expire: * @@ -111,19 +117,22 @@ thread_quantum_expire( /* * We bill CPU time to both the individual thread and its task. * - * Because this balance adjustment could potentially attempt to wake this very - * thread, we must credit the ledger before taking the thread lock. The ledger - * pointers are only manipulated by the thread itself at the ast boundary. + * Because this balance adjustment could potentially attempt to wake this + * very thread, we must credit the ledger before taking the thread lock. + * The ledger pointers are only manipulated by the thread itself at the ast + * boundary. + * + * TODO: This fails to account for the time between when the timer was + * armed and when it fired. It should be based on the system_timer and + * running a timer_update operation here. */ ledger_credit(thread->t_ledger, task_ledgers.cpu_time, thread->quantum_remaining); ledger_credit(thread->t_threadledger, thread_ledgers.cpu_time, thread->quantum_remaining); -#ifdef CONFIG_BANK if (thread->t_bankledger) { ledger_credit(thread->t_bankledger, bank_ledgers.cpu_time, (thread->quantum_remaining - thread->t_deduct_bank_ledger_time)); } thread->t_deduct_bank_ledger_time = 0; -#endif ctime = mach_absolute_time(); @@ -131,6 +140,10 @@ thread_quantum_expire( commpage_update_mach_approximate_time(ctime); #endif +#if MONOTONIC + mt_sched_update(thread); +#endif /* MONOTONIC */ + thread_lock(thread); /* @@ -143,14 +156,15 @@ thread_quantum_expire( /* * Check for fail-safe trip. */ - if ((thread->sched_mode == TH_MODE_REALTIME || thread->sched_mode == TH_MODE_FIXED) && - !(thread->sched_flags & TH_SFLAG_PROMOTED_MASK) && - !(thread->options & TH_OPT_SYSTEM_CRITICAL)) { - uint64_t new_computation; - - new_computation = ctime - thread->computation_epoch; - new_computation += thread->computation_metered; - if (new_computation > max_unsafe_computation) { + if ((thread->sched_mode == TH_MODE_REALTIME || thread->sched_mode == TH_MODE_FIXED) && + !(thread->sched_flags & TH_SFLAG_PROMOTED) && + !(thread->sched_flags & TH_SFLAG_PROMOTE_REASON_MASK) && + !(thread->options & TH_OPT_SYSTEM_CRITICAL)) { + uint64_t new_computation; + + new_computation = ctime - thread->computation_epoch; + new_computation += thread->computation_metered; + if (new_computation > max_unsafe_computation) { KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_FAILSAFE)|DBG_FUNC_NONE, (uintptr_t)thread->sched_pri, (uintptr_t)thread->sched_mode, 0, 0, 0); @@ -171,12 +185,7 @@ thread_quantum_expire( if (thread->sched_mode != TH_MODE_REALTIME) SCHED(quantum_expire)(thread); - processor->current_pri = thread->sched_pri; - processor->current_thmode = thread->sched_mode; - - /* Tell platform layer that we are still running this thread */ - urgency = thread_get_urgency(thread, &ignore1, &ignore2); - machine_thread_going_on_core(thread, urgency, 0); + processor_state_update_from_thread(processor, thread); /* * This quantum is up, give this thread another. @@ -193,31 +202,54 @@ thread_quantum_expire( * during privilege transitions, synthesize an event now. */ if (!thread->precise_user_kernel_time) { - timer_switch(PROCESSOR_DATA(processor, current_state), - ctime, - PROCESSOR_DATA(processor, current_state)); - timer_switch(PROCESSOR_DATA(processor, thread_timer), - ctime, - PROCESSOR_DATA(processor, thread_timer)); + timer_update(PROCESSOR_DATA(processor, current_state), ctime); + timer_update(PROCESSOR_DATA(processor, thread_timer), ctime); + timer_update(&thread->runnable_timer, ctime); } + processor->quantum_end = ctime + thread->quantum_remaining; /* - * Context switch check. + * Context switch check + * + * non-urgent flags don't affect kernel threads, so upgrade to urgent + * to ensure that rebalancing and non-recommendation kick in quickly. */ - if ((preempt = csw_check(processor, AST_QUANTUM)) != AST_NONE) + + ast_t check_reason = AST_QUANTUM; + if (thread->task == kernel_task) + check_reason |= AST_URGENT; + + if ((preempt = csw_check(processor, check_reason)) != AST_NONE) ast_on(preempt); + /* + * AST_KEVENT does not send an IPI when setting the AST, + * to avoid waiting for the next context switch to propagate the AST, + * the AST is propagated here at quantum expiration. + */ + ast_propagate(thread); + thread_unlock(thread); - timer_call_enter1(&processor->quantum_timer, thread, - processor->quantum_end, TIMER_CALL_SYS_CRITICAL | TIMER_CALL_LOCAL); + timer_call_quantum_timer_enter(&processor->quantum_timer, thread, + processor->quantum_end, ctime); + + /* Tell platform layer that we are still running this thread */ + urgency = thread_get_urgency(thread, &ignore1, &ignore2); + machine_thread_going_on_core(thread, urgency, 0, 0, ctime); + machine_switch_perfcontrol_state_update(QUANTUM_EXPIRY, ctime, + 0, thread); #if defined(CONFIG_SCHED_TIMESHARE_CORE) sched_timeshare_consider_maintenance(ctime); #endif /* CONFIG_SCHED_TIMESHARE_CORE */ +#if __arm__ || __arm64__ + if (thread->sched_mode == TH_MODE_REALTIME) + sched_consider_recommended_cores(ctime, thread); +#endif /* __arm__ || __arm64__ */ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_QUANTUM_EXPIRED) | DBG_FUNC_END, preempt, 0, 0, 0, 0); } @@ -235,17 +267,41 @@ thread_quantum_expire( void sched_set_thread_base_priority(thread_t thread, int priority) { - int old_priority = thread->base_pri; + assert(priority >= MINPRI); + uint64_t ctime = 0; + + if (thread->sched_mode == TH_MODE_REALTIME) + assert(priority <= BASEPRI_RTQUEUES); + else + assert(priority < BASEPRI_RTQUEUES); + + int old_base_pri = thread->base_pri; thread->base_pri = priority; - /* A thread is 'throttled' when its base priority is at or below MAXPRI_THROTTLE */ - if ((priority > MAXPRI_THROTTLE) && (old_priority <= MAXPRI_THROTTLE)) { - sched_set_thread_throttled(thread, FALSE); - } else if ((priority <= MAXPRI_THROTTLE) && (old_priority > MAXPRI_THROTTLE)) { - sched_set_thread_throttled(thread, TRUE); + if ((thread->state & TH_RUN) == TH_RUN) { + assert(thread->last_made_runnable_time != THREAD_NOT_RUNNABLE); + ctime = mach_approximate_time(); + thread->last_basepri_change_time = ctime; + } else { + assert(thread->last_basepri_change_time == THREAD_NOT_RUNNABLE); + assert(thread->last_made_runnable_time == THREAD_NOT_RUNNABLE); + } + + /* + * Currently the perfcontrol_attr depends on the base pri of the + * thread. Therefore, we use this function as the hook for the + * perfcontrol callout. + */ + if (thread == current_thread() && old_base_pri != priority) { + if (!ctime) { + ctime = mach_approximate_time(); + } + machine_switch_perfcontrol_state_update(PERFCONTROL_ATTR_UPDATE, + ctime, PERFCONTROL_CALLOUT_WAKE_UNSAFE, thread); } + sched_update_thread_bucket(thread); - thread_recompute_sched_pri(thread, FALSE); + thread_recompute_sched_pri(thread, SETPRI_DEFAULT); } /* @@ -255,28 +311,54 @@ sched_set_thread_base_priority(thread_t thread, int priority) * according to its base priority if the * thread has not been promoted or depressed. * - * This is the standard way to push base_pri changes into sched_pri, - * or to recalculate the appropriate sched_pri after clearing + * This is the only way to push base_pri changes into sched_pri, + * or to recalculate the appropriate sched_pri after changing * a promotion or depression. * * Called at splsched with the thread locked. + * + * TODO: Add an 'update urgency' flag to avoid urgency callouts on every rwlock operation */ void -thread_recompute_sched_pri( - thread_t thread, - boolean_t override_depress) +thread_recompute_sched_pri(thread_t thread, set_sched_pri_options_t options) { - int priority; + uint32_t sched_flags = thread->sched_flags; + sched_mode_t sched_mode = thread->sched_mode; - if (thread->sched_mode == TH_MODE_TIMESHARE) + int priority = thread->base_pri; + + if (sched_mode == TH_MODE_TIMESHARE) priority = SCHED(compute_timeshare_priority)(thread); - else - priority = thread->base_pri; - if ((!(thread->sched_flags & TH_SFLAG_PROMOTED_MASK) || (priority > thread->sched_pri)) && - (!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) || override_depress)) { - set_sched_pri(thread, priority); + if (sched_flags & TH_SFLAG_DEPRESS) { + /* thread_yield_internal overrides kernel mutex promotion */ + priority = DEPRESSPRI; + } else { + /* poll-depress is overridden by mutex promotion and promote-reasons */ + if ((sched_flags & TH_SFLAG_POLLDEPRESS)) { + priority = DEPRESSPRI; + } + + if (sched_flags & TH_SFLAG_PROMOTED) { + priority = MAX(priority, thread->promotion_priority); + + if (sched_mode != TH_MODE_REALTIME) + priority = MIN(priority, MAXPRI_PROMOTE); + } + + if (sched_flags & TH_SFLAG_PROMOTE_REASON_MASK) { + if (sched_flags & TH_SFLAG_RW_PROMOTED) + priority = MAX(priority, MINPRI_RWLOCK); + + if (sched_flags & TH_SFLAG_WAITQ_PROMOTED) + priority = MAX(priority, MINPRI_WAITQ); + + if (sched_flags & TH_SFLAG_EXEC_PROMOTED) + priority = MAX(priority, MINPRI_EXEC); + } } + + set_sched_pri(thread, priority, options); } void @@ -324,23 +406,8 @@ lightweight_update_priority(thread_t thread) priority = sched_compute_timeshare_priority(thread); - /* - * Adjust the scheduled priority like thread_recompute_sched_pri, - * except with the benefit of knowing the thread is on this core. - */ - if ((!(thread->sched_flags & TH_SFLAG_PROMOTED_MASK) || (priority > thread->sched_pri)) && - (!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK)) && - priority != thread->sched_pri) { - - thread->sched_pri = priority; - - KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_CHANGE_PRIORITY), - (uintptr_t)thread_tid(thread), - thread->base_pri, - thread->sched_pri, - 0, /* eventually, 'reason' */ - 0); - } + if (priority != thread->sched_pri) + thread_recompute_sched_pri(thread, SETPRI_LAZY); } } @@ -371,6 +438,39 @@ static struct shift_data sched_decay_shifts[SCHED_DECAY_TICKS] = { */ extern int sched_pri_decay_band_limit; +#ifdef CONFIG_EMBEDDED + +int +sched_compute_timeshare_priority(thread_t thread) +{ + int decay_amount = (thread->sched_usage >> thread->pri_shift); + int decay_limit = sched_pri_decay_band_limit; + + if (thread->base_pri > BASEPRI_FOREGROUND) { + decay_limit += (thread->base_pri - BASEPRI_FOREGROUND); + } + + if (decay_amount > decay_limit) { + decay_amount = decay_limit; + } + + /* start with base priority */ + int priority = thread->base_pri - decay_amount; + + if (priority < MAXPRI_THROTTLE) { + if (thread->task->max_priority > MAXPRI_THROTTLE) { + priority = MAXPRI_THROTTLE; + } else if (priority < MINPRI_USER) { + priority = MINPRI_USER; + } + } else if (priority > MAXPRI_KERNEL) { + priority = MAXPRI_KERNEL; + } + + return priority; +} + +#else /* CONFIG_EMBEDDED */ int sched_compute_timeshare_priority(thread_t thread) @@ -386,6 +486,7 @@ sched_compute_timeshare_priority(thread_t thread) return priority; } +#endif /* CONFIG_EMBEDDED */ /* * can_update_priority @@ -413,20 +514,14 @@ can_update_priority( */ void update_priority( - register thread_t thread) + thread_t thread) { - register unsigned ticks; - register uint32_t delta; + uint32_t ticks, delta; ticks = sched_tick - thread->sched_stamp; assert(ticks != 0); + thread->sched_stamp += ticks; - if (sched_use_combined_fgbg_decay) - thread->pri_shift = sched_combined_fgbg_pri_shift; - else if (thread->sched_flags & TH_SFLAG_THROTTLED) - thread->pri_shift = sched_background_pri_shift; - else - thread->pri_shift = sched_pri_shift; /* If requested, accelerate aging of sched_usage */ if (sched_decay_usage_age_factor > 1) @@ -437,12 +532,10 @@ update_priority( */ thread_timer_delta(thread, delta); if (ticks < SCHED_DECAY_TICKS) { - register struct shift_data *shiftp; - /* - * Accumulate timesharing usage only - * during contention for processor - * resources. + * Accumulate timesharing usage only during contention for processor + * resources. Use the pri_shift from the previous tick window to + * determine if the system was in a contended state. */ if (thread->pri_shift < INT8_MAX) thread->sched_usage += delta; @@ -450,25 +543,20 @@ update_priority( thread->cpu_usage += delta + thread->cpu_delta; thread->cpu_delta = 0; - shiftp = &sched_decay_shifts[ticks]; + struct shift_data *shiftp = &sched_decay_shifts[ticks]; + if (shiftp->shift2 > 0) { - thread->cpu_usage = - (thread->cpu_usage >> shiftp->shift1) + - (thread->cpu_usage >> shiftp->shift2); - thread->sched_usage = - (thread->sched_usage >> shiftp->shift1) + - (thread->sched_usage >> shiftp->shift2); - } - else { - thread->cpu_usage = - (thread->cpu_usage >> shiftp->shift1) - - (thread->cpu_usage >> -(shiftp->shift2)); - thread->sched_usage = - (thread->sched_usage >> shiftp->shift1) - - (thread->sched_usage >> -(shiftp->shift2)); + thread->cpu_usage = (thread->cpu_usage >> shiftp->shift1) + + (thread->cpu_usage >> shiftp->shift2); + thread->sched_usage = (thread->sched_usage >> shiftp->shift1) + + (thread->sched_usage >> shiftp->shift2); + } else { + thread->cpu_usage = (thread->cpu_usage >> shiftp->shift1) - + (thread->cpu_usage >> -(shiftp->shift2)); + thread->sched_usage = (thread->sched_usage >> shiftp->shift1) - + (thread->sched_usage >> -(shiftp->shift2)); } - } - else { + } else { thread->cpu_usage = thread->cpu_delta = 0; thread->sched_usage = 0; } @@ -482,120 +570,113 @@ update_priority( } /* - * Recompute scheduled priority if appropriate. + * Now that the thread's CPU usage has been accumulated and aged + * based on contention of the previous tick window, update the + * pri_shift of the thread to match the current global load/shift + * values. The updated pri_shift would be used to calculate the + * new priority of the thread. */ - if (thread->sched_mode == TH_MODE_TIMESHARE) { - int priority = sched_compute_timeshare_priority(thread); + thread->pri_shift = sched_pri_shifts[thread->th_sched_bucket]; - /* - * Adjust the scheduled priority like thread_recompute_sched_pri, - * except without setting an AST. - */ - if ((!(thread->sched_flags & TH_SFLAG_PROMOTED_MASK) || (priority > thread->sched_pri)) && - (!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK)) && - priority != thread->sched_pri) { + /* Recompute scheduled priority if appropriate. */ + if (thread->sched_mode == TH_MODE_TIMESHARE) + thread_recompute_sched_pri(thread, SETPRI_LAZY); +} - boolean_t removed = thread_run_queue_remove(thread); +#endif /* CONFIG_SCHED_TIMESHARE_CORE */ - thread->sched_pri = priority; - KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_CHANGE_PRIORITY), - (uintptr_t)thread_tid(thread), - thread->base_pri, - thread->sched_pri, - 0, /* eventually, 'reason' */ - 0); +/* + * TH_BUCKET_RUN is a count of *all* runnable non-idle threads. + * Each other bucket is a count of the runnable non-idle threads + * with that property. + */ +volatile uint32_t sched_run_buckets[TH_BUCKET_MAX]; - if (removed) - thread_run_queue_reinsert(thread, SCHED_TAILQ); - } - } +static void +sched_incr_bucket(sched_bucket_t bucket) +{ + assert(bucket >= TH_BUCKET_FIXPRI && + bucket <= TH_BUCKET_SHARE_BG); - return; + hw_atomic_add(&sched_run_buckets[bucket], 1); } -#endif /* CONFIG_SCHED_TIMESHARE_CORE */ - -#if MACH_ASSERT -/* sched_mode == TH_MODE_TIMESHARE controls whether a thread has a timeshare count when it has a run count */ +static void +sched_decr_bucket(sched_bucket_t bucket) +{ + assert(bucket >= TH_BUCKET_FIXPRI && + bucket <= TH_BUCKET_SHARE_BG); -void sched_share_incr(thread_t thread) { - assert((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN); - assert(thread->sched_mode == TH_MODE_TIMESHARE); - assert(thread->SHARE_COUNT == 0); - thread->SHARE_COUNT++; - (void)hw_atomic_add(&sched_share_count, 1); -} + assert(sched_run_buckets[bucket] > 0); -void sched_share_decr(thread_t thread) { - assert((thread->state & (TH_RUN|TH_IDLE)) != TH_RUN || thread->sched_mode != TH_MODE_TIMESHARE); - assert(thread->SHARE_COUNT == 1); - (void)hw_atomic_sub(&sched_share_count, 1); - thread->SHARE_COUNT--; + hw_atomic_sub(&sched_run_buckets[bucket], 1); } -/* TH_SFLAG_THROTTLED controls whether a thread has a background count when it has a run count and a share count */ +/* TH_RUN & !TH_IDLE controls whether a thread has a run count */ -void sched_background_incr(thread_t thread) { +uint32_t +sched_run_incr(thread_t thread) +{ assert((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN); - assert(thread->sched_mode == TH_MODE_TIMESHARE); - assert((thread->sched_flags & TH_SFLAG_THROTTLED) == TH_SFLAG_THROTTLED); - assert(thread->BG_COUNT == 0); - thread->BG_COUNT++; - int val = hw_atomic_add(&sched_background_count, 1); - assert(val >= 0); + uint32_t new_count = hw_atomic_add(&sched_run_buckets[TH_BUCKET_RUN], 1); - /* Always do the background change while holding a share count */ - assert(thread->SHARE_COUNT == 1); -} + sched_incr_bucket(thread->th_sched_bucket); -void sched_background_decr(thread_t thread) { - if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN && thread->sched_mode == TH_MODE_TIMESHARE) - assert((thread->sched_flags & TH_SFLAG_THROTTLED) != TH_SFLAG_THROTTLED); - assert(thread->BG_COUNT == 1); - int val = hw_atomic_sub(&sched_background_count, 1); - thread->BG_COUNT--; - assert(val >= 0); - assert(thread->BG_COUNT == 0); - - /* Always do the background change while holding a share count */ - assert(thread->SHARE_COUNT == 1); + return new_count; } +uint32_t +sched_run_decr(thread_t thread) +{ + assert((thread->state & (TH_RUN|TH_IDLE)) != TH_RUN); -void -assert_thread_sched_count(thread_t thread) { - /* Only 0 or 1 are acceptable values */ - assert(thread->BG_COUNT == 0 || thread->BG_COUNT == 1); - assert(thread->SHARE_COUNT == 0 || thread->SHARE_COUNT == 1); - - /* BG is only allowed when you already have a share count */ - if (thread->BG_COUNT == 1) - assert(thread->SHARE_COUNT == 1); - if (thread->SHARE_COUNT == 0) - assert(thread->BG_COUNT == 0); - - if ((thread->state & (TH_RUN|TH_IDLE)) != TH_RUN || - (thread->sched_mode != TH_MODE_TIMESHARE)) - assert(thread->SHARE_COUNT == 0); - - if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN && - (thread->sched_mode == TH_MODE_TIMESHARE)) - assert(thread->SHARE_COUNT == 1); - - if ((thread->state & (TH_RUN|TH_IDLE)) != TH_RUN || - (thread->sched_mode != TH_MODE_TIMESHARE) || - !(thread->sched_flags & TH_SFLAG_THROTTLED)) - assert(thread->BG_COUNT == 0); - - if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN && - (thread->sched_mode == TH_MODE_TIMESHARE) && - (thread->sched_flags & TH_SFLAG_THROTTLED)) - assert(thread->BG_COUNT == 1); + sched_decr_bucket(thread->th_sched_bucket); + + uint32_t new_count = hw_atomic_sub(&sched_run_buckets[TH_BUCKET_RUN], 1); + + return new_count; } -#endif /* MACH_ASSERT */ +static void +sched_update_thread_bucket(thread_t thread) +{ + sched_bucket_t old_bucket = thread->th_sched_bucket; + sched_bucket_t new_bucket = TH_BUCKET_RUN; + + switch (thread->sched_mode) { + case TH_MODE_FIXED: + case TH_MODE_REALTIME: + new_bucket = TH_BUCKET_FIXPRI; + break; + + case TH_MODE_TIMESHARE: + if (thread->base_pri > BASEPRI_DEFAULT) + new_bucket = TH_BUCKET_SHARE_FG; + else if (thread->base_pri > BASEPRI_UTILITY) + new_bucket = TH_BUCKET_SHARE_DF; + else if (thread->base_pri > MAXPRI_THROTTLE) + new_bucket = TH_BUCKET_SHARE_UT; + else + new_bucket = TH_BUCKET_SHARE_BG; + break; + + default: + panic("unexpected mode: %d", thread->sched_mode); + break; + } + + if (old_bucket != new_bucket) { + thread->th_sched_bucket = new_bucket; + thread->pri_shift = sched_pri_shifts[new_bucket]; + + if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN) { + sched_decr_bucket(old_bucket); + sched_incr_bucket(new_bucket); + } + } +} /* * Set the thread's true scheduling mode @@ -607,43 +688,22 @@ assert_thread_sched_count(thread_t thread) { void sched_set_thread_mode(thread_t thread, sched_mode_t new_mode) { - assert_thread_sched_count(thread); assert(thread->runq == PROCESSOR_NULL); - sched_mode_t old_mode = thread->sched_mode; - - thread->sched_mode = new_mode; - switch (new_mode) { - case TH_MODE_FIXED: - case TH_MODE_REALTIME: - if (old_mode == TH_MODE_TIMESHARE) { - if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN) { - if (thread->sched_flags & TH_SFLAG_THROTTLED) - sched_background_decr(thread); - - sched_share_decr(thread); - } - } - break; - - case TH_MODE_TIMESHARE: - if (old_mode != TH_MODE_TIMESHARE) { - if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN) { - sched_share_incr(thread); - - if (thread->sched_flags & TH_SFLAG_THROTTLED) - sched_background_incr(thread); - } - } - break; - - default: - panic("unexpected mode: %d", new_mode); - break; + case TH_MODE_FIXED: + case TH_MODE_REALTIME: + case TH_MODE_TIMESHARE: + break; + + default: + panic("unexpected mode: %d", new_mode); + break; } - assert_thread_sched_count(thread); + thread->sched_mode = new_mode; + + sched_update_thread_bucket(thread); } /* @@ -654,7 +714,6 @@ sched_thread_mode_demote(thread_t thread, uint32_t reason) { assert(reason & TH_SFLAG_DEMOTED_MASK); assert((thread->sched_flags & reason) != reason); - assert_thread_sched_count(thread); if (thread->policy_reset) return; @@ -679,8 +738,6 @@ sched_thread_mode_demote(thread_t thread, uint32_t reason) if (removed) thread_run_queue_reinsert(thread, SCHED_TAILQ); - - assert_thread_sched_count(thread); } /* @@ -695,8 +752,6 @@ sched_thread_mode_undemote(thread_t thread, uint32_t reason) assert(thread->sched_mode == TH_MODE_TIMESHARE); assert(thread->policy_reset == 0); - assert_thread_sched_count(thread); - thread->sched_flags &= ~reason; if (thread->sched_flags & TH_SFLAG_DEMOTED_MASK) { @@ -717,33 +772,167 @@ sched_thread_mode_undemote(thread_t thread, uint32_t reason) } /* - * Set the thread to be categorized as 'background' - * Called with thread mutex and thread lock held + * Promote thread to a specific priority + * + * Promotion must not last past syscall boundary + * Clients must always pair promote and unpromote 1:1 * - * TODO: Eventually, 'background' should be a true sched_mode. + * Called at splsched with thread locked */ void -sched_set_thread_throttled(thread_t thread, boolean_t wants_throttle) +sched_thread_promote_to_pri(thread_t thread, + int priority, + __kdebug_only uintptr_t trace_obj /* already unslid */) { - if (thread->policy_reset) - return; + assert((thread->sched_flags & TH_SFLAG_PROMOTED) != TH_SFLAG_PROMOTED); + assert(thread->promotion_priority == 0); + assert(priority <= MAXPRI_PROMOTE); + assert(priority > 0); - assert(((thread->sched_flags & TH_SFLAG_THROTTLED) ? TRUE : FALSE) != wants_throttle); + KDBG(MACHDBG_CODE(DBG_MACH_SCHED, MACH_PROMOTED), + thread_tid(thread), trace_obj, priority); - assert_thread_sched_count(thread); + thread->sched_flags |= TH_SFLAG_PROMOTED; + thread->promotion_priority = priority; - if (wants_throttle) { - thread->sched_flags |= TH_SFLAG_THROTTLED; - if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN && thread->sched_mode == TH_MODE_TIMESHARE) { - sched_background_incr(thread); - } - } else { - thread->sched_flags &= ~TH_SFLAG_THROTTLED; - if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN && thread->sched_mode == TH_MODE_TIMESHARE) { - sched_background_decr(thread); - } + thread_recompute_sched_pri(thread, SETPRI_DEFAULT); +} + + +/* + * Update a pre-existing priority promotion to have a higher priority floor + * Priority can only go up from the previous value + * Update must occur while a promotion is active + * + * Called at splsched with thread locked + */ +void +sched_thread_update_promotion_to_pri(thread_t thread, + int priority, + __kdebug_only uintptr_t trace_obj /* already unslid */) +{ + assert(thread->promotions > 0); + assert((thread->sched_flags & TH_SFLAG_PROMOTED) == TH_SFLAG_PROMOTED); + assert(thread->promotion_priority > 0); + assert(priority <= MAXPRI_PROMOTE); + + if (thread->promotion_priority < priority) { + KDBG(MACHDBG_CODE(DBG_MACH_SCHED, MACH_PROMOTED_UPDATE), + thread_tid(thread), trace_obj, priority); + + thread->promotion_priority = priority; + thread_recompute_sched_pri(thread, SETPRI_DEFAULT); } +} + +/* + * End a priority promotion + * Demotes a thread back to its expected priority without the promotion in place + * + * Called at splsched with thread locked + */ +void +sched_thread_unpromote(thread_t thread, + __kdebug_only uintptr_t trace_obj /* already unslid */) +{ + assert((thread->sched_flags & TH_SFLAG_PROMOTED) == TH_SFLAG_PROMOTED); + assert(thread->promotion_priority > 0); + + KDBG(MACHDBG_CODE(DBG_MACH_SCHED, MACH_UNPROMOTED), + thread_tid(thread), trace_obj, 0); + + thread->sched_flags &= ~TH_SFLAG_PROMOTED; + thread->promotion_priority = 0; + + thread_recompute_sched_pri(thread, SETPRI_DEFAULT); +} + +/* called with thread locked */ +void +assert_promotions_invariant(thread_t thread) +{ + if (thread->promotions > 0) + assert((thread->sched_flags & TH_SFLAG_PROMOTED) == TH_SFLAG_PROMOTED); + + if (thread->promotions == 0) + assert((thread->sched_flags & TH_SFLAG_PROMOTED) != TH_SFLAG_PROMOTED); +} + +/* + * Promote thread to have a sched pri floor for a specific reason + * + * Promotion must not last past syscall boundary + * Clients must always pair promote and demote 1:1, + * Handling nesting of the same promote reason is the client's responsibility + * + * Called at splsched with thread locked + */ +void +sched_thread_promote_reason(thread_t thread, + uint32_t reason, + __kdebug_only uintptr_t trace_obj /* already unslid */) +{ + assert(reason & TH_SFLAG_PROMOTE_REASON_MASK); + assert((thread->sched_flags & reason) != reason); - assert_thread_sched_count(thread); + switch (reason) { + case TH_SFLAG_RW_PROMOTED: + KDBG(MACHDBG_CODE(DBG_MACH_SCHED, MACH_RW_PROMOTE), + thread_tid(thread), thread->sched_pri, + thread->base_pri, trace_obj); + break; + case TH_SFLAG_WAITQ_PROMOTED: + KDBG(MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAITQ_PROMOTE), + thread_tid(thread), thread->sched_pri, + thread->base_pri, trace_obj); + break; + case TH_SFLAG_EXEC_PROMOTED: + KDBG(MACHDBG_CODE(DBG_MACH_SCHED, MACH_EXEC_PROMOTE), + thread_tid(thread), thread->sched_pri, + thread->base_pri, trace_obj); + break; + } + + thread->sched_flags |= reason; + + thread_recompute_sched_pri(thread, SETPRI_DEFAULT); } +/* + * End a specific promotion reason + * Demotes a thread back to its expected priority without the promotion in place + * + * Called at splsched with thread locked + */ +void +sched_thread_unpromote_reason(thread_t thread, + uint32_t reason, + __kdebug_only uintptr_t trace_obj /* already unslid */) +{ + assert(reason & TH_SFLAG_PROMOTE_REASON_MASK); + assert((thread->sched_flags & reason) == reason); + + switch (reason) { + case TH_SFLAG_RW_PROMOTED: + KDBG(MACHDBG_CODE(DBG_MACH_SCHED, MACH_RW_DEMOTE), + thread_tid(thread), thread->sched_pri, + thread->base_pri, trace_obj); + break; + case TH_SFLAG_WAITQ_PROMOTED: + KDBG(MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAITQ_DEMOTE), + thread_tid(thread), thread->sched_pri, + thread->base_pri, trace_obj); + break; + case TH_SFLAG_EXEC_PROMOTED: + KDBG(MACHDBG_CODE(DBG_MACH_SCHED, MACH_EXEC_DEMOTE), + thread_tid(thread), thread->sched_pri, + thread->base_pri, trace_obj); + break; + } + + thread->sched_flags &= ~reason; + + thread_recompute_sched_pri(thread, SETPRI_DEFAULT); +} + +