X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/6601e61aa18bf4f09af135ff61fc7f4771d23b06..440d4c6cfad24426bfddca7518f16c17f4e443f7:/osfmk/kern/priority.c diff --git a/osfmk/kern/priority.c b/osfmk/kern/priority.c index 9ff146229..a7fa6ea44 100644 --- a/osfmk/kern/priority.c +++ b/osfmk/kern/priority.c @@ -1,23 +1,29 @@ /* - * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2010 Apple Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * The contents of this file constitute Original Code as defined in and - * are subject to the Apple Public Source License Version 1.1 (the - * "License"). You may not use this file except in compliance with the - * License. Please obtain a copy of the License at - * http://www.apple.com/publicsource and read it before using this file. + * This file contains Original Code and/or Modifications of Original Code + * as defined in and that are subject to the Apple Public Source License + * Version 2.0 (the 'License'). You may not use this file except in + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * unlawful or unlicensed copies of an Apple operating system, or to + * circumvent, violate, or enable the circumvention or violation of, any + * terms of an Apple operating system software license agreement. * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this file. + * + * The Original Code and all software distributed under the License are + * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the - * License for the specific language governing rights and limitations - * under the License. + * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * Please see the License for the specific language governing rights and + * limitations under the License. * - * @APPLE_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * @OSF_COPYRIGHT@ @@ -63,15 +69,19 @@ #include #include #include +#include #include #include #include +#include #include /* * thread_quantum_expire: * * Recalculate the quantum and priority for a thread. + * + * Called at splsched. */ void @@ -79,50 +89,143 @@ thread_quantum_expire( timer_call_param_t p0, timer_call_param_t p1) { - register processor_t myprocessor = p0; - register thread_t thread = p1; - spl_t s; + processor_t processor = p0; + thread_t thread = p1; + ast_t preempt; - s = splsched(); - thread_lock(thread); + SCHED_STATS_QUANTUM_TIMER_EXPIRATION(processor); /* - * Check for fail-safe trip. + * 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. */ - if (!(thread->sched_mode & TH_MODE_TIMESHARE)) { - uint64_t new_computation; + ledger_credit(thread->t_ledger, task_ledgers.cpu_time, thread->current_quantum); + ledger_credit(thread->t_threadledger, thread_ledgers.cpu_time, thread->current_quantum); - new_computation = myprocessor->quantum_end; - new_computation -= thread->computation_epoch; - if (new_computation + thread->computation_metered > - max_unsafe_computation) { + thread_lock(thread); - if (thread->sched_mode & TH_MODE_REALTIME) { - thread->priority = DEPRESSPRI; + /* + * We've run up until our quantum expiration, and will (potentially) + * continue without re-entering the scheduler, so update this now. + */ + thread->last_run_time = processor->quantum_end; - thread->safe_mode |= TH_MODE_REALTIME; - thread->sched_mode &= ~TH_MODE_REALTIME; + /* + * Check for fail-safe trip. + */ + if ((thread->sched_mode == TH_MODE_REALTIME || thread->sched_mode == TH_MODE_FIXED) && + !(thread->sched_flags & TH_SFLAG_PROMOTED) && + !(thread->options & TH_OPT_SYSTEM_CRITICAL)) { + uint64_t new_computation; + + new_computation = processor->quantum_end - 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); + + if (thread->sched_mode == TH_MODE_REALTIME) { + thread->priority = DEPRESSPRI; + } + + thread->saved_mode = thread->sched_mode; + + if (SCHED(supports_timeshare_mode)) { + sched_share_incr(); + thread->sched_mode = TH_MODE_TIMESHARE; + } else { + /* XXX handle fixed->fixed case */ + thread->sched_mode = TH_MODE_FIXED; } - pset_share_incr(thread->processor_set); - - thread->safe_release = sched_tick + sched_safe_duration; - thread->sched_mode |= (TH_MODE_FAILSAFE|TH_MODE_TIMESHARE); - thread->sched_mode &= ~TH_MODE_PREEMPT; + thread->safe_release = processor->quantum_end + sched_safe_duration; + thread->sched_flags |= TH_SFLAG_FAILSAFE; } } /* * Recompute scheduled priority if appropriate. */ - if (thread->sched_stamp != sched_tick) - update_priority(thread); + if (SCHED(can_update_priority)(thread)) + SCHED(update_priority)(thread); else - if (thread->sched_mode & TH_MODE_TIMESHARE) { - register uint32_t delta; + SCHED(lightweight_update_priority)(thread); - thread_timer_delta(thread, delta); + SCHED(quantum_expire)(thread); + + processor->current_pri = thread->sched_pri; + processor->current_thmode = thread->sched_mode; + + /* + * This quantum is up, give this thread another. + */ + if (first_timeslice(processor)) + processor->timeslice--; + + thread_quantum_init(thread); + thread->last_quantum_refill_time = processor->quantum_end; + + /* Reload precise timing global policy to thread-local policy */ + thread->precise_user_kernel_time = use_precise_user_kernel_time(thread); + + /* + * Since non-precise user/kernel time doesn't update the state/thread timer + * during privilege transitions, synthesize an event now. + */ + if (!thread->precise_user_kernel_time) { + timer_switch(PROCESSOR_DATA(processor, current_state), + processor->quantum_end, + PROCESSOR_DATA(processor, current_state)); + timer_switch(PROCESSOR_DATA(processor, thread_timer), + processor->quantum_end, + PROCESSOR_DATA(processor, thread_timer)); + } + + processor->quantum_end = mach_absolute_time() + thread->current_quantum; + timer_call_enter1(&processor->quantum_timer, thread, + processor->quantum_end, TIMER_CALL_CRITICAL); + + /* + * Context switch check. + */ + if ((preempt = csw_check(processor)) != AST_NONE) + ast_on(preempt); + else { + processor_set_t pset = processor->processor_set; + pset_lock(pset); + + pset_pri_hint(pset, processor, processor->current_pri); + pset_count_hint(pset, processor, SCHED(processor_runq_count)(processor)); + + pset_unlock(pset); + } + + thread_unlock(thread); +} + +#if defined(CONFIG_SCHED_TRADITIONAL) + +void +sched_traditional_quantum_expire(thread_t thread __unused) +{ + /* + * No special behavior when a timeshare, fixed, or realtime thread + * uses up its entire quantum + */ +} + +void +lightweight_update_priority(thread_t thread) +{ + if (thread->sched_mode == TH_MODE_TIMESHARE) { + register uint32_t delta; + + thread_timer_delta(thread, delta); + /* * Accumulate timesharing usage only * during contention for processor @@ -130,38 +233,18 @@ thread_quantum_expire( */ if (thread->pri_shift < INT8_MAX) thread->sched_usage += delta; - + thread->cpu_delta += delta; - + /* * Adjust the scheduled priority if * the thread has not been promoted * and is not depressed. */ - if ( !(thread->sched_mode & TH_MODE_PROMOTED) && - !(thread->sched_mode & TH_MODE_ISDEPRESSED) ) + if ( !(thread->sched_flags & TH_SFLAG_PROMOTED) && + !(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) ) compute_my_priority(thread); - } - - /* - * This quantum is up, give this thread another. - */ - if (first_timeslice(myprocessor)) - myprocessor->timeslice--; - - thread_quantum_init(thread); - myprocessor->quantum_end += thread->current_quantum; - timer_call_enter1(&myprocessor->quantum_timer, - thread, myprocessor->quantum_end); - - thread_unlock(thread); - - /* - * Check for and schedule ast if needed. - */ - ast_check(myprocessor); - - splx(s); + } } /* @@ -189,6 +272,25 @@ static struct shift_data sched_decay_shifts[SCHED_DECAY_TICKS] = { * * Calculate the timesharing priority based upon usage and load. */ +#ifdef CONFIG_EMBEDDED + +#define do_priority_computation(thread, pri) \ + MACRO_BEGIN \ + (pri) = (thread)->priority /* start with base priority */ \ + - ((thread)->sched_usage >> (thread)->pri_shift); \ + if ((pri) < MAXPRI_THROTTLE) { \ + if ((thread)->task->max_priority > MAXPRI_THROTTLE) \ + (pri) = MAXPRI_THROTTLE; \ + else \ + if ((pri) < MINPRI_USER) \ + (pri) = MINPRI_USER; \ + } else \ + if ((pri) > MAXPRI_KERNEL) \ + (pri) = MAXPRI_KERNEL; \ + MACRO_END + +#else + #define do_priority_computation(thread, pri) \ MACRO_BEGIN \ (pri) = (thread)->priority /* start with base priority */ \ @@ -200,6 +302,10 @@ static struct shift_data sched_decay_shifts[SCHED_DECAY_TICKS] = { (pri) = MAXPRI_KERNEL; \ MACRO_END +#endif /* defined(CONFIG_SCHED_TRADITIONAL) */ + +#endif + /* * set_priority: * @@ -214,9 +320,11 @@ set_priority( register int priority) { thread->priority = priority; - compute_priority(thread, FALSE); + SCHED(compute_priority)(thread, FALSE); } +#if defined(CONFIG_SCHED_TRADITIONAL) + /* * compute_priority: * @@ -233,10 +341,10 @@ compute_priority( { register int priority; - if ( !(thread->sched_mode & TH_MODE_PROMOTED) && - (!(thread->sched_mode & TH_MODE_ISDEPRESSED) || + if ( !(thread->sched_flags & TH_SFLAG_PROMOTED) && + (!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) || override_depress ) ) { - if (thread->sched_mode & TH_MODE_TIMESHARE) + if (thread->sched_mode == TH_MODE_TIMESHARE) do_priority_computation(thread, priority); else priority = thread->priority; @@ -263,10 +371,27 @@ compute_my_priority( register int priority; do_priority_computation(thread, priority); - assert(thread->runq == RUN_QUEUE_NULL); + assert(thread->runq == PROCESSOR_NULL); thread->sched_pri = priority; } +/* + * can_update_priority + * + * Make sure we don't do re-dispatches more frequently than a scheduler tick. + * + * Called with the thread locked. + */ +boolean_t +can_update_priority( + thread_t thread) +{ + if (sched_tick == thread->sched_stamp) + return (FALSE); + else + return (TRUE); +} + /* * update_priority * @@ -284,7 +409,7 @@ update_priority( ticks = sched_tick - thread->sched_stamp; assert(ticks != 0); thread->sched_stamp += ticks; - thread->pri_shift = thread->processor_set->pri_shift; + thread->pri_shift = sched_pri_shift; /* * Gather cpu usage data. @@ -330,44 +455,89 @@ update_priority( /* * Check for fail-safe release. */ - if ( (thread->sched_mode & TH_MODE_FAILSAFE) && - thread->sched_stamp >= thread->safe_release ) { - if (!(thread->safe_mode & TH_MODE_TIMESHARE)) { - if (thread->safe_mode & TH_MODE_REALTIME) { + if ( (thread->sched_flags & TH_SFLAG_FAILSAFE) && + mach_absolute_time() >= thread->safe_release ) { + if (thread->saved_mode != TH_MODE_TIMESHARE) { + if (thread->saved_mode == TH_MODE_REALTIME) { thread->priority = BASEPRI_RTQUEUES; - - thread->sched_mode |= TH_MODE_REALTIME; } - thread->sched_mode &= ~TH_MODE_TIMESHARE; + thread->sched_mode = thread->saved_mode; + thread->saved_mode = TH_MODE_NONE; - if (thread->state & TH_RUN) - pset_share_decr(thread->processor_set); + if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN) + sched_share_decr(); - if (!(thread->sched_mode & TH_MODE_ISDEPRESSED)) + if (!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK)) set_sched_pri(thread, thread->priority); } - thread->safe_mode = 0; - thread->sched_mode &= ~TH_MODE_FAILSAFE; + thread->sched_flags &= ~TH_SFLAG_FAILSAFE; + } + +#if CONFIG_EMBEDDED + /* Check for pending throttle transitions, and safely switch queues */ + if (thread->sched_flags & TH_SFLAG_PENDING_THROTTLE_MASK) { + boolean_t removed = thread_run_queue_remove(thread); + + if (thread->sched_flags & TH_SFLAG_PENDING_THROTTLE_DEMOTION) { + if (thread->sched_mode == TH_MODE_REALTIME) { + thread->saved_mode = thread->sched_mode; + thread->sched_mode = TH_MODE_TIMESHARE; + + if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN) + sched_share_incr(); + } else { + /* + * It's possible that this is a realtime thread that has + * already tripped the failsafe, in which case saved_mode + * is already set correctly. + */ + if (!(thread->sched_flags & TH_SFLAG_FAILSAFE)) { + thread->saved_mode = thread->sched_mode; + } + thread->sched_flags &= ~TH_SFLAG_FAILSAFE; + } + thread->sched_flags |= TH_SFLAG_THROTTLED; + + } else { + if ((thread->sched_mode == TH_MODE_TIMESHARE) + && (thread->saved_mode == TH_MODE_REALTIME)) { + if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN) + sched_share_decr(); + } + + thread->sched_mode = thread->saved_mode; + thread->saved_mode = TH_MODE_NONE; + thread->sched_flags &= ~TH_SFLAG_THROTTLED; + } + + thread->sched_flags &= ~(TH_SFLAG_PENDING_THROTTLE_MASK); + + if (removed) + thread_setrun(thread, SCHED_TAILQ); } +#endif /* * Recompute scheduled priority if appropriate. */ - if ( (thread->sched_mode & TH_MODE_TIMESHARE) && - !(thread->sched_mode & TH_MODE_PROMOTED) && - !(thread->sched_mode & TH_MODE_ISDEPRESSED) ) { + if ( (thread->sched_mode == TH_MODE_TIMESHARE) && + !(thread->sched_flags & TH_SFLAG_PROMOTED) && + !(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) ) { register int new_pri; do_priority_computation(thread, new_pri); if (new_pri != thread->sched_pri) { - run_queue_t runq; + boolean_t removed = thread_run_queue_remove(thread); - runq = run_queue_remove(thread); thread->sched_pri = new_pri; - if (runq != RUN_QUEUE_NULL) + if (removed) thread_setrun(thread, SCHED_TAILQ); } } + + return; } + +#endif /* CONFIG_SCHED_TRADITIONAL */