From 0624c880bd5af45ae9095465e079fa55458515f6 Mon Sep 17 00:00:00 2001 From: Liam Date: Sun, 26 Jun 2022 18:52:16 -0400 Subject: kernel: use KScheduler from mesosphere --- src/core/hle/kernel/k_scheduler.cpp | 723 +++++++++++++++++++----------------- 1 file changed, 376 insertions(+), 347 deletions(-) (limited to 'src/core/hle/kernel/k_scheduler.cpp') diff --git a/src/core/hle/kernel/k_scheduler.cpp b/src/core/hle/kernel/k_scheduler.cpp index d599d2bcb..13915dbd9 100644 --- a/src/core/hle/kernel/k_scheduler.cpp +++ b/src/core/hle/kernel/k_scheduler.cpp @@ -27,69 +27,162 @@ static void IncrementScheduledCount(Kernel::KThread* thread) { } } -void KScheduler::RescheduleCores(KernelCore& kernel, u64 cores_pending_reschedule) { - auto scheduler = kernel.CurrentScheduler(); - - u32 current_core{0xF}; - bool must_context_switch{}; - if (scheduler) { - current_core = scheduler->core_id; - // TODO(bunnei): Should be set to true when we deprecate single core - must_context_switch = !kernel.IsPhantomModeForSingleCore(); - } - - while (cores_pending_reschedule != 0) { - const auto core = static_cast(std::countr_zero(cores_pending_reschedule)); - ASSERT(core < Core::Hardware::NUM_CPU_CORES); - if (!must_context_switch || core != current_core) { - auto& phys_core = kernel.PhysicalCore(core); - phys_core.Interrupt(); +KScheduler::KScheduler(KernelCore& kernel_) : kernel{kernel_} { + m_idle_stack = std::make_shared([this] { + while (true) { + ScheduleImplOffStack(); } - cores_pending_reschedule &= ~(1ULL << core); + }); + + m_state.needs_scheduling = true; +} + +KScheduler::~KScheduler() = default; + +void KScheduler::SetInterruptTaskRunnable() { + m_state.interrupt_task_runnable = true; + m_state.needs_scheduling = true; +} + +void KScheduler::RequestScheduleOnInterrupt() { + m_state.needs_scheduling = true; + + if (CanSchedule(kernel)) { + ScheduleOnInterrupt(); } +} - for (std::size_t core_id = 0; core_id < Core::Hardware::NUM_CPU_CORES; ++core_id) { - if (kernel.PhysicalCore(core_id).IsInterrupted()) { - KInterruptManager::HandleInterrupt(kernel, static_cast(core_id)); +void KScheduler::DisableScheduling(KernelCore& kernel) { + ASSERT(GetCurrentThread(kernel).GetDisableDispatchCount() >= 0); + GetCurrentThread(kernel).DisableDispatch(); +} + +void KScheduler::EnableScheduling(KernelCore& kernel, u64 cores_needing_scheduling) { + ASSERT(GetCurrentThread(kernel).GetDisableDispatchCount() >= 1); + + auto* scheduler = kernel.CurrentScheduler(); + + if (!scheduler) { + // HACK: we cannot schedule from this thread, it is not a core thread + RescheduleCores(kernel, cores_needing_scheduling); + if (GetCurrentThread(kernel).GetDisableDispatchCount() == 1) { + // Special case to ensure dummy threads that are waiting block + GetCurrentThread(kernel).IfDummyThreadTryWait(); } + GetCurrentThread(kernel).EnableDispatch(); + return; + } + + scheduler->RescheduleOtherCores(cores_needing_scheduling); + + if (GetCurrentThread(kernel).GetDisableDispatchCount() > 1) { + GetCurrentThread(kernel).EnableDispatch(); + } else { + scheduler->RescheduleCurrentCore(); + } +} + +u64 KScheduler::UpdateHighestPriorityThreads(KernelCore& kernel) { + if (IsSchedulerUpdateNeeded(kernel)) { + return UpdateHighestPriorityThreadsImpl(kernel); + } else { + return 0; + } +} + +void KScheduler::Schedule() { + ASSERT(GetCurrentThread(kernel).GetDisableDispatchCount() == 1); + ASSERT(m_core_id == GetCurrentCoreId(kernel)); + + ScheduleImpl(); +} + +void KScheduler::ScheduleOnInterrupt() { + GetCurrentThread(kernel).DisableDispatch(); + Schedule(); + GetCurrentThread(kernel).EnableDispatch(); +} + +void KScheduler::RescheduleCurrentCore() { + ASSERT(GetCurrentThread(kernel).GetDisableDispatchCount() == 1); + + GetCurrentThread(kernel).EnableDispatch(); + + if (m_state.needs_scheduling.load()) { + // Disable interrupts, and then check again if rescheduling is needed. + // KScopedInterruptDisable intr_disable; + + kernel.CurrentScheduler()->RescheduleCurrentCoreImpl(); } +} - if (must_context_switch) { - auto core_scheduler = kernel.CurrentScheduler(); - kernel.ExitSVCProfile(); - core_scheduler->RescheduleCurrentCore(); - kernel.EnterSVCProfile(); +void KScheduler::RescheduleCurrentCoreImpl() { + // Check that scheduling is needed. + if (m_state.needs_scheduling.load()) [[likely]] { + GetCurrentThread(kernel).DisableDispatch(); + Schedule(); + GetCurrentThread(kernel).EnableDispatch(); } } +void KScheduler::Initialize(KThread* idle_thread) { + // Set core ID/idle thread/interrupt task manager. + m_core_id = GetCurrentCoreId(kernel); + m_idle_thread = idle_thread; + // m_state.idle_thread_stack = m_idle_thread->GetStackTop(); + // m_state.interrupt_task_manager = &kernel.GetInterruptTaskManager(); + + // Insert the main thread into the priority queue. + // { + // KScopedSchedulerLock lk{kernel}; + // GetPriorityQueue(kernel).PushBack(GetCurrentThreadPointer(kernel)); + // SetSchedulerUpdateNeeded(kernel); + // } + + // Bind interrupt handler. + // kernel.GetInterruptManager().BindHandler( + // GetSchedulerInterruptHandler(kernel), KInterruptName::Scheduler, m_core_id, + // KInterruptController::PriorityLevel_Scheduler, false, false); + + // Set the current thread. + m_current_thread = GetCurrentThreadPointer(kernel); +} + +void KScheduler::Activate() { + ASSERT(GetCurrentThread(kernel).GetDisableDispatchCount() == 1); + + // m_state.should_count_idle = KTargetSystem::IsDebugMode(); + m_is_active = true; + RescheduleCurrentCore(); +} + u64 KScheduler::UpdateHighestPriorityThread(KThread* highest_thread) { - KScopedSpinLock lk{guard}; - if (KThread* prev_highest_thread = state.highest_priority_thread; - prev_highest_thread != highest_thread) { - if (prev_highest_thread != nullptr) { + if (KThread* prev_highest_thread = m_state.highest_priority_thread; + prev_highest_thread != highest_thread) [[likely]] { + if (prev_highest_thread != nullptr) [[likely]] { IncrementScheduledCount(prev_highest_thread); - prev_highest_thread->SetLastScheduledTick(system.CoreTiming().GetCPUTicks()); + prev_highest_thread->SetLastScheduledTick(kernel.System().CoreTiming().GetCPUTicks()); } - if (state.should_count_idle) { - if (highest_thread != nullptr) { + if (m_state.should_count_idle) { + if (highest_thread != nullptr) [[likely]] { if (KProcess* process = highest_thread->GetOwnerProcess(); process != nullptr) { - process->SetRunningThread(core_id, highest_thread, state.idle_count); + process->SetRunningThread(m_core_id, highest_thread, m_state.idle_count); } } else { - state.idle_count++; + m_state.idle_count++; } } - state.highest_priority_thread = highest_thread; - state.needs_scheduling.store(true); - return (1ULL << core_id); + m_state.highest_priority_thread = highest_thread; + m_state.needs_scheduling = true; + return (1ULL << m_core_id); } else { return 0; } } u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) { - ASSERT(kernel.GlobalSchedulerContext().IsLocked()); + ASSERT(IsSchedulerLockedByCurrentThread(kernel)); // Clear that we need to update. ClearSchedulerUpdateNeeded(kernel); @@ -98,18 +191,20 @@ u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) { KThread* top_threads[Core::Hardware::NUM_CPU_CORES]; auto& priority_queue = GetPriorityQueue(kernel); - /// We want to go over all cores, finding the highest priority thread and determining if - /// scheduling is needed for that core. + // We want to go over all cores, finding the highest priority thread and determining if + // scheduling is needed for that core. for (size_t core_id = 0; core_id < Core::Hardware::NUM_CPU_CORES; core_id++) { KThread* top_thread = priority_queue.GetScheduledFront(static_cast(core_id)); if (top_thread != nullptr) { - // If the thread has no waiters, we need to check if the process has a thread pinned. - if (top_thread->GetNumKernelWaiters() == 0) { - if (KProcess* parent = top_thread->GetOwnerProcess(); parent != nullptr) { - if (KThread* pinned = parent->GetPinnedThread(static_cast(core_id)); - pinned != nullptr && pinned != top_thread) { - // We prefer our parent's pinned thread if possible. However, we also don't - // want to schedule un-runnable threads. + // We need to check if the thread's process has a pinned thread. + if (KProcess* parent = top_thread->GetOwnerProcess()) { + // Check that there's a pinned thread other than the current top thread. + if (KThread* pinned = parent->GetPinnedThread(static_cast(core_id)); + pinned != nullptr && pinned != top_thread) { + // We need to prefer threads with kernel waiters to the pinned thread. + if (top_thread->GetNumKernelWaiters() == + 0 /* && top_thread != parent->GetExceptionThread() */) { + // If the pinned thread is runnable, use it. if (pinned->GetRawState() == ThreadState::Runnable) { top_thread = pinned; } else { @@ -129,7 +224,8 @@ u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) { // Idle cores are bad. We're going to try to migrate threads to each idle core in turn. while (idle_cores != 0) { - const auto core_id = static_cast(std::countr_zero(idle_cores)); + const s32 core_id = static_cast(std::countr_zero(idle_cores)); + if (KThread* suggested = priority_queue.GetSuggestedFront(core_id); suggested != nullptr) { s32 migration_candidates[Core::Hardware::NUM_CPU_CORES]; size_t num_candidates = 0; @@ -150,7 +246,6 @@ u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) { // The suggested thread isn't bound to its core, so we can migrate it! suggested->SetActiveCore(core_id); priority_queue.ChangeCore(suggested_core, suggested); - top_threads[core_id] = suggested; cores_needing_scheduling |= kernel.Scheduler(core_id).UpdateHighestPriorityThread(top_threads[core_id]); @@ -183,7 +278,6 @@ u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) { // Perform the migration. suggested->SetActiveCore(core_id); priority_queue.ChangeCore(candidate_core, suggested); - top_threads[core_id] = suggested; cores_needing_scheduling |= kernel.Scheduler(core_id).UpdateHighestPriorityThread( @@ -200,24 +294,223 @@ u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) { return cores_needing_scheduling; } +void KScheduler::SwitchThread(KThread* next_thread) { + KProcess* const cur_process = kernel.CurrentProcess(); + KThread* const cur_thread = GetCurrentThreadPointer(kernel); + + // We never want to schedule a null thread, so use the idle thread if we don't have a next. + if (next_thread == nullptr) { + next_thread = m_idle_thread; + } + + if (next_thread->GetCurrentCore() != m_core_id) { + next_thread->SetCurrentCore(m_core_id); + } + + // If we're not actually switching thread, there's nothing to do. + if (next_thread == cur_thread) { + return; + } + + // Next thread is now known not to be nullptr, and must not be dispatchable. + ASSERT(next_thread->GetDisableDispatchCount() == 1); + ASSERT(!next_thread->IsDummyThread()); + + // Update the CPU time tracking variables. + const s64 prev_tick = m_last_context_switch_time; + const s64 cur_tick = kernel.System().CoreTiming().GetCPUTicks(); + const s64 tick_diff = cur_tick - prev_tick; + cur_thread->AddCpuTime(m_core_id, tick_diff); + if (cur_process != nullptr) { + cur_process->UpdateCPUTimeTicks(tick_diff); + } + m_last_context_switch_time = cur_tick; + + // Update our previous thread. + if (cur_process != nullptr) { + if (!cur_thread->IsTerminationRequested() && cur_thread->GetActiveCore() == m_core_id) + [[likely]] { + m_state.prev_thread = cur_thread; + } else { + m_state.prev_thread = nullptr; + } + } + + // Switch the current process, if we're switching processes. + // if (KProcess *next_process = next_thread->GetOwnerProcess(); next_process != cur_process) { + // KProcess::Switch(cur_process, next_process); + // } + + // Set the new thread. + SetCurrentThread(kernel, next_thread); + m_current_thread = next_thread; + + // Set the new Thread Local region. + // cpu::SwitchThreadLocalRegion(GetInteger(next_thread->GetThreadLocalRegionAddress())); +} + +void KScheduler::ScheduleImpl() { + // First, clear the needs scheduling bool. + m_state.needs_scheduling.store(false, std::memory_order_seq_cst); + + // Load the appropriate thread pointers for scheduling. + KThread* const cur_thread{GetCurrentThreadPointer(kernel)}; + KThread* highest_priority_thread{m_state.highest_priority_thread}; + + // Check whether there are runnable interrupt tasks. + if (m_state.interrupt_task_runnable) { + // The interrupt task is runnable. + // We want to switch to the interrupt task/idle thread. + highest_priority_thread = nullptr; + } + + // If there aren't, we want to check if the highest priority thread is the same as the current + // thread. + if (highest_priority_thread == cur_thread) { + // If they're the same, then we can just return. + return; + } + + // The highest priority thread is not the same as the current thread. + // Switch to the idle thread stack and continue executing from there. + m_idle_cur_thread = cur_thread; + m_idle_highest_priority_thread = highest_priority_thread; + Common::Fiber::YieldTo(cur_thread->host_context, *m_idle_stack); + + // Returning from ScheduleImpl occurs after this thread has been scheduled again. +} + +void KScheduler::ScheduleImplOffStack() { + KThread* const cur_thread{m_idle_cur_thread}; + KThread* highest_priority_thread{m_idle_highest_priority_thread}; + + // Get a reference to the current thread's stack parameters. + auto& sp{cur_thread->GetStackParameters()}; + + // Save the original thread context. + { + auto& physical_core = kernel.System().CurrentPhysicalCore(); + auto& cpu_core = physical_core.ArmInterface(); + cpu_core.SaveContext(cur_thread->GetContext32()); + cpu_core.SaveContext(cur_thread->GetContext64()); + // Save the TPIDR_EL0 system register in case it was modified. + cur_thread->SetTPIDR_EL0(cpu_core.GetTPIDR_EL0()); + cpu_core.ClearExclusiveState(); + } + + // Check if the thread is terminated by checking the DPC flags. + if ((sp.dpc_flags & static_cast(DpcFlag::Terminated)) == 0) { + // The thread isn't terminated, so we want to unlock it. + sp.m_lock.store(false, std::memory_order_seq_cst); + } + + // The current thread's context has been entirely taken care of. + // Now we want to loop until we successfully switch the thread context. + while (true) { + // We're starting to try to do the context switch. + // Check if the highest priority thread is null. + if (!highest_priority_thread) { + // The next thread is nullptr! + // Switch to nullptr. This will actually switch to the idle thread. + SwitchThread(nullptr); + + // We've switched to the idle thread, so we want to process interrupt tasks until we + // schedule a non-idle thread. + while (!m_state.interrupt_task_runnable) { + // Check if we need scheduling. + if (m_state.needs_scheduling.load(std::memory_order_seq_cst)) { + goto retry; + } + + // Clear the previous thread. + m_state.prev_thread = nullptr; + + // Wait for an interrupt before checking again. + kernel.System().GetCpuManager().WaitForAndHandleInterrupt(); + } + + // Execute any pending interrupt tasks. + // m_state.interrupt_task_manager->DoTasks(); + + // Clear the interrupt task thread as runnable. + m_state.interrupt_task_runnable = false; + + // Retry the scheduling loop. + goto retry; + } else { + // We want to try to lock the highest priority thread's context. + // Try to take it. + bool expected{false}; + while (!highest_priority_thread->stack_parameters.m_lock.compare_exchange_strong( + expected, true, std::memory_order_seq_cst)) { + // The highest priority thread's context is already locked. + // Check if we need scheduling. If we don't, we can retry directly. + if (m_state.needs_scheduling.load(std::memory_order_seq_cst)) { + // If we do, another core is interfering, and we must start again. + goto retry; + } + expected = false; + } + + // It's time to switch the thread. + // Switch to the highest priority thread. + SwitchThread(highest_priority_thread); + + // Check if we need scheduling. If we do, then we can't complete the switch and should + // retry. + if (m_state.needs_scheduling.load(std::memory_order_seq_cst)) { + // Our switch failed. + // We should unlock the thread context, and then retry. + highest_priority_thread->stack_parameters.m_lock.store(false, + std::memory_order_seq_cst); + goto retry; + } else { + break; + } + } + + retry: + + // We failed to successfully do the context switch, and need to retry. + // Clear needs_scheduling. + m_state.needs_scheduling.store(false, std::memory_order_seq_cst); + + // Refresh the highest priority thread. + highest_priority_thread = m_state.highest_priority_thread; + } + + // Reload the guest thread context. + { + auto& cpu_core = kernel.System().CurrentArmInterface(); + cpu_core.LoadContext(highest_priority_thread->GetContext32()); + cpu_core.LoadContext(highest_priority_thread->GetContext64()); + cpu_core.SetTlsAddress(highest_priority_thread->GetTLSAddress()); + cpu_core.SetTPIDR_EL0(highest_priority_thread->GetTPIDR_EL0()); + cpu_core.LoadWatchpointArray(highest_priority_thread->GetOwnerProcess()->GetWatchpoints()); + cpu_core.ClearExclusiveState(); + } + + // Reload the host thread. + Common::Fiber::YieldTo(m_idle_stack, *highest_priority_thread->host_context); +} + void KScheduler::ClearPreviousThread(KernelCore& kernel, KThread* thread) { - ASSERT(kernel.GlobalSchedulerContext().IsLocked()); + ASSERT(IsSchedulerLockedByCurrentThread(kernel)); for (size_t i = 0; i < Core::Hardware::NUM_CPU_CORES; ++i) { // Get an atomic reference to the core scheduler's previous thread. - std::atomic_ref prev_thread(kernel.Scheduler(static_cast(i)).prev_thread); - static_assert(std::atomic_ref::is_always_lock_free); + auto& prev_thread{kernel.Scheduler(i).m_state.prev_thread}; // Atomically clear the previous thread if it's our target. KThread* compare = thread; - prev_thread.compare_exchange_strong(compare, nullptr); + prev_thread.compare_exchange_strong(compare, nullptr, std::memory_order_seq_cst); } } void KScheduler::OnThreadStateChanged(KernelCore& kernel, KThread* thread, ThreadState old_state) { - ASSERT(kernel.GlobalSchedulerContext().IsLocked()); + ASSERT(IsSchedulerLockedByCurrentThread(kernel)); // Check if the state has changed, because if it hasn't there's nothing to do. - const auto cur_state = thread->GetRawState(); + const ThreadState cur_state = thread->GetRawState(); if (cur_state == old_state) { return; } @@ -237,12 +530,12 @@ void KScheduler::OnThreadStateChanged(KernelCore& kernel, KThread* thread, Threa } void KScheduler::OnThreadPriorityChanged(KernelCore& kernel, KThread* thread, s32 old_priority) { - ASSERT(kernel.GlobalSchedulerContext().IsLocked()); + ASSERT(IsSchedulerLockedByCurrentThread(kernel)); // If the thread is runnable, we want to change its priority in the queue. if (thread->GetRawState() == ThreadState::Runnable) { GetPriorityQueue(kernel).ChangePriority(old_priority, - thread == kernel.GetCurrentEmuThread(), thread); + thread == GetCurrentThreadPointer(kernel), thread); IncrementScheduledCount(thread); SetSchedulerUpdateNeeded(kernel); } @@ -250,7 +543,7 @@ void KScheduler::OnThreadPriorityChanged(KernelCore& kernel, KThread* thread, s3 void KScheduler::OnThreadAffinityMaskChanged(KernelCore& kernel, KThread* thread, const KAffinityMask& old_affinity, s32 old_core) { - ASSERT(kernel.GlobalSchedulerContext().IsLocked()); + ASSERT(IsSchedulerLockedByCurrentThread(kernel)); // If the thread is runnable, we want to change its affinity in the queue. if (thread->GetRawState() == ThreadState::Runnable) { @@ -260,15 +553,14 @@ void KScheduler::OnThreadAffinityMaskChanged(KernelCore& kernel, KThread* thread } } -void KScheduler::RotateScheduledQueue(s32 cpu_core_id, s32 priority) { - ASSERT(system.GlobalSchedulerContext().IsLocked()); +void KScheduler::RotateScheduledQueue(KernelCore& kernel, s32 core_id, s32 priority) { + ASSERT(IsSchedulerLockedByCurrentThread(kernel)); // Get a reference to the priority queue. - auto& kernel = system.Kernel(); auto& priority_queue = GetPriorityQueue(kernel); // Rotate the front of the queue to the end. - KThread* top_thread = priority_queue.GetScheduledFront(cpu_core_id, priority); + KThread* top_thread = priority_queue.GetScheduledFront(core_id, priority); KThread* next_thread = nullptr; if (top_thread != nullptr) { next_thread = priority_queue.MoveToScheduledBack(top_thread); @@ -280,7 +572,7 @@ void KScheduler::RotateScheduledQueue(s32 cpu_core_id, s32 priority) { // While we have a suggested thread, try to migrate it! { - KThread* suggested = priority_queue.GetSuggestedFront(cpu_core_id, priority); + KThread* suggested = priority_queue.GetSuggestedFront(core_id, priority); while (suggested != nullptr) { // Check if the suggested thread is the top thread on its core. const s32 suggested_core = suggested->GetActiveCore(); @@ -301,7 +593,7 @@ void KScheduler::RotateScheduledQueue(s32 cpu_core_id, s32 priority) { // to the front of the queue. if (top_on_suggested_core == nullptr || top_on_suggested_core->GetPriority() >= HighestCoreMigrationAllowedPriority) { - suggested->SetActiveCore(cpu_core_id); + suggested->SetActiveCore(core_id); priority_queue.ChangeCore(suggested_core, suggested, true); IncrementScheduledCount(suggested); break; @@ -309,22 +601,21 @@ void KScheduler::RotateScheduledQueue(s32 cpu_core_id, s32 priority) { } // Get the next suggestion. - suggested = priority_queue.GetSamePriorityNext(cpu_core_id, suggested); + suggested = priority_queue.GetSamePriorityNext(core_id, suggested); } } // Now that we might have migrated a thread with the same priority, check if we can do better. - { - KThread* best_thread = priority_queue.GetScheduledFront(cpu_core_id); + KThread* best_thread = priority_queue.GetScheduledFront(core_id); if (best_thread == GetCurrentThreadPointer(kernel)) { - best_thread = priority_queue.GetScheduledNext(cpu_core_id, best_thread); + best_thread = priority_queue.GetScheduledNext(core_id, best_thread); } // If the best thread we can choose has a priority the same or worse than ours, try to // migrate a higher priority thread. if (best_thread != nullptr && best_thread->GetPriority() >= priority) { - KThread* suggested = priority_queue.GetSuggestedFront(cpu_core_id); + KThread* suggested = priority_queue.GetSuggestedFront(core_id); while (suggested != nullptr) { // If the suggestion's priority is the same as ours, don't bother. if (suggested->GetPriority() >= best_thread->GetPriority()) { @@ -343,7 +634,7 @@ void KScheduler::RotateScheduledQueue(s32 cpu_core_id, s32 priority) { if (top_on_suggested_core == nullptr || top_on_suggested_core->GetPriority() >= HighestCoreMigrationAllowedPriority) { - suggested->SetActiveCore(cpu_core_id); + suggested->SetActiveCore(core_id); priority_queue.ChangeCore(suggested_core, suggested, true); IncrementScheduledCount(suggested); break; @@ -351,7 +642,7 @@ void KScheduler::RotateScheduledQueue(s32 cpu_core_id, s32 priority) { } // Get the next suggestion. - suggested = priority_queue.GetSuggestedNext(cpu_core_id, suggested); + suggested = priority_queue.GetSuggestedNext(core_id, suggested); } } } @@ -360,64 +651,6 @@ void KScheduler::RotateScheduledQueue(s32 cpu_core_id, s32 priority) { SetSchedulerUpdateNeeded(kernel); } -bool KScheduler::CanSchedule(KernelCore& kernel) { - return kernel.GetCurrentEmuThread()->GetDisableDispatchCount() <= 1; -} - -bool KScheduler::IsSchedulerUpdateNeeded(const KernelCore& kernel) { - return kernel.GlobalSchedulerContext().scheduler_update_needed.load(std::memory_order_acquire); -} - -void KScheduler::SetSchedulerUpdateNeeded(KernelCore& kernel) { - kernel.GlobalSchedulerContext().scheduler_update_needed.store(true, std::memory_order_release); -} - -void KScheduler::ClearSchedulerUpdateNeeded(KernelCore& kernel) { - kernel.GlobalSchedulerContext().scheduler_update_needed.store(false, std::memory_order_release); -} - -void KScheduler::DisableScheduling(KernelCore& kernel) { - // If we are shutting down the kernel, none of this is relevant anymore. - if (kernel.IsShuttingDown()) { - return; - } - - ASSERT(GetCurrentThreadPointer(kernel)->GetDisableDispatchCount() >= 0); - GetCurrentThreadPointer(kernel)->DisableDispatch(); -} - -void KScheduler::EnableScheduling(KernelCore& kernel, u64 cores_needing_scheduling) { - // If we are shutting down the kernel, none of this is relevant anymore. - if (kernel.IsShuttingDown()) { - return; - } - - auto* current_thread = GetCurrentThreadPointer(kernel); - - ASSERT(current_thread->GetDisableDispatchCount() >= 1); - - if (current_thread->GetDisableDispatchCount() > 1) { - current_thread->EnableDispatch(); - } else { - RescheduleCores(kernel, cores_needing_scheduling); - } - - // Special case to ensure dummy threads that are waiting block. - current_thread->IfDummyThreadTryWait(); -} - -u64 KScheduler::UpdateHighestPriorityThreads(KernelCore& kernel) { - if (IsSchedulerUpdateNeeded(kernel)) { - return UpdateHighestPriorityThreadsImpl(kernel); - } else { - return 0; - } -} - -KSchedulerPriorityQueue& KScheduler::GetPriorityQueue(KernelCore& kernel) { - return kernel.GlobalSchedulerContext().priority_queue; -} - void KScheduler::YieldWithoutCoreMigration(KernelCore& kernel) { // Validate preconditions. ASSERT(CanSchedule(kernel)); @@ -437,7 +670,7 @@ void KScheduler::YieldWithoutCoreMigration(KernelCore& kernel) { // Perform the yield. { - KScopedSchedulerLock lock(kernel); + KScopedSchedulerLock sl{kernel}; const auto cur_state = cur_thread.GetRawState(); if (cur_state == ThreadState::Runnable) { @@ -476,7 +709,7 @@ void KScheduler::YieldWithCoreMigration(KernelCore& kernel) { // Perform the yield. { - KScopedSchedulerLock lock(kernel); + KScopedSchedulerLock sl{kernel}; const auto cur_state = cur_thread.GetRawState(); if (cur_state == ThreadState::Runnable) { @@ -496,7 +729,7 @@ void KScheduler::YieldWithCoreMigration(KernelCore& kernel) { if (KThread* running_on_suggested_core = (suggested_core >= 0) - ? kernel.Scheduler(suggested_core).state.highest_priority_thread + ? kernel.Scheduler(suggested_core).m_state.highest_priority_thread : nullptr; running_on_suggested_core != suggested) { // If the current thread's priority is higher than our suggestion's we prefer @@ -564,7 +797,7 @@ void KScheduler::YieldToAnyThread(KernelCore& kernel) { // Perform the yield. { - KScopedSchedulerLock lock(kernel); + KScopedSchedulerLock sl{kernel}; const auto cur_state = cur_thread.GetRawState(); if (cur_state == ThreadState::Runnable) { @@ -621,223 +854,19 @@ void KScheduler::YieldToAnyThread(KernelCore& kernel) { } } -KScheduler::KScheduler(Core::System& system_, s32 core_id_) : system{system_}, core_id{core_id_} { - switch_fiber = std::make_shared([this] { SwitchToCurrent(); }); - state.needs_scheduling.store(true); - state.interrupt_task_thread_runnable = false; - state.should_count_idle = false; - state.idle_count = 0; - state.idle_thread_stack = nullptr; - state.highest_priority_thread = nullptr; -} - -void KScheduler::Finalize() { - if (idle_thread) { - idle_thread->Close(); - idle_thread = nullptr; - } -} - -KScheduler::~KScheduler() { - ASSERT(!idle_thread); -} - -KThread* KScheduler::GetSchedulerCurrentThread() const { - if (auto result = current_thread.load(); result) { - return result; +void KScheduler::RescheduleOtherCores(u64 cores_needing_scheduling) { + if (const u64 core_mask = cores_needing_scheduling & ~(1ULL << m_core_id); core_mask != 0) { + RescheduleCores(kernel, core_mask); } - return idle_thread; -} - -u64 KScheduler::GetLastContextSwitchTicks() const { - return last_context_switch_time; } -void KScheduler::RescheduleCurrentCore() { - ASSERT(GetCurrentThread(system.Kernel()).GetDisableDispatchCount() == 1); - - auto& phys_core = system.Kernel().PhysicalCore(core_id); - if (phys_core.IsInterrupted()) { - phys_core.ClearInterrupt(); - } - - guard.Lock(); - if (state.needs_scheduling.load()) { - Schedule(); - } else { - GetCurrentThread(system.Kernel()).EnableDispatch(); - guard.Unlock(); - } -} - -void KScheduler::OnThreadStart() { - SwitchContextStep2(); -} - -void KScheduler::Unload(KThread* thread) { - ASSERT(thread); - - LOG_TRACE(Kernel, "core {}, unload thread {}", core_id, thread ? thread->GetName() : "nullptr"); - - if (thread->IsCallingSvc()) { - thread->ClearIsCallingSvc(); - } - - auto& physical_core = system.Kernel().PhysicalCore(core_id); - if (!physical_core.IsInitialized()) { - return; - } - - Core::ARM_Interface& cpu_core = physical_core.ArmInterface(); - cpu_core.SaveContext(thread->GetContext32()); - cpu_core.SaveContext(thread->GetContext64()); - // Save the TPIDR_EL0 system register in case it was modified. - thread->SetTPIDR_EL0(cpu_core.GetTPIDR_EL0()); - cpu_core.ClearExclusiveState(); - - if (!thread->IsTerminationRequested() && thread->GetActiveCore() == core_id) { - prev_thread = thread; - } else { - prev_thread = nullptr; - } - - thread->context_guard.unlock(); -} - -void KScheduler::Reload(KThread* thread) { - LOG_TRACE(Kernel, "core {}, reload thread {}", core_id, thread->GetName()); - - Core::ARM_Interface& cpu_core = system.ArmInterface(core_id); - cpu_core.LoadContext(thread->GetContext32()); - cpu_core.LoadContext(thread->GetContext64()); - cpu_core.LoadWatchpointArray(thread->GetOwnerProcess()->GetWatchpoints()); - cpu_core.SetTlsAddress(thread->GetTLSAddress()); - cpu_core.SetTPIDR_EL0(thread->GetTPIDR_EL0()); - cpu_core.ClearExclusiveState(); -} - -void KScheduler::SwitchContextStep2() { - // Load context of new thread - Reload(GetCurrentThreadPointer(system.Kernel())); - - RescheduleCurrentCore(); -} - -void KScheduler::Schedule() { - ASSERT(GetCurrentThread(system.Kernel()).GetDisableDispatchCount() == 1); - this->ScheduleImpl(); -} - -void KScheduler::ScheduleImpl() { - KThread* previous_thread = GetCurrentThreadPointer(system.Kernel()); - KThread* next_thread = state.highest_priority_thread; - - state.needs_scheduling.store(false); - - // We never want to schedule a null thread, so use the idle thread if we don't have a next. - if (next_thread == nullptr) { - next_thread = idle_thread; - } - - if (next_thread->GetCurrentCore() != core_id) { - next_thread->SetCurrentCore(core_id); - } - - // We never want to schedule a dummy thread, as these are only used by host threads for locking. - if (next_thread->GetThreadType() == ThreadType::Dummy) { - ASSERT_MSG(false, "Dummy threads should never be scheduled!"); - next_thread = idle_thread; - } - - // If we're not actually switching thread, there's nothing to do. - if (next_thread == current_thread.load()) { - previous_thread->EnableDispatch(); - guard.Unlock(); - return; - } - - // Update the CPU time tracking variables. - KProcess* const previous_process = system.Kernel().CurrentProcess(); - UpdateLastContextSwitchTime(previous_thread, previous_process); - - // Save context for previous thread - Unload(previous_thread); - - std::shared_ptr* old_context; - old_context = &previous_thread->GetHostContext(); - - // Set the new thread. - SetCurrentThread(system.Kernel(), next_thread); - current_thread.store(next_thread); - - guard.Unlock(); - - Common::Fiber::YieldTo(*old_context, *switch_fiber); - /// When a thread wakes up, the scheduler may have changed to other in another core. - auto& next_scheduler = *system.Kernel().CurrentScheduler(); - next_scheduler.SwitchContextStep2(); -} - -void KScheduler::SwitchToCurrent() { - while (true) { - { - KScopedSpinLock lk{guard}; - current_thread.store(state.highest_priority_thread); - state.needs_scheduling.store(false); +void KScheduler::RescheduleCores(KernelCore& kernel, u64 core_mask) { + // Send IPI + for (size_t i = 0; i < Core::Hardware::NUM_CPU_CORES; i++) { + if (core_mask & (1ULL << i)) { + kernel.PhysicalCore(i).Interrupt(); } - const auto is_switch_pending = [this] { - KScopedSpinLock lk{guard}; - return state.needs_scheduling.load(); - }; - do { - auto next_thread = current_thread.load(); - if (next_thread != nullptr) { - const auto locked = next_thread->context_guard.try_lock(); - if (state.needs_scheduling.load()) { - next_thread->context_guard.unlock(); - break; - } - if (next_thread->GetActiveCore() != core_id) { - next_thread->context_guard.unlock(); - break; - } - if (!locked) { - continue; - } - } - auto thread = next_thread ? next_thread : idle_thread; - SetCurrentThread(system.Kernel(), thread); - Common::Fiber::YieldTo(switch_fiber, *thread->GetHostContext()); - } while (!is_switch_pending()); } } -void KScheduler::UpdateLastContextSwitchTime(KThread* thread, KProcess* process) { - const u64 prev_switch_ticks = last_context_switch_time; - const u64 most_recent_switch_ticks = system.CoreTiming().GetCPUTicks(); - const u64 update_ticks = most_recent_switch_ticks - prev_switch_ticks; - - if (thread != nullptr) { - thread->AddCpuTime(core_id, update_ticks); - } - - if (process != nullptr) { - process->UpdateCPUTimeTicks(update_ticks); - } - - last_context_switch_time = most_recent_switch_ticks; -} - -void KScheduler::Initialize() { - idle_thread = KThread::Create(system.Kernel()); - ASSERT(KThread::InitializeIdleThread(system, idle_thread, core_id).IsSuccess()); - idle_thread->SetName(fmt::format("IdleThread:{}", core_id)); - idle_thread->EnableDispatch(); -} - -KScopedSchedulerLock::KScopedSchedulerLock(KernelCore& kernel) - : KScopedLock(kernel.GlobalSchedulerContext().SchedulerLock()) {} - -KScopedSchedulerLock::~KScopedSchedulerLock() = default; - } // namespace Kernel -- cgit v1.2.3