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kernel: use KScheduler from mesosphere

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This commit is contained in:
Liam 2022-06-26 18:52:16 -04:00
parent 53fb4a78a3
commit 0624c880bd
12 changed files with 572 additions and 611 deletions
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3
src/core/arm/arm_interface.cpp
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@ -155,9 +155,10 @@ void ARM_Interface::Run() {
break; break;
} }
// Handle syscalls and scheduling (this may change the current thread) // Handle syscalls and scheduling (this may change the current thread/core)
if (Has(hr, svc_call)) { if (Has(hr, svc_call)) {
Kernel::Svc::Call(system, GetSvcNumber()); Kernel::Svc::Call(system, GetSvcNumber());
break;
} }
if (Has(hr, break_loop) || !uses_wall_clock) { if (Has(hr, break_loop) || !uses_wall_clock) {
break; break;

169
src/core/cpu_manager.cpp
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@ -8,6 +8,7 @@
#include "core/core.h" #include "core/core.h"
#include "core/core_timing.h" #include "core/core_timing.h"
#include "core/cpu_manager.h" #include "core/cpu_manager.h"
#include "core/hle/kernel/k_interrupt_manager.h"
#include "core/hle/kernel/k_scheduler.h" #include "core/hle/kernel/k_scheduler.h"
#include "core/hle/kernel/k_thread.h" #include "core/hle/kernel/k_thread.h"
#include "core/hle/kernel/kernel.h" #include "core/hle/kernel/kernel.h"
@ -41,6 +42,14 @@ void CpuManager::Shutdown() {
} }
} }
void CpuManager::GuestActivateFunction() {
if (is_multicore) {
MultiCoreGuestActivate();
} else {
SingleCoreGuestActivate();
}
}
void CpuManager::GuestThreadFunction() { void CpuManager::GuestThreadFunction() {
if (is_multicore) { if (is_multicore) {
MultiCoreRunGuestThread(); MultiCoreRunGuestThread();
@ -49,36 +58,49 @@ void CpuManager::GuestThreadFunction() {
} }
} }
void CpuManager::GuestRewindFunction() {
if (is_multicore) {
MultiCoreRunGuestLoop();
} else {
SingleCoreRunGuestLoop();
}
}
void CpuManager::IdleThreadFunction() {
if (is_multicore) {
MultiCoreRunIdleThread();
} else {
SingleCoreRunIdleThread();
}
}
void CpuManager::ShutdownThreadFunction() { void CpuManager::ShutdownThreadFunction() {
ShutdownThread(); ShutdownThread();
} }
void CpuManager::WaitForAndHandleInterrupt() {
auto& kernel = system.Kernel();
auto& physical_core = kernel.CurrentPhysicalCore();
ASSERT(Kernel::GetCurrentThread(kernel).GetDisableDispatchCount() == 1);
if (!physical_core.IsInterrupted()) {
physical_core.Idle();
}
HandleInterrupt();
}
void CpuManager::HandleInterrupt() {
auto& kernel = system.Kernel();
auto core_index = kernel.CurrentPhysicalCoreIndex();
Kernel::KInterruptManager::HandleInterrupt(kernel, static_cast<s32>(core_index));
}
/////////////////////////////////////////////////////////////////////////////// ///////////////////////////////////////////////////////////////////////////////
/// MultiCore /// /// MultiCore ///
/////////////////////////////////////////////////////////////////////////////// ///////////////////////////////////////////////////////////////////////////////
void CpuManager::MultiCoreRunGuestThread() { void CpuManager::MultiCoreGuestActivate() {
// Similar to the HorizonKernelMain callback in HOS
auto& kernel = system.Kernel(); auto& kernel = system.Kernel();
kernel.CurrentScheduler()->OnThreadStart(); auto* scheduler = kernel.CurrentScheduler();
auto* thread = kernel.CurrentScheduler()->GetSchedulerCurrentThread();
auto& host_context = thread->GetHostContext(); scheduler->Activate();
host_context->SetRewindPoint([this] { GuestRewindFunction(); }); UNREACHABLE();
}
void CpuManager::MultiCoreRunGuestThread() {
// Similar to UserModeThreadStarter in HOS
auto& kernel = system.Kernel();
auto* thread = kernel.GetCurrentEmuThread();
thread->EnableDispatch();
MultiCoreRunGuestLoop(); MultiCoreRunGuestLoop();
} }
@ -91,18 +113,8 @@ void CpuManager::MultiCoreRunGuestLoop() {
physical_core->Run(); physical_core->Run();
physical_core = &kernel.CurrentPhysicalCore(); physical_core = &kernel.CurrentPhysicalCore();
} }
{
Kernel::KScopedDisableDispatch dd(kernel);
physical_core->ArmInterface().ClearExclusiveState();
}
}
}
void CpuManager::MultiCoreRunIdleThread() { HandleInterrupt();
auto& kernel = system.Kernel();
while (true) {
Kernel::KScopedDisableDispatch dd(kernel);
kernel.CurrentPhysicalCore().Idle();
} }
} }
@ -110,83 +122,20 @@ void CpuManager::MultiCoreRunIdleThread() {
/// SingleCore /// /// SingleCore ///
/////////////////////////////////////////////////////////////////////////////// ///////////////////////////////////////////////////////////////////////////////
void CpuManager::SingleCoreRunGuestThread() { void CpuManager::SingleCoreGuestActivate() {}
auto& kernel = system.Kernel();
kernel.CurrentScheduler()->OnThreadStart();
auto* thread = kernel.CurrentScheduler()->GetSchedulerCurrentThread();
auto& host_context = thread->GetHostContext();
host_context->SetRewindPoint([this] { GuestRewindFunction(); });
SingleCoreRunGuestLoop();
}
void CpuManager::SingleCoreRunGuestLoop() { void CpuManager::SingleCoreRunGuestThread() {}
auto& kernel = system.Kernel();
while (true) {
auto* physical_core = &kernel.CurrentPhysicalCore();
if (!physical_core->IsInterrupted()) {
physical_core->Run();
physical_core = &kernel.CurrentPhysicalCore();
}
kernel.SetIsPhantomModeForSingleCore(true);
system.CoreTiming().Advance();
kernel.SetIsPhantomModeForSingleCore(false);
physical_core->ArmInterface().ClearExclusiveState();
PreemptSingleCore();
auto& scheduler = kernel.Scheduler(current_core);
scheduler.RescheduleCurrentCore();
}
}
void CpuManager::SingleCoreRunIdleThread() { void CpuManager::SingleCoreRunGuestLoop() {}
auto& kernel = system.Kernel();
while (true) {
auto& physical_core = kernel.CurrentPhysicalCore();
PreemptSingleCore(false);
system.CoreTiming().AddTicks(1000U);
idle_count++;
auto& scheduler = physical_core.Scheduler();
scheduler.RescheduleCurrentCore();
}
}
void CpuManager::PreemptSingleCore(bool from_running_enviroment) { void CpuManager::PreemptSingleCore(bool from_running_enviroment) {}
{
auto& kernel = system.Kernel();
auto& scheduler = kernel.Scheduler(current_core);
Kernel::KThread* current_thread = scheduler.GetSchedulerCurrentThread();
if (idle_count >= 4 || from_running_enviroment) {
if (!from_running_enviroment) {
system.CoreTiming().Idle();
idle_count = 0;
}
kernel.SetIsPhantomModeForSingleCore(true);
system.CoreTiming().Advance();
kernel.SetIsPhantomModeForSingleCore(false);
}
current_core.store((current_core + 1) % Core::Hardware::NUM_CPU_CORES);
system.CoreTiming().ResetTicks();
scheduler.Unload(scheduler.GetSchedulerCurrentThread());
auto& next_scheduler = kernel.Scheduler(current_core);
Common::Fiber::YieldTo(current_thread->GetHostContext(), *next_scheduler.ControlContext());
}
// May have changed scheduler
{
auto& scheduler = system.Kernel().Scheduler(current_core);
scheduler.Reload(scheduler.GetSchedulerCurrentThread());
if (!scheduler.IsIdle()) {
idle_count = 0;
}
}
}
void CpuManager::ShutdownThread() { void CpuManager::ShutdownThread() {
auto& kernel = system.Kernel(); auto& kernel = system.Kernel();
auto* thread = kernel.GetCurrentEmuThread();
auto core = is_multicore ? kernel.CurrentPhysicalCoreIndex() : 0; auto core = is_multicore ? kernel.CurrentPhysicalCoreIndex() : 0;
auto* current_thread = kernel.GetCurrentEmuThread();
Common::Fiber::YieldTo(current_thread->GetHostContext(), *core_data[core].host_context); Common::Fiber::YieldTo(thread->GetHostContext(), *core_data[core].host_context);
UNREACHABLE(); UNREACHABLE();
} }
@ -218,9 +167,21 @@ void CpuManager::RunThread(std::size_t core) {
system.GPU().ObtainContext(); system.GPU().ObtainContext();
} }
auto* current_thread = system.Kernel().CurrentScheduler()->GetIdleThread(); auto& kernel = system.Kernel();
Kernel::SetCurrentThread(system.Kernel(), current_thread);
Common::Fiber::YieldTo(data.host_context, *current_thread->GetHostContext()); auto* main_thread = Kernel::KThread::Create(kernel);
main_thread->SetName(fmt::format("MainThread:{}", core));
ASSERT(Kernel::KThread::InitializeMainThread(system, main_thread, static_cast<s32>(core))
.IsSuccess());
auto* idle_thread = Kernel::KThread::Create(kernel);
ASSERT(Kernel::KThread::InitializeIdleThread(system, idle_thread, static_cast<s32>(core))
.IsSuccess());
kernel.SetCurrentEmuThread(main_thread);
kernel.CurrentScheduler()->Initialize(idle_thread);
Common::Fiber::YieldTo(data.host_context, *main_thread->GetHostContext());
} }
} // namespace Core } // namespace Core

14
src/core/cpu_manager.h
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@ -5,6 +5,7 @@
#include <array> #include <array>
#include <atomic> #include <atomic>
#include <csetjmp>
#include <functional> #include <functional>
#include <memory> #include <memory>
#include <thread> #include <thread>
@ -47,10 +48,14 @@ public:
gpu_barrier->Sync(); gpu_barrier->Sync();
} }
void WaitForAndHandleInterrupt();
void Initialize(); void Initialize();
void Shutdown(); void Shutdown();
std::function<void()> GetGuestThreadStartFunc() { std::function<void()> GetGuestActivateFunc() {
return [this] { GuestActivateFunction(); };
}
std::function<void()> GetGuestThreadFunc() {
return [this] { GuestThreadFunction(); }; return [this] { GuestThreadFunction(); };
} }
std::function<void()> GetIdleThreadStartFunc() { std::function<void()> GetIdleThreadStartFunc() {
@ -67,21 +72,22 @@ public:
} }
private: private:
void GuestActivateFunction();
void GuestThreadFunction(); void GuestThreadFunction();
void GuestRewindFunction();
void IdleThreadFunction(); void IdleThreadFunction();
void ShutdownThreadFunction(); void ShutdownThreadFunction();
void MultiCoreGuestActivate();
void MultiCoreRunGuestThread(); void MultiCoreRunGuestThread();
void MultiCoreRunGuestLoop(); void MultiCoreRunGuestLoop();
void MultiCoreRunIdleThread();
void SingleCoreGuestActivate();
void SingleCoreRunGuestThread(); void SingleCoreRunGuestThread();
void SingleCoreRunGuestLoop(); void SingleCoreRunGuestLoop();
void SingleCoreRunIdleThread();
static void ThreadStart(std::stop_token stop_token, CpuManager& cpu_manager, std::size_t core); static void ThreadStart(std::stop_token stop_token, CpuManager& cpu_manager, std::size_t core);
void HandleInterrupt();
void ShutdownThread(); void ShutdownThread();
void RunThread(std::size_t core); void RunThread(std::size_t core);

2
src/core/hle/kernel/global_scheduler_context.cpp
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@ -41,7 +41,7 @@ void GlobalSchedulerContext::PreemptThreads() {
ASSERT(IsLocked()); ASSERT(IsLocked());
for (u32 core_id = 0; core_id < Core::Hardware::NUM_CPU_CORES; core_id++) { for (u32 core_id = 0; core_id < Core::Hardware::NUM_CPU_CORES; core_id++) {
const u32 priority = preemption_priorities[core_id]; const u32 priority = preemption_priorities[core_id];
kernel.Scheduler(core_id).RotateScheduledQueue(core_id, priority); KScheduler::RotateScheduledQueue(kernel, core_id, priority);
// Signal an interrupt occurred. For core 3, this is a certainty, as preemption will result // Signal an interrupt occurred. For core 3, this is a certainty, as preemption will result
// in the rotator thread being scheduled. For cores 0-2, this is to simulate or system // in the rotator thread being scheduled. For cores 0-2, this is to simulate or system

7
src/core/hle/kernel/k_interrupt_manager.cpp
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@ -6,6 +6,7 @@
#include "core/hle/kernel/k_scheduler.h" #include "core/hle/kernel/k_scheduler.h"
#include "core/hle/kernel/k_thread.h" #include "core/hle/kernel/k_thread.h"
#include "core/hle/kernel/kernel.h" #include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/physical_core.h"
namespace Kernel::KInterruptManager { namespace Kernel::KInterruptManager {
@ -15,6 +16,9 @@ void HandleInterrupt(KernelCore& kernel, s32 core_id) {
return; return;
} }
// Acknowledge the interrupt.
kernel.PhysicalCore(core_id).ClearInterrupt();
auto& current_thread = GetCurrentThread(kernel); auto& current_thread = GetCurrentThread(kernel);
// If the user disable count is set, we may need to pin the current thread. // If the user disable count is set, we may need to pin the current thread.
@ -27,6 +31,9 @@ void HandleInterrupt(KernelCore& kernel, s32 core_id) {
// Set the interrupt flag for the thread. // Set the interrupt flag for the thread.
GetCurrentThread(kernel).SetInterruptFlag(); GetCurrentThread(kernel).SetInterruptFlag();
} }
// Request interrupt scheduling.
kernel.CurrentScheduler()->RequestScheduleOnInterrupt();
} }
} // namespace Kernel::KInterruptManager } // namespace Kernel::KInterruptManager

727
src/core/hle/kernel/k_scheduler.cpp
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@ -27,69 +27,162 @@ static void IncrementScheduledCount(Kernel::KThread* thread) {
} }
} }
void KScheduler::RescheduleCores(KernelCore& kernel, u64 cores_pending_reschedule) { KScheduler::KScheduler(KernelCore& kernel_) : kernel{kernel_} {
auto scheduler = kernel.CurrentScheduler(); m_idle_stack = std::make_shared<Common::Fiber>([this] {
while (true) {
ScheduleImplOffStack();
}
});
u32 current_core{0xF}; m_state.needs_scheduling = true;
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) { KScheduler::~KScheduler() = default;
const auto core = static_cast<u32>(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();
}
cores_pending_reschedule &= ~(1ULL << core);
}
for (std::size_t core_id = 0; core_id < Core::Hardware::NUM_CPU_CORES; ++core_id) { void KScheduler::SetInterruptTaskRunnable() {
if (kernel.PhysicalCore(core_id).IsInterrupted()) { m_state.interrupt_task_runnable = true;
KInterruptManager::HandleInterrupt(kernel, static_cast<s32>(core_id)); m_state.needs_scheduling = true;
} }
}
if (must_context_switch) { void KScheduler::RequestScheduleOnInterrupt() {
auto core_scheduler = kernel.CurrentScheduler(); m_state.needs_scheduling = true;
kernel.ExitSVCProfile();
core_scheduler->RescheduleCurrentCore(); if (CanSchedule(kernel)) {
kernel.EnterSVCProfile(); ScheduleOnInterrupt();
} }
} }
u64 KScheduler::UpdateHighestPriorityThread(KThread* highest_thread) { void KScheduler::DisableScheduling(KernelCore& kernel) {
KScopedSpinLock lk{guard}; ASSERT(GetCurrentThread(kernel).GetDisableDispatchCount() >= 0);
if (KThread* prev_highest_thread = state.highest_priority_thread; GetCurrentThread(kernel).DisableDispatch();
prev_highest_thread != highest_thread) { }
if (prev_highest_thread != nullptr) {
IncrementScheduledCount(prev_highest_thread); void KScheduler::EnableScheduling(KernelCore& kernel, u64 cores_needing_scheduling) {
prev_highest_thread->SetLastScheduledTick(system.CoreTiming().GetCPUTicks()); 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();
} }
if (state.should_count_idle) { GetCurrentThread(kernel).EnableDispatch();
if (highest_thread != nullptr) { 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();
}
}
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) {
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(kernel.System().CoreTiming().GetCPUTicks());
}
if (m_state.should_count_idle) {
if (highest_thread != nullptr) [[likely]] {
if (KProcess* process = highest_thread->GetOwnerProcess(); process != nullptr) { 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 { } else {
state.idle_count++; m_state.idle_count++;
} }
} }
state.highest_priority_thread = highest_thread; m_state.highest_priority_thread = highest_thread;
state.needs_scheduling.store(true); m_state.needs_scheduling = true;
return (1ULL << core_id); return (1ULL << m_core_id);
} else { } else {
return 0; return 0;
} }
} }
u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) { u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) {
ASSERT(kernel.GlobalSchedulerContext().IsLocked()); ASSERT(IsSchedulerLockedByCurrentThread(kernel));
// Clear that we need to update. // Clear that we need to update.
ClearSchedulerUpdateNeeded(kernel); ClearSchedulerUpdateNeeded(kernel);
@ -98,18 +191,20 @@ u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) {
KThread* top_threads[Core::Hardware::NUM_CPU_CORES]; KThread* top_threads[Core::Hardware::NUM_CPU_CORES];
auto& priority_queue = GetPriorityQueue(kernel); auto& priority_queue = GetPriorityQueue(kernel);
/// We want to go over all cores, finding the highest priority thread and determining if // We want to go over all cores, finding the highest priority thread and determining if
/// scheduling is needed for that core. // scheduling is needed for that core.
for (size_t core_id = 0; core_id < Core::Hardware::NUM_CPU_CORES; core_id++) { for (size_t core_id = 0; core_id < Core::Hardware::NUM_CPU_CORES; core_id++) {
KThread* top_thread = priority_queue.GetScheduledFront(static_cast<s32>(core_id)); KThread* top_thread = priority_queue.GetScheduledFront(static_cast<s32>(core_id));
if (top_thread != nullptr) { if (top_thread != nullptr) {
// If the thread has no waiters, we need to check if the process has a thread pinned. // We need to check if the thread's process has a pinned thread.
if (top_thread->GetNumKernelWaiters() == 0) { if (KProcess* parent = top_thread->GetOwnerProcess()) {
if (KProcess* parent = top_thread->GetOwnerProcess(); parent != nullptr) { // Check that there's a pinned thread other than the current top thread.
if (KThread* pinned = parent->GetPinnedThread(static_cast<s32>(core_id)); if (KThread* pinned = parent->GetPinnedThread(static_cast<s32>(core_id));
pinned != nullptr && pinned != top_thread) { pinned != nullptr && pinned != top_thread) {
// We prefer our parent's pinned thread if possible. However, we also don't // We need to prefer threads with kernel waiters to the pinned thread.
// want to schedule un-runnable threads. if (top_thread->GetNumKernelWaiters() ==
0 /* && top_thread != parent->GetExceptionThread() */) {
// If the pinned thread is runnable, use it.
if (pinned->GetRawState() == ThreadState::Runnable) { if (pinned->GetRawState() == ThreadState::Runnable) {
top_thread = pinned; top_thread = pinned;
} else { } 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. // Idle cores are bad. We're going to try to migrate threads to each idle core in turn.
while (idle_cores != 0) { while (idle_cores != 0) {
const auto core_id = static_cast<u32>(std::countr_zero(idle_cores)); const s32 core_id = static_cast<s32>(std::countr_zero(idle_cores));
if (KThread* suggested = priority_queue.GetSuggestedFront(core_id); suggested != nullptr) { if (KThread* suggested = priority_queue.GetSuggestedFront(core_id); suggested != nullptr) {
s32 migration_candidates[Core::Hardware::NUM_CPU_CORES]; s32 migration_candidates[Core::Hardware::NUM_CPU_CORES];
size_t num_candidates = 0; 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! // The suggested thread isn't bound to its core, so we can migrate it!
suggested->SetActiveCore(core_id); suggested->SetActiveCore(core_id);
priority_queue.ChangeCore(suggested_core, suggested); priority_queue.ChangeCore(suggested_core, suggested);
top_threads[core_id] = suggested; top_threads[core_id] = suggested;
cores_needing_scheduling |= cores_needing_scheduling |=
kernel.Scheduler(core_id).UpdateHighestPriorityThread(top_threads[core_id]); kernel.Scheduler(core_id).UpdateHighestPriorityThread(top_threads[core_id]);
@ -183,7 +278,6 @@ u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) {
// Perform the migration. // Perform the migration.
suggested->SetActiveCore(core_id); suggested->SetActiveCore(core_id);
priority_queue.ChangeCore(candidate_core, suggested); priority_queue.ChangeCore(candidate_core, suggested);
top_threads[core_id] = suggested; top_threads[core_id] = suggested;
cores_needing_scheduling |= cores_needing_scheduling |=
kernel.Scheduler(core_id).UpdateHighestPriorityThread( kernel.Scheduler(core_id).UpdateHighestPriorityThread(
@ -200,24 +294,223 @@ u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) {
return cores_needing_scheduling; 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<u32>(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) { 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) { for (size_t i = 0; i < Core::Hardware::NUM_CPU_CORES; ++i) {
// Get an atomic reference to the core scheduler's previous thread. // Get an atomic reference to the core scheduler's previous thread.
std::atomic_ref<KThread*> prev_thread(kernel.Scheduler(static_cast<s32>(i)).prev_thread); auto& prev_thread{kernel.Scheduler(i).m_state.prev_thread};
static_assert(std::atomic_ref<KThread*>::is_always_lock_free);
// Atomically clear the previous thread if it's our target. // Atomically clear the previous thread if it's our target.
KThread* compare = thread; 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) { 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. // 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) { if (cur_state == old_state) {
return; return;
} }
@ -237,12 +530,12 @@ void KScheduler::OnThreadStateChanged(KernelCore& kernel, KThread* thread, Threa
} }
void KScheduler::OnThreadPriorityChanged(KernelCore& kernel, KThread* thread, s32 old_priority) { 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 the thread is runnable, we want to change its priority in the queue.
if (thread->GetRawState() == ThreadState::Runnable) { if (thread->GetRawState() == ThreadState::Runnable) {
GetPriorityQueue(kernel).ChangePriority(old_priority, GetPriorityQueue(kernel).ChangePriority(old_priority,
thread == kernel.GetCurrentEmuThread(), thread); thread == GetCurrentThreadPointer(kernel), thread);
IncrementScheduledCount(thread); IncrementScheduledCount(thread);
SetSchedulerUpdateNeeded(kernel); SetSchedulerUpdateNeeded(kernel);
} }
@ -250,7 +543,7 @@ void KScheduler::OnThreadPriorityChanged(KernelCore& kernel, KThread* thread, s3
void KScheduler::OnThreadAffinityMaskChanged(KernelCore& kernel, KThread* thread, void KScheduler::OnThreadAffinityMaskChanged(KernelCore& kernel, KThread* thread,
const KAffinityMask& old_affinity, s32 old_core) { 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 the thread is runnable, we want to change its affinity in the queue.
if (thread->GetRawState() == ThreadState::Runnable) { 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) { void KScheduler::RotateScheduledQueue(KernelCore& kernel, s32 core_id, s32 priority) {
ASSERT(system.GlobalSchedulerContext().IsLocked()); ASSERT(IsSchedulerLockedByCurrentThread(kernel));
// Get a reference to the priority queue. // Get a reference to the priority queue.
auto& kernel = system.Kernel();
auto& priority_queue = GetPriorityQueue(kernel); auto& priority_queue = GetPriorityQueue(kernel);
// Rotate the front of the queue to the end. // 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; KThread* next_thread = nullptr;
if (top_thread != nullptr) { if (top_thread != nullptr) {
next_thread = priority_queue.MoveToScheduledBack(top_thread); 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! // 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) { while (suggested != nullptr) {
// Check if the suggested thread is the top thread on its core. // Check if the suggested thread is the top thread on its core.
const s32 suggested_core = suggested->GetActiveCore(); 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. // to the front of the queue.
if (top_on_suggested_core == nullptr || if (top_on_suggested_core == nullptr ||
top_on_suggested_core->GetPriority() >= HighestCoreMigrationAllowedPriority) { top_on_suggested_core->GetPriority() >= HighestCoreMigrationAllowedPriority) {
suggested->SetActiveCore(cpu_core_id); suggested->SetActiveCore(core_id);
priority_queue.ChangeCore(suggested_core, suggested, true); priority_queue.ChangeCore(suggested_core, suggested, true);
IncrementScheduledCount(suggested); IncrementScheduledCount(suggested);
break; break;
@ -309,22 +601,21 @@ void KScheduler::RotateScheduledQueue(s32 cpu_core_id, s32 priority) {
} }
// Get the next suggestion. // 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. // 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)) { 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 // If the best thread we can choose has a priority the same or worse than ours, try to
// migrate a higher priority thread. // migrate a higher priority thread.
if (best_thread != nullptr && best_thread->GetPriority() >= priority) { 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) { while (suggested != nullptr) {
// If the suggestion's priority is the same as ours, don't bother. // If the suggestion's priority is the same as ours, don't bother.
if (suggested->GetPriority() >= best_thread->GetPriority()) { 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 || if (top_on_suggested_core == nullptr ||
top_on_suggested_core->GetPriority() >= top_on_suggested_core->GetPriority() >=
HighestCoreMigrationAllowedPriority) { HighestCoreMigrationAllowedPriority) {
suggested->SetActiveCore(cpu_core_id); suggested->SetActiveCore(core_id);
priority_queue.ChangeCore(suggested_core, suggested, true); priority_queue.ChangeCore(suggested_core, suggested, true);
IncrementScheduledCount(suggested); IncrementScheduledCount(suggested);
break; break;
@ -351,7 +642,7 @@ void KScheduler::RotateScheduledQueue(s32 cpu_core_id, s32 priority) {
} }
// Get the next suggestion. // 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); 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) { void KScheduler::YieldWithoutCoreMigration(KernelCore& kernel) {
// Validate preconditions. // Validate preconditions.
ASSERT(CanSchedule(kernel)); ASSERT(CanSchedule(kernel));
@ -437,7 +670,7 @@ void KScheduler::YieldWithoutCoreMigration(KernelCore& kernel) {
// Perform the yield. // Perform the yield.
{ {
KScopedSchedulerLock lock(kernel); KScopedSchedulerLock sl{kernel};
const auto cur_state = cur_thread.GetRawState(); const auto cur_state = cur_thread.GetRawState();
if (cur_state == ThreadState::Runnable) { if (cur_state == ThreadState::Runnable) {
@ -476,7 +709,7 @@ void KScheduler::YieldWithCoreMigration(KernelCore& kernel) {
// Perform the yield. // Perform the yield.
{ {
KScopedSchedulerLock lock(kernel); KScopedSchedulerLock sl{kernel};
const auto cur_state = cur_thread.GetRawState(); const auto cur_state = cur_thread.GetRawState();
if (cur_state == ThreadState::Runnable) { if (cur_state == ThreadState::Runnable) {
@ -496,7 +729,7 @@ void KScheduler::YieldWithCoreMigration(KernelCore& kernel) {
if (KThread* running_on_suggested_core = if (KThread* running_on_suggested_core =
(suggested_core >= 0) (suggested_core >= 0)
? kernel.Scheduler(suggested_core).state.highest_priority_thread ? kernel.Scheduler(suggested_core).m_state.highest_priority_thread
: nullptr; : nullptr;
running_on_suggested_core != suggested) { running_on_suggested_core != suggested) {
// If the current thread's priority is higher than our suggestion's we prefer // 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. // Perform the yield.
{ {
KScopedSchedulerLock lock(kernel); KScopedSchedulerLock sl{kernel};
const auto cur_state = cur_thread.GetRawState(); const auto cur_state = cur_thread.GetRawState();
if (cur_state == ThreadState::Runnable) { 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_} { void KScheduler::RescheduleOtherCores(u64 cores_needing_scheduling) {
switch_fiber = std::make_shared<Common::Fiber>([this] { SwitchToCurrent(); }); if (const u64 core_mask = cores_needing_scheduling & ~(1ULL << m_core_id); core_mask != 0) {
state.needs_scheduling.store(true); RescheduleCores(kernel, core_mask);
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() { void KScheduler::RescheduleCores(KernelCore& kernel, u64 core_mask) {
ASSERT(!idle_thread); // Send IPI
} for (size_t i = 0; i < Core::Hardware::NUM_CPU_CORES; i++) {
if (core_mask & (1ULL << i)) {
KThread* KScheduler::GetSchedulerCurrentThread() const { kernel.PhysicalCore(i).Interrupt();
if (auto result = current_thread.load(); result) {
return result;
} }
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<Common::Fiber>* 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);
}
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 } // namespace Kernel

220
src/core/hle/kernel/k_scheduler.h
View File

@ -11,6 +11,7 @@
#include "core/hle/kernel/k_scheduler_lock.h" #include "core/hle/kernel/k_scheduler_lock.h"
#include "core/hle/kernel/k_scoped_lock.h" #include "core/hle/kernel/k_scoped_lock.h"
#include "core/hle/kernel/k_spin_lock.h" #include "core/hle/kernel/k_spin_lock.h"
#include "core/hle/kernel/k_thread.h"
namespace Common { namespace Common {
class Fiber; class Fiber;
@ -23,184 +24,139 @@ class System;
namespace Kernel { namespace Kernel {
class KernelCore; class KernelCore;
class KInterruptTaskManager;
class KProcess; class KProcess;
class SchedulerLock;
class KThread; class KThread;
class KScopedDisableDispatch;
class KScopedSchedulerLock;
class KScopedSchedulerLockAndSleep;
class KScheduler final { class KScheduler final {
public: public:
explicit KScheduler(Core::System& system_, s32 core_id_); YUZU_NON_COPYABLE(KScheduler);
YUZU_NON_MOVEABLE(KScheduler);
using LockType = KAbstractSchedulerLock<KScheduler>;
explicit KScheduler(KernelCore& kernel);
~KScheduler(); ~KScheduler();
void Finalize(); void Initialize(KThread* idle_thread);
void Activate();
/// Reschedules to the next available thread (call after current thread is suspended) void SetInterruptTaskRunnable();
void RescheduleCurrentCore(); void RequestScheduleOnInterrupt();
/// Reschedules cores pending reschedule, to be called on EnableScheduling. u64 GetIdleCount() {
static void RescheduleCores(KernelCore& kernel, u64 cores_pending_reschedule); return m_state.idle_count;
/// The next two are for SingleCore Only.
/// Unload current thread before preempting core.
void Unload(KThread* thread);
/// Reload current thread after core preemption.
void Reload(KThread* thread);
/// Gets the current running thread
[[nodiscard]] KThread* GetSchedulerCurrentThread() const;
/// Gets the idle thread
[[nodiscard]] KThread* GetIdleThread() const {
return idle_thread;
} }
/// Returns true if the scheduler is idle KThread* GetIdleThread() const {
[[nodiscard]] bool IsIdle() const { return m_idle_thread;
return GetSchedulerCurrentThread() == idle_thread;
} }
/// Gets the timestamp for the last context switch in ticks. KThread* GetPreviousThread() const {
[[nodiscard]] u64 GetLastContextSwitchTicks() const; return m_state.prev_thread;
[[nodiscard]] bool ContextSwitchPending() const {
return state.needs_scheduling.load(std::memory_order_relaxed);
} }
void Initialize(); KThread* GetSchedulerCurrentThread() const {
return m_current_thread.load();
void OnThreadStart();
[[nodiscard]] std::shared_ptr<Common::Fiber>& ControlContext() {
return switch_fiber;
} }
[[nodiscard]] const std::shared_ptr<Common::Fiber>& ControlContext() const { s64 GetLastContextSwitchTime() const {
return switch_fiber; return m_last_context_switch_time;
} }
[[nodiscard]] u64 UpdateHighestPriorityThread(KThread* highest_thread); // Static public API.
static bool CanSchedule(KernelCore& kernel) {
return kernel.GetCurrentEmuThread()->GetDisableDispatchCount() == 0;
}
static bool IsSchedulerLockedByCurrentThread(KernelCore& kernel) {
return kernel.GlobalSchedulerContext().scheduler_lock.IsLockedByCurrentThread();
}
/** static bool IsSchedulerUpdateNeeded(KernelCore& kernel) {
* Takes a thread and moves it to the back of the it's priority list. return kernel.GlobalSchedulerContext().scheduler_update_needed;
* }
* @note This operation can be redundant and no scheduling is changed if marked as so. static void SetSchedulerUpdateNeeded(KernelCore& kernel) {
*/ kernel.GlobalSchedulerContext().scheduler_update_needed = true;
static void YieldWithoutCoreMigration(KernelCore& kernel); }
static void ClearSchedulerUpdateNeeded(KernelCore& kernel) {
kernel.GlobalSchedulerContext().scheduler_update_needed = false;
}
/** static void DisableScheduling(KernelCore& kernel);
* Takes a thread and moves it to the back of the it's priority list. static void EnableScheduling(KernelCore& kernel, u64 cores_needing_scheduling);
* Afterwards, tries to pick a suggested thread from the suggested queue that has worse time or
* a better priority than the next thread in the core.
*
* @note This operation can be redundant and no scheduling is changed if marked as so.
*/
static void YieldWithCoreMigration(KernelCore& kernel);
/** static u64 UpdateHighestPriorityThreads(KernelCore& kernel);
* Takes a thread and moves it out of the scheduling queue.
* and into the suggested queue. If no thread can be scheduled afterwards in that core,
* a suggested thread is obtained instead.
*
* @note This operation can be redundant and no scheduling is changed if marked as so.
*/
static void YieldToAnyThread(KernelCore& kernel);
static void ClearPreviousThread(KernelCore& kernel, KThread* thread); static void ClearPreviousThread(KernelCore& kernel, KThread* thread);
/// Notify the scheduler a thread's status has changed.
static void OnThreadStateChanged(KernelCore& kernel, KThread* thread, ThreadState old_state); static void OnThreadStateChanged(KernelCore& kernel, KThread* thread, ThreadState old_state);
/// Notify the scheduler a thread's priority has changed.
static void OnThreadPriorityChanged(KernelCore& kernel, KThread* thread, s32 old_priority); static void OnThreadPriorityChanged(KernelCore& kernel, KThread* thread, s32 old_priority);
/// Notify the scheduler a thread's core and/or affinity mask has changed.
static void OnThreadAffinityMaskChanged(KernelCore& kernel, KThread* thread, static void OnThreadAffinityMaskChanged(KernelCore& kernel, KThread* thread,
const KAffinityMask& old_affinity, s32 old_core); const KAffinityMask& old_affinity, s32 old_core);
static bool CanSchedule(KernelCore& kernel); static void RotateScheduledQueue(KernelCore& kernel, s32 core_id, s32 priority);
static bool IsSchedulerUpdateNeeded(const KernelCore& kernel); static void RescheduleCores(KernelCore& kernel, u64 cores_needing_scheduling);
static void SetSchedulerUpdateNeeded(KernelCore& kernel);
static void ClearSchedulerUpdateNeeded(KernelCore& kernel); static void YieldWithoutCoreMigration(KernelCore& kernel);
static void DisableScheduling(KernelCore& kernel); static void YieldWithCoreMigration(KernelCore& kernel);
static void EnableScheduling(KernelCore& kernel, u64 cores_needing_scheduling); static void YieldToAnyThread(KernelCore& kernel);
[[nodiscard]] static u64 UpdateHighestPriorityThreads(KernelCore& kernel);
private: private:
friend class GlobalSchedulerContext; // Static private API.
static KSchedulerPriorityQueue& GetPriorityQueue(KernelCore& kernel) {
return kernel.GlobalSchedulerContext().priority_queue;
}
static u64 UpdateHighestPriorityThreadsImpl(KernelCore& kernel);
/** // Instanced private API.
* Takes care of selecting the new scheduled threads in three steps: void ScheduleImpl();
* void ScheduleImplOffStack();
* 1. First a thread is selected from the top of the priority queue. If no thread void SwitchThread(KThread* next_thread);
* is obtained then we move to step two, else we are done.
*
* 2. Second we try to get a suggested thread that's not assigned to any core or
* that is not the top thread in that core.
*
* 3. Third is no suggested thread is found, we do a second pass and pick a running
* thread in another core and swap it with its current thread.
*
* returns the cores needing scheduling.
*/
[[nodiscard]] static u64 UpdateHighestPriorityThreadsImpl(KernelCore& kernel);
[[nodiscard]] static KSchedulerPriorityQueue& GetPriorityQueue(KernelCore& kernel);
void RotateScheduledQueue(s32 cpu_core_id, s32 priority);
void Schedule(); void Schedule();
void ScheduleOnInterrupt();
/// Switches the CPU's active thread context to that of the specified thread void RescheduleOtherCores(u64 cores_needing_scheduling);
void ScheduleImpl(); void RescheduleCurrentCore();
void RescheduleCurrentCoreImpl();
/// When a thread wakes up, it must run this through it's new scheduler u64 UpdateHighestPriorityThread(KThread* thread);
void SwitchContextStep2();
/** private:
* Called on every context switch to update the internal timestamp friend class KScopedDisableDispatch;
* This also updates the running time ticks for the given thread and
* process using the following difference:
*
* ticks += most_recent_ticks - last_context_switch_ticks
*
* The internal tick timestamp for the scheduler is simply the
* most recent tick count retrieved. No special arithmetic is
* applied to it.
*/
void UpdateLastContextSwitchTime(KThread* thread, KProcess* process);
void SwitchToCurrent();
KThread* prev_thread{};
std::atomic<KThread*> current_thread{};
KThread* idle_thread{};
std::shared_ptr<Common::Fiber> switch_fiber{};
struct SchedulingState { struct SchedulingState {
std::atomic<bool> needs_scheduling{}; std::atomic<bool> needs_scheduling{false};
bool interrupt_task_thread_runnable{}; bool interrupt_task_runnable{false};
bool should_count_idle{}; bool should_count_idle{false};
u64 idle_count{}; u64 idle_count{0};
KThread* highest_priority_thread{}; KThread* highest_priority_thread{nullptr};
void* idle_thread_stack{}; void* idle_thread_stack{nullptr};
std::atomic<KThread*> prev_thread{nullptr};
KInterruptTaskManager* interrupt_task_manager{nullptr};
}; };
SchedulingState state; KernelCore& kernel;
SchedulingState m_state;
bool m_is_active{false};
s32 m_core_id{0};
s64 m_last_context_switch_time{0};
KThread* m_idle_thread{nullptr};
std::atomic<KThread*> m_current_thread{nullptr};
Core::System& system; std::shared_ptr<Common::Fiber> m_idle_stack{};
u64 last_context_switch_time{}; KThread* m_idle_cur_thread{};
const s32 core_id; KThread* m_idle_highest_priority_thread{};
KSpinLock guard{};
}; };
class [[nodiscard]] KScopedSchedulerLock : KScopedLock<GlobalSchedulerContext::LockType> { class KScopedSchedulerLock : public KScopedLock<KScheduler::LockType> {
public: public:
explicit KScopedSchedulerLock(KernelCore& kernel); explicit KScopedSchedulerLock(KernelCore& kernel)
~KScopedSchedulerLock(); : KScopedLock(kernel.GlobalSchedulerContext().scheduler_lock) {}
~KScopedSchedulerLock() = default;
}; };
} // namespace Kernel } // namespace Kernel

2
src/core/hle/kernel/k_scheduler_lock.h
View File

@ -5,9 +5,11 @@
#include <atomic> #include <atomic>
#include "common/assert.h" #include "common/assert.h"
#include "core/hle/kernel/k_interrupt_manager.h"
#include "core/hle/kernel/k_spin_lock.h" #include "core/hle/kernel/k_spin_lock.h"
#include "core/hle/kernel/k_thread.h" #include "core/hle/kernel/k_thread.h"
#include "core/hle/kernel/kernel.h" #include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/physical_core.h"
namespace Kernel { namespace Kernel {

11
src/core/hle/kernel/k_thread.cpp
View File

@ -261,9 +261,14 @@ Result KThread::InitializeDummyThread(KThread* thread) {
return thread->Initialize({}, {}, {}, DummyThreadPriority, 3, {}, ThreadType::Dummy); return thread->Initialize({}, {}, {}, DummyThreadPriority, 3, {}, ThreadType::Dummy);
} }
Result KThread::InitializeMainThread(Core::System& system, KThread* thread, s32 virt_core) {
return InitializeThread(thread, {}, {}, {}, IdleThreadPriority, virt_core, {}, ThreadType::Main,
system.GetCpuManager().GetGuestActivateFunc());
}
Result KThread::InitializeIdleThread(Core::System& system, KThread* thread, s32 virt_core) { Result KThread::InitializeIdleThread(Core::System& system, KThread* thread, s32 virt_core) {
return InitializeThread(thread, {}, {}, {}, IdleThreadPriority, virt_core, {}, ThreadType::Main, return InitializeThread(thread, {}, {}, {}, IdleThreadPriority, virt_core, {}, ThreadType::Main,
system.GetCpuManager().GetIdleThreadStartFunc()); abort);
} }
Result KThread::InitializeHighPriorityThread(Core::System& system, KThread* thread, Result KThread::InitializeHighPriorityThread(Core::System& system, KThread* thread,
@ -277,7 +282,7 @@ Result KThread::InitializeUserThread(Core::System& system, KThread* thread, KThr
KProcess* owner) { KProcess* owner) {
system.Kernel().GlobalSchedulerContext().AddThread(thread); system.Kernel().GlobalSchedulerContext().AddThread(thread);
return InitializeThread(thread, func, arg, user_stack_top, prio, virt_core, owner, return InitializeThread(thread, func, arg, user_stack_top, prio, virt_core, owner,
ThreadType::User, system.GetCpuManager().GetGuestThreadStartFunc()); ThreadType::User, system.GetCpuManager().GetGuestThreadFunc());
} }
void KThread::PostDestroy(uintptr_t arg) { void KThread::PostDestroy(uintptr_t arg) {
@ -1058,6 +1063,8 @@ void KThread::Exit() {
// Register the thread as a work task. // Register the thread as a work task.
KWorkerTaskManager::AddTask(kernel, KWorkerTaskManager::WorkerType::Exit, this); KWorkerTaskManager::AddTask(kernel, KWorkerTaskManager::WorkerType::Exit, this);
} }
UNREACHABLE_MSG("KThread::Exit() would return");
} }
Result KThread::Sleep(s64 timeout) { Result KThread::Sleep(s64 timeout) {

5
src/core/hle/kernel/k_thread.h
View File

@ -110,6 +110,7 @@ void SetCurrentThread(KernelCore& kernel, KThread* thread);
[[nodiscard]] KThread* GetCurrentThreadPointer(KernelCore& kernel); [[nodiscard]] KThread* GetCurrentThreadPointer(KernelCore& kernel);
[[nodiscard]] KThread& GetCurrentThread(KernelCore& kernel); [[nodiscard]] KThread& GetCurrentThread(KernelCore& kernel);
[[nodiscard]] s32 GetCurrentCoreId(KernelCore& kernel); [[nodiscard]] s32 GetCurrentCoreId(KernelCore& kernel);
size_t CaptureBacktrace(void** buffer, size_t max);
class KThread final : public KAutoObjectWithSlabHeapAndContainer<KThread, KWorkerTask>, class KThread final : public KAutoObjectWithSlabHeapAndContainer<KThread, KWorkerTask>,
public boost::intrusive::list_base_hook<> { public boost::intrusive::list_base_hook<> {
@ -413,6 +414,9 @@ public:
[[nodiscard]] static Result InitializeDummyThread(KThread* thread); [[nodiscard]] static Result InitializeDummyThread(KThread* thread);
[[nodiscard]] static Result InitializeMainThread(Core::System& system, KThread* thread,
s32 virt_core);
[[nodiscard]] static Result InitializeIdleThread(Core::System& system, KThread* thread, [[nodiscard]] static Result InitializeIdleThread(Core::System& system, KThread* thread,
s32 virt_core); s32 virt_core);
@ -435,6 +439,7 @@ public:
bool is_pinned; bool is_pinned;
s32 disable_count; s32 disable_count;
KThread* cur_thread; KThread* cur_thread;
std::atomic<bool> m_lock;
}; };
[[nodiscard]] StackParameters& GetStackParameters() { [[nodiscard]] StackParameters& GetStackParameters() {

10
src/core/hle/kernel/kernel.cpp
View File

@ -75,7 +75,6 @@ struct KernelCore::Impl {
InitializeSystemResourceLimit(kernel, system.CoreTiming()); InitializeSystemResourceLimit(kernel, system.CoreTiming());
InitializeMemoryLayout(); InitializeMemoryLayout();
Init::InitializeKPageBufferSlabHeap(system); Init::InitializeKPageBufferSlabHeap(system);
InitializeSchedulers();
InitializeShutdownThreads(); InitializeShutdownThreads();
InitializePreemption(kernel); InitializePreemption(kernel);
@ -148,7 +147,6 @@ struct KernelCore::Impl {
shutdown_threads[core_id] = nullptr; shutdown_threads[core_id] = nullptr;
} }
schedulers[core_id]->Finalize();
schedulers[core_id].reset(); schedulers[core_id].reset();
} }
@ -195,17 +193,11 @@ struct KernelCore::Impl {
exclusive_monitor = exclusive_monitor =
Core::MakeExclusiveMonitor(system.Memory(), Core::Hardware::NUM_CPU_CORES); Core::MakeExclusiveMonitor(system.Memory(), Core::Hardware::NUM_CPU_CORES);
for (u32 i = 0; i < Core::Hardware::NUM_CPU_CORES; i++) { for (u32 i = 0; i < Core::Hardware::NUM_CPU_CORES; i++) {
schedulers[i] = std::make_unique<Kernel::KScheduler>(system, i); schedulers[i] = std::make_unique<Kernel::KScheduler>(system.Kernel());
cores.emplace_back(i, system, *schedulers[i], interrupts); cores.emplace_back(i, system, *schedulers[i], interrupts);
} }
} }
void InitializeSchedulers() {
for (u32 i = 0; i < Core::Hardware::NUM_CPU_CORES; i++) {
cores[i].Scheduler().Initialize();
}
}
// Creates the default system resource limit // Creates the default system resource limit
void InitializeSystemResourceLimit(KernelCore& kernel, void InitializeSystemResourceLimit(KernelCore& kernel,
const Core::Timing::CoreTiming& core_timing) { const Core::Timing::CoreTiming& core_timing) {

7
src/core/hle/kernel/svc.cpp
View File

@ -887,7 +887,7 @@ static Result GetInfo(Core::System& system, u64* result, u64 info_id, Handle han
const auto* const current_thread = GetCurrentThreadPointer(system.Kernel()); const auto* const current_thread = GetCurrentThreadPointer(system.Kernel());
const bool same_thread = current_thread == thread.GetPointerUnsafe(); const bool same_thread = current_thread == thread.GetPointerUnsafe();
const u64 prev_ctx_ticks = scheduler.GetLastContextSwitchTicks(); const u64 prev_ctx_ticks = scheduler.GetLastContextSwitchTime();
u64 out_ticks = 0; u64 out_ticks = 0;
if (same_thread && info_sub_id == 0xFFFFFFFFFFFFFFFF) { if (same_thread && info_sub_id == 0xFFFFFFFFFFFFFFFF) {
const u64 thread_ticks = current_thread->GetCpuTime(); const u64 thread_ticks = current_thread->GetCpuTime();
@ -3026,11 +3026,6 @@ void Call(Core::System& system, u32 immediate) {
} }
kernel.ExitSVCProfile(); kernel.ExitSVCProfile();
if (!thread->IsCallingSvc()) {
auto* host_context = thread->GetHostContext().get();
host_context->Rewind();
}
} }
} // namespace Kernel::Svc } // namespace Kernel::Svc