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Merge pull request #2971 from FernandoS27/new-scheduler-v2

Kernel: Implement a New Thread Scheduler V2
This commit is contained in:
David 2019-10-28 10:53:27 +11:00 committed by GitHub
commit 4c5731c34f
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GPG Key ID: 4AEE18F83AFDEB23
19 changed files with 1034 additions and 447 deletions

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@ -304,6 +304,13 @@ public:
return levels[priority == Depth ? 63 : priority].back();
}
void clear() {
used_priorities = 0;
for (std::size_t i = 0; i < Depth; i++) {
levels[i].clear();
}
}
private:
using const_list_iterator = typename std::list<T>::const_iterator;

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@ -409,6 +409,12 @@ void System::PrepareReschedule() {
CurrentCpuCore().PrepareReschedule();
}
void System::PrepareReschedule(const u32 core_index) {
if (core_index < GlobalScheduler().CpuCoresCount()) {
CpuCore(core_index).PrepareReschedule();
}
}
PerfStatsResults System::GetAndResetPerfStats() {
return impl->GetAndResetPerfStats();
}
@ -449,6 +455,16 @@ const Kernel::Scheduler& System::Scheduler(std::size_t core_index) const {
return CpuCore(core_index).Scheduler();
}
/// Gets the global scheduler
Kernel::GlobalScheduler& System::GlobalScheduler() {
return impl->kernel.GlobalScheduler();
}
/// Gets the global scheduler
const Kernel::GlobalScheduler& System::GlobalScheduler() const {
return impl->kernel.GlobalScheduler();
}
Kernel::Process* System::CurrentProcess() {
return impl->kernel.CurrentProcess();
}

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@ -24,6 +24,7 @@ class VfsFilesystem;
} // namespace FileSys
namespace Kernel {
class GlobalScheduler;
class KernelCore;
class Process;
class Scheduler;
@ -184,6 +185,9 @@ public:
/// Prepare the core emulation for a reschedule
void PrepareReschedule();
/// Prepare the core emulation for a reschedule
void PrepareReschedule(u32 core_index);
/// Gets and resets core performance statistics
PerfStatsResults GetAndResetPerfStats();
@ -238,6 +242,12 @@ public:
/// Gets the scheduler for the CPU core with the specified index
const Kernel::Scheduler& Scheduler(std::size_t core_index) const;
/// Gets the global scheduler
Kernel::GlobalScheduler& GlobalScheduler();
/// Gets the global scheduler
const Kernel::GlobalScheduler& GlobalScheduler() const;
/// Provides a pointer to the current process
Kernel::Process* CurrentProcess();

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@ -52,7 +52,8 @@ bool CpuBarrier::Rendezvous() {
Cpu::Cpu(System& system, ExclusiveMonitor& exclusive_monitor, CpuBarrier& cpu_barrier,
std::size_t core_index)
: cpu_barrier{cpu_barrier}, core_timing{system.CoreTiming()}, core_index{core_index} {
: cpu_barrier{cpu_barrier}, global_scheduler{system.GlobalScheduler()},
core_timing{system.CoreTiming()}, core_index{core_index} {
#ifdef ARCHITECTURE_x86_64
arm_interface = std::make_unique<ARM_Dynarmic>(system, exclusive_monitor, core_index);
#else
@ -60,7 +61,7 @@ Cpu::Cpu(System& system, ExclusiveMonitor& exclusive_monitor, CpuBarrier& cpu_ba
LOG_WARNING(Core, "CPU JIT requested, but Dynarmic not available");
#endif
scheduler = std::make_unique<Kernel::Scheduler>(system, *arm_interface);
scheduler = std::make_unique<Kernel::Scheduler>(system, *arm_interface, core_index);
}
Cpu::~Cpu() = default;
@ -81,21 +82,21 @@ void Cpu::RunLoop(bool tight_loop) {
return;
}
Reschedule();
// If we don't have a currently active thread then don't execute instructions,
// instead advance to the next event and try to yield to the next thread
if (Kernel::GetCurrentThread() == nullptr) {
LOG_TRACE(Core, "Core-{} idling", core_index);
core_timing.Idle();
core_timing.Advance();
PrepareReschedule();
} else {
if (tight_loop) {
arm_interface->Run();
} else {
arm_interface->Step();
}
core_timing.Advance();
}
core_timing.Advance();
Reschedule();
}
@ -106,18 +107,18 @@ void Cpu::SingleStep() {
void Cpu::PrepareReschedule() {
arm_interface->PrepareReschedule();
reschedule_pending = true;
}
void Cpu::Reschedule() {
if (!reschedule_pending) {
return;
}
reschedule_pending = false;
// Lock the global kernel mutex when we manipulate the HLE state
std::lock_guard lock{HLE::g_hle_lock};
scheduler->Reschedule();
std::lock_guard lock(HLE::g_hle_lock);
global_scheduler.SelectThread(core_index);
scheduler->TryDoContextSwitch();
}
void Cpu::Shutdown() {
scheduler->Shutdown();
}
} // namespace Core

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@ -12,8 +12,9 @@
#include "common/common_types.h"
namespace Kernel {
class GlobalScheduler;
class Scheduler;
}
} // namespace Kernel
namespace Core {
class System;
@ -83,6 +84,8 @@ public:
return core_index;
}
void Shutdown();
static std::unique_ptr<ExclusiveMonitor> MakeExclusiveMonitor(std::size_t num_cores);
private:
@ -90,6 +93,7 @@ private:
std::unique_ptr<ARM_Interface> arm_interface;
CpuBarrier& cpu_barrier;
Kernel::GlobalScheduler& global_scheduler;
std::unique_ptr<Kernel::Scheduler> scheduler;
Timing::CoreTiming& core_timing;

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@ -58,6 +58,7 @@ void CpuCoreManager::Shutdown() {
thread_to_cpu.clear();
for (auto& cpu_core : cores) {
cpu_core->Shutdown();
cpu_core.reset();
}

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@ -202,15 +202,13 @@ void RegisterModule(std::string name, VAddr beg, VAddr end, bool add_elf_ext) {
}
static Kernel::Thread* FindThreadById(s64 id) {
for (u32 core = 0; core < Core::NUM_CPU_CORES; core++) {
const auto& threads = Core::System::GetInstance().Scheduler(core).GetThreadList();
const auto& threads = Core::System::GetInstance().GlobalScheduler().GetThreadList();
for (auto& thread : threads) {
if (thread->GetThreadID() == static_cast<u64>(id)) {
current_core = core;
current_core = thread->GetProcessorID();
return thread.get();
}
}
}
return nullptr;
}
@ -647,12 +645,10 @@ static void HandleQuery() {
SendReply(buffer.c_str());
} else if (strncmp(query, "fThreadInfo", strlen("fThreadInfo")) == 0) {
std::string val = "m";
for (u32 core = 0; core < Core::NUM_CPU_CORES; core++) {
const auto& threads = Core::System::GetInstance().Scheduler(core).GetThreadList();
const auto& threads = Core::System::GetInstance().GlobalScheduler().GetThreadList();
for (const auto& thread : threads) {
val += fmt::format("{:x},", thread->GetThreadID());
}
}
val.pop_back();
SendReply(val.c_str());
} else if (strncmp(query, "sThreadInfo", strlen("sThreadInfo")) == 0) {
@ -661,13 +657,11 @@ static void HandleQuery() {
std::string buffer;
buffer += "l<?xml version=\"1.0\"?>";
buffer += "<threads>";
for (u32 core = 0; core < Core::NUM_CPU_CORES; core++) {
const auto& threads = Core::System::GetInstance().Scheduler(core).GetThreadList();
const auto& threads = Core::System::GetInstance().GlobalScheduler().GetThreadList();
for (const auto& thread : threads) {
buffer +=
fmt::format(R"*(<thread id="{:x}" core="{:d}" name="Thread {:x}"></thread>)*",
thread->GetThreadID(), core, thread->GetThreadID());
}
thread->GetThreadID(), thread->GetProcessorID(), thread->GetThreadID());
}
buffer += "</threads>";
SendReply(buffer.c_str());

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@ -22,6 +22,7 @@ namespace Kernel {
namespace {
// Wake up num_to_wake (or all) threads in a vector.
void WakeThreads(const std::vector<SharedPtr<Thread>>& waiting_threads, s32 num_to_wake) {
auto& system = Core::System::GetInstance();
// Only process up to 'target' threads, unless 'target' is <= 0, in which case process
// them all.
std::size_t last = waiting_threads.size();
@ -35,6 +36,7 @@ void WakeThreads(const std::vector<SharedPtr<Thread>>& waiting_threads, s32 num_
waiting_threads[i]->SetWaitSynchronizationResult(RESULT_SUCCESS);
waiting_threads[i]->SetArbiterWaitAddress(0);
waiting_threads[i]->ResumeFromWait();
system.PrepareReschedule(waiting_threads[i]->GetProcessorID());
}
}
} // Anonymous namespace
@ -89,13 +91,21 @@ ResultCode AddressArbiter::ModifyByWaitingCountAndSignalToAddressIfEqual(VAddr a
// Determine the modified value depending on the waiting count.
s32 updated_value;
if (num_to_wake <= 0) {
if (waiting_threads.empty()) {
updated_value = value + 1;
} else if (num_to_wake <= 0 || waiting_threads.size() <= static_cast<u32>(num_to_wake)) {
} else {
updated_value = value - 1;
}
} else {
if (waiting_threads.empty()) {
updated_value = value + 1;
} else if (waiting_threads.size() <= static_cast<u32>(num_to_wake)) {
updated_value = value - 1;
} else {
updated_value = value;
}
}
if (static_cast<s32>(Memory::Read32(address)) != value) {
return ERR_INVALID_STATE;
@ -169,30 +179,22 @@ ResultCode AddressArbiter::WaitForAddressImpl(VAddr address, s64 timeout) {
current_thread->WakeAfterDelay(timeout);
system.CpuCore(current_thread->GetProcessorID()).PrepareReschedule();
system.PrepareReschedule(current_thread->GetProcessorID());
return RESULT_TIMEOUT;
}
std::vector<SharedPtr<Thread>> AddressArbiter::GetThreadsWaitingOnAddress(VAddr address) const {
const auto RetrieveWaitingThreads = [this](std::size_t core_index,
std::vector<SharedPtr<Thread>>& waiting_threads,
VAddr arb_addr) {
const auto& scheduler = system.Scheduler(core_index);
const auto& thread_list = scheduler.GetThreadList();
for (const auto& thread : thread_list) {
if (thread->GetArbiterWaitAddress() == arb_addr) {
waiting_threads.push_back(thread);
}
}
};
// Retrieve all threads that are waiting for this address.
std::vector<SharedPtr<Thread>> threads;
RetrieveWaitingThreads(0, threads, address);
RetrieveWaitingThreads(1, threads, address);
RetrieveWaitingThreads(2, threads, address);
RetrieveWaitingThreads(3, threads, address);
const auto& scheduler = system.GlobalScheduler();
const auto& thread_list = scheduler.GetThreadList();
for (const auto& thread : thread_list) {
if (thread->GetArbiterWaitAddress() == address) {
threads.push_back(thread);
}
}
// Sort them by priority, such that the highest priority ones come first.
std::sort(threads.begin(), threads.end(),

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@ -12,12 +12,15 @@
#include "core/core.h"
#include "core/core_timing.h"
#include "core/core_timing_util.h"
#include "core/hle/kernel/address_arbiter.h"
#include "core/hle/kernel/client_port.h"
#include "core/hle/kernel/errors.h"
#include "core/hle/kernel/handle_table.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/process.h"
#include "core/hle/kernel/resource_limit.h"
#include "core/hle/kernel/scheduler.h"
#include "core/hle/kernel/thread.h"
#include "core/hle/lock.h"
#include "core/hle/result.h"
@ -58,12 +61,8 @@ static void ThreadWakeupCallback(u64 thread_handle, [[maybe_unused]] s64 cycles_
if (thread->HasWakeupCallback()) {
resume = thread->InvokeWakeupCallback(ThreadWakeupReason::Timeout, thread, nullptr, 0);
}
}
if (thread->GetMutexWaitAddress() != 0 || thread->GetCondVarWaitAddress() != 0 ||
thread->GetWaitHandle() != 0) {
ASSERT(thread->GetStatus() == ThreadStatus::WaitMutex ||
thread->GetStatus() == ThreadStatus::WaitCondVar);
} else if (thread->GetStatus() == ThreadStatus::WaitMutex ||
thread->GetStatus() == ThreadStatus::WaitCondVar) {
thread->SetMutexWaitAddress(0);
thread->SetCondVarWaitAddress(0);
thread->SetWaitHandle(0);
@ -83,18 +82,23 @@ static void ThreadWakeupCallback(u64 thread_handle, [[maybe_unused]] s64 cycles_
}
if (resume) {
if (thread->GetStatus() == ThreadStatus::WaitCondVar ||
thread->GetStatus() == ThreadStatus::WaitArb) {
thread->SetWaitSynchronizationResult(RESULT_TIMEOUT);
}
thread->ResumeFromWait();
}
}
struct KernelCore::Impl {
explicit Impl(Core::System& system) : system{system} {}
explicit Impl(Core::System& system) : system{system}, global_scheduler{system} {}
void Initialize(KernelCore& kernel) {
Shutdown();
InitializeSystemResourceLimit(kernel);
InitializeThreads();
InitializePreemption();
}
void Shutdown() {
@ -110,6 +114,9 @@ struct KernelCore::Impl {
thread_wakeup_callback_handle_table.Clear();
thread_wakeup_event_type = nullptr;
preemption_event = nullptr;
global_scheduler.Shutdown();
named_ports.clear();
}
@ -132,6 +139,18 @@ struct KernelCore::Impl {
system.CoreTiming().RegisterEvent("ThreadWakeupCallback", ThreadWakeupCallback);
}
void InitializePreemption() {
preemption_event = system.CoreTiming().RegisterEvent(
"PreemptionCallback", [this](u64 userdata, s64 cycles_late) {
global_scheduler.PreemptThreads();
s64 time_interval = Core::Timing::msToCycles(std::chrono::milliseconds(10));
system.CoreTiming().ScheduleEvent(time_interval, preemption_event);
});
s64 time_interval = Core::Timing::msToCycles(std::chrono::milliseconds(10));
system.CoreTiming().ScheduleEvent(time_interval, preemption_event);
}
std::atomic<u32> next_object_id{0};
std::atomic<u64> next_kernel_process_id{Process::InitialKIPIDMin};
std::atomic<u64> next_user_process_id{Process::ProcessIDMin};
@ -140,10 +159,12 @@ struct KernelCore::Impl {
// Lists all processes that exist in the current session.
std::vector<SharedPtr<Process>> process_list;
Process* current_process = nullptr;
Kernel::GlobalScheduler global_scheduler;
SharedPtr<ResourceLimit> system_resource_limit;
Core::Timing::EventType* thread_wakeup_event_type = nullptr;
Core::Timing::EventType* preemption_event = nullptr;
// TODO(yuriks): This can be removed if Thread objects are explicitly pooled in the future,
// allowing us to simply use a pool index or similar.
Kernel::HandleTable thread_wakeup_callback_handle_table;
@ -203,6 +224,14 @@ const std::vector<SharedPtr<Process>>& KernelCore::GetProcessList() const {
return impl->process_list;
}
Kernel::GlobalScheduler& KernelCore::GlobalScheduler() {
return impl->global_scheduler;
}
const Kernel::GlobalScheduler& KernelCore::GlobalScheduler() const {
return impl->global_scheduler;
}
void KernelCore::AddNamedPort(std::string name, SharedPtr<ClientPort> port) {
impl->named_ports.emplace(std::move(name), std::move(port));
}

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@ -21,6 +21,7 @@ namespace Kernel {
class AddressArbiter;
class ClientPort;
class GlobalScheduler;
class HandleTable;
class Process;
class ResourceLimit;
@ -75,6 +76,12 @@ public:
/// Retrieves the list of processes.
const std::vector<SharedPtr<Process>>& GetProcessList() const;
/// Gets the sole instance of the global scheduler
Kernel::GlobalScheduler& GlobalScheduler();
/// Gets the sole instance of the global scheduler
const Kernel::GlobalScheduler& GlobalScheduler() const;
/// Adds a port to the named port table
void AddNamedPort(std::string name, SharedPtr<ClientPort> port);

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@ -139,6 +139,9 @@ ResultCode Mutex::Release(VAddr address) {
thread->SetCondVarWaitAddress(0);
thread->SetMutexWaitAddress(0);
thread->SetWaitHandle(0);
thread->SetWaitSynchronizationResult(RESULT_SUCCESS);
system.PrepareReschedule();
return RESULT_SUCCESS;
}

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@ -213,10 +213,7 @@ void Process::PrepareForTermination() {
}
};
stop_threads(system.Scheduler(0).GetThreadList());
stop_threads(system.Scheduler(1).GetThreadList());
stop_threads(system.Scheduler(2).GetThreadList());
stop_threads(system.Scheduler(3).GetThreadList());
stop_threads(system.GlobalScheduler().GetThreadList());
FreeTLSRegion(tls_region_address);
tls_region_address = 0;

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@ -1,8 +1,13 @@
// Copyright 2018 yuzu emulator team
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
//
// SelectThreads, Yield functions originally by TuxSH.
// licensed under GPLv2 or later under exception provided by the author.
#include <algorithm>
#include <set>
#include <unordered_set>
#include <utility>
#include "common/assert.h"
@ -17,56 +22,405 @@
namespace Kernel {
std::mutex Scheduler::scheduler_mutex;
GlobalScheduler::GlobalScheduler(Core::System& system) : system{system} {
is_reselection_pending = false;
}
Scheduler::Scheduler(Core::System& system, Core::ARM_Interface& cpu_core)
: cpu_core{cpu_core}, system{system} {}
void GlobalScheduler::AddThread(SharedPtr<Thread> thread) {
thread_list.push_back(std::move(thread));
}
Scheduler::~Scheduler() {
for (auto& thread : thread_list) {
thread->Stop();
void GlobalScheduler::RemoveThread(const Thread* thread) {
thread_list.erase(std::remove(thread_list.begin(), thread_list.end(), thread),
thread_list.end());
}
/*
* UnloadThread selects a core and forces it to unload its current thread's context
*/
void GlobalScheduler::UnloadThread(s32 core) {
Scheduler& sched = system.Scheduler(core);
sched.UnloadThread();
}
/*
* SelectThread takes care of selecting the new scheduled thread.
* It does it in 3 steps:
* - First a thread is selected from the top of the priority queue. If no thread
* is obtained then we move to step two, else we are done.
* - 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.
* - 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.
*/
void GlobalScheduler::SelectThread(u32 core) {
const auto update_thread = [](Thread* thread, Scheduler& sched) {
if (thread != sched.selected_thread) {
if (thread == nullptr) {
++sched.idle_selection_count;
}
sched.selected_thread = thread;
}
sched.is_context_switch_pending = sched.selected_thread != sched.current_thread;
std::atomic_thread_fence(std::memory_order_seq_cst);
};
Scheduler& sched = system.Scheduler(core);
Thread* current_thread = nullptr;
// Step 1: Get top thread in schedule queue.
current_thread = scheduled_queue[core].empty() ? nullptr : scheduled_queue[core].front();
if (current_thread) {
update_thread(current_thread, sched);
return;
}
// Step 2: Try selecting a suggested thread.
Thread* winner = nullptr;
std::set<s32> sug_cores;
for (auto thread : suggested_queue[core]) {
s32 this_core = thread->GetProcessorID();
Thread* thread_on_core = nullptr;
if (this_core >= 0) {
thread_on_core = scheduled_queue[this_core].front();
}
if (this_core < 0 || thread != thread_on_core) {
winner = thread;
break;
}
sug_cores.insert(this_core);
}
// if we got a suggested thread, select it, else do a second pass.
if (winner && winner->GetPriority() > 2) {
if (winner->IsRunning()) {
UnloadThread(winner->GetProcessorID());
}
TransferToCore(winner->GetPriority(), core, winner);
update_thread(winner, sched);
return;
}
// Step 3: Select a suggested thread from another core
for (auto& src_core : sug_cores) {
auto it = scheduled_queue[src_core].begin();
it++;
if (it != scheduled_queue[src_core].end()) {
Thread* thread_on_core = scheduled_queue[src_core].front();
Thread* to_change = *it;
if (thread_on_core->IsRunning() || to_change->IsRunning()) {
UnloadThread(src_core);
}
TransferToCore(thread_on_core->GetPriority(), core, thread_on_core);
current_thread = thread_on_core;
break;
}
}
update_thread(current_thread, sched);
}
/*
* YieldThread takes a thread and moves it to the back of the it's priority list
* This operation can be redundant and no scheduling is changed if marked as so.
*/
bool GlobalScheduler::YieldThread(Thread* yielding_thread) {
// Note: caller should use critical section, etc.
const u32 core_id = static_cast<u32>(yielding_thread->GetProcessorID());
const u32 priority = yielding_thread->GetPriority();
// Yield the thread
ASSERT_MSG(yielding_thread == scheduled_queue[core_id].front(priority),
"Thread yielding without being in front");
scheduled_queue[core_id].yield(priority);
Thread* winner = scheduled_queue[core_id].front(priority);
return AskForReselectionOrMarkRedundant(yielding_thread, winner);
}
/*
* YieldThreadAndBalanceLoad takes a thread and moves it to the back of the it's priority list.
* 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.
* This operation can be redundant and no scheduling is changed if marked as so.
*/
bool GlobalScheduler::YieldThreadAndBalanceLoad(Thread* yielding_thread) {
// Note: caller should check if !thread.IsSchedulerOperationRedundant and use critical section,
// etc.
const u32 core_id = static_cast<u32>(yielding_thread->GetProcessorID());
const u32 priority = yielding_thread->GetPriority();
// Yield the thread
ASSERT_MSG(yielding_thread == scheduled_queue[core_id].front(priority),
"Thread yielding without being in front");
scheduled_queue[core_id].yield(priority);
std::array<Thread*, NUM_CPU_CORES> current_threads;
for (u32 i = 0; i < NUM_CPU_CORES; i++) {
current_threads[i] = scheduled_queue[i].empty() ? nullptr : scheduled_queue[i].front();
}
Thread* next_thread = scheduled_queue[core_id].front(priority);
Thread* winner = nullptr;
for (auto& thread : suggested_queue[core_id]) {
const s32 source_core = thread->GetProcessorID();
if (source_core >= 0) {
if (current_threads[source_core] != nullptr) {
if (thread == current_threads[source_core] ||
current_threads[source_core]->GetPriority() < min_regular_priority) {
continue;
}
}
}
if (next_thread->GetLastRunningTicks() >= thread->GetLastRunningTicks() ||
next_thread->GetPriority() < thread->GetPriority()) {
if (thread->GetPriority() <= priority) {
winner = thread;
break;
}
}
}
if (winner != nullptr) {
if (winner != yielding_thread) {
if (winner->IsRunning()) {
UnloadThread(winner->GetProcessorID());
}
TransferToCore(winner->GetPriority(), core_id, winner);
}
} else {
winner = next_thread;
}
return AskForReselectionOrMarkRedundant(yielding_thread, winner);
}
/*
* YieldThreadAndWaitForLoadBalancing takes a thread and moves it out of the scheduling queue
* and into the suggested queue. If no thread can be squeduled afterwards in that core,
* a suggested thread is obtained instead.
* This operation can be redundant and no scheduling is changed if marked as so.
*/
bool GlobalScheduler::YieldThreadAndWaitForLoadBalancing(Thread* yielding_thread) {
// Note: caller should check if !thread.IsSchedulerOperationRedundant and use critical section,
// etc.
Thread* winner = nullptr;
const u32 core_id = static_cast<u32>(yielding_thread->GetProcessorID());
// Remove the thread from its scheduled mlq, put it on the corresponding "suggested" one instead
TransferToCore(yielding_thread->GetPriority(), -1, yielding_thread);
// If the core is idle, perform load balancing, excluding the threads that have just used this
// function...
if (scheduled_queue[core_id].empty()) {
// Here, "current_threads" is calculated after the ""yield"", unlike yield -1
std::array<Thread*, NUM_CPU_CORES> current_threads;
for (u32 i = 0; i < NUM_CPU_CORES; i++) {
current_threads[i] = scheduled_queue[i].empty() ? nullptr : scheduled_queue[i].front();
}
for (auto& thread : suggested_queue[core_id]) {
const s32 source_core = thread->GetProcessorID();
if (source_core < 0 || thread == current_threads[source_core]) {
continue;
}
if (current_threads[source_core] == nullptr ||
current_threads[source_core]->GetPriority() >= min_regular_priority) {
winner = thread;
}
break;
}
if (winner != nullptr) {
if (winner != yielding_thread) {
if (winner->IsRunning()) {
UnloadThread(winner->GetProcessorID());
}
TransferToCore(winner->GetPriority(), core_id, winner);
}
} else {
winner = yielding_thread;
}
}
return AskForReselectionOrMarkRedundant(yielding_thread, winner);
}
void GlobalScheduler::PreemptThreads() {
for (std::size_t core_id = 0; core_id < NUM_CPU_CORES; core_id++) {
const u32 priority = preemption_priorities[core_id];
if (scheduled_queue[core_id].size(priority) > 0) {
scheduled_queue[core_id].front(priority)->IncrementYieldCount();
scheduled_queue[core_id].yield(priority);
if (scheduled_queue[core_id].size(priority) > 1) {
scheduled_queue[core_id].front(priority)->IncrementYieldCount();
}
}
Thread* current_thread =
scheduled_queue[core_id].empty() ? nullptr : scheduled_queue[core_id].front();
Thread* winner = nullptr;
for (auto& thread : suggested_queue[core_id]) {
const s32 source_core = thread->GetProcessorID();
if (thread->GetPriority() != priority) {
continue;
}
if (source_core >= 0) {
Thread* next_thread = scheduled_queue[source_core].empty()
? nullptr
: scheduled_queue[source_core].front();
if (next_thread != nullptr && next_thread->GetPriority() < 2) {
break;
}
if (next_thread == thread) {
continue;
}
}
if (current_thread != nullptr &&
current_thread->GetLastRunningTicks() >= thread->GetLastRunningTicks()) {
winner = thread;
break;
}
}
if (winner != nullptr) {
if (winner->IsRunning()) {
UnloadThread(winner->GetProcessorID());
}
TransferToCore(winner->GetPriority(), core_id, winner);
current_thread =
winner->GetPriority() <= current_thread->GetPriority() ? winner : current_thread;
}
if (current_thread != nullptr && current_thread->GetPriority() > priority) {
for (auto& thread : suggested_queue[core_id]) {
const s32 source_core = thread->GetProcessorID();
if (thread->GetPriority() < priority) {
continue;
}
if (source_core >= 0) {
Thread* next_thread = scheduled_queue[source_core].empty()
? nullptr
: scheduled_queue[source_core].front();
if (next_thread != nullptr && next_thread->GetPriority() < 2) {
break;
}
if (next_thread == thread) {
continue;
}
}
if (current_thread != nullptr &&
current_thread->GetLastRunningTicks() >= thread->GetLastRunningTicks()) {
winner = thread;
break;
}
}
if (winner != nullptr) {
if (winner->IsRunning()) {
UnloadThread(winner->GetProcessorID());
}
TransferToCore(winner->GetPriority(), core_id, winner);
current_thread = winner;
}
}
is_reselection_pending.store(true, std::memory_order_release);
}
}
void GlobalScheduler::Suggest(u32 priority, u32 core, Thread* thread) {
suggested_queue[core].add(thread, priority);
}
void GlobalScheduler::Unsuggest(u32 priority, u32 core, Thread* thread) {
suggested_queue[core].remove(thread, priority);
}
void GlobalScheduler::Schedule(u32 priority, u32 core, Thread* thread) {
ASSERT_MSG(thread->GetProcessorID() == core, "Thread must be assigned to this core.");
scheduled_queue[core].add(thread, priority);
}
void GlobalScheduler::SchedulePrepend(u32 priority, u32 core, Thread* thread) {
ASSERT_MSG(thread->GetProcessorID() == core, "Thread must be assigned to this core.");
scheduled_queue[core].add(thread, priority, false);
}
void GlobalScheduler::Reschedule(u32 priority, u32 core, Thread* thread) {
scheduled_queue[core].remove(thread, priority);
scheduled_queue[core].add(thread, priority);
}
void GlobalScheduler::Unschedule(u32 priority, u32 core, Thread* thread) {
scheduled_queue[core].remove(thread, priority);
}
void GlobalScheduler::TransferToCore(u32 priority, s32 destination_core, Thread* thread) {
const bool schedulable = thread->GetPriority() < THREADPRIO_COUNT;
const s32 source_core = thread->GetProcessorID();
if (source_core == destination_core || !schedulable) {
return;
}
thread->SetProcessorID(destination_core);
if (source_core >= 0) {
Unschedule(priority, source_core, thread);
}
if (destination_core >= 0) {
Unsuggest(priority, destination_core, thread);
Schedule(priority, destination_core, thread);
}
if (source_core >= 0) {
Suggest(priority, source_core, thread);
}
}
bool GlobalScheduler::AskForReselectionOrMarkRedundant(Thread* current_thread, Thread* winner) {
if (current_thread == winner) {
current_thread->IncrementYieldCount();
return true;
} else {
is_reselection_pending.store(true, std::memory_order_release);
return false;
}
}
void GlobalScheduler::Shutdown() {
for (std::size_t core = 0; core < NUM_CPU_CORES; core++) {
scheduled_queue[core].clear();
suggested_queue[core].clear();
}
thread_list.clear();
}
GlobalScheduler::~GlobalScheduler() = default;
Scheduler::Scheduler(Core::System& system, Core::ARM_Interface& cpu_core, u32 core_id)
: system(system), cpu_core(cpu_core), core_id(core_id) {}
Scheduler::~Scheduler() = default;
bool Scheduler::HaveReadyThreads() const {
std::lock_guard lock{scheduler_mutex};
return !ready_queue.empty();
return system.GlobalScheduler().HaveReadyThreads(core_id);
}
Thread* Scheduler::GetCurrentThread() const {
return current_thread.get();
}
Thread* Scheduler::GetSelectedThread() const {
return selected_thread.get();
}
void Scheduler::SelectThreads() {
system.GlobalScheduler().SelectThread(core_id);
}
u64 Scheduler::GetLastContextSwitchTicks() const {
return last_context_switch_time;
}
Thread* Scheduler::PopNextReadyThread() {
Thread* next = nullptr;
Thread* thread = GetCurrentThread();
if (thread && thread->GetStatus() == ThreadStatus::Running) {
if (ready_queue.empty()) {
return thread;
void Scheduler::TryDoContextSwitch() {
if (is_context_switch_pending) {
SwitchContext();
}
// We have to do better than the current thread.
// This call returns null when that's not possible.
next = ready_queue.front();
if (next == nullptr || next->GetPriority() >= thread->GetPriority()) {
next = thread;
}
} else {
if (ready_queue.empty()) {
return nullptr;
}
next = ready_queue.front();
}
return next;
}
void Scheduler::SwitchContext(Thread* new_thread) {
Thread* previous_thread = GetCurrentThread();
void Scheduler::UnloadThread() {
Thread* const previous_thread = GetCurrentThread();
Process* const previous_process = system.Kernel().CurrentProcess();
UpdateLastContextSwitchTime(previous_thread, previous_process);
@ -80,23 +434,52 @@ void Scheduler::SwitchContext(Thread* new_thread) {
if (previous_thread->GetStatus() == ThreadStatus::Running) {
// This is only the case when a reschedule is triggered without the current thread
// yielding execution (i.e. an event triggered, system core time-sliced, etc)
ready_queue.add(previous_thread, previous_thread->GetPriority(), false);
previous_thread->SetStatus(ThreadStatus::Ready);
}
previous_thread->SetIsRunning(false);
}
current_thread = nullptr;
}
void Scheduler::SwitchContext() {
Thread* const previous_thread = GetCurrentThread();
Thread* const new_thread = GetSelectedThread();
is_context_switch_pending = false;
if (new_thread == previous_thread) {
return;
}
Process* const previous_process = system.Kernel().CurrentProcess();
UpdateLastContextSwitchTime(previous_thread, previous_process);
// Save context for previous thread
if (previous_thread) {
cpu_core.SaveContext(previous_thread->GetContext());
// Save the TPIDR_EL0 system register in case it was modified.
previous_thread->SetTPIDR_EL0(cpu_core.GetTPIDR_EL0());
if (previous_thread->GetStatus() == ThreadStatus::Running) {
// This is only the case when a reschedule is triggered without the current thread
// yielding execution (i.e. an event triggered, system core time-sliced, etc)
previous_thread->SetStatus(ThreadStatus::Ready);
}
previous_thread->SetIsRunning(false);
}
// Load context of new thread
if (new_thread) {
ASSERT_MSG(new_thread->GetProcessorID() == this->core_id,
"Thread must be assigned to this core.");
ASSERT_MSG(new_thread->GetStatus() == ThreadStatus::Ready,
"Thread must be ready to become running.");
// Cancel any outstanding wakeup events for this thread
new_thread->CancelWakeupTimer();
current_thread = new_thread;
ready_queue.remove(new_thread, new_thread->GetPriority());
new_thread->SetStatus(ThreadStatus::Running);
new_thread->SetIsRunning(true);
auto* const thread_owner_process = current_thread->GetOwnerProcess();
if (previous_process != thread_owner_process) {
@ -130,124 +513,9 @@ void Scheduler::UpdateLastContextSwitchTime(Thread* thread, Process* process) {
last_context_switch_time = most_recent_switch_ticks;
}
void Scheduler::Reschedule() {
std::lock_guard lock{scheduler_mutex};
Thread* cur = GetCurrentThread();
Thread* next = PopNextReadyThread();
if (cur && next) {
LOG_TRACE(Kernel, "context switch {} -> {}", cur->GetObjectId(), next->GetObjectId());
} else if (cur) {
LOG_TRACE(Kernel, "context switch {} -> idle", cur->GetObjectId());
} else if (next) {
LOG_TRACE(Kernel, "context switch idle -> {}", next->GetObjectId());
}
SwitchContext(next);
}
void Scheduler::AddThread(SharedPtr<Thread> thread) {
std::lock_guard lock{scheduler_mutex};
thread_list.push_back(std::move(thread));
}
void Scheduler::RemoveThread(Thread* thread) {
std::lock_guard lock{scheduler_mutex};
thread_list.erase(std::remove(thread_list.begin(), thread_list.end(), thread),
thread_list.end());
}
void Scheduler::ScheduleThread(Thread* thread, u32 priority) {
std::lock_guard lock{scheduler_mutex};
ASSERT(thread->GetStatus() == ThreadStatus::Ready);
ready_queue.add(thread, priority);
}
void Scheduler::UnscheduleThread(Thread* thread, u32 priority) {
std::lock_guard lock{scheduler_mutex};
ASSERT(thread->GetStatus() == ThreadStatus::Ready);
ready_queue.remove(thread, priority);
}
void Scheduler::SetThreadPriority(Thread* thread, u32 priority) {
std::lock_guard lock{scheduler_mutex};
if (thread->GetPriority() == priority) {
return;
}
// If thread was ready, adjust queues
if (thread->GetStatus() == ThreadStatus::Ready)
ready_queue.adjust(thread, thread->GetPriority(), priority);
}
Thread* Scheduler::GetNextSuggestedThread(u32 core, u32 maximum_priority) const {
std::lock_guard lock{scheduler_mutex};
const u32 mask = 1U << core;
for (auto* thread : ready_queue) {
if ((thread->GetAffinityMask() & mask) != 0 && thread->GetPriority() < maximum_priority) {
return thread;
}
}
return nullptr;
}
void Scheduler::YieldWithoutLoadBalancing(Thread* thread) {
ASSERT(thread != nullptr);
// Avoid yielding if the thread isn't even running.
ASSERT(thread->GetStatus() == ThreadStatus::Running);
// Sanity check that the priority is valid
ASSERT(thread->GetPriority() < THREADPRIO_COUNT);
// Yield this thread -- sleep for zero time and force reschedule to different thread
GetCurrentThread()->Sleep(0);
}
void Scheduler::YieldWithLoadBalancing(Thread* thread) {
ASSERT(thread != nullptr);
const auto priority = thread->GetPriority();
const auto core = static_cast<u32>(thread->GetProcessorID());
// Avoid yielding if the thread isn't even running.
ASSERT(thread->GetStatus() == ThreadStatus::Running);
// Sanity check that the priority is valid
ASSERT(priority < THREADPRIO_COUNT);
// Sleep for zero time to be able to force reschedule to different thread
GetCurrentThread()->Sleep(0);
Thread* suggested_thread = nullptr;
// Search through all of the cpu cores (except this one) for a suggested thread.
// Take the first non-nullptr one
for (unsigned cur_core = 0; cur_core < Core::NUM_CPU_CORES; ++cur_core) {
const auto res =
system.CpuCore(cur_core).Scheduler().GetNextSuggestedThread(core, priority);
// If scheduler provides a suggested thread
if (res != nullptr) {
// And its better than the current suggested thread (or is the first valid one)
if (suggested_thread == nullptr ||
suggested_thread->GetPriority() > res->GetPriority()) {
suggested_thread = res;
}
}
}
// If a suggested thread was found, queue that for this core
if (suggested_thread != nullptr)
suggested_thread->ChangeCore(core, suggested_thread->GetAffinityMask());
}
void Scheduler::YieldAndWaitForLoadBalancing(Thread* thread) {
UNIMPLEMENTED_MSG("Wait for load balancing thread yield type is not implemented!");
void Scheduler::Shutdown() {
current_thread = nullptr;
selected_thread = nullptr;
}
} // namespace Kernel

View File

@ -20,124 +20,172 @@ namespace Kernel {
class Process;
class Scheduler final {
class GlobalScheduler final {
public:
explicit Scheduler(Core::System& system, Core::ARM_Interface& cpu_core);
~Scheduler();
/// Returns whether there are any threads that are ready to run.
bool HaveReadyThreads() const;
/// Reschedules to the next available thread (call after current thread is suspended)
void Reschedule();
/// Gets the current running thread
Thread* GetCurrentThread() const;
/// Gets the timestamp for the last context switch in ticks.
u64 GetLastContextSwitchTicks() const;
static constexpr u32 NUM_CPU_CORES = 4;
explicit GlobalScheduler(Core::System& system);
~GlobalScheduler();
/// Adds a new thread to the scheduler
void AddThread(SharedPtr<Thread> thread);
/// Removes a thread from the scheduler
void RemoveThread(Thread* thread);
/// Schedules a thread that has become "ready"
void ScheduleThread(Thread* thread, u32 priority);
/// Unschedules a thread that was already scheduled
void UnscheduleThread(Thread* thread, u32 priority);
/// Sets the priority of a thread in the scheduler
void SetThreadPriority(Thread* thread, u32 priority);
/// Gets the next suggested thread for load balancing
Thread* GetNextSuggestedThread(u32 core, u32 minimum_priority) const;
/**
* YieldWithoutLoadBalancing -- analogous to normal yield on a system
* Moves the thread to the end of the ready queue for its priority, and then reschedules the
* system to the new head of the queue.
*
* Example (Single Core -- but can be extrapolated to multi):
* ready_queue[prio=0]: ThreadA, ThreadB, ThreadC (->exec order->)
* Currently Running: ThreadR
*
* ThreadR calls YieldWithoutLoadBalancing
*
* ThreadR is moved to the end of ready_queue[prio=0]:
* ready_queue[prio=0]: ThreadA, ThreadB, ThreadC, ThreadR (->exec order->)
* Currently Running: Nothing
*
* System is rescheduled (ThreadA is popped off of queue):
* ready_queue[prio=0]: ThreadB, ThreadC, ThreadR (->exec order->)
* Currently Running: ThreadA
*
* If the queue is empty at time of call, no yielding occurs. This does not cross between cores
* or priorities at all.
*/
void YieldWithoutLoadBalancing(Thread* thread);
/**
* YieldWithLoadBalancing -- yield but with better selection of the new running thread
* Moves the current thread to the end of the ready queue for its priority, then selects a
* 'suggested thread' (a thread on a different core that could run on this core) from the
* scheduler, changes its core, and reschedules the current core to that thread.
*
* Example (Dual Core -- can be extrapolated to Quad Core, this is just normal yield if it were
* single core):
* ready_queue[core=0][prio=0]: ThreadA, ThreadB (affinities not pictured as irrelevant
* ready_queue[core=1][prio=0]: ThreadC[affinity=both], ThreadD[affinity=core1only]
* Currently Running: ThreadQ on Core 0 || ThreadP on Core 1
*
* ThreadQ calls YieldWithLoadBalancing
*
* ThreadQ is moved to the end of ready_queue[core=0][prio=0]:
* ready_queue[core=0][prio=0]: ThreadA, ThreadB
* ready_queue[core=1][prio=0]: ThreadC[affinity=both], ThreadD[affinity=core1only]
* Currently Running: ThreadQ on Core 0 || ThreadP on Core 1
*
* A list of suggested threads for each core is compiled
* Suggested Threads: {ThreadC on Core 1}
* If this were quad core (as the switch is), there could be between 0 and 3 threads in this
* list. If there are more than one, the thread is selected by highest prio.
*
* ThreadC is core changed to Core 0:
* ready_queue[core=0][prio=0]: ThreadC, ThreadA, ThreadB, ThreadQ
* ready_queue[core=1][prio=0]: ThreadD
* Currently Running: None on Core 0 || ThreadP on Core 1
*
* System is rescheduled (ThreadC is popped off of queue):
* ready_queue[core=0][prio=0]: ThreadA, ThreadB, ThreadQ
* ready_queue[core=1][prio=0]: ThreadD
* Currently Running: ThreadC on Core 0 || ThreadP on Core 1
*
* If no suggested threads can be found this will behave just as normal yield. If there are
* multiple candidates for the suggested thread on a core, the highest prio is taken.
*/
void YieldWithLoadBalancing(Thread* thread);
/// Currently unknown -- asserts as unimplemented on call
void YieldAndWaitForLoadBalancing(Thread* thread);
void RemoveThread(const Thread* thread);
/// Returns a list of all threads managed by the scheduler
const std::vector<SharedPtr<Thread>>& GetThreadList() const {
return thread_list;
}
private:
/**
* Pops and returns the next thread from the thread queue
* @return A pointer to the next ready thread
*/
Thread* PopNextReadyThread();
// Add a thread to the suggested queue of a cpu core. Suggested threads may be
// picked if no thread is scheduled to run on the core.
void Suggest(u32 priority, u32 core, Thread* thread);
// Remove a thread to the suggested queue of a cpu core. Suggested threads may be
// picked if no thread is scheduled to run on the core.
void Unsuggest(u32 priority, u32 core, Thread* thread);
// Add a thread to the scheduling queue of a cpu core. The thread is added at the
// back the queue in its priority level
void Schedule(u32 priority, u32 core, Thread* thread);
// Add a thread to the scheduling queue of a cpu core. The thread is added at the
// front the queue in its priority level
void SchedulePrepend(u32 priority, u32 core, Thread* thread);
// Reschedule an already scheduled thread based on a new priority
void Reschedule(u32 priority, u32 core, Thread* thread);
// Unschedule a thread.
void Unschedule(u32 priority, u32 core, Thread* thread);
// Transfers a thread into an specific core. If the destination_core is -1
// it will be unscheduled from its source code and added into its suggested
// queue.
void TransferToCore(u32 priority, s32 destination_core, Thread* thread);
/*
* UnloadThread selects a core and forces it to unload its current thread's context
*/
void UnloadThread(s32 core);
/*
* SelectThread takes care of selecting the new scheduled thread.
* It does it in 3 steps:
* - First a thread is selected from the top of the priority queue. If no thread
* is obtained then we move to step two, else we are done.
* - 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.
* - 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.
*/
void SelectThread(u32 core);
bool HaveReadyThreads(u32 core_id) const {
return !scheduled_queue[core_id].empty();
}
/*
* YieldThread takes a thread and moves it to the back of the it's priority list
* This operation can be redundant and no scheduling is changed if marked as so.
*/
bool YieldThread(Thread* thread);
/*
* YieldThreadAndBalanceLoad takes a thread and moves it to the back of the it's priority list.
* 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.
* This operation can be redundant and no scheduling is changed if marked as so.
*/
bool YieldThreadAndBalanceLoad(Thread* thread);
/*
* YieldThreadAndWaitForLoadBalancing takes a thread and moves it out of the scheduling queue
* and into the suggested queue. If no thread can be squeduled afterwards in that core,
* a suggested thread is obtained instead.
* This operation can be redundant and no scheduling is changed if marked as so.
*/
bool YieldThreadAndWaitForLoadBalancing(Thread* thread);
/*
* PreemptThreads this operation rotates the scheduling queues of threads at
* a preemption priority and then does some core rebalancing. Preemption priorities
* can be found in the array 'preemption_priorities'. This operation happens
* every 10ms.
*/
void PreemptThreads();
u32 CpuCoresCount() const {
return NUM_CPU_CORES;
}
void SetReselectionPending() {
is_reselection_pending.store(true, std::memory_order_release);
}
bool IsReselectionPending() const {
return is_reselection_pending.load(std::memory_order_acquire);
}
void Shutdown();
private:
bool AskForReselectionOrMarkRedundant(Thread* current_thread, Thread* winner);
static constexpr u32 min_regular_priority = 2;
std::array<Common::MultiLevelQueue<Thread*, THREADPRIO_COUNT>, NUM_CPU_CORES> scheduled_queue;
std::array<Common::MultiLevelQueue<Thread*, THREADPRIO_COUNT>, NUM_CPU_CORES> suggested_queue;
std::atomic<bool> is_reselection_pending;
// `preemption_priorities` are the priority levels at which the global scheduler
// preempts threads every 10 ms. They are ordered from Core 0 to Core 3
std::array<u32, NUM_CPU_CORES> preemption_priorities = {59, 59, 59, 62};
/// Lists all thread ids that aren't deleted/etc.
std::vector<SharedPtr<Thread>> thread_list;
Core::System& system;
};
class Scheduler final {
public:
explicit Scheduler(Core::System& system, Core::ARM_Interface& cpu_core, u32 core_id);
~Scheduler();
/// Returns whether there are any threads that are ready to run.
bool HaveReadyThreads() const;
/// Reschedules to the next available thread (call after current thread is suspended)
void TryDoContextSwitch();
/// Unloads currently running thread
void UnloadThread();
/// Select the threads in top of the scheduling multilist.
void SelectThreads();
/// Gets the current running thread
Thread* GetCurrentThread() const;
/// Gets the currently selected thread from the top of the multilevel queue
Thread* GetSelectedThread() const;
/// Gets the timestamp for the last context switch in ticks.
u64 GetLastContextSwitchTicks() const;
bool ContextSwitchPending() const {
return is_context_switch_pending;
}
/// Shutdowns the scheduler.
void Shutdown();
private:
friend class GlobalScheduler;
/**
* Switches the CPU's active thread context to that of the specified thread
* @param new_thread The thread to switch to
*/
void SwitchContext(Thread* new_thread);
void SwitchContext();
/**
* Called on every context switch to update the internal timestamp
@ -152,19 +200,16 @@ private:
*/
void UpdateLastContextSwitchTime(Thread* thread, Process* process);
/// Lists all thread ids that aren't deleted/etc.
std::vector<SharedPtr<Thread>> thread_list;
/// Lists only ready thread ids.
Common::MultiLevelQueue<Thread*, THREADPRIO_LOWEST + 1> ready_queue;
SharedPtr<Thread> current_thread = nullptr;
Core::ARM_Interface& cpu_core;
u64 last_context_switch_time = 0;
SharedPtr<Thread> selected_thread = nullptr;
Core::System& system;
static std::mutex scheduler_mutex;
Core::ARM_Interface& cpu_core;
u64 last_context_switch_time = 0;
u64 idle_selection_count = 0;
const u32 core_id;
bool is_context_switch_pending = false;
};
} // namespace Kernel

View File

@ -516,7 +516,7 @@ static ResultCode WaitSynchronization(Core::System& system, Handle* index, VAddr
thread->WakeAfterDelay(nano_seconds);
thread->SetWakeupCallback(DefaultThreadWakeupCallback);
system.CpuCore(thread->GetProcessorID()).PrepareReschedule();
system.PrepareReschedule(thread->GetProcessorID());
return RESULT_TIMEOUT;
}
@ -534,6 +534,7 @@ static ResultCode CancelSynchronization(Core::System& system, Handle thread_hand
}
thread->CancelWait();
system.PrepareReschedule(thread->GetProcessorID());
return RESULT_SUCCESS;
}
@ -1066,6 +1067,8 @@ static ResultCode SetThreadActivity(Core::System& system, Handle handle, u32 act
}
thread->SetActivity(static_cast<ThreadActivity>(activity));
system.PrepareReschedule(thread->GetProcessorID());
return RESULT_SUCCESS;
}
@ -1147,7 +1150,7 @@ static ResultCode SetThreadPriority(Core::System& system, Handle handle, u32 pri
thread->SetPriority(priority);
system.CpuCore(thread->GetProcessorID()).PrepareReschedule();
system.PrepareReschedule(thread->GetProcessorID());
return RESULT_SUCCESS;
}
@ -1503,7 +1506,7 @@ static ResultCode CreateThread(Core::System& system, Handle* out_handle, VAddr e
thread->SetName(
fmt::format("thread[entry_point={:X}, handle={:X}]", entry_point, *new_thread_handle));
system.CpuCore(thread->GetProcessorID()).PrepareReschedule();
system.PrepareReschedule(thread->GetProcessorID());
return RESULT_SUCCESS;
}
@ -1525,7 +1528,7 @@ static ResultCode StartThread(Core::System& system, Handle thread_handle) {
thread->ResumeFromWait();
if (thread->GetStatus() == ThreadStatus::Ready) {
system.CpuCore(thread->GetProcessorID()).PrepareReschedule();
system.PrepareReschedule(thread->GetProcessorID());
}
return RESULT_SUCCESS;
@ -1537,7 +1540,7 @@ static void ExitThread(Core::System& system) {
auto* const current_thread = system.CurrentScheduler().GetCurrentThread();
current_thread->Stop();
system.CurrentScheduler().RemoveThread(current_thread);
system.GlobalScheduler().RemoveThread(current_thread);
system.PrepareReschedule();
}
@ -1553,17 +1556,18 @@ static void SleepThread(Core::System& system, s64 nanoseconds) {
auto& scheduler = system.CurrentScheduler();
auto* const current_thread = scheduler.GetCurrentThread();
bool is_redundant = false;
if (nanoseconds <= 0) {
switch (static_cast<SleepType>(nanoseconds)) {
case SleepType::YieldWithoutLoadBalancing:
scheduler.YieldWithoutLoadBalancing(current_thread);
is_redundant = current_thread->YieldSimple();
break;
case SleepType::YieldWithLoadBalancing:
scheduler.YieldWithLoadBalancing(current_thread);
is_redundant = current_thread->YieldAndBalanceLoad();
break;
case SleepType::YieldAndWaitForLoadBalancing:
scheduler.YieldAndWaitForLoadBalancing(current_thread);
is_redundant = current_thread->YieldAndWaitForLoadBalancing();
break;
default:
UNREACHABLE_MSG("Unimplemented sleep yield type '{:016X}'!", nanoseconds);
@ -1572,10 +1576,13 @@ static void SleepThread(Core::System& system, s64 nanoseconds) {
current_thread->Sleep(nanoseconds);
}
// Reschedule all CPU cores
for (std::size_t i = 0; i < Core::NUM_CPU_CORES; ++i) {
system.CpuCore(i).PrepareReschedule();
if (is_redundant) {
// If it's redundant, the core is pretty much idle. Some games keep idling
// a core while it's doing nothing, we advance timing to avoid costly continuous
// calls.
system.CoreTiming().AddTicks(2000);
}
system.PrepareReschedule(current_thread->GetProcessorID());
}
/// Wait process wide key atomic
@ -1601,6 +1608,8 @@ static ResultCode WaitProcessWideKeyAtomic(Core::System& system, VAddr mutex_add
return ERR_INVALID_ADDRESS;
}
ASSERT(condition_variable_addr == Common::AlignDown(condition_variable_addr, 4));
auto* const current_process = system.Kernel().CurrentProcess();
const auto& handle_table = current_process->GetHandleTable();
SharedPtr<Thread> thread = handle_table.Get<Thread>(thread_handle);
@ -1622,7 +1631,7 @@ static ResultCode WaitProcessWideKeyAtomic(Core::System& system, VAddr mutex_add
// Note: Deliberately don't attempt to inherit the lock owner's priority.
system.CpuCore(current_thread->GetProcessorID()).PrepareReschedule();
system.PrepareReschedule(current_thread->GetProcessorID());
return RESULT_SUCCESS;
}
@ -1632,24 +1641,19 @@ static ResultCode SignalProcessWideKey(Core::System& system, VAddr condition_var
LOG_TRACE(Kernel_SVC, "called, condition_variable_addr=0x{:X}, target=0x{:08X}",
condition_variable_addr, target);
const auto RetrieveWaitingThreads = [&system](std::size_t core_index,
std::vector<SharedPtr<Thread>>& waiting_threads,
VAddr condvar_addr) {
const auto& scheduler = system.Scheduler(core_index);
const auto& thread_list = scheduler.GetThreadList();
for (const auto& thread : thread_list) {
if (thread->GetCondVarWaitAddress() == condvar_addr)
waiting_threads.push_back(thread);
}
};
ASSERT(condition_variable_addr == Common::AlignDown(condition_variable_addr, 4));
// Retrieve a list of all threads that are waiting for this condition variable.
std::vector<SharedPtr<Thread>> waiting_threads;
RetrieveWaitingThreads(0, waiting_threads, condition_variable_addr);
RetrieveWaitingThreads(1, waiting_threads, condition_variable_addr);
RetrieveWaitingThreads(2, waiting_threads, condition_variable_addr);
RetrieveWaitingThreads(3, waiting_threads, condition_variable_addr);
const auto& scheduler = system.GlobalScheduler();
const auto& thread_list = scheduler.GetThreadList();
for (const auto& thread : thread_list) {
if (thread->GetCondVarWaitAddress() == condition_variable_addr) {
waiting_threads.push_back(thread);
}
}
// Sort them by priority, such that the highest priority ones come first.
std::sort(waiting_threads.begin(), waiting_threads.end(),
[](const SharedPtr<Thread>& lhs, const SharedPtr<Thread>& rhs) {
@ -1679,18 +1683,20 @@ static ResultCode SignalProcessWideKey(Core::System& system, VAddr condition_var
// Atomically read the value of the mutex.
u32 mutex_val = 0;
u32 update_val = 0;
const VAddr mutex_address = thread->GetMutexWaitAddress();
do {
monitor.SetExclusive(current_core, thread->GetMutexWaitAddress());
monitor.SetExclusive(current_core, mutex_address);
// If the mutex is not yet acquired, acquire it.
mutex_val = Memory::Read32(thread->GetMutexWaitAddress());
mutex_val = Memory::Read32(mutex_address);
if (mutex_val != 0) {
monitor.ClearExclusive();
break;
update_val = mutex_val | Mutex::MutexHasWaitersFlag;
} else {
update_val = thread->GetWaitHandle();
}
} while (!monitor.ExclusiveWrite32(current_core, thread->GetMutexWaitAddress(),
thread->GetWaitHandle()));
} while (!monitor.ExclusiveWrite32(current_core, mutex_address, update_val));
if (mutex_val == 0) {
// We were able to acquire the mutex, resume this thread.
ASSERT(thread->GetStatus() == ThreadStatus::WaitCondVar);
@ -1704,20 +1710,9 @@ static ResultCode SignalProcessWideKey(Core::System& system, VAddr condition_var
thread->SetLockOwner(nullptr);
thread->SetMutexWaitAddress(0);
thread->SetWaitHandle(0);
system.CpuCore(thread->GetProcessorID()).PrepareReschedule();
thread->SetWaitSynchronizationResult(RESULT_SUCCESS);
system.PrepareReschedule(thread->GetProcessorID());
} else {
// Atomically signal that the mutex now has a waiting thread.
do {
monitor.SetExclusive(current_core, thread->GetMutexWaitAddress());
// Ensure that the mutex value is still what we expect.
u32 value = Memory::Read32(thread->GetMutexWaitAddress());
// TODO(Subv): When this happens, the kernel just clears the exclusive state and
// retries the initial read for this thread.
ASSERT_MSG(mutex_val == value, "Unhandled synchronization primitive case");
} while (!monitor.ExclusiveWrite32(current_core, thread->GetMutexWaitAddress(),
mutex_val | Mutex::MutexHasWaitersFlag));
// The mutex is already owned by some other thread, make this thread wait on it.
const Handle owner_handle = static_cast<Handle>(mutex_val & Mutex::MutexOwnerMask);
const auto& handle_table = system.Kernel().CurrentProcess()->GetHandleTable();
@ -1728,6 +1723,7 @@ static ResultCode SignalProcessWideKey(Core::System& system, VAddr condition_var
thread->SetStatus(ThreadStatus::WaitMutex);
owner->AddMutexWaiter(thread);
system.PrepareReschedule(thread->GetProcessorID());
}
}
@ -1754,7 +1750,12 @@ static ResultCode WaitForAddress(Core::System& system, VAddr address, u32 type,
const auto arbitration_type = static_cast<AddressArbiter::ArbitrationType>(type);
auto& address_arbiter = system.Kernel().CurrentProcess()->GetAddressArbiter();
return address_arbiter.WaitForAddress(address, arbitration_type, value, timeout);
const ResultCode result =
address_arbiter.WaitForAddress(address, arbitration_type, value, timeout);
if (result == RESULT_SUCCESS) {
system.PrepareReschedule();
}
return result;
}
// Signals to an address (via Address Arbiter)
@ -2040,7 +2041,10 @@ static ResultCode SetThreadCoreMask(Core::System& system, Handle thread_handle,
return ERR_INVALID_HANDLE;
}
system.PrepareReschedule(thread->GetProcessorID());
thread->ChangeCore(core, affinity_mask);
system.PrepareReschedule(thread->GetProcessorID());
return RESULT_SUCCESS;
}
@ -2151,6 +2155,7 @@ static ResultCode SignalEvent(Core::System& system, Handle handle) {
}
writable_event->Signal();
system.PrepareReschedule();
return RESULT_SUCCESS;
}

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@ -45,15 +45,7 @@ void Thread::Stop() {
callback_handle);
kernel.ThreadWakeupCallbackHandleTable().Close(callback_handle);
callback_handle = 0;
// Clean up thread from ready queue
// This is only needed when the thread is terminated forcefully (SVC TerminateProcess)
if (status == ThreadStatus::Ready || status == ThreadStatus::Paused) {
scheduler->UnscheduleThread(this, current_priority);
}
status = ThreadStatus::Dead;
SetStatus(ThreadStatus::Dead);
WakeupAllWaitingThreads();
// Clean up any dangling references in objects that this thread was waiting for
@ -132,17 +124,16 @@ void Thread::ResumeFromWait() {
wakeup_callback = nullptr;
if (activity == ThreadActivity::Paused) {
status = ThreadStatus::Paused;
SetStatus(ThreadStatus::Paused);
return;
}
status = ThreadStatus::Ready;
ChangeScheduler();
SetStatus(ThreadStatus::Ready);
}
void Thread::CancelWait() {
ASSERT(GetStatus() == ThreadStatus::WaitSynch);
ClearWaitObjects();
SetWaitSynchronizationResult(ERR_SYNCHRONIZATION_CANCELED);
ResumeFromWait();
}
@ -205,9 +196,9 @@ ResultVal<SharedPtr<Thread>> Thread::Create(KernelCore& kernel, std::string name
thread->name = std::move(name);
thread->callback_handle = kernel.ThreadWakeupCallbackHandleTable().Create(thread).Unwrap();
thread->owner_process = &owner_process;
auto& scheduler = kernel.GlobalScheduler();
scheduler.AddThread(thread);
thread->tls_address = thread->owner_process->CreateTLSRegion();
thread->scheduler = &system.Scheduler(processor_id);
thread->scheduler->AddThread(thread);
thread->owner_process->RegisterThread(thread.get());
@ -250,6 +241,22 @@ void Thread::SetStatus(ThreadStatus new_status) {
return;
}
switch (new_status) {
case ThreadStatus::Ready:
case ThreadStatus::Running:
SetSchedulingStatus(ThreadSchedStatus::Runnable);
break;
case ThreadStatus::Dormant:
SetSchedulingStatus(ThreadSchedStatus::None);
break;
case ThreadStatus::Dead:
SetSchedulingStatus(ThreadSchedStatus::Exited);
break;
default:
SetSchedulingStatus(ThreadSchedStatus::Paused);
break;
}
if (status == ThreadStatus::Running) {
last_running_ticks = Core::System::GetInstance().CoreTiming().GetTicks();
}
@ -311,8 +318,7 @@ void Thread::UpdatePriority() {
return;
}
scheduler->SetThreadPriority(this, new_priority);
current_priority = new_priority;
SetCurrentPriority(new_priority);
if (!lock_owner) {
return;
@ -328,47 +334,7 @@ void Thread::UpdatePriority() {
}
void Thread::ChangeCore(u32 core, u64 mask) {
ideal_core = core;
affinity_mask = mask;
ChangeScheduler();
}
void Thread::ChangeScheduler() {
if (status != ThreadStatus::Ready) {
return;
}
auto& system = Core::System::GetInstance();
std::optional<s32> new_processor_id{GetNextProcessorId(affinity_mask)};
if (!new_processor_id) {
new_processor_id = processor_id;
}
if (ideal_core != -1 && system.Scheduler(ideal_core).GetCurrentThread() == nullptr) {
new_processor_id = ideal_core;
}
ASSERT(*new_processor_id < 4);
// Add thread to new core's scheduler
auto& next_scheduler = system.Scheduler(*new_processor_id);
if (*new_processor_id != processor_id) {
// Remove thread from previous core's scheduler
scheduler->RemoveThread(this);
next_scheduler.AddThread(this);
}
processor_id = *new_processor_id;
// If the thread was ready, unschedule from the previous core and schedule on the new core
scheduler->UnscheduleThread(this, current_priority);
next_scheduler.ScheduleThread(this, current_priority);
// Change thread's scheduler
scheduler = &next_scheduler;
system.CpuCore(processor_id).PrepareReschedule();
SetCoreAndAffinityMask(core, mask);
}
bool Thread::AllWaitObjectsReady() const {
@ -388,10 +354,8 @@ void Thread::SetActivity(ThreadActivity value) {
if (value == ThreadActivity::Paused) {
// Set status if not waiting
if (status == ThreadStatus::Ready) {
status = ThreadStatus::Paused;
} else if (status == ThreadStatus::Running) {
status = ThreadStatus::Paused;
if (status == ThreadStatus::Ready || status == ThreadStatus::Running) {
SetStatus(ThreadStatus::Paused);
Core::System::GetInstance().CpuCore(processor_id).PrepareReschedule();
}
} else if (status == ThreadStatus::Paused) {
@ -408,6 +372,170 @@ void Thread::Sleep(s64 nanoseconds) {
WakeAfterDelay(nanoseconds);
}
bool Thread::YieldSimple() {
auto& scheduler = kernel.GlobalScheduler();
return scheduler.YieldThread(this);
}
bool Thread::YieldAndBalanceLoad() {
auto& scheduler = kernel.GlobalScheduler();
return scheduler.YieldThreadAndBalanceLoad(this);
}
bool Thread::YieldAndWaitForLoadBalancing() {
auto& scheduler = kernel.GlobalScheduler();
return scheduler.YieldThreadAndWaitForLoadBalancing(this);
}
void Thread::SetSchedulingStatus(ThreadSchedStatus new_status) {
const u32 old_flags = scheduling_state;
scheduling_state = (scheduling_state & static_cast<u32>(ThreadSchedMasks::HighMask)) |
static_cast<u32>(new_status);
AdjustSchedulingOnStatus(old_flags);
}
void Thread::SetCurrentPriority(u32 new_priority) {
const u32 old_priority = std::exchange(current_priority, new_priority);
AdjustSchedulingOnPriority(old_priority);
}
ResultCode Thread::SetCoreAndAffinityMask(s32 new_core, u64 new_affinity_mask) {
const auto HighestSetCore = [](u64 mask, u32 max_cores) {
for (s32 core = max_cores - 1; core >= 0; core--) {
if (((mask >> core) & 1) != 0) {
return core;
}
}
return -1;
};
const bool use_override = affinity_override_count != 0;
if (new_core == THREADPROCESSORID_DONT_UPDATE) {
new_core = use_override ? ideal_core_override : ideal_core;
if ((new_affinity_mask & (1ULL << new_core)) == 0) {
return ERR_INVALID_COMBINATION;
}
}
if (use_override) {
ideal_core_override = new_core;
affinity_mask_override = new_affinity_mask;
} else {
const u64 old_affinity_mask = std::exchange(affinity_mask, new_affinity_mask);
ideal_core = new_core;
if (old_affinity_mask != new_affinity_mask) {
const s32 old_core = processor_id;
if (processor_id >= 0 && ((affinity_mask >> processor_id) & 1) == 0) {
if (ideal_core < 0) {
processor_id = HighestSetCore(affinity_mask, GlobalScheduler::NUM_CPU_CORES);
} else {
processor_id = ideal_core;
}
}
AdjustSchedulingOnAffinity(old_affinity_mask, old_core);
}
}
return RESULT_SUCCESS;
}
void Thread::AdjustSchedulingOnStatus(u32 old_flags) {
if (old_flags == scheduling_state) {
return;
}
auto& scheduler = kernel.GlobalScheduler();
if (static_cast<ThreadSchedStatus>(old_flags & static_cast<u32>(ThreadSchedMasks::LowMask)) ==
ThreadSchedStatus::Runnable) {
// In this case the thread was running, now it's pausing/exitting
if (processor_id >= 0) {
scheduler.Unschedule(current_priority, processor_id, this);
}
for (s32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
scheduler.Unsuggest(current_priority, static_cast<u32>(core), this);
}
}
} else if (GetSchedulingStatus() == ThreadSchedStatus::Runnable) {
// The thread is now set to running from being stopped
if (processor_id >= 0) {
scheduler.Schedule(current_priority, processor_id, this);
}
for (s32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
scheduler.Suggest(current_priority, static_cast<u32>(core), this);
}
}
}
scheduler.SetReselectionPending();
}
void Thread::AdjustSchedulingOnPriority(u32 old_priority) {
if (GetSchedulingStatus() != ThreadSchedStatus::Runnable) {
return;
}
auto& scheduler = Core::System::GetInstance().GlobalScheduler();
if (processor_id >= 0) {
scheduler.Unschedule(old_priority, processor_id, this);
}
for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
scheduler.Unsuggest(old_priority, core, this);
}
}
// Add thread to the new priority queues.
Thread* current_thread = GetCurrentThread();
if (processor_id >= 0) {
if (current_thread == this) {
scheduler.SchedulePrepend(current_priority, processor_id, this);
} else {
scheduler.Schedule(current_priority, processor_id, this);
}
}
for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
scheduler.Suggest(current_priority, core, this);
}
}
scheduler.SetReselectionPending();
}
void Thread::AdjustSchedulingOnAffinity(u64 old_affinity_mask, s32 old_core) {
auto& scheduler = Core::System::GetInstance().GlobalScheduler();
if (GetSchedulingStatus() != ThreadSchedStatus::Runnable ||
current_priority >= THREADPRIO_COUNT) {
return;
}
for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (((old_affinity_mask >> core) & 1) != 0) {
if (core == old_core) {
scheduler.Unschedule(current_priority, core, this);
} else {
scheduler.Unsuggest(current_priority, core, this);
}
}
}
for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (((affinity_mask >> core) & 1) != 0) {
if (core == processor_id) {
scheduler.Schedule(current_priority, core, this);
} else {
scheduler.Suggest(current_priority, core, this);
}
}
}
scheduler.SetReselectionPending();
}
////////////////////////////////////////////////////////////////////////////////////////////////////
/**

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@ -75,6 +75,26 @@ enum class ThreadActivity : u32 {
Paused = 1,
};
enum class ThreadSchedStatus : u32 {
None = 0,
Paused = 1,
Runnable = 2,
Exited = 3,
};
enum class ThreadSchedFlags : u32 {
ProcessPauseFlag = 1 << 4,
ThreadPauseFlag = 1 << 5,
ProcessDebugPauseFlag = 1 << 6,
KernelInitPauseFlag = 1 << 8,
};
enum class ThreadSchedMasks : u32 {
LowMask = 0x000f,
HighMask = 0xfff0,
ForcePauseMask = 0x0070,
};
class Thread final : public WaitObject {
public:
using MutexWaitingThreads = std::vector<SharedPtr<Thread>>;
@ -278,6 +298,10 @@ public:
return processor_id;
}
void SetProcessorID(s32 new_core) {
processor_id = new_core;
}
Process* GetOwnerProcess() {
return owner_process;
}
@ -295,6 +319,9 @@ public:
}
void ClearWaitObjects() {
for (const auto& waiting_object : wait_objects) {
waiting_object->RemoveWaitingThread(this);
}
wait_objects.clear();
}
@ -383,11 +410,47 @@ public:
/// Sleeps this thread for the given amount of nanoseconds.
void Sleep(s64 nanoseconds);
/// Yields this thread without rebalancing loads.
bool YieldSimple();
/// Yields this thread and does a load rebalancing.
bool YieldAndBalanceLoad();
/// Yields this thread and if the core is left idle, loads are rebalanced
bool YieldAndWaitForLoadBalancing();
void IncrementYieldCount() {
yield_count++;
}
u64 GetYieldCount() const {
return yield_count;
}
ThreadSchedStatus GetSchedulingStatus() const {
return static_cast<ThreadSchedStatus>(scheduling_state &
static_cast<u32>(ThreadSchedMasks::LowMask));
}
bool IsRunning() const {
return is_running;
}
void SetIsRunning(bool value) {
is_running = value;
}
private:
explicit Thread(KernelCore& kernel);
~Thread() override;
void ChangeScheduler();
void SetSchedulingStatus(ThreadSchedStatus new_status);
void SetCurrentPriority(u32 new_priority);
ResultCode SetCoreAndAffinityMask(s32 new_core, u64 new_affinity_mask);
void AdjustSchedulingOnStatus(u32 old_flags);
void AdjustSchedulingOnPriority(u32 old_priority);
void AdjustSchedulingOnAffinity(u64 old_affinity_mask, s32 old_core);
Core::ARM_Interface::ThreadContext context{};
@ -409,6 +472,8 @@ private:
u64 total_cpu_time_ticks = 0; ///< Total CPU running ticks.
u64 last_running_ticks = 0; ///< CPU tick when thread was last running
u64 yield_count = 0; ///< Number of redundant yields carried by this thread.
///< a redundant yield is one where no scheduling is changed
s32 processor_id = 0;
@ -453,6 +518,13 @@ private:
ThreadActivity activity = ThreadActivity::Normal;
s32 ideal_core_override = -1;
u64 affinity_mask_override = 0x1;
u32 affinity_override_count = 0;
u32 scheduling_state = 0;
bool is_running = false;
std::string name;
};

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@ -6,6 +6,9 @@
#include "common/assert.h"
#include "common/common_types.h"
#include "common/logging/log.h"
#include "core/core.h"
#include "core/core_cpu.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/object.h"
#include "core/hle/kernel/process.h"
#include "core/hle/kernel/thread.h"
@ -82,9 +85,6 @@ void WaitObject::WakeupWaitingThread(SharedPtr<Thread> thread) {
const std::size_t index = thread->GetWaitObjectIndex(this);
for (const auto& object : thread->GetWaitObjects()) {
object->RemoveWaitingThread(thread.get());
}
thread->ClearWaitObjects();
thread->CancelWakeupTimer();
@ -95,6 +95,7 @@ void WaitObject::WakeupWaitingThread(SharedPtr<Thread> thread) {
}
if (resume) {
thread->ResumeFromWait();
Core::System::GetInstance().PrepareReschedule(thread->GetProcessorID());
}
}

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@ -66,10 +66,7 @@ std::vector<std::unique_ptr<WaitTreeThread>> WaitTreeItem::MakeThreadItemList()
};
const auto& system = Core::System::GetInstance();
add_threads(system.Scheduler(0).GetThreadList());
add_threads(system.Scheduler(1).GetThreadList());
add_threads(system.Scheduler(2).GetThreadList());
add_threads(system.Scheduler(3).GetThreadList());
add_threads(system.GlobalScheduler().GetThreadList());
return item_list;
}