Thread: Implement priority boost for starved threads.

SVC: Return correct error code on invalid CreateThread processor ID.

SVC: Assert when creating a thread with an invalid userland priority.
This commit is contained in:
bunnei 2015-03-23 23:55:21 -04:00
parent ee3377b67d
commit 7b9f428b23
5 changed files with 92 additions and 28 deletions

View file

@ -40,6 +40,18 @@ struct ThreadQueueList {
return -1; return -1;
} }
T get_first() {
Queue *cur = first;
while (cur != nullptr) {
if (!cur->data.empty()) {
return cur->data.front();
}
cur = cur->next_nonempty;
}
return T();
}
T pop_first() { T pop_first() {
Queue *cur = first; Queue *cur = first;
while (cur != nullptr) { while (cur != nullptr) {
@ -79,6 +91,12 @@ struct ThreadQueueList {
cur->data.push_back(thread_id); cur->data.push_back(thread_id);
} }
void move(const T& thread_id, Priority old_priority, Priority new_priority) {
remove(old_priority, thread_id);
prepare(new_priority);
push_back(new_priority, thread_id);
}
void remove(Priority priority, const T& thread_id) { void remove(Priority priority, const T& thread_id) {
Queue *cur = &queues[priority]; Queue *cur = &queues[priority];
boost::remove_erase(cur->data, thread_id); boost::remove_erase(cur->data, thread_id);

View file

@ -46,6 +46,13 @@ template<ResultCode func(u32*, u32, u32, u32, u32, u32)> void Wrap(){
FuncReturn(retval); FuncReturn(retval);
} }
template<ResultCode func(u32*, s32, u32, u32, u32, s32)> void Wrap() {
u32 param_1 = 0;
u32 retval = func(&param_1, PARAM(0), PARAM(1), PARAM(2), PARAM(3), PARAM(4)).raw;
Core::g_app_core->SetReg(1, param_1);
FuncReturn(retval);
}
template<ResultCode func(s32*, u32*, s32, bool, s64)> void Wrap() { template<ResultCode func(s32*, u32*, s32, bool, s64)> void Wrap() {
s32 param_1 = 0; s32 param_1 = 0;
s32 retval = func(&param_1, (Handle*)Memory::GetPointer(PARAM(1)), (s32)PARAM(2), s32 retval = func(&param_1, (Handle*)Memory::GetPointer(PARAM(1)), (s32)PARAM(2),

View file

@ -140,6 +140,29 @@ void ArbitrateAllThreads(u32 address) {
} }
} }
/// Boost low priority threads (temporarily) that have been starved
static void PriorityBoostStarvedThreads() {
u64 current_ticks = CoreTiming::GetTicks();
for (auto& thread : thread_list) {
// TODO(bunnei): Threads that have been waiting to be scheduled for `boost_ticks` (or
// longer) will have their priority temporarily adjusted to 1 higher than the highest
// priority thread to prevent thread starvation. This general behavior has been verified
// on hardware. However, this is almost certainly not perfect, and the real CTR OS scheduler
// should probably be reversed to verify this.
const u64 boost_timeout = 2000000; // Boost threads that have been ready for > this long
u64 delta = current_ticks - thread->last_running_ticks;
if (thread->status == THREADSTATUS_READY && delta > boost_timeout && !thread->idle) {
const s32 boost_priority = std::max(ready_queue.get_first()->current_priority - 1, 0);
ready_queue.move(thread, thread->current_priority, boost_priority);
thread->current_priority = boost_priority;
}
}
}
/** /**
* Switches the CPU's active thread context to that of the specified thread * Switches the CPU's active thread context to that of the specified thread
* @param new_thread The thread to switch to * @param new_thread The thread to switch to
@ -151,6 +174,7 @@ static void SwitchContext(Thread* new_thread) {
// Save context for previous thread // Save context for previous thread
if (previous_thread) { if (previous_thread) {
previous_thread->last_running_ticks = CoreTiming::GetTicks();
Core::g_app_core->SaveContext(previous_thread->context); Core::g_app_core->SaveContext(previous_thread->context);
if (previous_thread->status == THREADSTATUS_RUNNING) { if (previous_thread->status == THREADSTATUS_RUNNING) {
@ -168,6 +192,9 @@ static void SwitchContext(Thread* new_thread) {
ready_queue.remove(new_thread->current_priority, new_thread); ready_queue.remove(new_thread->current_priority, new_thread);
new_thread->status = THREADSTATUS_RUNNING; new_thread->status = THREADSTATUS_RUNNING;
// Restores thread to its nominal priority if it has been temporarily changed
new_thread->current_priority = new_thread->nominal_priority;
Core::g_app_core->LoadContext(new_thread->context); Core::g_app_core->LoadContext(new_thread->context);
} else { } else {
current_thread = nullptr; current_thread = nullptr;
@ -364,7 +391,8 @@ ResultVal<SharedPtr<Thread>> Thread::Create(std::string name, VAddr entry_point,
thread->status = THREADSTATUS_DORMANT; thread->status = THREADSTATUS_DORMANT;
thread->entry_point = entry_point; thread->entry_point = entry_point;
thread->stack_top = stack_top; thread->stack_top = stack_top;
thread->initial_priority = thread->current_priority = priority; thread->nominal_priority = thread->current_priority = priority;
thread->last_running_ticks = CoreTiming::GetTicks();
thread->processor_id = processor_id; thread->processor_id = processor_id;
thread->wait_set_output = false; thread->wait_set_output = false;
thread->wait_all = false; thread->wait_all = false;
@ -400,18 +428,11 @@ static void ClampPriority(const Thread* thread, s32* priority) {
void Thread::SetPriority(s32 priority) { void Thread::SetPriority(s32 priority) {
ClampPriority(this, &priority); ClampPriority(this, &priority);
if (current_priority == priority) {
return;
}
if (status == THREADSTATUS_READY) {
// If thread was ready, adjust queues // If thread was ready, adjust queues
ready_queue.remove(current_priority, this); if (status == THREADSTATUS_READY)
ready_queue.prepare(priority); ready_queue.move(this, current_priority, priority);
ready_queue.push_back(priority, this);
}
current_priority = priority; nominal_priority = current_priority = priority;
} }
SharedPtr<Thread> SetupIdleThread() { SharedPtr<Thread> SetupIdleThread() {
@ -440,6 +461,9 @@ SharedPtr<Thread> SetupMainThread(u32 stack_size, u32 entry_point, s32 priority)
void Reschedule() { void Reschedule() {
Thread* prev = GetCurrentThread(); Thread* prev = GetCurrentThread();
PriorityBoostStarvedThreads();
Thread* next = PopNextReadyThread(); Thread* next = PopNextReadyThread();
HLE::g_reschedule = false; HLE::g_reschedule = false;

View file

@ -17,16 +17,19 @@
#include "core/hle/kernel/kernel.h" #include "core/hle/kernel/kernel.h"
#include "core/hle/result.h" #include "core/hle/result.h"
enum ThreadPriority { enum ThreadPriority : s32{
THREADPRIO_HIGHEST = 0x0, ///< Highest thread priority THREADPRIO_HIGHEST = 0, ///< Highest thread priority
THREADPRIO_DEFAULT = 0x30, ///< Default thread priority for userland apps THREADPRIO_USERLAND_MAX = 24, ///< Highest thread priority for userland apps
THREADPRIO_LOWEST = 0x3F, ///< Lowest thread priority THREADPRIO_DEFAULT = 48, ///< Default thread priority for userland apps
THREADPRIO_LOWEST = 63, ///< Lowest thread priority
}; };
enum ThreadProcessorId { enum ThreadProcessorId : s32 {
THREADPROCESSORID_0 = 0xFFFFFFFE, ///< Enables core appcode THREADPROCESSORID_DEFAULT = -2, ///< Run thread on default core specified by exheader
THREADPROCESSORID_1 = 0xFFFFFFFD, ///< Enables core syscore THREADPROCESSORID_ALL = -1, ///< Run thread on either core
THREADPROCESSORID_ALL = 0xFFFFFFFC, ///< Enables both cores THREADPROCESSORID_0 = 0, ///< Run thread on core 0 (AppCore)
THREADPROCESSORID_1 = 1, ///< Run thread on core 1 (SysCore)
THREADPROCESSORID_MAX = 2, ///< Processor ID must be less than this
}; };
enum ThreadStatus { enum ThreadStatus {
@ -134,8 +137,10 @@ public:
u32 entry_point; u32 entry_point;
u32 stack_top; u32 stack_top;
s32 initial_priority; s32 nominal_priority; ///< Nominal thread priority, as set by the emulated application
s32 current_priority; s32 current_priority; ///< Current thread priority, can be temporarily changed
u64 last_running_ticks; ///< CPU tick when thread was last running
s32 processor_id; s32 processor_id;

View file

@ -312,7 +312,7 @@ static ResultCode GetResourceLimitCurrentValues(s64* values, Handle resource_lim
} }
/// Creates a new thread /// Creates a new thread
static ResultCode CreateThread(u32* out_handle, u32 priority, u32 entry_point, u32 arg, u32 stack_top, u32 processor_id) { static ResultCode CreateThread(Handle* out_handle, s32 priority, u32 entry_point, u32 arg, u32 stack_top, s32 processor_id) {
using Kernel::Thread; using Kernel::Thread;
std::string name; std::string name;
@ -323,6 +323,21 @@ static ResultCode CreateThread(u32* out_handle, u32 priority, u32 entry_point, u
name = Common::StringFromFormat("unknown-%08x", entry_point); name = Common::StringFromFormat("unknown-%08x", entry_point);
} }
// TODO(bunnei): Implement resource limits to return an error code instead of the below assert.
// The error code should be: Description::NotAuthorized, Module::OS, Summary::WrongArgument,
// Level::Permanent
ASSERT_MSG(priority >= THREADPRIO_USERLAND_MAX, "Unexpected thread priority!");
if (priority > THREADPRIO_LOWEST) {
return ResultCode(ErrorDescription::OutOfRange, ErrorModule::OS,
ErrorSummary::InvalidArgument, ErrorLevel::Usage);
}
if (processor_id > THREADPROCESSORID_MAX) {
return ResultCode(ErrorDescription::OutOfRange, ErrorModule::Kernel,
ErrorSummary::InvalidArgument, ErrorLevel::Permanent);
}
CASCADE_RESULT(SharedPtr<Thread> thread, Kernel::Thread::Create( CASCADE_RESULT(SharedPtr<Thread> thread, Kernel::Thread::Create(
name, entry_point, priority, arg, processor_id, stack_top)); name, entry_point, priority, arg, processor_id, stack_top));
CASCADE_RESULT(*out_handle, Kernel::g_handle_table.Create(std::move(thread))); CASCADE_RESULT(*out_handle, Kernel::g_handle_table.Create(std::move(thread)));
@ -331,11 +346,6 @@ static ResultCode CreateThread(u32* out_handle, u32 priority, u32 entry_point, u
"threadpriority=0x%08X, processorid=0x%08X : created handle=0x%08X", entry_point, "threadpriority=0x%08X, processorid=0x%08X : created handle=0x%08X", entry_point,
name.c_str(), arg, stack_top, priority, processor_id, *out_handle); name.c_str(), arg, stack_top, priority, processor_id, *out_handle);
if (THREADPROCESSORID_1 == processor_id) {
LOG_WARNING(Kernel_SVC,
"thread designated for system CPU core (UNIMPLEMENTED) will be run with app core scheduling");
}
HLE::Reschedule(__func__); HLE::Reschedule(__func__);
return RESULT_SUCCESS; return RESULT_SUCCESS;