Scheduler: Implement Yield Count and Core migration on Thread Preemption.

This commit is contained in:
Fernando Sahmkow 2019-09-11 12:14:37 -04:00 committed by FernandoS27
parent 2d382de6fa
commit 0cf26cee59
2 changed files with 85 additions and 5 deletions

View File

@ -241,10 +241,83 @@ bool GlobalScheduler::YieldThreadAndWaitForLoadBalancing(Thread* yielding_thread
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) > 1) {
if (scheduled_queue[core_id].size(priority) > 0) {
scheduled_queue[core_id].front(priority)->IncrementYieldCount();
scheduled_queue[core_id].yield(priority);
reselection_pending.store(true, std::memory_order_release);
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;
}
}
reselection_pending.store(true, std::memory_order_release);
}
}
@ -260,9 +333,7 @@ void GlobalScheduler::SchedulePrepend(u32 priority, u32 core, Thread* thread) {
bool GlobalScheduler::AskForReselectionOrMarkRedundant(Thread* current_thread, Thread* winner) {
if (current_thread == winner) {
// TODO(blinkhawk): manage redundant operations, this is not implemented.
// as its mostly an optimization.
// current_thread->SetRedundantSchedulerOperation();
current_thread->IncrementYieldCount();
return true;
} else {
reselection_pending.store(true, std::memory_order_release);

View File

@ -416,6 +416,14 @@ public:
/// 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 & ThreadSchedMasks::LowMask);
}
@ -460,6 +468,7 @@ 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 innecessaries yields occured.
s32 processor_id = 0;