DonkeyKongCountryReturns_Low-Boost:lowprioritythreads

This commit is contained in:
citra 2017-10-17 17:58:57 +01:00
parent b57455646a
commit e000d756d7

View File

@ -143,6 +143,28 @@ 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) {
const s32 priority = (ready_queue.get_first()->current_priority - 1, 0);
thread->BoostPriority(priority);
}
}
}
/**
* Switches the CPU's active thread context to that of the specified thread
* @param new_thread The thread to switch to
@ -178,6 +200,9 @@ static void SwitchContext(Thread* new_thread) {
ready_queue.remove(new_thread->current_priority, new_thread);
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;
if (previous_process != current_thread->owner_process) {
Kernel::g_current_process = current_thread->owner_process;
SetCurrentPageTable(&Kernel::g_current_process->vm_manager.page_table);
@ -513,6 +538,7 @@ bool HaveReadyThreads() {
}
void Reschedule() {
PriorityBoostStarvedThreads();
Thread* cur = GetCurrentThread();
Thread* next = PopNextReadyThread();