Kernel: Initial implementation of thread preemption.

This commit is contained in:
Fernando Sahmkow 2019-09-10 11:04:40 -04:00 committed by FernandoS27
parent 103f3a2fe5
commit b49c0dab87
3 changed files with 30 additions and 0 deletions

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@ -12,6 +12,7 @@
#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/handle_table.h"
@ -96,6 +97,7 @@ struct KernelCore::Impl {
InitializeSystemResourceLimit(kernel);
InitializeThreads();
InitializePreemption();
}
void Shutdown() {
@ -111,6 +113,7 @@ struct KernelCore::Impl {
thread_wakeup_callback_handle_table.Clear();
thread_wakeup_event_type = nullptr;
preemption_event = nullptr;
named_ports.clear();
}
@ -133,6 +136,18 @@ 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};
@ -146,6 +161,7 @@ struct KernelCore::Impl {
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;

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@ -238,6 +238,16 @@ bool GlobalScheduler::YieldThreadAndWaitForLoadBalancing(Thread* 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 u64 priority = preemption_priorities[core_id];
if (scheduled_queue[core_id].size(priority) > 1) {
scheduled_queue[core_id].yield(priority);
reselection_pending.store(true, std::memory_order_release);
}
}
}
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);

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@ -133,6 +133,8 @@ public:
*/
bool YieldThreadAndWaitForLoadBalancing(Thread* thread);
void PreemptThreads();
u32 CpuCoresCount() const {
return NUM_CPU_CORES;
}
@ -153,6 +155,8 @@ private:
std::array<Common::MultiLevelQueue<Thread*, THREADPRIO_COUNT>, NUM_CPU_CORES> suggested_queue;
std::atomic<bool> reselection_pending;
std::array<u64, 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;