From b178089251200bd0309afcbcb06b43e7c82dc3bc Mon Sep 17 00:00:00 2001 From: Subv Date: Sat, 22 Jul 2017 19:37:26 -0500 Subject: Kernel/Threads: Don't clear the CPU instruction cache when performing a context switch from an idle thread into a thread in the same process. We were unnecessarily clearing the cache when going from Process A -> Idle -> Process A, this caused extreme performance regressions. --- src/core/hle/kernel/thread.cpp | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'src/core/hle/kernel/thread.cpp') diff --git a/src/core/hle/kernel/thread.cpp b/src/core/hle/kernel/thread.cpp index b7f094f46..f77c39d18 100644 --- a/src/core/hle/kernel/thread.cpp +++ b/src/core/hle/kernel/thread.cpp @@ -171,6 +171,8 @@ static void SwitchContext(Thread* new_thread) { // Cancel any outstanding wakeup events for this thread CoreTiming::UnscheduleEvent(ThreadWakeupEventType, new_thread->callback_handle); + auto previous_process = Kernel::g_current_process; + current_thread = new_thread; ready_queue.remove(new_thread->current_priority, new_thread); @@ -179,7 +181,7 @@ static void SwitchContext(Thread* new_thread) { Core::CPU().LoadContext(new_thread->context); Core::CPU().SetCP15Register(CP15_THREAD_URO, new_thread->GetTLSAddress()); - if (!previous_thread || previous_thread->owner_process != current_thread->owner_process) { + if (previous_process != current_thread->owner_process) { Kernel::g_current_process = current_thread->owner_process; Memory::current_page_table = &Kernel::g_current_process->vm_manager.page_table; // We have switched processes and thus, page tables, clear the instruction cache so we -- cgit v1.2.3