From b6d3fa8c66999e351cd961f7dd4a57d35973c974 Mon Sep 17 00:00:00 2001
From: Eladash <elad3356p@gmail.com>
Date: Wed, 14 Sep 2022 19:45:11 +0300
Subject: [PATCH] CPU preemption control: avoidance in reservation operations

---
 rpcs3/Emu/CPU/CPUThread.cpp | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/rpcs3/Emu/CPU/CPUThread.cpp b/rpcs3/Emu/CPU/CPUThread.cpp
index c01b4b9eb2..96c80a8cdf 100644
--- a/rpcs3/Emu/CPU/CPUThread.cpp
+++ b/rpcs3/Emu/CPU/CPUThread.cpp
@@ -898,6 +898,23 @@ bool cpu_thread::check_state() noexcept
 
 			if (state0 & cpu_flag::yield && cpu_flag::wait - state0)
 			{
+				if (auto spu = try_get<spu_thread>())
+				{
+					if (spu->raddr && spu->rtime == vm::reservation_acquire(spu->raddr) && spu->getllar_spin_count < 10)
+					{
+						// Reservation operation is a critical section (but this may result in false positives)
+						continue;
+					}
+				}
+				else if (auto ppu = try_get<ppu_thread>())
+				{
+					if (ppu->raddr && ppu->rtime == vm::reservation_acquire(ppu->raddr))
+					{
+						// Same
+						continue;
+					}
+				}
+
 				// Short sleep when yield flag is present alone (makes no sense when other methods which can stop thread execution have been done)
 				// Pass a mask of a single bit which is often unused to avoid notifications
 				s_dummy_atomic.wait(0, 1u << 30, atomic_wait_timeout{80'000});