From 97f2b6b701b66b72de82ed7e7ae12c28ed43162b Mon Sep 17 00:00:00 2001
From: elad335 <18193363+elad335@users.noreply.github.com>
Date: Tue, 29 Oct 2024 16:11:44 +0200
Subject: [PATCH] Fix get_system_time()

---
 rpcs3/Emu/Cell/lv2/sys_time.cpp |  4 ++--
 rpcs3/main.cpp                  |  3 ---
 rpcs3/util/sysinfo.cpp          | 42 +++++++++++++++++++++------------
 rpcs3/util/sysinfo.hpp          |  2 --
 4 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/rpcs3/Emu/Cell/lv2/sys_time.cpp b/rpcs3/Emu/Cell/lv2/sys_time.cpp
index adc15da13a..b04be640bc 100644
--- a/rpcs3/Emu/Cell/lv2/sys_time.cpp
+++ b/rpcs3/Emu/Cell/lv2/sys_time.cpp
@@ -212,9 +212,9 @@ u64 get_system_time()
 		const u64 tsc = utils::get_tsc();
 
 #if _MSC_VER
-		const u64 result = static_cast<u64>(u128_from_mul(tsc, 1000000ull) / freq) * g_cfg.core.clocks_scale / 100u;
+		const u64 result = static_cast<u64>(u128_from_mul(tsc, 1000000ull) / freq);
 #else
-		const u64 result = (tsc / freq * 1000000ull + tsc % freq * 1000000ull / freq) * g_cfg.core.clocks_scale / 100u;
+		const u64 result = (tsc / freq * 1000000ull + tsc % freq * 1000000ull / freq);
 #endif
 		return result;
 	}
diff --git a/rpcs3/main.cpp b/rpcs3/main.cpp
index a6f7acf285..1c2e73ecf9 100644
--- a/rpcs3/main.cpp
+++ b/rpcs3/main.cpp
@@ -569,9 +569,6 @@ int main(int argc, char** argv)
 
 	ensure(thread_ctrl::is_main(), "Not main thread");
 
-	// Initialize TSC freq (in case it isn't)
-	static_cast<void>(utils::ensure_tsc_freq_init());
-
 	// Initialize thread pool finalizer (on first use)
 	static_cast<void>(named_thread("", [](int) {}));
 
diff --git a/rpcs3/util/sysinfo.cpp b/rpcs3/util/sysinfo.cpp
index f8e122a4e9..4eca3a6705 100755
--- a/rpcs3/util/sysinfo.cpp
+++ b/rpcs3/util/sysinfo.cpp
@@ -734,9 +734,24 @@ bool utils::get_low_power_mode()
 #endif
 }
 
-static constexpr ullong round_tsc(ullong val)
+static constexpr ullong round_tsc(ullong val, ullong known_error)
 {
-	return utils::rounded_div(val, 100'000) * 100'000;
+	if (known_error >= 500'000)
+	{
+		// Do not accept large errors
+		return 0;
+	}
+
+	ullong by = 1000;
+	known_error /= 1000;
+
+	while (known_error && by < 100'000)
+	{
+		by *= 10;
+		known_error /= 10;
+	}
+
+	return utils::rounded_div(val, by) * by;
 }
 
 namespace utils
@@ -744,7 +759,7 @@ namespace utils
 	u64 s_tsc_freq = 0;
 }
 
-named_thread<std::function<void()>> s_thread_evaluate_tsc_freq("TSC Evaluate Thread", []()
+static const bool s_tsc_freq_evaluated = []() -> bool
 {
 	static const ullong cal_tsc = []() -> ullong
 	{
@@ -763,7 +778,7 @@ named_thread<std::function<void()>> s_thread_evaluate_tsc_freq("TSC Evaluate Thr
 			return 0;
 
 		if (freq.QuadPart <= 9'999'999)
-			return round_tsc(freq.QuadPart * 1024);
+			return 0;
 
 		const ullong timer_freq = freq.QuadPart;
 #else
@@ -788,6 +803,8 @@ named_thread<std::function<void()>> s_thread_evaluate_tsc_freq("TSC Evaluate Thr
 		const ullong sec_base = ts0.tv_sec;
 #endif
 
+		constexpr usz sleep_time_ms = 20;
+
 		for (usz sample = 0; sample < sample_count; sample++)
 		{
 			for (usz i = 0; i < retry_count; i++)
@@ -823,11 +840,11 @@ named_thread<std::function<void()>> s_thread_evaluate_tsc_freq("TSC Evaluate Thr
 
 			if (sample < sample_count - 1)
 			{
-				// Sleep 20ms between first and last sample
+				// Sleep between first and last sample
 #ifdef _WIN32
-				Sleep(20);
+				Sleep(sleep_time_ms);
 #else
-				usleep(20'000);
+				usleep(sleep_time_ms * 1000);
 #endif
 			}
 		}
@@ -843,17 +860,12 @@ named_thread<std::function<void()>> s_thread_evaluate_tsc_freq("TSC Evaluate Thr
 		const u64 res = utils::udiv128(static_cast<u64>(data >> 64), static_cast<u64>(data), (timer_data[1] - timer_data[0]));
 
 		// Rounding
-		return round_tsc(res);
+		return round_tsc(res, utils::mul_saturate<u64>(utils::add_saturate<u64>(rdtsc_diff[0], rdtsc_diff[1]), utils::aligned_div(timer_freq, timer_data[1] - timer_data[0])));
 	}();
 
 	atomic_storage<u64>::release(utils::s_tsc_freq, cal_tsc);
-});
-
-void utils::ensure_tsc_freq_init()
-{
-	// Join thread
-	s_thread_evaluate_tsc_freq();
-}
+	return true;
+}();
 
 u64 utils::get_total_memory()
 {
diff --git a/rpcs3/util/sysinfo.hpp b/rpcs3/util/sysinfo.hpp
index 5c38d433f0..4081b3a9cf 100755
--- a/rpcs3/util/sysinfo.hpp
+++ b/rpcs3/util/sysinfo.hpp
@@ -94,6 +94,4 @@ namespace utils
 	{
 		return s_tsc_freq;
 	}
-
-	void ensure_tsc_freq_init();
 }