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-rw-r--r--src/common/x64/native_clock.cpp17
1 files changed, 12 insertions, 5 deletions
diff --git a/src/common/x64/native_clock.cpp b/src/common/x64/native_clock.cpp
index 8b08332ab..bc1a973b0 100644
--- a/src/common/x64/native_clock.cpp
+++ b/src/common/x64/native_clock.cpp
@@ -6,6 +6,7 @@
#include <thread>
#include "common/atomic_ops.h"
+#include "common/steady_clock.h"
#include "common/uint128.h"
#include "common/x64/native_clock.h"
@@ -39,6 +40,12 @@ static u64 FencedRDTSC() {
}
#endif
+template <u64 Nearest>
+static u64 RoundToNearest(u64 value) {
+ const auto mod = value % Nearest;
+ return mod >= (Nearest / 2) ? (value - mod + Nearest) : (value - mod);
+}
+
u64 EstimateRDTSCFrequency() {
// Discard the first result measuring the rdtsc.
FencedRDTSC();
@@ -46,18 +53,18 @@ u64 EstimateRDTSCFrequency() {
FencedRDTSC();
// Get the current time.
- const auto start_time = std::chrono::steady_clock::now();
+ const auto start_time = Common::SteadyClock::Now();
const u64 tsc_start = FencedRDTSC();
- // Wait for 200 milliseconds.
- std::this_thread::sleep_for(std::chrono::milliseconds{200});
- const auto end_time = std::chrono::steady_clock::now();
+ // Wait for 250 milliseconds.
+ std::this_thread::sleep_for(std::chrono::milliseconds{250});
+ const auto end_time = Common::SteadyClock::Now();
const u64 tsc_end = FencedRDTSC();
// Calculate differences.
const u64 timer_diff = static_cast<u64>(
std::chrono::duration_cast<std::chrono::nanoseconds>(end_time - start_time).count());
const u64 tsc_diff = tsc_end - tsc_start;
const u64 tsc_freq = MultiplyAndDivide64(tsc_diff, 1000000000ULL, timer_diff);
- return tsc_freq;
+ return RoundToNearest<1000>(tsc_freq);
}
namespace X64 {