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-rw-r--r--src/common/x64/cpu_wait.cpp33
1 files changed, 21 insertions, 12 deletions
diff --git a/src/common/x64/cpu_wait.cpp b/src/common/x64/cpu_wait.cpp
index c53dd4945..11b9c4d83 100644
--- a/src/common/x64/cpu_wait.cpp
+++ b/src/common/x64/cpu_wait.cpp
@@ -13,24 +13,30 @@
namespace Common::X64 {
+namespace {
+
+// 100,000 cycles is a reasonable amount of time to wait to save on CPU resources.
+// For reference:
+// At 1 GHz, 100K cycles is 100us
+// At 2 GHz, 100K cycles is 50us
+// At 4 GHz, 100K cycles is 25us
+constexpr auto PauseCycles = 100'000U;
+
+} // Anonymous namespace
+
#ifdef _MSC_VER
__forceinline static void TPAUSE() {
- // 100,000 cycles is a reasonable amount of time to wait to save on CPU resources.
- // For reference:
- // At 1 GHz, 100K cycles is 100us
- // At 2 GHz, 100K cycles is 50us
- // At 4 GHz, 100K cycles is 25us
- static constexpr auto PauseCycles = 100'000;
_tpause(0, FencedRDTSC() + PauseCycles);
}
+
+__forceinline static void MWAITX() {
+ // monitor_var should be aligned to a cache line.
+ alignas(64) u64 monitor_var{};
+ _mm_monitorx(&monitor_var, 0, 0);
+ _mm_mwaitx(/* extensions*/ 2, /* hints */ 0, /* cycles */ PauseCycles);
+}
#else
static void TPAUSE() {
- // 100,000 cycles is a reasonable amount of time to wait to save on CPU resources.
- // For reference:
- // At 1 GHz, 100K cycles is 100us
- // At 2 GHz, 100K cycles is 50us
- // At 4 GHz, 100K cycles is 25us
- static constexpr auto PauseCycles = 100'000;
const auto tsc = FencedRDTSC() + PauseCycles;
const auto eax = static_cast<u32>(tsc & 0xFFFFFFFF);
const auto edx = static_cast<u32>(tsc >> 32);
@@ -40,9 +46,12 @@ static void TPAUSE() {
void MicroSleep() {
static const bool has_waitpkg = GetCPUCaps().waitpkg;
+ static const bool has_monitorx = GetCPUCaps().monitorx;
if (has_waitpkg) {
TPAUSE();
+ } else if (has_monitorx) {
+ MWAITX();
} else {
std::this_thread::yield();
}