src/hotspot/cpu/x86/globals_x86.hpp

rev 56776 : v2.00 -> v2.07 (CR7/v2.07/10-for-jdk14) patches combined into one; merge with 8230876.patch (2019.10.17) and jdk-14+21.

@@ -92,13 +92,24 @@
 
 define_pd_global(intx, InitArrayShortSize, 8*BytesPerLong);
 
 #if defined(_LP64) || defined(_WINDOWS)
 define_pd_global(bool, ThreadLocalHandshakes, true);
+// ObjectMonitor ref_count is implemented in LP64 C2 fast_lock()
+// and fast_unlock() so we don't need the handshake by default.
+#ifdef _LP64
+define_pd_global(bool, HandshakeAfterDeflateIdleMonitors, false);
+#else
+define_pd_global(bool, HandshakeAfterDeflateIdleMonitors, true);
+#endif
 #else
 // get_thread() is slow on linux 32 bit, therefore off by default
 define_pd_global(bool, ThreadLocalHandshakes, false);
+// ObjectMonitor ref_count not implemented in C2 fast_lock() or
+// fast_unlock() so use a handshake for safety.
+// Will use a safepoint instead of a handshake on this platform.
+define_pd_global(bool, HandshakeAfterDeflateIdleMonitors, true);
 #endif
 
 #define ARCH_FLAGS(develop, \
                    product, \
                    diagnostic, \