diff -r fcad92f425c5 -r 56bf71d64d51 src/hotspot/os_cpu/linux_ppc/atomic_linux_ppc.hpp
--- a/src/hotspot/os_cpu/linux_ppc/atomic_linux_ppc.hpp	Mon Nov 25 14:06:13 2019 +0100
+++ b/src/hotspot/os_cpu/linux_ppc/atomic_linux_ppc.hpp	Mon Nov 25 12:22:13 2019 +0100
@@ -30,6 +30,7 @@
 #error "Atomic currently only implemented for PPC64"
 #endif
 
+#include "orderAccess_linux_ppc.hpp"
 #include "utilities/debug.hpp"
 
 // Implementation of class atomic
@@ -399,4 +400,16 @@
   return old_value;
 }
 
+template<size_t byte_size>
+struct Atomic::PlatformOrderedLoad<byte_size, X_ACQUIRE>
+{
+  template <typename T>
+  T operator()(const volatile T* p) const {
+    T t = Atomic::load(p);
+    // Use twi-isync for load_acquire (faster than lwsync).
+    __asm__ __volatile__ ("twi 0,%0,0\n isync\n" : : "r" (t) : "memory");
+    return t;
+  }
+};
+
 #endif // OS_CPU_LINUX_PPC_ATOMIC_LINUX_PPC_HPP