diff -up jdk8/hotspot/src/os_cpu/linux_zero/vm/globals_linux_zero.hpp.ppc64 jdk8/hotspot/src/os_cpu/linux_zero/vm/globals_linux_zero.hpp
--- jdk8/hotspot/src/os_cpu/linux_zero/vm/globals_linux_zero.hpp.ppc64	2013-02-22 19:02:06.000000000 +0100
+++ jdk8/hotspot/src/os_cpu/linux_zero/vm/globals_linux_zero.hpp	2013-04-18 16:21:24.897403406 +0200
@@ -32,11 +32,11 @@
 //
 
 define_pd_global(bool,  DontYieldALot,           false);
-define_pd_global(intx,  ThreadStackSize,         1536);
+define_pd_global(intx,  ThreadStackSize,         1664);
 #ifdef _LP64
-define_pd_global(intx,  VMThreadStackSize,       1024);
+define_pd_global(intx,  VMThreadStackSize,       1664);
 #else
-define_pd_global(intx,  VMThreadStackSize,       512);
+define_pd_global(intx,  VMThreadStackSize,       1152);
 #endif // _LP64
 define_pd_global(intx,  CompilerThreadStackSize, 0);
 define_pd_global(uintx, JVMInvokeMethodSlack,    8192);