diff -Nru ../openjdk.orig/hotspot/build/linux/makefiles/dtrace.make ../openjdk/hotspot/build/linux/makefiles/dtrace.make
--- ../openjdk.orig/hotspot/build/linux/makefiles/dtrace.make	2009-04-24 08:30:52.000000000 +0100
+++ ../openjdk/hotspot/build/linux/makefiles/dtrace.make	2010-03-30 20:43:06.000000000 +0100
@@ -25,3 +25,7 @@
 # Linux does not build jvm_db
 LIBJVM_DB =
 
+# But it does have a Systemtap dtrace compatible sys/sdt.h
+CFLAGS += -DDTRACE_ENABLED
+
+# It doesn't support HAVE_DTRACE_H though.
diff -Nru ../openjdk.orig/hotspot/src/share/vm/prims/jni.cpp ../openjdk/hotspot/src/share/vm/prims/jni.cpp
--- ../openjdk.orig/hotspot/src/share/vm/prims/jni.cpp	2010-03-30 20:41:19.000000000 +0100
+++ ../openjdk/hotspot/src/share/vm/prims/jni.cpp	2010-03-30 20:43:06.000000000 +0100
@@ -1744,10 +1744,7 @@
 JNI_QUICK_ENTRY(void, jni_Set##Result##Field(JNIEnv *env, jobject obj, jfieldID fieldID, Argument value)) \
   JNIWrapper("Set" XSTR(Result) "Field"); \
 \
-  HS_DTRACE_PROBE_CDECL_N(hotspot_jni, Set##Result##Field__entry, \
-    ( JNIEnv*, jobject, jfieldID FP_SELECT_##Result(COMMA Argument,/*empty*/) ) ); \
-  HS_DTRACE_PROBE_N(hotspot_jni, Set##Result##Field__entry, \
-    ( env, obj, fieldID FP_SELECT_##Result(COMMA value,/*empty*/) ) ); \
+  FP_SELECT_##Result(DTRACE_PROBE4(hotspot_jni, Set##Result##Field__entry, env, obj, fieldID, value),DTRACE_PROBE3(hotspot_jni, Set##Result##Field__entry, env, obj, fieldID)); \
 \
   oop o = JNIHandles::resolve_non_null(obj); \
   klassOop k = o->klass(); \
@@ -1921,10 +1918,7 @@
 \
 JNI_ENTRY(void, jni_SetStatic##Result##Field(JNIEnv *env, jclass clazz, jfieldID fieldID, Argument value)) \
   JNIWrapper("SetStatic" XSTR(Result) "Field"); \
-  HS_DTRACE_PROBE_CDECL_N(hotspot_jni, SetStatic##Result##Field__entry,\
-    ( JNIEnv*, jclass, jfieldID FP_SELECT_##Result(COMMA Argument,/*empty*/) ) ); \
-  HS_DTRACE_PROBE_N(hotspot_jni, SetStatic##Result##Field__entry, \
-    ( env, clazz, fieldID FP_SELECT_##Result(COMMA value,/*empty*/) ) ); \
+  FP_SELECT_##Result(DTRACE_PROBE4(hotspot_jni, SetStatic##Result##Field__entry, env, clazz, fieldID, value),DTRACE_PROBE3(hotspot_jni, SetStatic##Result##Field__entry, env, clazz, fieldID)); \
 \
   JNIid* id = jfieldIDWorkaround::from_static_jfieldID(fieldID); \
   assert(id->is_static_field_id(), "invalid static field id"); \
@@ -2107,7 +2101,7 @@
   DT_RETURN_MARK(GetObjectArrayElement, jobject, (const jobject&)ret);
   objArrayOop a = objArrayOop(JNIHandles::resolve_non_null(array));
   if (a->is_within_bounds(index)) {
-    jobject ret = JNIHandles::make_local(env, a->obj_at(index));
+    ret = JNIHandles::make_local(env, a->obj_at(index));
     return ret;
   } else {
     char buf[jintAsStringSize];
@@ -2141,14 +2135,14 @@
 
 #define DEFINE_NEWSCALARARRAY(Return,Allocator,Result) \
 \
-  DT_RETURN_MARK_DECL_FOR(Result, New##Result##Array, Return);\
+  DT_RETURN_MARK_DECL(New##Result##Array, Return);\
 \
 JNI_ENTRY(Return, \
           jni_New##Result##Array(JNIEnv *env, jsize len)) \
   JNIWrapper("New" XSTR(Result) "Array"); \
   DTRACE_PROBE2(hotspot_jni, New##Result##Array__entry, env, len);\
   Return ret = NULL;\
-  DT_RETURN_MARK_FOR(Result, New##Result##Array, Return, (const Return&)ret);\
+  DT_RETURN_MARK(New##Result##Array, Return, (const Return&)ret);\
 \
   oop obj= oopFactory::Allocator(len, CHECK_0); \
   ret = (Return) JNIHandles::make_local(env, obj); \
diff -Nru ../openjdk.orig/hotspot/src/share/vm/runtime/arguments.cpp ../openjdk/hotspot/src/share/vm/runtime/arguments.cpp
--- ../openjdk.orig/hotspot/src/share/vm/runtime/arguments.cpp	2010-03-30 20:41:21.000000000 +0100
+++ ../openjdk/hotspot/src/share/vm/runtime/arguments.cpp	2010-03-30 20:43:54.000000000 +0100
@@ -2164,16 +2164,16 @@
       FLAG_SET_CMDLINE(bool, DisplayVMOutputToStderr, false);
       FLAG_SET_CMDLINE(bool, DisplayVMOutputToStdout, true);
     } else if (match_option(option, "-XX:+ExtendedDTraceProbes", &tail)) {
-#ifdef SOLARIS
+#ifdef DTRACE_ENABLED
       FLAG_SET_CMDLINE(bool, ExtendedDTraceProbes, true);
       FLAG_SET_CMDLINE(bool, DTraceMethodProbes, true);
       FLAG_SET_CMDLINE(bool, DTraceAllocProbes, true);
       FLAG_SET_CMDLINE(bool, DTraceMonitorProbes, true);
-#else // ndef SOLARIS
+#else // ndef DTRACE_ENABLED
       jio_fprintf(defaultStream::error_stream(),
-                  "ExtendedDTraceProbes flag is only applicable on Solaris\n");
+                  "ExtendedDTraceProbes flag is only applicable on dtrace enabled builds\n");
       return JNI_EINVAL;
-#endif // ndef SOLARIS
+#endif // ndef DTRACE_ENABLED
     } else 
 #ifdef ASSERT    
     if (match_option(option, "-XX:+FullGCALot", &tail)) {
diff -Nru ../openjdk.orig/hotspot/src/share/vm/utilities/dtrace.hpp ../openjdk/hotspot/src/share/vm/utilities/dtrace.hpp
--- ../openjdk.orig/hotspot/src/share/vm/utilities/dtrace.hpp	2009-04-24 08:30:57.000000000 +0100
+++ ../openjdk/hotspot/src/share/vm/utilities/dtrace.hpp	2010-03-30 20:43:06.000000000 +0100
@@ -3,6 +3,7 @@
 #endif
 /*
  * Copyright 2005-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2009 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,14 +26,14 @@
  *  
  */
 
-#if defined(SOLARIS) && defined(DTRACE_ENABLED)
+#if defined(DTRACE_ENABLED)
 
 #include <sys/sdt.h>
 
 #define DTRACE_ONLY(x) x
 #define NOT_DTRACE(x)
 
-#else // ndef SOLARIS || ndef DTRACE_ENABLED
+#else // ndef DTRACE_ENABLED
 
 #define DTRACE_ONLY(x)
 #define NOT_DTRACE(x) x
@@ -43,9 +44,16 @@
 #define DTRACE_PROBE3(a,b,c,d,e) {;}
 #define DTRACE_PROBE4(a,b,c,d,e,f) {;}
 #define DTRACE_PROBE5(a,b,c,d,e,f,g) {;}
+#define DTRACE_PROBE6(a,b,c,d,e,f,g,h) {;}
+#define DTRACE_PROBE7(a,b,c,d,e,f,g,h,i) {;}
+#define DTRACE_PROBE8(a,b,c,d,e,f,g,h,i,j) {;}
+#define DTRACE_PROBE9(a,b,c,d,e,f,g,h,i,j,k) {;}
+#define DTRACE_PROBE10(a,b,c,d,e,f,g,h,i,j,k,l) {;}
 
 #endif
 
+#if defined(SOLARIS)
+// Solaris dtrace needs actual extern function decls.
 #define HS_DTRACE_PROBE_FN(provider,name)\
   __dtrace_##provider##___##name
 
@@ -53,6 +61,11 @@
   DTRACE_ONLY(extern "C" void HS_DTRACE_PROBE_FN(provider,name) args)
 #define HS_DTRACE_PROBE_CDECL_N(provider,name,args) \
   DTRACE_ONLY(extern void HS_DTRACE_PROBE_FN(provider,name) args)
+#else
+// Systemtap dtrace compatible probes on GNU/Linux don't.
+#define HS_DTRACE_PROBE_DECL_N(provider,name,args)
+#define HS_DTRACE_PROBE_CDECL_N(provider,name,args)
+#endif 
 
 /* Dtrace probe declarations */
 #define HS_DTRACE_PROBE_DECL(provider,name) \
@@ -91,6 +104,8 @@
     uintptr_t,uintptr_t,uintptr_t))
 
 /* Dtrace probe definitions */
+#if defined(SOLARIS)
+// Solaris dtrace uses actual function calls.
 #define HS_DTRACE_PROBE_N(provider,name, args) \
   DTRACE_ONLY(HS_DTRACE_PROBE_FN(provider,name) args)