diff -r 5ddfcf4b079e -r 2f644f85485d src/share/vm/utilities/debug.cpp
--- a/src/share/vm/utilities/debug.cpp	Thu Dec 02 17:21:12 2010 -0800
+++ b/src/share/vm/utilities/debug.cpp	Fri Dec 03 01:34:31 2010 -0800
@@ -399,8 +399,14 @@
 extern "C" void disnm(intptr_t p) {
   Command c("disnm");
   CodeBlob* cb = CodeCache::find_blob((address) p);
-  cb->print();
-  Disassembler::decode(cb);
+  nmethod* nm = cb->as_nmethod_or_null();
+  if (nm) {
+    nm->print();
+    Disassembler::decode(nm);
+  } else {
+    cb->print();
+    Disassembler::decode(cb);
+  }
 }