diff --git a/src/share/vm/asm/codeBuffer.cpp b/src/share/vm/asm/codeBuffer.cpp
index 64994a9f4fc78bfb089a6467d64189c957c7122c..bb1ae18fcb57af6596b50801d1ab688594c3eb65 100644
--- a/src/share/vm/asm/codeBuffer.cpp
+++ b/src/share/vm/asm/codeBuffer.cpp
@@ -1026,25 +1026,30 @@ class CodeComment: public CHeapObj<mtCode> {
     }
     return a;
   }
+
+  // Convenience for add_comment.
+  CodeComment* find_last(intptr_t offset) {
+    CodeComment* a = find(offset);
+    if (a != NULL) {
+      while ((a->_next != NULL) && (a->_next->_offset == offset)) {
+        a = a->_next;
+      }
+    }
+    return a;
+  }
 };
 
 
 void CodeComments::add_comment(intptr_t offset, const char * comment) {
-  CodeComment* c = new CodeComment(offset, comment);
-  CodeComment* insert = NULL;
-  if (_comments != NULL) {
-    CodeComment* c = _comments->find(offset);
-    insert = c;
-    while (c && c->offset() == offset) {
-      insert = c;
-      c = c->next();
-    }
-  }
-  if (insert) {
-    // insert after comments with same offset
-    c->set_next(insert->next());
-    insert->set_next(c);
+  CodeComment* c      = new CodeComment(offset, comment);
+  CodeComment* inspos = (_comments == NULL) ? NULL : _comments->find_last(offset);
+
+  if (inspos) {
+    // insert after already existing comments with same offset
+    c->set_next(inspos->next());
+    inspos->set_next(c);
   } else {
+    // no comments with such offset, yet. Insert before anything else.
     c->set_next(_comments);
     _comments = c;
   }
@@ -1052,12 +1057,11 @@ void CodeComments::add_comment(intptr_t offset, const char * comment) {
 
 
 void CodeComments::assign(CodeComments& other) {
-  assert(_comments == NULL, "don't overwrite old value");
   _comments = other._comments;
 }
 
 
-void CodeComments::print_block_comment(outputStream* stream, intptr_t offset) {
+void CodeComments::print_block_comment(outputStream* stream, intptr_t offset) const {
   if (_comments != NULL) {
     CodeComment* c = _comments->find(offset);
     while (c && c->offset() == offset) {
@@ -1085,6 +1089,7 @@ void CodeComments::free() {
 
 
 void CodeBuffer::decode() {
+  ttyLocker ttyl;
   Disassembler::decode(decode_begin(), insts_end());
   _decode_begin = insts_end();
 }
@@ -1096,6 +1101,7 @@ void CodeBuffer::skip_decode() {
 
 
 void CodeBuffer::decode_all() {
+  ttyLocker ttyl;
   for (int n = 0; n < (int)SECT_LIMIT; n++) {
     // dump contents of each section
     CodeSection* cs = code_section(n);
diff --git a/src/share/vm/asm/codeBuffer.hpp b/src/share/vm/asm/codeBuffer.hpp
index 0e01a9fbf82bdf2b0092016774d1f26ac21a2a52..63dba2dbb0dcbea9abe567f0a295dd5a3aaf025e 100644
--- a/src/share/vm/asm/codeBuffer.hpp
+++ b/src/share/vm/asm/codeBuffer.hpp
@@ -253,7 +253,7 @@ public:
   }
 
   void add_comment(intptr_t offset, const char * comment) PRODUCT_RETURN;
-  void print_block_comment(outputStream* stream, intptr_t offset)  PRODUCT_RETURN;
+  void print_block_comment(outputStream* stream, intptr_t offset) const PRODUCT_RETURN;
   void assign(CodeComments& other)  PRODUCT_RETURN;
   void free() PRODUCT_RETURN;
 };
diff --git a/src/share/vm/code/codeBlob.cpp b/src/share/vm/code/codeBlob.cpp
index 425ad7f317c40f7364929f7ccbcd92d66af0dddc..779235f25fe5eee979b029d37770b1c7d7bfd4f6 100644
--- a/src/share/vm/code/codeBlob.cpp
+++ b/src/share/vm/code/codeBlob.cpp
@@ -162,8 +162,10 @@ void CodeBlob::trace_new_stub(CodeBlob* stub, const char* name1, const char* nam
     assert(strlen(name1) + strlen(name2) < sizeof(stub_id), "");
     jio_snprintf(stub_id, sizeof(stub_id), "%s%s", name1, name2);
     if (PrintStubCode) {
+      ttyLocker ttyl;
       tty->print_cr("Decoding %s " INTPTR_FORMAT, stub_id, (intptr_t) stub);
       Disassembler::decode(stub->code_begin(), stub->code_end());
+      tty->cr();
     }
     Forte::register_stub(stub_id, stub->code_begin(), stub->code_end());
 
@@ -548,6 +550,7 @@ void RuntimeStub::verify() {
 }
 
 void RuntimeStub::print_on(outputStream* st) const {
+  ttyLocker ttyl;
   CodeBlob::print_on(st);
   st->print("Runtime Stub (" INTPTR_FORMAT "): ", this);
   st->print_cr(name());
@@ -563,6 +566,7 @@ void SingletonBlob::verify() {
 }
 
 void SingletonBlob::print_on(outputStream* st) const {
+  ttyLocker ttyl;
   CodeBlob::print_on(st);
   st->print_cr(name());
   Disassembler::decode((CodeBlob*)this, st);
diff --git a/src/share/vm/code/codeBlob.hpp b/src/share/vm/code/codeBlob.hpp
index a8b73ae76019d2246480ab821edc007b7b8b1f61..1d47bd9729ca260b9e97ff7363a4464a4e0b03f0 100644
--- a/src/share/vm/code/codeBlob.hpp
+++ b/src/share/vm/code/codeBlob.hpp
@@ -184,7 +184,7 @@ class CodeBlob VALUE_OBJ_CLASS_SPEC {
   static void trace_new_stub(CodeBlob* blob, const char* name1, const char* name2 = "");
 
   // Print the comment associated with offset on stream, if there is one
-  virtual void print_block_comment(outputStream* stream, address block_begin) {
+  virtual void print_block_comment(outputStream* stream, address block_begin) const {
     intptr_t offset = (intptr_t)(block_begin - code_begin());
     _comments.print_block_comment(stream, offset);
   }
diff --git a/src/share/vm/code/icBuffer.hpp b/src/share/vm/code/icBuffer.hpp
index 340dbb893e88a477210eed51aea39bd411cd19bd..36d0c761666a2dc8f7d7c6dc866966b0eef33b36 100644
--- a/src/share/vm/code/icBuffer.hpp
+++ b/src/share/vm/code/icBuffer.hpp
@@ -25,6 +25,7 @@
 #ifndef SHARE_VM_CODE_ICBUFFER_HPP
 #define SHARE_VM_CODE_ICBUFFER_HPP
 
+#include "asm/codeBuffer.hpp"
 #include "code/stubs.hpp"
 #include "interpreter/bytecodes.hpp"
 #include "memory/allocation.hpp"
@@ -48,7 +49,8 @@ class ICStub: public Stub {
  protected:
   friend class ICStubInterface;
   // This will be called only by ICStubInterface
-  void    initialize(int size) { _size = size; _ic_site = NULL; }
+  void    initialize(int size,
+                     CodeComments comments)      { _size = size; _ic_site = NULL; }
   void    finalize(); // called when a method is removed
 
   // General info
diff --git a/src/share/vm/code/nmethod.cpp b/src/share/vm/code/nmethod.cpp
index ac1b22c692633cd4064b4e2fda1e89650e4dfe09..61cd15037c62f47cc0e559ab33e21a4b3e7ce6e4 100644
--- a/src/share/vm/code/nmethod.cpp
+++ b/src/share/vm/code/nmethod.cpp
@@ -2672,7 +2672,7 @@ ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
   return NULL;
 }
 
-void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) {
+void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
   if (block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
diff --git a/src/share/vm/code/nmethod.hpp b/src/share/vm/code/nmethod.hpp
index e7c067c3fa0edc566468442864d9fddefafd09d9..ea39b71e28bcff76f3fb516dea8da99920c2da3b 100644
--- a/src/share/vm/code/nmethod.hpp
+++ b/src/share/vm/code/nmethod.hpp
@@ -653,11 +653,11 @@ public:
   void log_state_change() const;
 
   // Prints block-level comments, including nmethod specific block labels:
-  virtual void print_block_comment(outputStream* stream, address block_begin) {
+  virtual void print_block_comment(outputStream* stream, address block_begin) const {
     print_nmethod_labels(stream, block_begin);
     CodeBlob::print_block_comment(stream, block_begin);
   }
-  void print_nmethod_labels(outputStream* stream, address block_begin);
+  void print_nmethod_labels(outputStream* stream, address block_begin) const;
 
   // Prints a comment for one native instruction (reloc info, pc desc)
   void print_code_comment_on(outputStream* st, int column, address begin, address end);
diff --git a/src/share/vm/code/stubs.cpp b/src/share/vm/code/stubs.cpp
index 124c0a64068836dd81a7f65b2473f3bc0127c044..0d5e61c8e0318e0d8b6fcaac69922ed75bb8bbd6 100644
--- a/src/share/vm/code/stubs.cpp
+++ b/src/share/vm/code/stubs.cpp
@@ -101,7 +101,8 @@ Stub* StubQueue::stub_containing(address pc) const {
 
 Stub* StubQueue::request_committed(int code_size) {
   Stub* s = request(code_size);
-  if (s != NULL) commit(code_size);
+  CodeComments comments;
+  if (s != NULL) commit(code_size, comments);
   return s;
 }
 
@@ -118,7 +119,8 @@ Stub* StubQueue::request(int requested_code_size) {
       assert(_buffer_limit == _buffer_size, "buffer must be fully usable");
       if (_queue_end + requested_size <= _buffer_size) {
         // code fits in at the end => nothing to do
-        stub_initialize(s, requested_size);
+        CodeComments comments;
+        stub_initialize(s, requested_size, comments);
         return s;
       } else {
         // stub doesn't fit in at the queue end
@@ -135,7 +137,8 @@ Stub* StubQueue::request(int requested_code_size) {
     // Queue: |XXX|.......|XXXXXXX|.......|
     //        ^0  ^end    ^begin  ^limit  ^size
     s = current_stub();
-    stub_initialize(s, requested_size);
+    CodeComments comments;
+    stub_initialize(s, requested_size, comments);
     return s;
   }
   // Not enough space left
@@ -144,12 +147,12 @@ Stub* StubQueue::request(int requested_code_size) {
 }
 
 
-void StubQueue::commit(int committed_code_size) {
+void StubQueue::commit(int committed_code_size, CodeComments& comments) {
   assert(committed_code_size > 0, "committed_code_size must be > 0");
   int committed_size = round_to(stub_code_size_to_size(committed_code_size), CodeEntryAlignment);
   Stub* s = current_stub();
   assert(committed_size <= stub_size(s), "committed size must not exceed requested size");
-  stub_initialize(s, committed_size);
+  stub_initialize(s, committed_size, comments);
   _queue_end += committed_size;
   _number_of_stubs++;
   if (_mutex != NULL) _mutex->unlock();
diff --git a/src/share/vm/code/stubs.hpp b/src/share/vm/code/stubs.hpp
index afc8f04d46c7852d07979f717ae6dc842d64412f..5701a45a57154d55ecf4c3a6c8b7d2de232cf4c0 100644
--- a/src/share/vm/code/stubs.hpp
+++ b/src/share/vm/code/stubs.hpp
@@ -25,6 +25,7 @@
 #ifndef SHARE_VM_CODE_STUBS_HPP
 #define SHARE_VM_CODE_STUBS_HPP
 
+#include "asm/codeBuffer.hpp"
 #include "memory/allocation.hpp"
 #ifdef TARGET_OS_FAMILY_linux
 # include "os_linux.inline.hpp"
@@ -71,7 +72,8 @@
 class Stub VALUE_OBJ_CLASS_SPEC {
  public:
   // Initialization/finalization
-  void    initialize(int size)                   { ShouldNotCallThis(); }                // called to initialize/specify the stub's size
+  void    initialize(int size,
+                     CodeComments& comments)     { ShouldNotCallThis(); }                // called to initialize/specify the stub's size
   void    finalize()                             { ShouldNotCallThis(); }                // called before the stub is deallocated
 
   // General info/converters
@@ -104,7 +106,8 @@ class Stub VALUE_OBJ_CLASS_SPEC {
 class StubInterface: public CHeapObj<mtCode> {
  public:
   // Initialization/finalization
-  virtual void    initialize(Stub* self, int size)         = 0; // called after creation (called twice if allocated via (request, commit))
+  virtual void    initialize(Stub* self, int size,
+                             CodeComments& comments)       = 0; // called after creation (called twice if allocated via (request, commit))
   virtual void    finalize(Stub* self)                     = 0; // called before deallocation
 
   // General info/converters
@@ -132,7 +135,8 @@ class StubInterface: public CHeapObj<mtCode> {
                                                            \
    public:                                                 \
     /* Initialization/finalization */                      \
-    virtual void    initialize(Stub* self, int size)       { cast(self)->initialize(size); }       \
+    virtual void    initialize(Stub* self, int size,       \
+                               CodeComments& comments)     { cast(self)->initialize(size, comments); } \
     virtual void    finalize(Stub* self)                   { cast(self)->finalize(); }             \
                                                            \
     /* General info */                                     \
@@ -171,7 +175,8 @@ class StubQueue: public CHeapObj<mtCode> {
   Stub* current_stub() const                     { return stub_at(_queue_end); }
 
   // Stub functionality accessed via interface
-  void  stub_initialize(Stub* s, int size)       { assert(size % CodeEntryAlignment == 0, "size not aligned"); _stub_interface->initialize(s, size); }
+  void  stub_initialize(Stub* s, int size,
+                        CodeComments& comments)  { assert(size % CodeEntryAlignment == 0, "size not aligned"); _stub_interface->initialize(s, size, comments); }
   void  stub_finalize(Stub* s)                   { _stub_interface->finalize(s); }
   int   stub_size(Stub* s) const                 { return _stub_interface->size(s); }
   bool  stub_contains(Stub* s, address pc) const { return _stub_interface->code_begin(s) <= pc && pc < _stub_interface->code_end(s); }
@@ -200,7 +205,8 @@ class StubQueue: public CHeapObj<mtCode> {
   // Stub allocation (atomic transactions)
   Stub* request_committed(int code_size);        // request a stub that provides exactly code_size space for code
   Stub* request(int requested_code_size);        // request a stub with a (maximum) code space - locks the queue
-  void  commit (int committed_code_size);        // commit the previously requested stub - unlocks the queue
+  void  commit (int committed_code_size,
+                CodeComments& comments);         // commit the previously requested stub - unlocks the queue
 
   // Stub deallocation
   void  remove_first();                          // remove the first stub in the queue
diff --git a/src/share/vm/compiler/disassembler.cpp b/src/share/vm/compiler/disassembler.cpp
index 9603e863eddc61f733042dde11dc0e52d187f173..3be1533a050bf1b3885c28606f92ceac16b5fa57 100644
--- a/src/share/vm/compiler/disassembler.cpp
+++ b/src/share/vm/compiler/disassembler.cpp
@@ -148,6 +148,7 @@ class decode_env {
  private:
   nmethod*      _nm;
   CodeBlob*     _code;
+  CodeComments  _comments;
   outputStream* _output;
   address       _start, _end;
 
@@ -187,7 +188,7 @@ class decode_env {
   void print_address(address value);
 
  public:
-  decode_env(CodeBlob* code, outputStream* output);
+  decode_env(CodeBlob* code, outputStream* output, CodeComments c = CodeComments());
 
   address decode_instructions(address start, address end);
 
@@ -229,12 +230,13 @@ class decode_env {
   const char* options() { return _option_buf; }
 };
 
-decode_env::decode_env(CodeBlob* code, outputStream* output) {
+decode_env::decode_env(CodeBlob* code, outputStream* output, CodeComments c) {
   memset(this, 0, sizeof(*this));
   _output = output ? output : tty;
   _code = code;
   if (code != NULL && code->is_nmethod())
     _nm = (nmethod*) code;
+  _comments.assign(c);
 
   // by default, output pc but not bytes:
   _print_pc       = true;
@@ -356,6 +358,7 @@ void decode_env::print_insn_labels() {
   if (cb != NULL) {
     cb->print_block_comment(st, p);
   }
+  _comments.print_block_comment(st, (intptr_t)(p - _start));
   if (_print_pc) {
     st->print("  " PTR_FORMAT ": ", p);
   }
@@ -467,10 +470,9 @@ void Disassembler::decode(CodeBlob* cb, outputStream* st) {
   env.decode_instructions(cb->code_begin(), cb->code_end());
 }
 
-
-void Disassembler::decode(address start, address end, outputStream* st) {
+void Disassembler::decode(address start, address end, outputStream* st, CodeComments c) {
   if (!load_library())  return;
-  decode_env env(CodeCache::find_blob_unsafe(start), st);
+  decode_env env(CodeCache::find_blob_unsafe(start), st, c);
   env.decode_instructions(start, end);
 }
 
diff --git a/src/share/vm/compiler/disassembler.hpp b/src/share/vm/compiler/disassembler.hpp
index a70b8ccd378da6f90611348dc3fd77e77663b546..0d05514a88a15297879a8a332461a49f8d51222a 100644
--- a/src/share/vm/compiler/disassembler.hpp
+++ b/src/share/vm/compiler/disassembler.hpp
@@ -25,6 +25,7 @@
 #ifndef SHARE_VM_COMPILER_DISASSEMBLER_HPP
 #define SHARE_VM_COMPILER_DISASSEMBLER_HPP
 
+#include "asm/codeBuffer.hpp"
 #include "runtime/globals.hpp"
 #ifdef TARGET_OS_FAMILY_linux
 # include "os_linux.inline.hpp"
@@ -87,7 +88,7 @@ class Disassembler {
   }
   static void decode(CodeBlob *cb,               outputStream* st = NULL);
   static void decode(nmethod* nm,                outputStream* st = NULL);
-  static void decode(address begin, address end, outputStream* st = NULL);
+  static void decode(address begin, address end, outputStream* st = NULL, CodeComments c = CodeComments());
 };
 
 #endif // SHARE_VM_COMPILER_DISASSEMBLER_HPP
diff --git a/src/share/vm/interpreter/interpreter.cpp b/src/share/vm/interpreter/interpreter.cpp
index 9e329ebf851ae67a8921a09dd0b113b43aa63943..dad8f9ec7519e343e2fe00082b68ac60ed5f6401 100644
--- a/src/share/vm/interpreter/interpreter.cpp
+++ b/src/share/vm/interpreter/interpreter.cpp
@@ -60,6 +60,8 @@ void InterpreterCodelet::verify() {
 
 
 void InterpreterCodelet::print_on(outputStream* st) const {
+  ttyLocker ttyl;
+
   if (PrintInterpreter) {
     st->cr();
     st->print_cr("----------------------------------------------------------------------");
@@ -72,7 +74,7 @@ void InterpreterCodelet::print_on(outputStream* st) const {
 
   if (PrintInterpreter) {
     st->cr();
-    Disassembler::decode(code_begin(), code_end(), st);
+    Disassembler::decode(code_begin(), code_end(), st, DEBUG_ONLY(_comments) NOT_DEBUG(CodeComments()));
   }
 }
 
diff --git a/src/share/vm/interpreter/interpreter.hpp b/src/share/vm/interpreter/interpreter.hpp
index 0ab0be74770028ab1ef32b6f5c2806f3b99e2a2f..478edb1b3156ae4f936d4e6b37e668615a12661d 100644
--- a/src/share/vm/interpreter/interpreter.hpp
+++ b/src/share/vm/interpreter/interpreter.hpp
@@ -48,10 +48,12 @@ class InterpreterCodelet: public Stub {
   int         _size;                             // the size in bytes
   const char* _description;                      // a description of the codelet, for debugging & printing
   Bytecodes::Code _bytecode;                     // associated bytecode if any
+  DEBUG_ONLY(CodeComments _comments;)            // Comments for annotating assembler output.
 
  public:
   // Initialization/finalization
-  void    initialize(int size)                   { _size = size; }
+  void    initialize(int size,
+                     CodeComments& comments)     { _size = size; DEBUG_ONLY(_comments.assign(comments);) }
   void    finalize()                             { ShouldNotCallThis(); }
 
   // General info/converters
@@ -129,7 +131,7 @@ class CodeletMark: ResourceMark {
 
 
     // commit Codelet
-    AbstractInterpreter::code()->commit((*_masm)->code()->pure_insts_size());
+    AbstractInterpreter::code()->commit((*_masm)->code()->pure_insts_size(), (*_masm)->code()->comments());
     // make sure nobody can use _masm outside a CodeletMark lifespan
     *_masm = NULL;
   }
diff --git a/src/share/vm/runtime/sharedRuntime.cpp b/src/share/vm/runtime/sharedRuntime.cpp
index f5a038e2870d031957c77202529d2301ea47315e..a0ef0abc2f9320fe7dc8757663abe89f9aed2f30 100644
--- a/src/share/vm/runtime/sharedRuntime.cpp
+++ b/src/share/vm/runtime/sharedRuntime.cpp
@@ -2460,6 +2460,7 @@ AdapterHandlerEntry* AdapterHandlerLibrary::get_adapter(methodHandle method) {
 #ifndef PRODUCT
     // debugging suppport
     if (PrintAdapterHandlers || PrintStubCode) {
+      ttyLocker ttyl;
       entry->print_adapter_on(tty);
       tty->print_cr("i2c argument handler #%d for: %s %s (%d bytes generated)",
                     _adapters->number_of_entries(), (method->is_static() ? "static" : "receiver"),
@@ -2467,8 +2468,10 @@ AdapterHandlerEntry* AdapterHandlerLibrary::get_adapter(methodHandle method) {
       tty->print_cr("c2i argument handler starts at %p",entry->get_c2i_entry());
       if (Verbose || PrintStubCode) {
         address first_pc = entry->base_address();
-        if (first_pc != NULL)
+        if (first_pc != NULL) {
           Disassembler::decode(first_pc, first_pc + insts_size);
+          tty->cr();
+        }
       }
     }
 #endif