diff --git a/projects/roctracer/inc/roctracer_roctx.h b/projects/roctracer/inc/roctracer_roctx.h
index 59936c2732..94cdbe48ab 100644
--- a/projects/roctracer/inc/roctracer_roctx.h
+++ b/projects/roctracer/inc/roctracer_roctx.h
@@ -74,20 +74,6 @@ typedef struct roctx_api_data_s {
   } args;
 } roctx_api_data_t;
 
-// Regiter ROCTX callback for given operation id
-bool RegisterApiCallback(uint32_t op, void* callback, void* arg);
-
-// Remove ROCTX callback for given operation id
-bool RemoveApiCallback(uint32_t op);
-
-// Iterate range stack to support tracing start/stop
-typedef struct {
-  const char* message;
-  uint32_t tid;
-} roctx_range_data_t;
-typedef void (*roctx_range_iterate_cb_t)(const roctx_range_data_t* data, void* arg);
-void RangeStackIterate(roctx_range_iterate_cb_t callback, void* arg);
-
 #ifdef __cplusplus
 }  // extern "C" block
 #endif  // __cplusplus
diff --git a/projects/roctracer/src/core/loader.h b/projects/roctracer/src/core/loader.h
index 17b0d1ae58..b6a6d91edd 100644
--- a/projects/roctracer/src/core/loader.h
+++ b/projects/roctracer/src/core/loader.h
@@ -278,19 +278,16 @@ class RocTxApi {
  public:
   typedef BaseLoader<RocTxApi> Loader;
 
-  typedef decltype(RegisterApiCallback) RegisterApiCallback_t;
-  typedef decltype(RemoveApiCallback) RemoveApiCallback_t;
-  typedef decltype(RangeStackIterate) RangeStackIterate_t;
+  typedef bool(RegisterApiCallback_t)(uint32_t op, void* callback, void* arg);
+  typedef bool(RemoveApiCallback_t)(uint32_t op);
 
   RegisterApiCallback_t* RegisterApiCallback;
   RemoveApiCallback_t* RemoveApiCallback;
-  RangeStackIterate_t* RangeStackIterate;
 
  protected:
   void init(Loader* loader) {
     RegisterApiCallback = loader->GetFun<RegisterApiCallback_t>("RegisterApiCallback");
     RemoveApiCallback = loader->GetFun<RemoveApiCallback_t>("RemoveApiCallback");
-    RangeStackIterate = loader->GetFun<RangeStackIterate_t>("RangeStackIterate");
   }
 };
 
diff --git a/projects/roctracer/src/roctx/roctx.cpp b/projects/roctracer/src/roctx/roctx.cpp
index 7c049c3f7e..8dda086764 100644
--- a/projects/roctracer/src/roctx/roctx.cpp
+++ b/projects/roctracer/src/roctx/roctx.cpp
@@ -22,11 +22,6 @@
 #include "inc/roctracer_roctx.h"
 
 #include <cassert>
-#include <cstring>
-#include <unordered_map>
-#include <mutex>
-#include <stack>
-#include <string>
 
 #include "inc/ext/prof_protocol.h"
 #include "core/callback_table.h"
@@ -63,14 +58,7 @@ typedef enum {
 namespace {
 
 roctracer::CallbackTable<ROCTX_API_ID_NUMBER> callbacks;
-std::unordered_map<uint32_t, std::stack<std::string>> message_stack_map;
-std::mutex message_stack_mutex;
-
-thread_local auto& message_stack = []() -> decltype(message_stack_map)::mapped_type& {
-  const auto tid = syscall(__NR_gettid);
-  std::lock_guard lock(message_stack_mutex);
-  return message_stack_map[tid];
-}();
+thread_local int range_level(0);
 
 }  // namespace
 
@@ -106,8 +94,7 @@ PUBLIC_API int roctxRangePushA(const char* message) {
                      api_callback_arg);
   }
 
-  message_stack.emplace(message);
-  return message_stack.size() - 1;
+  return range_level++;
   API_METHOD_CATCH(-1);
 }
 
@@ -120,12 +107,8 @@ PUBLIC_API int roctxRangePop() {
                      api_callback_arg);
   }
 
-  if (message_stack.empty()) {
-    EXC_RAISING(ROCTX_STATUS_ERROR, "Pop from empty stack!");
-  }
-
-  message_stack.pop();
-  return message_stack.size();
+  if (range_level == 0) EXC_RAISING(ROCTX_STATUS_ERROR, "Pop from empty stack!");
+  return --range_level;
   API_METHOD_CATCH(-1)
 }
 
@@ -157,26 +140,13 @@ PUBLIC_API void roctxRangeStop(roctx_range_id_t rangeId) {
   API_METHOD_SUFFIX_NRET
 }
 
-PUBLIC_API void RangeStackIterate(roctx_range_iterate_cb_t callback, void* arg) {
-  std::lock_guard lock(message_stack_mutex);
-  for (auto&& [tid, message_stack] : message_stack_map) {
-    // Since we can't iterate a std::stack, we must first make a copy and then unwind it.
-    for (auto stack_copy = message_stack; !stack_copy.empty(); stack_copy.pop()) {
-      roctx_range_data_t data{};
-      data.message = stack_copy.top().c_str();
-      data.tid = tid;
-      callback(&data, arg);
-    }
-  }
-}
-
-PUBLIC_API bool RegisterApiCallback(uint32_t op, void* callback, void* arg) {
+extern "C" PUBLIC_API bool RegisterApiCallback(uint32_t op, void* callback, void* arg) {
   if (op >= ROCTX_API_ID_NUMBER) return false;
   callbacks.Set(op, reinterpret_cast<activity_rtapi_callback_t>(callback), arg);
   return true;
 }
 
-PUBLIC_API bool RemoveApiCallback(uint32_t op) {
+extern "C" PUBLIC_API bool RemoveApiCallback(uint32_t op) {
   if (op >= ROCTX_API_ID_NUMBER) return false;
   callbacks.Set(op, nullptr, nullptr);
   return true;
diff --git a/projects/roctracer/test/tool/tracer_tool.cpp b/projects/roctracer/test/tool/tracer_tool.cpp
index 5e9d4b20cb..51c7ca1d0c 100644
--- a/projects/roctracer/test/tool/tracer_tool.cpp
+++ b/projects/roctracer/test/tool/tracer_tool.cpp
@@ -256,39 +256,22 @@ struct roctx_trace_entry_t {
 roctracer::TraceBuffer<roctx_trace_entry_t>* roctx_trace_buffer = NULL;
 
 // rocTX callback function
-static inline void roctx_callback_fun(uint32_t domain, uint32_t cid, uint32_t tid,
-                                      roctx_range_id_t rid, const char* message) {
+void roctx_api_callback(uint32_t domain, uint32_t cid, const void* callback_data,
+                        void* /* user_arg */) {
+  const roctx_api_data_t* data = reinterpret_cast<const roctx_api_data_t*>(callback_data);
+
   roctx_trace_entry_t* entry = roctx_trace_buffer->GetEntry();
   entry->cid = cid;
   entry->time = util::timestamp_ns();
   entry->pid = GetPid();
-  entry->tid = tid;
-  entry->rid = rid;
-  entry->message = (message != NULL) ? strdup(message) : NULL;
+  entry->tid = GetTid();
+  entry->rid = data->args.id;
+  entry->message = (data->args.message != NULL)
+      ? strdup(data->args.message) /* FIXME: Who frees the message? */
+      : NULL;
   entry->valid.store(roctracer::TRACE_ENTRY_COMPLETE, std::memory_order_release);
 }
 
-void roctx_api_callback(uint32_t domain, uint32_t cid, const void* callback_data, void* arg) {
-  (void)arg;
-  const roctx_api_data_t* data = reinterpret_cast<const roctx_api_data_t*>(callback_data);
-  roctx_callback_fun(domain, cid, GetTid(), data->args.id, data->args.message);
-}
-
-// rocTX Start/Stop callbacks
-void roctx_range_start_callback(const roctx_range_data_t* data, void* arg) {
-  roctx_callback_fun(ACTIVITY_DOMAIN_ROCTX, ROCTX_API_ID_roctxRangePushA, data->tid, 0,
-                     data->message);
-}
-void roctx_range_stop_callback(const roctx_range_data_t* data, void* arg) {
-  roctx_callback_fun(ACTIVITY_DOMAIN_ROCTX, ROCTX_API_ID_roctxRangePop, data->tid, 0, NULL);
-}
-void start_callback() {
-  roctracer::RocTxLoader::Instance().RangeStackIterate(roctx_range_start_callback, NULL);
-}
-void stop_callback() {
-  roctracer::RocTxLoader::Instance().RangeStackIterate(roctx_range_stop_callback, NULL);
-}
-
 // rocTX buffer flush function
 void roctx_flush_cb(roctx_trace_entry_t* entry) {
   std::ostringstream os;
@@ -859,9 +842,6 @@ void tool_load() {
     roctx_file_handle = open_output_file(output_prefix, "roctx_trace.txt");
 
     // initialize HSA tracing
-    roctracer_ext_properties_t properties{start_callback, stop_callback};
-    roctracer_set_properties(ACTIVITY_DOMAIN_EXT_API, &properties);
-
     fprintf(stdout, "    rocTX-trace()\n");
     fflush(stdout);
     ROCTRACER_CALL(