--- old/src/share/vm/jfr/metadata/metadata.xml	2021-01-22 14:12:43.817191672 +0800
+++ new/src/share/vm/jfr/metadata/metadata.xml	2021-01-22 14:12:43.697186985 +0800
@@ -26,8 +26,9 @@
 
 <Metadata>
 
-  <Event name="ThreadStart" category="Java Application" label="Java Thread Start" thread="true" startTime="false">
-    <Field type="Thread" name="thread" label="Java Thread" />
+  <Event name="ThreadStart" category="Java Application" label="Java Thread Start" thread="true" startTime="false" stackTrace="true">
+    <Field type="Thread" name="thread" label="New Java Thread" />
+    <Field type="Thread" name="parentThread" label="Parent Java Thread" />
   </Event>
 
   <Event name="ThreadEnd" category="Java Application" label="Java Thread End" thread="true" startTime="false">
--- old/src/share/vm/jfr/support/jfrThreadLocal.cpp	2021-01-22 14:12:44.519219088 +0800
+++ new/src/share/vm/jfr/support/jfrThreadLocal.cpp	2021-01-22 14:12:44.402214519 +0800
@@ -55,7 +55,11 @@
   _stack_trace_hash(0),
   _stackdepth(0),
   _entering_suspend_flag(0),
-  _dead(false) {}
+  _dead(false) {
+
+  Thread* thread = Thread::current_or_null();
+  _parent_trace_id = thread != NULL ? thread->jfr_thread_local()->trace_id() : (traceid)0;
+}
 
 u8 JfrThreadLocal::add_data_lost(u8 value) {
   _data_lost += value;
@@ -78,6 +82,7 @@
 static void send_java_thread_start_event(JavaThread* jt) {
   EventThreadStart event;
   event.set_thread(jt->jfr_thread_local()->thread_id());
+  event.set_parentThread(jt->jfr_thread_local()->parent_thread_id());
   event.commit();
 }
 
@@ -89,6 +94,9 @@
       send_java_thread_start_event((JavaThread*)t);
     }
   }
+  if (t->jfr_thread_local()->has_cached_stack_trace()) {
+    t->jfr_thread_local()->clear_cached_stack_trace();
+  }
 }
 
 static void send_java_thread_end_events(traceid id, JavaThread* jt) {
--- old/src/share/vm/jfr/support/jfrThreadLocal.hpp	2021-01-22 14:12:45.182244981 +0800
+++ new/src/share/vm/jfr/support/jfrThreadLocal.hpp	2021-01-22 14:12:45.071240646 +0800
@@ -51,6 +51,7 @@
   mutable u4 _stackdepth;
   volatile jint _entering_suspend_flag;
   bool _dead;
+  traceid _parent_trace_id;
 
   JfrBuffer* install_native_buffer() const;
   JfrBuffer* install_java_buffer() const;
@@ -127,6 +128,10 @@
     _trace_id = thread_id;
   }
 
+  traceid parent_thread_id() const {
+    return _parent_trace_id;
+  }
+
   void set_cached_stack_trace_id(traceid id, unsigned int hash = 0) {
     _stack_trace_id = id;
     _stack_trace_hash = hash;
--- old/src/share/vm/prims/jni.cpp	2021-01-22 14:12:45.841270718 +0800
+++ new/src/share/vm/prims/jni.cpp	2021-01-22 14:12:45.726266227 +0800
@@ -5025,7 +5025,14 @@
   EventThreadStart event;
   if (event.should_commit()) {
     event.set_thread(JFR_THREAD_ID(jt));
-    event.commit();
+    event.set_parentThread((traceid)0);
+    if (EventThreadStart::is_stacktrace_enabled()) {
+      jt->jfr_thread_local()->set_cached_stack_trace_id((traceid)0);
+      event.commit();
+      jt->jfr_thread_local()->clear_cached_stack_trace();
+    } else {
+      event.commit();
+    }
   }
 }
 
--- old/src/share/vm/prims/jvm.cpp	2021-01-22 14:12:46.540298017 +0800
+++ new/src/share/vm/prims/jvm.cpp	2021-01-22 14:12:46.426293565 +0800
@@ -96,6 +96,7 @@
 #endif // INCLUDE_ALL_GCS
 
 #include <errno.h>
+#include <jfr/recorder/jfrRecorder.hpp>
 
 #ifndef USDT2
 HS_DTRACE_PROBE_DECL1(hotspot, thread__sleep__begin, long long);
@@ -3162,6 +3163,15 @@
               "unable to create new native thread");
   }
 
+#if INCLUDE_JFR
+  if (JfrRecorder::is_recording() && EventThreadStart::is_enabled() &&
+      EventThreadStart::is_stacktrace_enabled()) {
+    JfrThreadLocal* tl = native_thread->jfr_thread_local();
+    // skip Thread.start() and Thread.start0()
+    tl->set_cached_stack_trace_id(JfrStackTraceRepository::record(thread, 2));
+  }
+#endif
+
   Thread::start(native_thread);
 
 JVM_END
--- old/src/share/vm/runtime/thread.hpp	2021-01-22 14:12:47.235325160 +0800
+++ new/src/share/vm/runtime/thread.hpp	2021-01-22 14:12:47.122320747 +0800
@@ -331,6 +331,7 @@
 
   // Returns the current thread
   static inline Thread* current();
+  static inline Thread* current_or_null();
 
   // Common thread operations
   static void set_priority(Thread* thread, ThreadPriority priority);
@@ -683,6 +684,13 @@
   return thread;
 }
 
+inline Thread* Thread::current_or_null() {
+  if (ThreadLocalStorage::is_initialized()) {
+    return ThreadLocalStorage::thread();
+  }
+  return NULL;
+}
+
 // Name support for threads.  non-JavaThread subclasses with multiple
 // uniquely named instances should derive from this.
 class NamedThread: public Thread {