4 files changed, 33 insertions, 0 deletions
diff --git a/cpukit/score/src/threadcreateidle.c b/cpukit/score/src/threadcreateidle.c
index 52c3ad4534..d71315005b 100644
--- a/cpukit/score/src/threadcreateidle.c
+++ b/cpukit/score/src/threadcreateidle.c
@@ -75,6 +75,9 @@ static void _Thread_Create_idle_for_CPU( Per_CPU_Control *cpu )
    */
   cpu->heir      =
   cpu->executing = idle;
+#if defined(RTEMS_SMP)
+  cpu->ancestor = idle;
+#endif
 
   idle->is_idle = true;
   idle->Start.Entry.adaptor = _Thread_Entry_adaptor_idle;
diff --git a/cpukit/score/src/threaddispatch.c b/cpukit/score/src/threaddispatch.c
index cd32f5a1d2..3b611f7a7a 100644
--- a/cpukit/score/src/threaddispatch.c
+++ b/cpukit/score/src/threaddispatch.c
@@ -297,10 +297,15 @@ void _Thread_Do_dispatch( Per_CPU_Control *cpu_self, ISR_Level level )
 
     _ISR_Local_enable( level );
 
+#if !defined(RTEMS_SMP)
     _User_extensions_Thread_switch( executing, heir );
+#endif
     _Thread_Save_fp( executing );
     _Context_Switch( &executing->Registers, &heir->Registers );
     _Thread_Restore_fp( executing );
+#if defined(RTEMS_SMP)
+    _User_extensions_Thread_switch( NULL, executing );
+#endif
 
     /*
      * We have to obtain this value again after the context switch since the
diff --git a/cpukit/score/src/threadhandler.c b/cpukit/score/src/threadhandler.c
index 6ddb303299..4b8e386a67 100644
--- a/cpukit/score/src/threadhandler.c
+++ b/cpukit/score/src/threadhandler.c
@@ -97,6 +97,10 @@ void _Thread_Handler( void )
    */
   _Thread_Restore_fp( executing );
 
+#if defined(RTEMS_SMP)
+  _User_extensions_Thread_switch( NULL, executing );
+#endif
+
   /*
    * Do not use the level of the thread control block, since it has a
    * different format.
diff --git a/cpukit/score/src/userextaddset.c b/cpukit/score/src/userextaddset.c
index 2b13dfad62..70e9fb008f 100644
--- a/cpukit/score/src/userextaddset.c
+++ b/cpukit/score/src/userextaddset.c
@@ -20,8 +20,28 @@
 #endif
 
 #include <rtems/score/userextimpl.h>
+#include <rtems/score/smp.h>
 #include <rtems/score/percpu.h>
 
+static void _User_extensions_Set_ancestors( void )
+{
+#if defined(RTEMS_SMP)
+  if ( _Chain_Is_empty( &_User_extensions_Switches_list ) ) {
+    uint32_t cpu_max;
+    uint32_t cpu_index;
+
+    cpu_max = _SMP_Get_processor_maximum();
+
+    for ( cpu_index = 0 ; cpu_index < cpu_max ; ++cpu_index ) {
+       Per_CPU_Control *cpu;
+
+       cpu = _Per_CPU_Get_by_index( cpu_index );
+       cpu->ancestor = cpu->executing;
+    }
+  }
+#endif
+}
+
 void _User_extensions_Add_set(
   User_extensions_Control *the_extension
 )
@@ -45,6 +65,7 @@ void _User_extensions_Add_set(
       the_extension->Callouts.thread_switch;
 
     _Per_CPU_Acquire_all( &lock_context );
+    _User_extensions_Set_ancestors();
     _Chain_Initialize_node( &the_extension->Switch.Node );
     _Chain_Append_unprotected(
       &_User_extensions_Switches_list,