score: Add clustered/partitioned scheduling

Clustered/partitioned scheduling helps to control the worst-case
latencies in the system.  The goal is to reduce the amount of shared
state in the system and thus prevention of lock contention.  Modern
multi-processor systems tend to have several layers of data and
instruction caches.  With clustered/partitioned scheduling it is
possible to honour the cache topology of a system and thus avoid
expensive cache synchronization traffic.

We have clustered scheduling in case the set of processors of a system
is partitioned into non-empty pairwise-disjoint subsets.  These subsets
are called clusters.  Clusters with a cardinality of one are partitions.
Each cluster is owned by exactly one scheduler instance.

1 files changed, 5 insertions, 1 deletions

diff --git a/cpukit/score/src/threadcreateidle.c b/cpukit/score/src/threadcreateidle.c
index e044b92905..2a242658a5 100644
--- a/cpukit/score/src/threadcreateidle.c
+++ b/cpukit/score/src/threadcreateidle.c
@@ -19,6 +19,7 @@
 #endif
 
 #include <rtems/score/threadimpl.h>
+#include <rtems/score/schedulerimpl.h>
 #include <rtems/score/stackimpl.h>
 #include <rtems/config.h>
 
@@ -39,6 +40,7 @@ static void _Thread_Create_idle_for_cpu( Per_CPU_Control *per_cpu )
   _Thread_Initialize(
     &_Thread_Internal_information,
     idle,
+    _Scheduler_Get_by_CPU( per_cpu ),
     NULL,        /* allocate the stack */
     _Stack_Ensure_minimum( rtems_configuration_get_idle_task_stack_size() ),
     CPU_IDLE_TASK_IS_FP,
@@ -75,6 +77,8 @@ void _Thread_Create_idle( void )
   for ( processor = 0 ; processor < processor_count ; ++processor ) {
     Per_CPU_Control *per_cpu = _Per_CPU_Get_by_index( processor );
 
-    _Thread_Create_idle_for_cpu( per_cpu );
+    if ( _Per_CPU_Is_processor_started( per_cpu ) ) {
+      _Thread_Create_idle_for_cpu( per_cpu );
+    }
   }
 }