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, 19 insertions, 0 deletions

diff --git a/cpukit/score/include/rtems/score/percpu.h b/cpukit/score/include/rtems/score/percpu.h
index 9a6b1698fb..e491ffa002 100644
--- a/cpukit/score/include/rtems/score/percpu.h
+++ b/cpukit/score/include/rtems/score/percpu.h
@@ -316,6 +316,12 @@ typedef struct {
      * @see _Per_CPU_State_change().
      */
     Per_CPU_State state;
+
+    /**
+     * @brief Indicates if the processor has been successfully started via
+     * _CPU_SMP_Start_processor().
+     */
+    bool started;
   #endif
 
   Per_CPU_Stats Stats;
@@ -462,6 +468,19 @@ static inline uint32_t _Per_CPU_Get_index( const Per_CPU_Control *per_cpu )
   return ( uint32_t ) ( per_cpu_envelope - &_Per_CPU_Information[ 0 ] );
 }
 
+static inline bool _Per_CPU_Is_processor_started(
+  const Per_CPU_Control *per_cpu
+)
+{
+#if defined( RTEMS_SMP )
+  return per_cpu->started;
+#else
+  (void) per_cpu;
+
+  return true;
+#endif
+}
+
 #if defined( RTEMS_SMP )
 
 static inline void _Per_CPU_Send_interrupt( const Per_CPU_Control *per_cpu )