score: Rework SMP multicast action

Use a FIFO list of jobs per processor to carry out the SMP multicast
action.  Use a done indicator per job to reduce the bus traffic a bit.

cpukit/include/rtems/score/percpu.h

@@ -74,6 +74,8 @@ struct _Thread_Control;
 
 struct Scheduler_Context;
 
+struct Per_CPU_Job;
+
 /**
  *  @defgroup PerCPU RTEMS Per CPU Information
  *
@@ -494,6 +496,37 @@ typedef struct Per_CPU_Control {
      */
     Atomic_Uintptr before_multitasking_action;
 
+    /**
+     * @brief FIFO list of jobs to be performed by this processor.
+     *
+     * @see _SMP_Multicast_action().
+     */
+    struct {
+      /**
+       * @brief Lock to protect the FIFO list of jobs to be performed by this
+       * processor.
+       */
+      ISR_lock_Control Lock;
+
+      /**
+       * @brief Head of the FIFO list of jobs to be performed by this
+       * processor.
+       *
+       * This member is protected by the Per_CPU_Control::Jobs::Lock lock.
+       */
+      struct Per_CPU_Job *head;
+
+      /**
+       * @brief Tail of the FIFO list of jobs to be performed by this
+       * processor.
+       *
+       * This member is only valid if the head is not @c NULL.
+       *
+       * This member is protected by the Per_CPU_Control::Jobs::Lock lock.
+       */
+      struct Per_CPU_Job **tail;
+    } Jobs;
+
     /**
      * @brief Indicates if the processor has been successfully started via
      * _CPU_SMP_Start_processor().
@@ -710,6 +743,13 @@ bool _Per_CPU_State_wait_for_non_initial_state(
   uint32_t timeout_in_ns
 );
 
+/**
+ * @brief Performs the jobs of the specified processor.
+ *
+ * @param[in, out] cpu The jobs of this processor will be performed.
+ */
+void _Per_CPU_Perform_jobs( Per_CPU_Control *cpu );
+
 #endif /* defined( RTEMS_SMP ) */
 
 /*

cpukit/include/rtems/score/smpimpl.h

@@ -51,11 +51,11 @@ extern "C" {
 #define SMP_MESSAGE_TEST 0x2UL
 
 /**
- * @brief SMP message to request a multicast action.
+ * @brief SMP message to perform per-processor jobs.
  *
  * @see _SMP_Send_message().
  */
-#define SMP_MESSAGE_MULTICAST_ACTION 0x4UL
+#define SMP_MESSAGE_PERFORM_JOBS 0x4UL
 
 /**
  * @brief SMP message to request a clock tick.
@@ -157,11 +157,6 @@ static inline void _SMP_Set_test_message_handler(
   _SMP_Test_message_handler = handler;
 }
 
-/**
- * @brief Processes all pending multicast actions.
- */
-void _SMP_Multicast_actions_process( void );
-
 /**
  * @brief Interrupt handler for inter-processor interrupts.
  *
@@ -195,8 +190,8 @@ static inline long unsigned _SMP_Inter_processor_interrupt_handler(
       ( *_SMP_Test_message_handler )( cpu_self );
     }
 
-    if ( ( message & SMP_MESSAGE_MULTICAST_ACTION ) != 0 ) {
-      _SMP_Multicast_actions_process();
+    if ( ( message & SMP_MESSAGE_PERFORM_JOBS ) != 0 ) {
+      _Per_CPU_Perform_jobs( cpu_self );
     }
   }
 

cpukit/score/src/smp.c

@@ -118,6 +118,7 @@ void _SMP_Handler_initialize( void )
 
     cpu = _Per_CPU_Get_by_index( cpu_index );
     _ISR_lock_Set_name( &cpu->Lock, "Per-CPU" );
+    _ISR_lock_Set_name( &cpu->Jobs.Lock, "Per-CPU Jobs" );
     _ISR_lock_Set_name( &cpu->Watchdog.Lock, "Per-CPU Watchdog" );
     _Chain_Initialize_empty( &cpu->Threads_in_need_for_help );
   }

testsuites/smptests/smpcache01/init.c

@@ -126,12 +126,15 @@ static void call_tests_isr_disabled( SMP_barrier_State *bs )
   broadcast_test_init();
 
   for (i = 0; i < RTEMS_ARRAY_SIZE( test_cases ); ++i) {
-    ISR_Level isr_level;
+    Per_CPU_Control *cpu_self;
+    ISR_Level        isr_level;
 
+    cpu_self = _Thread_Dispatch_disable();
     _ISR_Local_disable( isr_level );
     barrier( bs );
     ( *test_cases[ i ] )();
     _ISR_Local_enable( isr_level );
+    _Thread_Dispatch_enable( cpu_self );
     barrier( bs );
   }
 

testsuites/smptests/smpmulticast01/init.c

@@ -59,11 +59,14 @@ static void multicast_action_irq_disabled(
   void *arg
 )
 {
+  Per_CPU_Control *cpu_self;
   rtems_interrupt_level level;
 
+  cpu_self = _Thread_Dispatch_disable();
   rtems_interrupt_local_disable(level);
   _SMP_Multicast_action(targets, handler, arg);
   rtems_interrupt_local_enable(level);
+  _Thread_Dispatch_enable(cpu_self);
 }
 
 static void multicast_action_dispatch_disabled(