In SMP configurations, on 64-bit architectures use plain atomic
operations to set/get the priority value of a scheduler node. On 32-bit
architectures use an ISR lock. Using a sequence lock has no real
benefit since it uses atomic read-modify-write operations for both the
read and the write lock. Simply use a ticket lock instead so that only
one SMP synchronization primitive is used for everything.
---
cpukit/include/rtems/score/schedulernode.h | 14 ++--
.../include/rtems/score/schedulernodeimpl.h | 64 +++++++++++++------
.../score/src/schedulerdefaultnodedestroy.c | 4 +-
3 files changed, 57 insertions(+), 25 deletions(-)
diff --git a/cpukit/include/rtems/score/schedulernode.h
b/cpukit/include/rtems/score/schedulernode.h
index 1dba200dca..e344479718 100644
--- a/cpukit/include/rtems/score/schedulernode.h
+++ b/cpukit/include/rtems/score/schedulernode.h
@@ -28,7 +28,7 @@
#include <rtems/score/basedefs.h>
#include <rtems/score/chain.h>
#include <rtems/score/priority.h>
-#include <rtems/score/smplockseq.h>
+#include <rtems/score/isrlock.h>
/**
* @addtogroup RTEMSScoreScheduler
@@ -197,14 +197,20 @@ struct Scheduler_Node {
* least-significant bit which indicates if the thread should be appended
* (bit set) or prepended (bit cleared) to its priority group, see
* SCHEDULER_PRIORITY_APPEND().
+ *
+ * @see _Scheduler_Node_get_priority() and _Scheduler_Node_set_priority().
*/
+#if defined(RTEMS_SMP) && CPU_SIZEOF_POINTER == 8
+ Atomic_Ulong value;
+#else
Priority_Control value;
+#endif
-#if defined(RTEMS_SMP)
+#if defined(RTEMS_SMP) && CPU_SIZEOF_POINTER != 8
/**
- * @brief Sequence lock to synchronize priority value updates.
+ * @brief The lock protects the priority value.
*/
- SMP_sequence_lock_Control Lock;
+ ISR_lock_Control Lock;
#endif
} Priority;
};
diff --git a/cpukit/include/rtems/score/schedulernodeimpl.h
b/cpukit/include/rtems/score/schedulernodeimpl.h
index 3da29bb37e..3f90d4a6f5 100644
--- a/cpukit/include/rtems/score/schedulernodeimpl.h
+++ b/cpukit/include/rtems/score/schedulernodeimpl.h
@@ -100,13 +100,36 @@ RTEMS_INLINE_ROUTINE void _Scheduler_Node_do_initialize(
node->Wait.Priority.scheduler = scheduler;
node->user = the_thread;
node->idle = NULL;
- _SMP_sequence_lock_Initialize( &node->Priority.Lock );
+#if CPU_SIZEOF_POINTER != 8
+ _ISR_lock_Initialize( &node->Priority.Lock, "Scheduler Node Priority" );
+#endif
#else
(void) scheduler;
(void) the_thread;
#endif
}
+/**
+ * @brief Destroys a node.
+ *
+ * @param scheduler is the scheduler of the node.
+ *
+ * @param[in, out] node is the node to destroy.
+ */
+RTEMS_INLINE_ROUTINE void _Scheduler_Node_do_destroy(
+ const struct _Scheduler_Control *scheduler,
+ Scheduler_Node *node
+)
+{
+ (void) scheduler;
+
+#if defined(RTEMS_SMP) && CPU_SIZEOF_POINTER != 8
+ _ISR_lock_Destroy( &node->Priority.Lock );
+#else
+ (void) node;
+#endif
+}
+
/**
* @brief Gets the scheduler of the node.
*
@@ -148,17 +171,18 @@ RTEMS_INLINE_ROUTINE Priority_Control
_Scheduler_Node_get_priority(
{
Priority_Control priority;
-#if defined(RTEMS_SMP)
- unsigned int seq;
-
- do {
- seq = _SMP_sequence_lock_Read_begin( &node->Priority.Lock );
-#endif
-
- priority = node->Priority.value;
+#if defined(RTEMS_SMP) && CPU_SIZEOF_POINTER == 8
+ priority = _Atomic_Fetch_add_ulong(
+ &node->Priority.value,
+ 0,
+ ATOMIC_ORDER_RELAXED
+ );
+#else
+ ISR_lock_Context lock_context;
-#if defined(RTEMS_SMP)
- } while ( _SMP_sequence_lock_Read_retry( &node->Priority.Lock, seq ) );
+ _ISR_lock_Acquire( &node->Priority.Lock, &lock_context );
+ priority = node->Priority.value;
+ _ISR_lock_Release( &node->Priority.Lock, &lock_context );
#endif
return priority;
@@ -180,16 +204,18 @@ RTEMS_INLINE_ROUTINE void _Scheduler_Node_set_priority(
Priority_Flags flags
)
{
-#if defined(RTEMS_SMP)
- unsigned int seq;
-
- seq = _SMP_sequence_lock_Write_begin( &node->Priority.Lock );
-#endif
+#if defined(RTEMS_SMP) && CPU_SIZEOF_POINTER == 8
+ _Atomic_Store_ulong(
+ &node->Priority.value,
+ new_priority | (Priority_Control) flags,
+ ATOMIC_ORDER_RELAXED
+ );
+#else
+ ISR_lock_Context lock_context;
+ _ISR_lock_Acquire( &node->Priority.Lock, &lock_context );
node->Priority.value = new_priority | ( (Priority_Control) flags );
-
-#if defined(RTEMS_SMP)
- _SMP_sequence_lock_Write_end( &node->Priority.Lock, seq );
+ _ISR_lock_Release( &node->Priority.Lock, &lock_context );
#endif
}
diff --git a/cpukit/score/src/schedulerdefaultnodedestroy.c
b/cpukit/score/src/schedulerdefaultnodedestroy.c
index 796896d854..33cdfd4c69 100644
--- a/cpukit/score/src/schedulerdefaultnodedestroy.c
+++ b/cpukit/score/src/schedulerdefaultnodedestroy.c
@@ -21,12 +21,12 @@
#endif
#include <rtems/score/scheduler.h>
+#include <rtems/score/schedulernodeimpl.h>
void _Scheduler_default_Node_destroy(
const Scheduler_Control *scheduler,
Scheduler_Node *node
)
{
- (void) scheduler;
- (void) node;
+ _Scheduler_Node_do_destroy( scheduler, node );
}
--
2.26.2
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