[PATCH 1/5] score: Fix priority discipline handling
Sebastian Huber
sebastian.huber at embedded-brains.de
Tue Aug 31 11:24:21 UTC 2021
The priority queues in clustered scheduling configurations use a per
scheduler priority queue rotation to ensure FIFO fairness across
schedulers. This mechanism is implemented in the thread queue surrender
operation. Unfortunately some semaphore and message queue directives
used wrongly the thread queue extract operation. Fix this through the
use of _Thread_queue_Surrender().
Update #4358.
---
cpukit/include/rtems/posix/muteximpl.h | 48 +--------
cpukit/include/rtems/score/coremuteximpl.h | 51 +---------
cpukit/include/rtems/score/coresemimpl.h | 20 ++--
cpukit/include/rtems/score/threadqimpl.h | 43 ++++++++
cpukit/posix/src/condsignalsupp.c | 31 +++---
cpukit/posix/src/sempost.c | 14 +--
cpukit/score/src/semaphore.c | 28 ++----
cpukit/score/src/threadqenqueue.c | 109 +++++++++++++++++++++
8 files changed, 196 insertions(+), 148 deletions(-)
diff --git a/cpukit/include/rtems/posix/muteximpl.h b/cpukit/include/rtems/posix/muteximpl.h
index 5d20bc1ef6..3decb6f4ac 100644
--- a/cpukit/include/rtems/posix/muteximpl.h
+++ b/cpukit/include/rtems/posix/muteximpl.h
@@ -382,10 +382,7 @@ RTEMS_INLINE_ROUTINE Status_Control _POSIX_Mutex_Ceiling_surrender(
Thread_queue_Context *queue_context
)
{
- unsigned int nest_level;
- ISR_lock_Context lock_context;
- Per_CPU_Control *cpu_self;
- Thread_queue_Heads *heads;
+ unsigned int nest_level;
if ( !_POSIX_Mutex_Is_owner( the_mutex, executing ) ) {
_POSIX_Mutex_Release( the_mutex, queue_context );
@@ -400,48 +397,13 @@ RTEMS_INLINE_ROUTINE Status_Control _POSIX_Mutex_Ceiling_surrender(
return STATUS_SUCCESSFUL;
}
- _Thread_Resource_count_decrement( executing );
-
- _Thread_queue_Context_clear_priority_updates( queue_context );
- _Thread_Wait_acquire_default_critical( executing, &lock_context );
- _Thread_Priority_remove(
+ return _Thread_queue_Surrender_priority_ceiling(
+ &the_mutex->Recursive.Mutex.Queue.Queue,
executing,
&the_mutex->Priority_ceiling,
- queue_context
+ queue_context,
+ POSIX_MUTEX_PRIORITY_CEILING_TQ_OPERATIONS
);
- _Thread_Wait_release_default_critical( executing, &lock_context );
-
- cpu_self = _Thread_queue_Dispatch_disable( queue_context );
-
- heads = the_mutex->Recursive.Mutex.Queue.Queue.heads;
-
- if ( heads != NULL ) {
- const Thread_queue_Operations *operations;
- Thread_Control *new_owner;
-
- operations = POSIX_MUTEX_PRIORITY_CEILING_TQ_OPERATIONS;
- new_owner = ( *operations->first )( heads );
- _POSIX_Mutex_Set_owner( the_mutex, new_owner );
- _Thread_Resource_count_increment( new_owner );
- _Thread_Priority_add(
- new_owner,
- &the_mutex->Priority_ceiling,
- queue_context
- );
- _Thread_queue_Extract_critical(
- &the_mutex->Recursive.Mutex.Queue.Queue,
- operations,
- new_owner,
- queue_context
- );
- } else {
- _POSIX_Mutex_Set_owner( the_mutex, NULL );
- _POSIX_Mutex_Release( the_mutex, queue_context );
- }
-
- _Thread_Priority_update( queue_context );
- _Thread_Dispatch_enable( cpu_self );
- return STATUS_SUCCESSFUL;
}
#define POSIX_MUTEX_ABSTIME_TRY_LOCK ((uintptr_t) 1)
diff --git a/cpukit/include/rtems/score/coremuteximpl.h b/cpukit/include/rtems/score/coremuteximpl.h
index 426c4c5a95..757efbde9b 100644
--- a/cpukit/include/rtems/score/coremuteximpl.h
+++ b/cpukit/include/rtems/score/coremuteximpl.h
@@ -529,10 +529,7 @@ RTEMS_INLINE_ROUTINE Status_Control _CORE_ceiling_mutex_Surrender(
Thread_queue_Context *queue_context
)
{
- unsigned int nest_level;
- ISR_lock_Context lock_context;
- Per_CPU_Control *cpu_self;
- Thread_Control *new_owner;
+ unsigned int nest_level;
_CORE_mutex_Acquire_critical( &the_mutex->Recursive.Mutex, queue_context );
@@ -549,53 +546,13 @@ RTEMS_INLINE_ROUTINE Status_Control _CORE_ceiling_mutex_Surrender(
return STATUS_SUCCESSFUL;
}
- _Thread_Resource_count_decrement( executing );
-
- _Thread_queue_Context_clear_priority_updates( queue_context );
- _Thread_Wait_acquire_default_critical( executing, &lock_context );
- _Thread_Priority_remove(
+ return _Thread_queue_Surrender_priority_ceiling(
+ &the_mutex->Recursive.Mutex.Wait_queue.Queue,
executing,
&the_mutex->Priority_ceiling,
- queue_context
- );
- _Thread_Wait_release_default_critical( executing, &lock_context );
-
- new_owner = _Thread_queue_First_locked(
- &the_mutex->Recursive.Mutex.Wait_queue,
+ queue_context,
CORE_MUTEX_TQ_OPERATIONS
);
- _CORE_mutex_Set_owner( &the_mutex->Recursive.Mutex, new_owner );
-
- cpu_self = _Thread_Dispatch_disable_critical(
- &queue_context->Lock_context.Lock_context
- );
-
- if ( new_owner != NULL ) {
-#if defined(RTEMS_MULTIPROCESSING)
- if ( _Objects_Is_local_id( new_owner->Object.id ) )
-#endif
- {
- _Thread_Resource_count_increment( new_owner );
- _Thread_Priority_add(
- new_owner,
- &the_mutex->Priority_ceiling,
- queue_context
- );
- }
-
- _Thread_queue_Extract_critical(
- &the_mutex->Recursive.Mutex.Wait_queue.Queue,
- CORE_MUTEX_TQ_OPERATIONS,
- new_owner,
- queue_context
- );
- } else {
- _CORE_mutex_Release( &the_mutex->Recursive.Mutex, queue_context );
- }
-
- _Thread_Priority_update( queue_context );
- _Thread_Dispatch_enable( cpu_self );
- return STATUS_SUCCESSFUL;
}
/** @} */
diff --git a/cpukit/include/rtems/score/coresemimpl.h b/cpukit/include/rtems/score/coresemimpl.h
index ba4825bce9..40b58cbda7 100644
--- a/cpukit/include/rtems/score/coresemimpl.h
+++ b/cpukit/include/rtems/score/coresemimpl.h
@@ -133,23 +133,21 @@ RTEMS_INLINE_ROUTINE Status_Control _CORE_semaphore_Surrender(
Thread_queue_Context *queue_context
)
{
- Thread_Control *the_thread;
- Status_Control status;
+ Status_Control status;
+ Thread_queue_Heads *heads;
status = STATUS_SUCCESSFUL;
_CORE_semaphore_Acquire_critical( the_semaphore, queue_context );
- the_thread = _Thread_queue_First_locked(
- &the_semaphore->Wait_queue,
- operations
- );
- if ( the_thread != NULL ) {
- _Thread_queue_Extract_critical(
+ heads = the_semaphore->Wait_queue.Queue.heads;
+
+ if ( heads != NULL ) {
+ _Thread_queue_Surrender_no_priority(
&the_semaphore->Wait_queue.Queue,
- operations,
- the_thread,
- queue_context
+ heads,
+ queue_context,
+ operations
);
} else {
if ( the_semaphore->count < maximum_count )
diff --git a/cpukit/include/rtems/score/threadqimpl.h b/cpukit/include/rtems/score/threadqimpl.h
index 44efc1fcd0..2465fc4499 100644
--- a/cpukit/include/rtems/score/threadqimpl.h
+++ b/cpukit/include/rtems/score/threadqimpl.h
@@ -1080,6 +1080,49 @@ void _Thread_queue_Surrender(
const Thread_queue_Operations *operations
);
+/**
+ * @brief Surrenders the thread queue previously owned by the thread to the
+ * first enqueued thread.
+ *
+ * The owner of the thread queue must be set to NULL by the caller.
+ *
+ * This function releases the thread queue lock. In addition it performs a
+ * thread dispatch if necessary.
+ *
+ * @param[in, out] queue The actual thread queue.
+ * @param heads The thread queue heads. It must not be NULL.
+ * @param queue_context The thread queue context of the lock acquire.
+ * @param operations The thread queue operations.
+ */
+void _Thread_queue_Surrender_no_priority(
+ Thread_queue_Queue *queue,
+ Thread_queue_Heads *heads,
+ Thread_queue_Context *queue_context,
+ const Thread_queue_Operations *operations
+);
+
+/**
+ * @brief Surrenders the thread queue previously owned by the thread to the
+ * first enqueued thread.
+ *
+ * The owner of the thread queue must be set to NULL by the caller.
+ *
+ * This function releases the thread queue lock. In addition it performs a
+ * thread dispatch if necessary.
+ *
+ * @param[in, out] queue The actual thread queue.
+ * @param heads The thread queue heads. It must not be NULL.
+ * @param queue_context The thread queue context of the lock acquire.
+ * @param operations The thread queue operations.
+ */
+Status_Control _Thread_queue_Surrender_priority_ceiling(
+ Thread_queue_Queue *queue,
+ Thread_Control *executing,
+ Priority_Node *ceiling_priority,
+ Thread_queue_Context *queue_context,
+ const Thread_queue_Operations *operations
+);
+
#if defined(RTEMS_SMP)
/**
* @brief Surrenders the thread queue previously owned by the thread to the
diff --git a/cpukit/posix/src/condsignalsupp.c b/cpukit/posix/src/condsignalsupp.c
index dd3886ae69..188e61ec75 100644
--- a/cpukit/posix/src/condsignalsupp.c
+++ b/cpukit/posix/src/condsignalsupp.c
@@ -35,36 +35,33 @@ int _POSIX_Condition_variables_Signal_support(
{
POSIX_Condition_variables_Control *the_cond;
unsigned long flags;
- const Thread_queue_Operations *operations;
- Thread_queue_Heads *heads;
+ Thread_queue_Context queue_context;
the_cond = _POSIX_Condition_variables_Get( cond );
POSIX_CONDITION_VARIABLES_VALIDATE_OBJECT( the_cond, flags );
- operations = POSIX_CONDITION_VARIABLES_TQ_OPERATIONS;
+ _Thread_queue_Context_initialize( &queue_context );
do {
- Thread_queue_Context queue_context;
+ Thread_queue_Heads *heads;
- _Thread_queue_Context_initialize( &queue_context );
_POSIX_Condition_variables_Acquire( the_cond, &queue_context );
heads = the_cond->Queue.Queue.heads;
- if ( heads != NULL ) {
- Thread_Control *the_thread;
-
- the_thread = ( *operations->first )( heads );
- _Thread_queue_Extract_critical(
- &the_cond->Queue.Queue,
- operations,
- the_thread,
- &queue_context
- );
- } else {
+ if ( heads == NULL ) {
the_cond->mutex = POSIX_CONDITION_VARIABLES_NO_MUTEX;
_POSIX_Condition_variables_Release( the_cond, &queue_context );
+
+ return 0;
}
- } while ( is_broadcast && heads != NULL );
+
+ _Thread_queue_Surrender_no_priority(
+ &the_cond->Queue.Queue,
+ heads,
+ &queue_context,
+ POSIX_CONDITION_VARIABLES_TQ_OPERATIONS
+ );
+ } while ( is_broadcast );
return 0;
}
diff --git a/cpukit/posix/src/sempost.c b/cpukit/posix/src/sempost.c
index f1fb7fa693..49142b25a2 100644
--- a/cpukit/posix/src/sempost.c
+++ b/cpukit/posix/src/sempost.c
@@ -47,18 +47,12 @@ int sem_post( sem_t *_sem )
}
if ( RTEMS_PREDICT_TRUE( heads != NULL ) ) {
- const Thread_queue_Operations *operations;
- Thread_Control *first;
-
_Thread_queue_Context_set_ISR_level( &queue_context, level );
- operations = SEMAPHORE_TQ_OPERATIONS;
- first = ( *operations->first )( heads );
-
- _Thread_queue_Extract_critical(
+ _Thread_queue_Surrender_no_priority(
&sem->Queue.Queue,
- operations,
- first,
- &queue_context
+ heads,
+ &queue_context,
+ SEMAPHORE_TQ_OPERATIONS
);
return 0;
}
diff --git a/cpukit/score/src/semaphore.c b/cpukit/score/src/semaphore.c
index db3c3a91eb..7743939973 100644
--- a/cpukit/score/src/semaphore.c
+++ b/cpukit/score/src/semaphore.c
@@ -159,18 +159,12 @@ void _Semaphore_Post( struct _Semaphore_Control *_sem )
++sem->count;
_Sem_Queue_release( sem, level, &queue_context );
} else {
- const Thread_queue_Operations *operations;
- Thread_Control *first;
-
_Thread_queue_Context_set_ISR_level( &queue_context, level );
- operations = SEMAPHORE_TQ_OPERATIONS;
- first = ( *operations->first )( heads );
-
- _Thread_queue_Extract_critical(
+ _Thread_queue_Surrender_no_priority(
&sem->Queue.Queue,
- operations,
- first,
- &queue_context
+ heads,
+ &queue_context,
+ SEMAPHORE_TQ_OPERATIONS
);
}
}
@@ -192,18 +186,12 @@ void _Semaphore_Post_binary( struct _Semaphore_Control *_sem )
sem->count = 1;
_Sem_Queue_release( sem, level, &queue_context );
} else {
- const Thread_queue_Operations *operations;
- Thread_Control *first;
-
_Thread_queue_Context_set_ISR_level( &queue_context, level );
- operations = SEMAPHORE_TQ_OPERATIONS;
- first = ( *operations->first )( heads );
-
- _Thread_queue_Extract_critical(
+ _Thread_queue_Surrender_no_priority(
&sem->Queue.Queue,
- operations,
- first,
- &queue_context
+ heads,
+ &queue_context,
+ SEMAPHORE_TQ_OPERATIONS
);
}
}
diff --git a/cpukit/score/src/threadqenqueue.c b/cpukit/score/src/threadqenqueue.c
index d187e32fbc..d165e30da7 100644
--- a/cpukit/score/src/threadqenqueue.c
+++ b/cpukit/score/src/threadqenqueue.c
@@ -711,6 +711,115 @@ void _Thread_queue_Surrender(
_Thread_Dispatch_enable( cpu_self );
}
+void _Thread_queue_Surrender_no_priority(
+ Thread_queue_Queue *queue,
+ Thread_queue_Heads *heads,
+ Thread_queue_Context *queue_context,
+ const Thread_queue_Operations *operations
+)
+{
+ Thread_Control *the_thread;
+ bool unblock;
+ Per_CPU_Control *cpu_self;
+
+ _Assert( heads != NULL );
+ _Assert( queue->owner == NULL );
+
+ the_thread = ( *operations->surrender )( queue, heads, NULL, queue_context );
+
+#if defined(RTEMS_MULTIPROCESSING)
+ _Thread_queue_MP_set_callout( the_thread, queue_context );
+#endif
+
+ unblock = _Thread_queue_Make_ready_again( the_thread );
+
+ cpu_self = _Thread_queue_Dispatch_disable( queue_context );
+ _Thread_queue_Queue_release(
+ queue,
+ &queue_context->Lock_context.Lock_context
+ );
+
+ if ( unblock ) {
+ _Thread_Remove_timer_and_unblock( the_thread, queue );
+ }
+
+ _Thread_Dispatch_enable( cpu_self );
+}
+
+Status_Control _Thread_queue_Surrender_priority_ceiling(
+ Thread_queue_Queue *queue,
+ Thread_Control *executing,
+ Priority_Node *priority_ceiling,
+ Thread_queue_Context *queue_context,
+ const Thread_queue_Operations *operations
+)
+{
+ ISR_lock_Context lock_context;
+ Thread_queue_Heads *heads;
+ Thread_Control *new_owner;
+ bool unblock;
+ Per_CPU_Control *cpu_self;
+
+ _Thread_Resource_count_decrement( executing );
+
+ _Thread_queue_Context_clear_priority_updates( queue_context );
+ _Thread_Wait_acquire_default_critical( executing, &lock_context );
+ _Thread_Priority_remove( executing, priority_ceiling, queue_context );
+ _Thread_Wait_release_default_critical( executing, &lock_context );
+
+ heads = queue->heads;
+ queue->owner = NULL;
+
+ if ( heads == NULL ) {
+ cpu_self = _Thread_Dispatch_disable_critical(
+ &queue_context->Lock_context.Lock_context
+ );
+ _Thread_queue_Queue_release(
+ queue,
+ &queue_context->Lock_context.Lock_context
+ );
+ _Thread_Priority_update( queue_context );
+ _Thread_Dispatch_direct( cpu_self );
+ return STATUS_SUCCESSFUL;
+ }
+
+ new_owner = ( *operations->surrender )(
+ queue,
+ heads,
+ NULL,
+ queue_context
+ );
+
+ queue->owner = new_owner;
+
+ unblock = _Thread_queue_Make_ready_again( new_owner );
+
+#if defined(RTEMS_MULTIPROCESSING)
+ if ( _Objects_Is_local_id( new_owner->Object.id ) )
+#endif
+ {
+ _Thread_Resource_count_increment( new_owner );
+ _Thread_Wait_acquire_default_critical( new_owner, &lock_context );
+ _Thread_Priority_add( new_owner, priority_ceiling, queue_context );
+ _Thread_Wait_release_default_critical( new_owner, &lock_context );
+ }
+
+ cpu_self = _Thread_queue_Dispatch_disable( queue_context );
+ _Thread_queue_Queue_release(
+ queue,
+ &queue_context->Lock_context.Lock_context
+ );
+
+ _Thread_Priority_update( queue_context );
+
+ if ( unblock ) {
+ _Thread_Remove_timer_and_unblock( new_owner, queue );
+ }
+
+ _Thread_Dispatch_direct( cpu_self );
+ return STATUS_SUCCESSFUL;
+}
+
#if defined(RTEMS_SMP)
void _Thread_queue_Surrender_sticky(
Thread_queue_Queue *queue,
--
2.26.2
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