[PATCH 14/14] score: Avoid Giant lock for scheduler set/get
Sebastian Huber
sebastian.huber at embedded-brains.de
Wed May 11 13:23:41 UTC 2016
Update #2555.
---
cpukit/rtems/src/taskgetscheduler.c | 52 +++++++++++-------------
cpukit/rtems/src/tasksetscheduler.c | 50 +++++++++++++----------
cpukit/score/include/rtems/score/schedulerimpl.h | 42 ++++++++++++++-----
cpukit/score/include/rtems/score/threadimpl.h | 8 ++++
cpukit/score/include/rtems/score/threadqimpl.h | 26 ++++++++++--
5 files changed, 113 insertions(+), 65 deletions(-)
diff --git a/cpukit/rtems/src/taskgetscheduler.c b/cpukit/rtems/src/taskgetscheduler.c
index 47895a4..9d8bbb6 100644
--- a/cpukit/rtems/src/taskgetscheduler.c
+++ b/cpukit/rtems/src/taskgetscheduler.c
@@ -24,37 +24,31 @@ rtems_status_code rtems_task_get_scheduler(
rtems_id *scheduler_id
)
{
- rtems_status_code sc;
-
- if ( scheduler_id != NULL ) {
- Thread_Control *the_thread;
- Objects_Locations location;
- const Scheduler_Control *scheduler;
-
- the_thread = _Thread_Get( task_id, &location );
-
- switch ( location ) {
- case OBJECTS_LOCAL:
- scheduler = _Scheduler_Get( the_thread );
- *scheduler_id = _Scheduler_Build_id(
- _Scheduler_Get_index( scheduler )
- );
- _Objects_Put( &the_thread->Object );
- sc = RTEMS_SUCCESSFUL;
- break;
+ Thread_Control *the_thread;
+ ISR_lock_Context lock_context;
+ const Scheduler_Control *scheduler;
+
+ if ( scheduler_id == NULL ) {
+ return RTEMS_INVALID_ADDRESS;
+ }
+
+ the_thread = _Thread_Get_interrupt_disable( task_id, &lock_context );
+
+ if ( the_thread == NULL ) {
#if defined(RTEMS_MULTIPROCESSING)
- case OBJECTS_REMOTE:
- _Thread_Dispatch();
- sc = RTEMS_ILLEGAL_ON_REMOTE_OBJECT;
- break;
-#endif
- default:
- sc = RTEMS_INVALID_ID;
- break;
+ if ( _Thread_MP_Is_remote( task_id ) ) {
+ return RTEMS_ILLEGAL_ON_REMOTE_OBJECT;
}
- } else {
- sc = RTEMS_INVALID_ADDRESS;
+#endif
+
+ return RTEMS_INVALID_ID;
}
- return sc;
+ _Thread_State_acquire_critical( the_thread, &lock_context );
+
+ scheduler = _Scheduler_Get( the_thread );
+ *scheduler_id = _Scheduler_Build_id( _Scheduler_Get_index( scheduler ) );
+
+ _Thread_State_release( the_thread, &lock_context );
+ return RTEMS_SUCCESSFUL;
}
diff --git a/cpukit/rtems/src/tasksetscheduler.c b/cpukit/rtems/src/tasksetscheduler.c
index e055530..428ef3d 100644
--- a/cpukit/rtems/src/tasksetscheduler.c
+++ b/cpukit/rtems/src/tasksetscheduler.c
@@ -24,34 +24,40 @@ rtems_status_code rtems_task_set_scheduler(
rtems_id scheduler_id
)
{
- rtems_status_code sc;
const Scheduler_Control *scheduler;
+ Thread_Control *the_thread;
+ ISR_lock_Context lock_context;
+ ISR_lock_Context state_lock_context;
+ Per_CPU_Control *cpu_self;
+ void *lock;
+ bool ok;
- if ( _Scheduler_Get_by_id( scheduler_id, &scheduler ) ) {
- Thread_Control *the_thread;
- Objects_Locations location;
+ if ( !_Scheduler_Get_by_id( scheduler_id, &scheduler ) ) {
+ return RTEMS_INVALID_ID;
+ }
- the_thread = _Thread_Get( task_id, &location );
+ the_thread = _Thread_Get_interrupt_disable( task_id, &lock_context );
- switch ( location ) {
- case OBJECTS_LOCAL:
- _Scheduler_Set( scheduler, the_thread );
- _Objects_Put( &the_thread->Object );
- sc = RTEMS_SUCCESSFUL;
- break;
+ if ( the_thread == NULL ) {
#if defined(RTEMS_MULTIPROCESSING)
- case OBJECTS_REMOTE:
- _Thread_Dispatch();
- sc = RTEMS_ILLEGAL_ON_REMOTE_OBJECT;
- break;
-#endif
- default:
- sc = RTEMS_INVALID_ID;
- break;
+ if ( _Thread_MP_Is_remote( task_id ) ) {
+ return RTEMS_ILLEGAL_ON_REMOTE_OBJECT;
}
- } else {
- sc = RTEMS_INVALID_ID;
+#endif
+
+ return RTEMS_INVALID_ID;
}
- return sc;
+ cpu_self = _Thread_Dispatch_disable_critical( &lock_context );
+ _ISR_lock_ISR_enable( &lock_context );
+
+ lock = _Thread_Lock_acquire( the_thread, &lock_context );
+ _Thread_State_acquire_critical( the_thread, &state_lock_context );
+
+ ok = _Scheduler_Set( scheduler, the_thread );
+
+ _Thread_State_release_critical( the_thread, &state_lock_context );
+ _Thread_Lock_release( lock, &lock_context );
+ _Thread_Dispatch_enable( cpu_self );
+ return ok ? RTEMS_SUCCESSFUL : RTEMS_INCORRECT_STATE;
}
diff --git a/cpukit/score/include/rtems/score/schedulerimpl.h b/cpukit/score/include/rtems/score/schedulerimpl.h
index c149a9e..2e5b025 100644
--- a/cpukit/score/include/rtems/score/schedulerimpl.h
+++ b/cpukit/score/include/rtems/score/schedulerimpl.h
@@ -599,25 +599,45 @@ RTEMS_INLINE_ROUTINE bool _Scheduler_Has_processor_ownership(
#endif
}
-RTEMS_INLINE_ROUTINE void _Scheduler_Set(
+RTEMS_INLINE_ROUTINE bool _Scheduler_Set(
const Scheduler_Control *scheduler,
Thread_Control *the_thread
)
{
#if defined(RTEMS_SMP)
- const Scheduler_Control *current_scheduler = _Scheduler_Get( the_thread );
-
- if ( current_scheduler != scheduler ) {
- _Thread_Set_state( the_thread, STATES_MIGRATING );
- _Scheduler_Node_destroy( current_scheduler, the_thread );
- the_thread->Scheduler.own_control = scheduler;
- the_thread->Scheduler.control = scheduler;
- _Scheduler_Node_initialize( scheduler, the_thread );
- _Scheduler_Update_priority( the_thread, the_thread->current_priority );
- _Thread_Clear_state( the_thread, STATES_MIGRATING );
+ const Scheduler_Control *current_scheduler;
+ States_Control current_state;
+
+ current_scheduler = _Scheduler_Get( the_thread );
+
+ if ( current_scheduler == scheduler ) {
+ return true;
+ }
+
+ if ( _Thread_Owns_resources( the_thread ) ) {
+ return false;
+ }
+
+ current_state = the_thread->current_state;
+
+ if ( _States_Is_ready( current_state ) ) {
+ _Scheduler_Block( the_thread );
}
+
+ _Scheduler_Node_destroy( current_scheduler, the_thread );
+ the_thread->Scheduler.own_control = scheduler;
+ the_thread->Scheduler.control = scheduler;
+ _Scheduler_Node_initialize( scheduler, the_thread );
+ _Scheduler_Update_priority( the_thread, the_thread->current_priority );
+
+ if ( _States_Is_ready( current_state ) ) {
+ _Scheduler_Unblock( the_thread );
+ }
+
+ return true;
#else
(void) scheduler;
+ return true;
#endif
}
diff --git a/cpukit/score/include/rtems/score/threadimpl.h b/cpukit/score/include/rtems/score/threadimpl.h
index 931eec0..1ea49dd 100644
--- a/cpukit/score/include/rtems/score/threadimpl.h
+++ b/cpukit/score/include/rtems/score/threadimpl.h
@@ -359,6 +359,14 @@ RTEMS_INLINE_ROUTINE Thread_Control *_Thread_State_acquire_for_executing(
return executing;
}
+RTEMS_INLINE_ROUTINE void _Thread_State_release_critical(
+ Thread_Control *the_thread,
+ ISR_lock_Context *lock_context
+)
+{
+ _Thread_queue_Release_critical( &the_thread->Join_queue, lock_context );
+}
+
RTEMS_INLINE_ROUTINE void _Thread_State_release(
Thread_Control *the_thread,
ISR_lock_Context *lock_context
diff --git a/cpukit/score/include/rtems/score/threadqimpl.h b/cpukit/score/include/rtems/score/threadqimpl.h
index e6cd401..ec222bd 100644
--- a/cpukit/score/include/rtems/score/threadqimpl.h
+++ b/cpukit/score/include/rtems/score/threadqimpl.h
@@ -108,7 +108,7 @@ RTEMS_INLINE_ROUTINE void _Thread_queue_Queue_do_acquire_critical(
_Thread_queue_Queue_do_acquire_critical( queue, lock_context )
#endif
-RTEMS_INLINE_ROUTINE void _Thread_queue_Queue_release(
+RTEMS_INLINE_ROUTINE void _Thread_queue_Queue_release_critical(
Thread_queue_Queue *queue,
ISR_lock_Context *lock_context
)
@@ -118,7 +118,18 @@ RTEMS_INLINE_ROUTINE void _Thread_queue_Queue_release(
&queue->Lock,
&lock_context->Lock_context.Stats_context
);
+#else
+ (void) queue;
+ (void) lock_context;
#endif
+}
+
+RTEMS_INLINE_ROUTINE void _Thread_queue_Queue_release(
+ Thread_queue_Queue *queue,
+ ISR_lock_Context *lock_context
+)
+{
+ _Thread_queue_Queue_release_critical( queue, lock_context );
_ISR_lock_ISR_enable( lock_context );
}
@@ -159,7 +170,7 @@ RTEMS_INLINE_ROUTINE bool _Thread_queue_Is_lock_owner(
}
#endif
-RTEMS_INLINE_ROUTINE void _Thread_queue_Release(
+RTEMS_INLINE_ROUTINE void _Thread_queue_Release_critical(
Thread_queue_Control *the_thread_queue,
ISR_lock_Context *lock_context
)
@@ -170,12 +181,21 @@ RTEMS_INLINE_ROUTINE void _Thread_queue_Release(
the_thread_queue->owner = SMP_LOCK_NO_OWNER;
#endif
#endif
- _Thread_queue_Queue_release(
+ _Thread_queue_Queue_release_critical(
&the_thread_queue->Queue,
lock_context
);
}
+RTEMS_INLINE_ROUTINE void _Thread_queue_Release(
+ Thread_queue_Control *the_thread_queue,
+ ISR_lock_Context *lock_context
+)
+{
+ _Thread_queue_Release_critical( the_thread_queue, lock_context );
+ _ISR_lock_ISR_enable( lock_context );
+}
+
Thread_Control *_Thread_queue_Do_dequeue(
Thread_queue_Control *the_thread_queue,
const Thread_queue_Operations *operations
--
1.8.4.5
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