[rtems commit] score: Remove victim thread from CPU allocation
Sebastian Huber
sebh at rtems.org
Tue Nov 23 13:34:54 UTC 2021
Module: rtems
Branch: master
Commit: d0434b886332fab34ad5dca292de3a2db90e0615
Changeset: http://git.rtems.org/rtems/commit/?id=d0434b886332fab34ad5dca292de3a2db90e0615
Author: Sebastian Huber <sebastian.huber at embedded-brains.de>
Date: Fri Oct 29 14:45:28 2021 +0200
score: Remove victim thread from CPU allocation
Update #4531.
---
cpukit/include/rtems/score/schedulersmpimpl.h | 113 ++++++++++++--------------
cpukit/score/src/scheduleredfsmp.c | 22 ++---
cpukit/score/src/schedulerstrongapa.c | 10 +--
3 files changed, 65 insertions(+), 80 deletions(-)
diff --git a/cpukit/include/rtems/score/schedulersmpimpl.h b/cpukit/include/rtems/score/schedulersmpimpl.h
index f4383e9..1c6054b 100644
--- a/cpukit/include/rtems/score/schedulersmpimpl.h
+++ b/cpukit/include/rtems/score/schedulersmpimpl.h
@@ -343,8 +343,7 @@ typedef void ( *Scheduler_SMP_Enqueue_scheduled )(
typedef void ( *Scheduler_SMP_Allocate_processor )(
Scheduler_Context *context,
Scheduler_Node *scheduled,
- Thread_Control *victim_thread,
- Per_CPU_Control *victim_cpu
+ Per_CPU_Control *cpu
);
typedef void ( *Scheduler_SMP_Register_idle )(
@@ -640,100 +639,101 @@ static inline Scheduler_SMP_Action _Scheduler_SMP_Try_to_schedule(
}
/**
- * @brief Allocates the cpu for the scheduled thread.
+ * @brief Allocates a processor to the user of the scheduled node.
*
* Attempts to prevent migrations but does not take into account affinity.
*
- * @param context The scheduler context instance.
- * @param scheduled The scheduled node that should be executed next.
- * @param victim If the heir is this node's thread, no processor is allocated.
- * @param[in, out] victim_cpu The cpu to allocate.
+ * @param[in, out] context is the scheduler context.
+ *
+ * @param[in, out] scheduled is the scheduled node that gets the processor allocated.
+ *
+ * @param[in, out] cpu is the processor to allocate.
*/
static inline void _Scheduler_SMP_Allocate_processor_lazy(
Scheduler_Context *context,
Scheduler_Node *scheduled,
- Thread_Control *victim_thread,
- Per_CPU_Control *victim_cpu
+ Per_CPU_Control *cpu
)
{
Thread_Control *scheduled_thread = _Scheduler_Node_get_user( scheduled );
Per_CPU_Control *scheduled_cpu = _Thread_Get_CPU( scheduled_thread );
Per_CPU_Control *cpu_self = _Per_CPU_Get();
- Thread_Control *heir;
_Assert( _ISR_Get_level() != 0 );
- if ( _Thread_Is_executing_on_a_processor( scheduled_thread ) ) {
- if ( _Scheduler_SMP_Is_processor_owned_by_us( context, scheduled_cpu ) ) {
- heir = scheduled_cpu->heir;
- _Thread_Dispatch_update_heir(
- cpu_self,
- scheduled_cpu,
- scheduled_thread
- );
- } else {
- /* We have to force a migration to our processor set */
- heir = scheduled_thread;
- }
- } else {
- heir = scheduled_thread;
+ if ( cpu == scheduled_cpu ) {
+ _Thread_Set_CPU( scheduled_thread, cpu );
+ _Thread_Dispatch_update_heir( cpu_self, cpu, scheduled_thread );
+
+ return;
}
- if ( heir != victim_thread ) {
- _Thread_Set_CPU( heir, victim_cpu );
- _Thread_Dispatch_update_heir( cpu_self, victim_cpu, heir );
+ if (
+ _Thread_Is_executing_on_a_processor( scheduled_thread ) &&
+ _Scheduler_SMP_Is_processor_owned_by_us( context, scheduled_cpu )
+ ) {
+ Thread_Control *heir = scheduled_cpu->heir;
+ _Thread_Dispatch_update_heir( cpu_self, scheduled_cpu, scheduled_thread );
+ _Thread_Set_CPU( heir, cpu );
+ _Thread_Dispatch_update_heir( cpu_self, cpu, heir );
+
+ return;
}
+
+ _Thread_Set_CPU( scheduled_thread, cpu );
+ _Thread_Dispatch_update_heir( cpu_self, cpu, scheduled_thread );
}
/**
- * @brief Allocates the cpu for the scheduled thread.
+ * @brief Allocates exactly the processor to the user of the scheduled node.
*
* This method is slightly different from
* _Scheduler_SMP_Allocate_processor_lazy() in that it does what it is asked to
* do. _Scheduler_SMP_Allocate_processor_lazy() attempts to prevent migrations
* but does not take into account affinity.
*
- * @param context This parameter is unused.
- * @param scheduled The scheduled node whose thread should be executed next.
- * @param victim This parameter is unused.
- * @param[in, out] victim_cpu The cpu to allocate.
+ * @param[in, out] context is the scheduler context.
+ *
+ * @param[in, out] scheduled is the scheduled node that gets the processor allocated.
+ *
+ * @param[in, out] cpu is the processor to allocate.
*/
static inline void _Scheduler_SMP_Allocate_processor_exact(
Scheduler_Context *context,
Scheduler_Node *scheduled,
- Thread_Control *victim_thread,
- Per_CPU_Control *victim_cpu
+ Per_CPU_Control *cpu
)
{
Thread_Control *scheduled_thread = _Scheduler_Node_get_user( scheduled );
Per_CPU_Control *cpu_self = _Per_CPU_Get();
(void) context;
- (void) victim_thread;
- _Thread_Set_CPU( scheduled_thread, victim_cpu );
- _Thread_Dispatch_update_heir( cpu_self, victim_cpu, scheduled_thread );
+ _Thread_Set_CPU( scheduled_thread, cpu );
+ _Thread_Dispatch_update_heir( cpu_self, cpu, scheduled_thread );
}
/**
- * @brief Allocates the cpu for the scheduled thread using the given allocation function.
+ * @brief Allocates the processor to the user of the scheduled node using the
+ * given allocation handler.
*
- * @param context The scheduler context instance.
- * @param scheduled The scheduled node that should be executed next.
- * @param victim If the heir is this node's thread, no processor is allocated.
- * @param[in, out] victim_cpu The cpu to allocate.
- * @param allocate_processor The function to use for the allocation of @a victim_cpu.
+ * @param[in, out] context is the scheduler context.
+ *
+ * @param[in, out] scheduled is the scheduled node that gets the processor allocated.
+ *
+ * @param[in, out] cpu is the processor to allocate.
+ *
+ * @param allocate_processor is the handler which should allocate the processor.
*/
static inline void _Scheduler_SMP_Allocate_processor(
Scheduler_Context *context,
Scheduler_Node *scheduled,
- Thread_Control *victim_thread,
- Per_CPU_Control *victim_cpu,
+ Per_CPU_Control *cpu,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
_Scheduler_SMP_Node_change_state( scheduled, SCHEDULER_SMP_NODE_SCHEDULED );
- ( *allocate_processor )( context, scheduled, victim_thread, victim_cpu );
+ ( *allocate_processor )( context, scheduled, cpu );
}
/**
@@ -760,9 +760,8 @@ static inline void _Scheduler_SMP_Preempt(
)
{
Thread_Control *victim_owner;
- Thread_Control *victim_user;
ISR_lock_Context lock_context;
- Per_CPU_Control *victim_cpu;
+ Per_CPU_Control *cpu;
_Scheduler_SMP_Node_change_state( victim, SCHEDULER_SMP_NODE_READY );
@@ -770,8 +769,7 @@ static inline void _Scheduler_SMP_Preempt(
_Thread_Scheduler_acquire_critical( victim_owner, &lock_context );
if ( RTEMS_PREDICT_TRUE( victim_idle == NULL ) ) {
- victim_user = victim_owner;
- victim_cpu = _Thread_Get_CPU( victim_owner );
+ cpu = _Thread_Get_CPU( victim_owner );
if ( victim_owner->Scheduler.state == THREAD_SCHEDULER_SCHEDULED ) {
_Scheduler_Thread_change_state( victim_owner, THREAD_SCHEDULER_READY );
@@ -779,17 +777,16 @@ static inline void _Scheduler_SMP_Preempt(
if ( victim_owner->Scheduler.helping_nodes > 0 ) {
ISR_lock_Context lock_context_2;
- _Per_CPU_Acquire( victim_cpu, &lock_context_2 );
+ _Per_CPU_Acquire( cpu, &lock_context_2 );
_Chain_Append_unprotected(
- &victim_cpu->Threads_in_need_for_help,
+ &cpu->Threads_in_need_for_help,
&victim_owner->Scheduler.Help_node
);
- _Per_CPU_Release( victim_cpu, &lock_context_2 );
+ _Per_CPU_Release( cpu, &lock_context_2 );
}
}
} else {
- victim_user = victim_idle;
- victim_cpu = _Thread_Get_CPU( victim_idle );
+ cpu = _Thread_Get_CPU( victim_idle );
}
_Thread_Scheduler_release_critical( victim_owner, &lock_context );
@@ -797,8 +794,7 @@ static inline void _Scheduler_SMP_Preempt(
_Scheduler_SMP_Allocate_processor(
context,
scheduled,
- victim_user,
- victim_cpu,
+ cpu,
allocate_processor
);
}
@@ -1123,10 +1119,8 @@ static inline void _Scheduler_SMP_Schedule_highest_ready(
Scheduler_Release_idle_node release_idle_node
)
{
- Thread_Control *victim_thread;
Scheduler_SMP_Action action;
- victim_thread = _Scheduler_Node_get_user( victim );
(void) _Scheduler_Release_idle_thread_if_necessary(
victim,
release_idle_node,
@@ -1146,7 +1140,6 @@ static inline void _Scheduler_SMP_Schedule_highest_ready(
_Scheduler_SMP_Allocate_processor(
context,
highest_ready,
- victim_thread,
victim_cpu,
allocate_processor
);
diff --git a/cpukit/score/src/scheduleredfsmp.c b/cpukit/score/src/scheduleredfsmp.c
index 7a1c3c5..3de3be1 100644
--- a/cpukit/score/src/scheduleredfsmp.c
+++ b/cpukit/score/src/scheduleredfsmp.c
@@ -478,46 +478,42 @@ static inline void _Scheduler_EDF_SMP_Release_idle(
static inline void _Scheduler_EDF_SMP_Allocate_processor(
Scheduler_Context *context,
Scheduler_Node *scheduled_base,
- Thread_Control *victim_thread,
- Per_CPU_Control *victim_cpu
+ Per_CPU_Control *cpu
)
{
Scheduler_EDF_SMP_Context *self;
Scheduler_EDF_SMP_Node *scheduled;
uint8_t rqi;
- (void) victim_thread;
self = _Scheduler_EDF_SMP_Get_self( context );
scheduled = _Scheduler_EDF_SMP_Node_downcast( scheduled_base );
rqi = scheduled->ready_queue_index;
if ( rqi != 0 ) {
- Per_CPU_Control *desired_cpu;
+ Per_CPU_Control *affine_cpu;
- desired_cpu = _Per_CPU_Get_by_index( rqi - 1 );
+ affine_cpu = _Per_CPU_Get_by_index( rqi - 1 );
- if ( victim_cpu != desired_cpu ) {
+ if ( cpu != affine_cpu ) {
Scheduler_EDF_SMP_Node *node;
node = _Scheduler_EDF_SMP_Get_allocated( self, rqi );
_Assert( node->ready_queue_index == 0 );
- _Scheduler_EDF_SMP_Set_allocated( self, node, victim_cpu );
+ _Scheduler_EDF_SMP_Set_allocated( self, node, cpu );
_Scheduler_SMP_Allocate_processor_exact(
context,
&node->Base.Base,
- NULL,
- victim_cpu
+ cpu
);
- victim_cpu = desired_cpu;
+ cpu = affine_cpu;
}
}
- _Scheduler_EDF_SMP_Set_allocated( self, scheduled, victim_cpu );
+ _Scheduler_EDF_SMP_Set_allocated( self, scheduled, cpu );
_Scheduler_SMP_Allocate_processor_exact(
context,
&scheduled->Base.Base,
- NULL,
- victim_cpu
+ cpu
);
}
diff --git a/cpukit/score/src/schedulerstrongapa.c b/cpukit/score/src/schedulerstrongapa.c
index 36ceaed..265ef1a 100644
--- a/cpukit/score/src/schedulerstrongapa.c
+++ b/cpukit/score/src/schedulerstrongapa.c
@@ -157,25 +157,21 @@ static inline Scheduler_Node *_Scheduler_strong_APA_Get_scheduled(
static inline void _Scheduler_strong_APA_Allocate_processor(
Scheduler_Context *context,
Scheduler_Node *scheduled_base,
- Thread_Control *victim_thread,
- Per_CPU_Control *victim_cpu
+ Per_CPU_Control *cpu
)
{
Scheduler_strong_APA_Node *scheduled;
Scheduler_strong_APA_Context *self;
- (void) victim_thread;
-
scheduled = _Scheduler_strong_APA_Node_downcast( scheduled_base );
self = _Scheduler_strong_APA_Get_self( context );
- _Scheduler_strong_APA_Set_scheduled( self, scheduled_base, victim_cpu );
+ _Scheduler_strong_APA_Set_scheduled( self, scheduled_base, cpu );
_Scheduler_SMP_Allocate_processor_exact(
context,
&( scheduled->Base.Base ),
- NULL,
- victim_cpu
+ cpu
);
}
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