This change allows for the migration of higher priority tasks on the
arrival of a lower priority task limited by affinity constraints.
Change license to BSD-2-Clause according to file history and
re-licensing agreement.
---
cpukit/include/rtems/scheduler.h | 10 +-
.../include/rtems/score/schedulerstrongapa.h | 162 ++-
cpukit/score/src/schedulerstrongapa.c | 991 ++
3 files changed, 929 insertions(+), 234 deletions(-)
diff --git a/cpukit/include/rtems/scheduler.h b/cpukit/include/rtems/scheduler.h
index 955a83cfb4..76d84fd787 100644
--- a/cpukit/include/rtems/scheduler.h
+++ b/cpukit/include/rtems/scheduler.h
@@ -251,22 +251,24 @@
#ifdef CONFIGURE_SCHEDULER_STRONG_APA
#include
+ #ifndef CONFIGURE_MAXIMUM_PROCESSORS
+#error "CONFIGURE_MAXIMUM_PROCESSORS must be defined to configure the
Strong APA scheduler"
+ #endif
+
#define SCHEDULER_STRONG_APA_CONTEXT_NAME( name ) \
SCHEDULER_CONTEXT_NAME( strong_APA_ ## name )
#define RTEMS_SCHEDULER_STRONG_APA( name, prio_count ) \
static struct { \
Scheduler_strong_APA_Context Base; \
- Chain_ControlReady[ ( prio_count ) ]; \
+ Scheduler_strong_APA_CPU CPU[ CONFIGURE_MAXIMUM_PROCESSORS ]; \
} SCHEDULER_STRONG_APA_CONTEXT_NAME( name )
#define RTEMS_SCHEDULER_TABLE_STRONG_APA( name, obj_name ) \
{ \
_STRONG_APA_CONTEXT_NAME( name ).Base.Base.Base, \
SCHEDULER_STRONG_APA_ENTRY_POINTS, \
- RTEMS_ARRAY_SIZE( \
-SCHEDULER_STRONG_APA_CONTEXT_NAME( name ).Ready \
- ) - 1, \
+ SCHEDULER_STRONG_APA_MAXIMUM_PRIORITY, \
( obj_name ) \
SCHEDULER_CONTROL_IS_NON_PREEMPT_MODE_SUPPORTED( false ) \
}
diff --git a/cpukit/include/rtems/score/schedulerstrongapa.h
b/cpukit/include/rtems/score/schedulerstrongapa.h
index 530eadc279..acbeb7893a 100644
--- a/cpukit/include/rtems/score/schedulerstrongapa.h
+++ b/cpukit/include/rtems/score/schedulerstrongapa.h
@@ -8,30 +8,46 @@
*/
/*
- * Copyright (c) 2013, 2018 embedded brains GmbH. All rights reserved.
+ * SPDX-License-Identifier: BSD-2-Clause
*
- * embedded brains GmbH
- * Dornierstr. 4
- * 82178 Puchheim
- * Germany
- *
+ * Copyright (C) 2020 Richi Dubey
+ * Copyright (c) 2013, 2018 embedded brains GmbH
*
- * The license and distribution terms for this file may be
- * found in the file LICENSE in this distribution or at
- * http://www.rtems.org/license/LICENSE.
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *notice, this list of conditions and the following disclaimer in the
+ *documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _RTEMS_SCORE_SCHEDULERSTRONGAPA_H
#define _RTEMS_SCORE_SCHEDULERSTRONGAPA_H
#include
-#include
#include
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
+/* Forward Declaration of Per_CPU_Control */
+struct Per_CPU_Control;
+
/**
* @defgroup RTEMSScoreSchedulerStrongAPA Strong APA Scheduler
*
@@ -39,42 +55,95 @@ extern "C" {
*
* @brief This group contains the Strong APA Scheduler implementation.
*
- * This is an implementation of the global fixed priority scheduler (G-FP). It
- * uses one ready chain per priority to ensure constant time insert operations.
- * The scheduled chain uses linear insert operations and has at most processor
- * count entries. Since the processor and priority count are constants all
- * scheduler operations complete in a bounded execution time.
- *
- * The the_thread preempt mode will be ignored.
+ * This is an implementation of the Strong APA scheduler defined by
+ * Cerqueira et al. in Linux's Processor Affinity API, Refined:
+ * Shifting Real-Time Tasks Towards Higher Schedulability.
*
+ * The scheduled and ready nodes are accessed via the
+ * Scheduler_strong_APA_Context::Ready which helps in backtracking when a
+
