source: rtems/cpukit/score/src/schedulerpriorityunblock.c @ 2afb22b

5
Last change on this file since 2afb22b was c597fb1, checked in by Sebastian Huber <sebastian.huber@…>, on 11/09/17 at 15:21:37

score: Optimize scheduler priority updates

Thread priority changes may append or prepend the thread to its priority
group on the scheduler ready queue. Previously, a separate priority
value and a prepend-it flag in the scheduler node were used to propagate
a priority change to the scheduler.

Now, use an append-it bit in the priority control and reduce the plain
priority value to 63 bits.

This change leads to a significant code size reduction (about 25%) of
the SMP schedulers. The negligible increase of the standard priority
scheduler is due to some additional shift operations
(SCHEDULER_PRIORITY_MAP() and SCHEDULER_PRIORITY_UNMAP()).

Before:

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136 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleblock.o
464 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimplechangepriority.o

24 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimple.o

108 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleschedule.o
292 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleunblock.o
264 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleyield.o

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280 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityblock.o
488 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerprioritychangepriority.o
200 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriority.o
164 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityschedule.o
328 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityunblock.o
200 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityyield.o

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24112 arm-rtems5/c/imx7/cpukit/score/src/libscore_a-scheduleredfsmp.o

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37204 sparc-rtems5/c/gr740/cpukit/score/src/libscore_a-scheduleredfsmp.o

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42236 powerpc-rtems5/c/qoriq_e6500_32/cpukit/score/src/libscore_a-scheduleredfsmp.o

After:

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136 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleblock.o
272 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimplechangepriority.o

24 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimple.o

108 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleschedule.o
292 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleunblock.o
264 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulersimpleyield.o

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280 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityblock.o
488 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerprioritychangepriority.o
208 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriority.o
164 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityschedule.o
332 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityunblock.o
200 sparc-rtems5/c/erc32/cpukit/score/src/libscore_a-schedulerpriorityyield.o

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18860 arm-rtems5/c/imx7/cpukit/score/src/libscore_a-scheduleredfsmp.o

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28520 sparc-rtems5/c/gr740/cpukit/score/src/libscore_a-scheduleredfsmp.o

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32664 powerpc-rtems5/c/qoriq_e6500_32/cpukit/score/src/libscore_a-scheduleredfsmp.o

  • Property mode set to 100644
File size: 2.0 KB
Line 
1/**
2 *  @file
3 *
4 *  @brief Scheduler Priority Unblock
5 *  @ingroup ScoreScheduler
6 */
7
8/*
9 *  Scheduler Handler
10 *
11 *  Copyright (C) 2010 Gedare Bloom.
12 *  Copyright (C) 2011 On-Line Applications Research Corporation (OAR).
13 *
14 *  The license and distribution terms for this file may be
15 *  found in the file LICENSE in this distribution or at
16 *  http://www.rtems.org/license/LICENSE.
17 */
18
19#if HAVE_CONFIG_H
20#include "config.h"
21#endif
22
23#include <rtems/score/schedulerpriorityimpl.h>
24
25void _Scheduler_priority_Unblock (
26  const Scheduler_Control *scheduler,
27  Thread_Control          *the_thread,
28  Scheduler_Node          *node
29)
30{
31  Scheduler_priority_Context *context;
32  Scheduler_priority_Node    *the_node;
33  unsigned int                priority;
34  unsigned int                unmapped_priority;
35
36  context = _Scheduler_priority_Get_context( scheduler );
37  the_node = _Scheduler_priority_Node_downcast( node );
38  priority = (unsigned int ) _Scheduler_Node_get_priority( &the_node->Base );
39  unmapped_priority = SCHEDULER_PRIORITY_UNMAP( priority );
40
41  if ( unmapped_priority != the_node->Ready_queue.current_priority ) {
42    _Scheduler_priority_Ready_queue_update(
43      &the_node->Ready_queue,
44      unmapped_priority,
45      &context->Bit_map,
46      &context->Ready[ 0 ]
47    );
48  }
49
50  _Scheduler_priority_Ready_queue_enqueue(
51    &the_thread->Object.Node,
52    &the_node->Ready_queue,
53    &context->Bit_map
54  );
55
56  /* TODO: flash critical section? */
57
58  /*
59   *  If the thread that was unblocked is more important than the heir,
60   *  then we have a new heir.  This may or may not result in a
61   *  context switch.
62   *
63   *  Normal case:
64   *    If the current thread is preemptible, then we need to do
65   *    a context switch.
66   *  Pseudo-ISR case:
67   *    Even if the thread isn't preemptible, if the new heir is
68   *    a pseudo-ISR system task, we need to do a context switch.
69   */
70  if ( priority < _Thread_Get_priority( _Thread_Heir ) ) {
71    _Scheduler_Update_heir( the_thread, priority == PRIORITY_PSEUDO_ISR );
72  }
73}
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