source: rtems/cpukit/score/src/schedulersimpleunblock.c @ 2548d14

5
Last change on this file since 2548d14 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

text filename

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

text filename

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: 1.6 KB
Line 
1/**
2 * @file
3 *
4 * @brief Scheduler Simple Handler / Unblock
5 * @ingroup ScoreScheduler
6 */
7
8/*
9 *  COPYRIGHT (c) 2011.
10 *  On-Line Applications Research Corporation (OAR).
11 *
12 *  The license and distribution terms for this file may be
13 *  found in found in the file LICENSE in this distribution or at
14 *  http://www.rtems.org/license/LICENSE.
15 */
16
17#if HAVE_CONFIG_H
18#include "config.h"
19#endif
20
21#include <rtems/score/schedulersimpleimpl.h>
22#include <rtems/score/thread.h>
23
24void _Scheduler_simple_Unblock(
25  const Scheduler_Control *scheduler,
26  Thread_Control          *the_thread,
27  Scheduler_Node          *node
28)
29{
30  Scheduler_simple_Context *context;
31  unsigned int              priority;
32  unsigned int              insert_priority;
33
34  (void) node;
35
36  context = _Scheduler_simple_Get_context( scheduler );
37  priority = _Thread_Get_priority( the_thread );
38  insert_priority = SCHEDULER_PRIORITY_APPEND( priority );
39  _Scheduler_simple_Insert( &context->Ready, the_thread, insert_priority );
40
41  /*
42   *  If the thread that was unblocked is more important than the heir,
43   *  then we have a new heir.  This may or may not result in a
44   *  context switch.
45   *
46   *  Normal case:
47   *    If the current thread is preemptible, then we need to do
48   *    a context switch.
49   *  Pseudo-ISR case:
50   *    Even if the thread isn't preemptible, if the new heir is
51   *    a pseudo-ISR system task, we need to do a context switch.
52   */
53  if ( priority < _Thread_Get_priority( _Thread_Heir ) ) {
54    _Scheduler_Update_heir(
55      the_thread,
56      priority == PRIORITY_PSEUDO_ISR
57    );
58  }
59}
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