source: rtems/cpukit/score/src/schedulercbsunblock.c @ 21275b58

5
Last change on this file since 21275b58 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

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: 2.1 KB
Line 
1/**
2 * @file
3 *
4 * @brief Unblocks a Thread from the Queue
5 *
6 * @ingroup ScoreScheduler
7 */
8
9/*
10 *  Copyright (C) 2011 Petr Benes.
11 *  Copyright (C) 2011 On-Line Applications Research Corporation (OAR).
12 *
13 *  The license and distribution terms for this file may be
14 *  found in the file LICENSE in this distribution or at
15 *  http://www.rtems.org/license/LICENSE.
16 */
17
18#if HAVE_CONFIG_H
19#include "config.h"
20#endif
21
22#include <rtems/score/schedulercbsimpl.h>
23#include <rtems/score/scheduleredfimpl.h>
24#include <rtems/score/schedulerimpl.h>
25#include <rtems/score/threadimpl.h>
26#include <rtems/score/watchdogimpl.h>
27
28void _Scheduler_CBS_Unblock(
29  const Scheduler_Control *scheduler,
30  Thread_Control          *the_thread,
31  Scheduler_Node          *node
32)
33{
34  Scheduler_CBS_Node   *the_node;
35  Scheduler_CBS_Server *serv_info;
36  Priority_Control      priority;
37
38  the_node = _Scheduler_CBS_Node_downcast( node );
39  serv_info = the_node->cbs_server;
40  priority = _Scheduler_Node_get_priority( &the_node->Base.Base );
41  priority = SCHEDULER_PRIORITY_PURIFY( priority );
42
43  /*
44   * Late unblock rule for deadline-driven tasks. The remaining time to
45   * deadline must be sufficient to serve the remaining computation time
46   * without increased utilization of this task. It might cause a deadline
47   * miss of another task.
48   */
49  if ( serv_info != NULL && ( priority & SCHEDULER_EDF_PRIO_MSB ) == 0 ) {
50    time_t deadline = serv_info->parameters.deadline;
51    time_t budget = serv_info->parameters.budget;
52    uint32_t deadline_left = the_thread->cpu_time_budget;
53    Priority_Control budget_left = priority - _Watchdog_Ticks_since_boot;
54
55    if ( deadline * budget_left > budget * deadline_left ) {
56      Thread_queue_Context queue_context;
57
58      /* Put late unblocked task to background until the end of period. */
59      _Thread_queue_Context_clear_priority_updates( &queue_context );
60      _Scheduler_CBS_Cancel_job(
61        scheduler,
62        the_thread,
63        the_node->deadline_node,
64        &queue_context
65      );
66    }
67  }
68
69  _Scheduler_EDF_Unblock( scheduler, the_thread, &the_node->Base.Base );
70}
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