source: rtems-docs/c-user/config/bdbuf.rst @ 657f744

Last change on this file since 657f744 was 1c8ce33, checked in by Sebastian Huber <sebastian.huber@…>, on 11/16/21 at 07:17:31

c-user: Use rubric for configuration options

Clear the page for each configuration options similar to the directives.

Use a rubric instead of a definition list for the application
configuration options similar to the directive documentation pages. For
direcives and application configuration options use the same rubric
order.

Generalize value constraints to constraints.

This patch does not change hand written content.
  • Property mode set to 100644
File size: 12.1 KB
Line 
1.. SPDX-License-Identifier: CC-BY-SA-4.0
2
3.. Copyright (C) 2020, 2021 embedded brains GmbH (http://www.embedded-brains.de)
4.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
5
6.. This file is part of the RTEMS quality process and was automatically
7.. generated.  If you find something that needs to be fixed or
8.. worded better please post a report or patch to an RTEMS mailing list
9.. or raise a bug report:
10..
11.. https://www.rtems.org/bugs.html
12..
13.. For information on updating and regenerating please refer to the How-To
14.. section in the Software Requirements Engineering chapter of the
15.. RTEMS Software Engineering manual.  The manual is provided as a part of
16.. a release.  For development sources please refer to the online
17.. documentation at:
18..
19.. https://docs.rtems.org
20
21.. Generated from spec:/acfg/if/group-bdbuf
22
23Block Device Cache Configuration
24================================
25
26This section describes configuration options related to the Block Device Cache
27(bdbuf).
28
29.. Generated from spec:/acfg/if/appl-needs-libblock
30
31.. raw:: latex
32
33    \clearpage
34
35.. index:: CONFIGURE_APPLICATION_NEEDS_LIBBLOCK
36
37.. _CONFIGURE_APPLICATION_NEEDS_LIBBLOCK:
38
39CONFIGURE_APPLICATION_NEEDS_LIBBLOCK
40------------------------------------
41
42.. rubric:: CONSTANT:
43
44``CONFIGURE_APPLICATION_NEEDS_LIBBLOCK``
45
46.. rubric:: OPTION TYPE:
47
48This configuration option is a boolean feature define.
49
50.. rubric:: DEFAULT CONFIGURATION:
51
52If this configuration option is undefined, then the described feature is not
53enabled.
54
55.. rubric:: DESCRIPTION:
56
57In case this configuration option is defined, then the Block Device Cache is
58initialized during system initialization.
59
60.. rubric:: NOTES:
61
62Each option of the Block Device Cache (bdbuf) configuration can be explicitly
63set by the user with the configuration options below.  The Block Device Cache
64is used for example by the RFS and DOSFS filesystems.
65
66.. Generated from spec:/acfg/if/bdbuf-buffer-max-size
67
68.. raw:: latex
69
70    \clearpage
71
72.. index:: CONFIGURE_BDBUF_BUFFER_MAX_SIZE
73
74.. _CONFIGURE_BDBUF_BUFFER_MAX_SIZE:
75
76CONFIGURE_BDBUF_BUFFER_MAX_SIZE
77-------------------------------
78
79.. rubric:: CONSTANT:
80
81``CONFIGURE_BDBUF_BUFFER_MAX_SIZE``
82
83.. rubric:: OPTION TYPE:
84
85This configuration option is an integer define.
86
87.. rubric:: DEFAULT VALUE:
88
89The default value is 4096.
90
91.. rubric:: DESCRIPTION:
92
93The value of this configuration option defines the maximum size of a buffer
94in bytes.
95
96.. rubric:: CONSTRAINTS:
97
98The following constraints apply to this configuration option:
99
100* The value of the configuration option shall be greater than or equal to zero.
101
102* The value of the configuration option shall be an integral multiple of
103  :ref:`CONFIGURE_BDBUF_BUFFER_MIN_SIZE`.
104
105.. Generated from spec:/acfg/if/bdbuf-buffer-min-size
106
107.. raw:: latex
108
109    \clearpage
110
111.. index:: CONFIGURE_BDBUF_BUFFER_MIN_SIZE
112
113.. _CONFIGURE_BDBUF_BUFFER_MIN_SIZE:
114
115CONFIGURE_BDBUF_BUFFER_MIN_SIZE
116-------------------------------
117
118.. rubric:: CONSTANT:
119
120``CONFIGURE_BDBUF_BUFFER_MIN_SIZE``
121
122.. rubric:: OPTION TYPE:
123
124This configuration option is an integer define.
125
126.. rubric:: DEFAULT VALUE:
127
128The default value is 512.
129
130.. rubric:: DESCRIPTION:
131
132The value of this configuration option defines the minimum size of a buffer
133in bytes.
134
135.. rubric:: CONSTRAINTS:
136
137The following constraints apply to this configuration option:
138
139* The value of the configuration option shall be greater than or equal to zero.
140
141* The value of the configuration option shall be less than or equal to
142  `UINT32_MAX <https://en.cppreference.com/w/c/types/integer>`_.
143
144.. Generated from spec:/acfg/if/bdbuf-cache-memory-size
145
146.. raw:: latex
147
148    \clearpage
149
150.. index:: CONFIGURE_BDBUF_CACHE_MEMORY_SIZE
151
152.. _CONFIGURE_BDBUF_CACHE_MEMORY_SIZE:
153
154CONFIGURE_BDBUF_CACHE_MEMORY_SIZE
155---------------------------------
156
157.. rubric:: CONSTANT:
158
159``CONFIGURE_BDBUF_CACHE_MEMORY_SIZE``
160
161.. rubric:: OPTION TYPE:
162
163This configuration option is an integer define.
164
165.. rubric:: DEFAULT VALUE:
166
167The default value is 32768.
168
169.. rubric:: DESCRIPTION:
170
171The value of this configuration option defines the size of the cache memory
172in bytes.
173
174.. rubric:: CONSTRAINTS:
175
176The following constraints apply to this configuration option:
177
178* The value of the configuration option shall be greater than or equal to zero.
179
180* The value of the configuration option shall be less than or equal to
181  `SIZE_MAX <https://en.cppreference.com/w/c/types/limits>`_.
182
183.. Generated from spec:/acfg/if/bdbuf-max-read-ahead-blocks
184
185.. raw:: latex
186
187    \clearpage
188
189.. index:: CONFIGURE_BDBUF_MAX_READ_AHEAD_BLOCKS
190
191.. _CONFIGURE_BDBUF_MAX_READ_AHEAD_BLOCKS:
192
193CONFIGURE_BDBUF_MAX_READ_AHEAD_BLOCKS
194-------------------------------------
195
196.. rubric:: CONSTANT:
197
198``CONFIGURE_BDBUF_MAX_READ_AHEAD_BLOCKS``
199
200.. rubric:: OPTION TYPE:
201
202This configuration option is an integer define.
203
204.. rubric:: DEFAULT VALUE:
205
206The default value is 0.
207
208.. rubric:: DESCRIPTION:
209
210The value of this configuration option defines the maximum blocks per
211read-ahead request.
212
213.. rubric:: NOTES:
214
215A value of 0 disables the read-ahead task (default).  The read-ahead task
216will issue speculative read transfers if a sequential access pattern is
217detected.  This can improve the performance on some systems.
218
219.. rubric:: CONSTRAINTS:
220
221The following constraints apply to this configuration option:
222
223* The value of the configuration option shall be greater than or equal to zero.
224
225* The value of the configuration option shall be less than or equal to
226  `UINT32_MAX <https://en.cppreference.com/w/c/types/integer>`_.
227
228.. Generated from spec:/acfg/if/bdbuf-max-write-blocks
229
230.. raw:: latex
231
232    \clearpage
233
234.. index:: CONFIGURE_BDBUF_MAX_WRITE_BLOCKS
235
236.. _CONFIGURE_BDBUF_MAX_WRITE_BLOCKS:
237
238CONFIGURE_BDBUF_MAX_WRITE_BLOCKS
239--------------------------------
240
241.. rubric:: CONSTANT:
242
243``CONFIGURE_BDBUF_MAX_WRITE_BLOCKS``
244
245.. rubric:: OPTION TYPE:
246
247This configuration option is an integer define.
248
249.. rubric:: DEFAULT VALUE:
250
251The default value is 16.
252
253.. rubric:: DESCRIPTION:
254
255The value of this configuration option defines the maximum blocks per write
256request.
257
258.. rubric:: CONSTRAINTS:
259
260The following constraints apply to this configuration option:
261
262* The value of the configuration option shall be greater than or equal to zero.
263
264* The value of the configuration option shall be less than or equal to
265  `UINT32_MAX <https://en.cppreference.com/w/c/types/integer>`_.
266
267.. Generated from spec:/acfg/if/bdbuf-read-ahead-task-priority
268
269.. raw:: latex
270
271    \clearpage
272
273.. index:: CONFIGURE_BDBUF_READ_AHEAD_TASK_PRIORITY
274
275.. _CONFIGURE_BDBUF_READ_AHEAD_TASK_PRIORITY:
276
277CONFIGURE_BDBUF_READ_AHEAD_TASK_PRIORITY
278----------------------------------------
279
280.. rubric:: CONSTANT:
281
282``CONFIGURE_BDBUF_READ_AHEAD_TASK_PRIORITY``
283
284.. rubric:: OPTION TYPE:
285
286This configuration option is an integer define.
287
288.. rubric:: DEFAULT VALUE:
289
290The default value is 15.
291
292.. rubric:: DESCRIPTION:
293
294The value of this configuration option defines the read-ahead task priority.
295
296.. rubric:: CONSTRAINTS:
297
298The value of the configuration option shall be a valid Classic API task
299priority.  The set of valid task priorities depends on the scheduler
300configuration.
301
302.. Generated from spec:/acfg/if/bdbuf-task-stack-size
303
304.. raw:: latex
305
306    \clearpage
307
308.. index:: CONFIGURE_BDBUF_TASK_STACK_SIZE
309
310.. _CONFIGURE_BDBUF_TASK_STACK_SIZE:
311
312CONFIGURE_BDBUF_TASK_STACK_SIZE
313-------------------------------
314
315.. rubric:: CONSTANT:
316
317``CONFIGURE_BDBUF_TASK_STACK_SIZE``
318
319.. rubric:: OPTION TYPE:
320
321This configuration option is an integer define.
322
323.. rubric:: DEFAULT VALUE:
324
325The default value is :c:macro:`RTEMS_MINIMUM_STACK_SIZE`.
326
327.. rubric:: DESCRIPTION:
328
329The value of this configuration option defines the task stack size of the
330Block Device Cache tasks in bytes.
331
332.. rubric:: CONSTRAINTS:
333
334The following constraints apply to this configuration option:
335
336* The value of the configuration option shall be greater than or equal to
337  :ref:`CONFIGURE_MINIMUM_TASK_STACK_SIZE`.
338
339* The value of the configuration option shall be less than or equal to a
340  BSP-specific and application-specific value which depends on the size of the
341  memory available to the application.
342
343* The value of the configuration option shall be small enough so that the task
344  stack space calculation carried out by ``<rtems/confdefs.h>`` does not
345  overflow an integer of type `uintptr_t
346  <https://en.cppreference.com/w/c/types/integer>`_.
347
348.. Generated from spec:/acfg/if/bdbuf-swapout-block-hold
349
350.. raw:: latex
351
352    \clearpage
353
354.. index:: CONFIGURE_SWAPOUT_BLOCK_HOLD
355
356.. _CONFIGURE_SWAPOUT_BLOCK_HOLD:
357
358CONFIGURE_SWAPOUT_BLOCK_HOLD
359----------------------------
360
361.. rubric:: CONSTANT:
362
363``CONFIGURE_SWAPOUT_BLOCK_HOLD``
364
365.. rubric:: OPTION TYPE:
366
367This configuration option is an integer define.
368
369.. rubric:: DEFAULT VALUE:
370
371The default value is 1000.
372
373.. rubric:: DESCRIPTION:
374
375The value of this configuration option defines the swapout task maximum block
376hold time in milliseconds.
377
378.. rubric:: CONSTRAINTS:
379
380The following constraints apply to this configuration option:
381
382* The value of the configuration option shall be greater than or equal to zero.
383
384* The value of the configuration option shall be less than or equal to
385  `UINT32_MAX <https://en.cppreference.com/w/c/types/integer>`_.
386
387.. Generated from spec:/acfg/if/bdbuf-swapout-swap-period
388
389.. raw:: latex
390
391    \clearpage
392
393.. index:: CONFIGURE_SWAPOUT_SWAP_PERIOD
394
395.. _CONFIGURE_SWAPOUT_SWAP_PERIOD:
396
397CONFIGURE_SWAPOUT_SWAP_PERIOD
398-----------------------------
399
400.. rubric:: CONSTANT:
401
402``CONFIGURE_SWAPOUT_SWAP_PERIOD``
403
404.. rubric:: OPTION TYPE:
405
406This configuration option is an integer define.
407
408.. rubric:: DEFAULT VALUE:
409
410The default value is 250.
411
412.. rubric:: DESCRIPTION:
413
414The value of this configuration option defines the swapout task swap period
415in milliseconds.
416
417.. rubric:: CONSTRAINTS:
418
419The following constraints apply to this configuration option:
420
421* The value of the configuration option shall be greater than or equal to zero.
422
423* The value of the configuration option shall be less than or equal to
424  `UINT32_MAX <https://en.cppreference.com/w/c/types/integer>`_.
425
426.. Generated from spec:/acfg/if/bdbuf-swapout-task-priority
427
428.. raw:: latex
429
430    \clearpage
431
432.. index:: CONFIGURE_SWAPOUT_TASK_PRIORITY
433
434.. _CONFIGURE_SWAPOUT_TASK_PRIORITY:
435
436CONFIGURE_SWAPOUT_TASK_PRIORITY
437-------------------------------
438
439.. rubric:: CONSTANT:
440
441``CONFIGURE_SWAPOUT_TASK_PRIORITY``
442
443.. rubric:: OPTION TYPE:
444
445This configuration option is an integer define.
446
447.. rubric:: DEFAULT VALUE:
448
449The default value is 15.
450
451.. rubric:: DESCRIPTION:
452
453The value of this configuration option defines the swapout task priority.
454
455.. rubric:: CONSTRAINTS:
456
457The value of the configuration option shall be a valid Classic API task
458priority.  The set of valid task priorities depends on the scheduler
459configuration.
460
461.. Generated from spec:/acfg/if/bdbuf-swapout-worker-tasks
462
463.. raw:: latex
464
465    \clearpage
466
467.. index:: CONFIGURE_SWAPOUT_WORKER_TASKS
468
469.. _CONFIGURE_SWAPOUT_WORKER_TASKS:
470
471CONFIGURE_SWAPOUT_WORKER_TASKS
472------------------------------
473
474.. rubric:: CONSTANT:
475
476``CONFIGURE_SWAPOUT_WORKER_TASKS``
477
478.. rubric:: OPTION TYPE:
479
480This configuration option is an integer define.
481
482.. rubric:: DEFAULT VALUE:
483
484The default value is 0.
485
486.. rubric:: DESCRIPTION:
487
488The value of this configuration option defines the swapout worker task count.
489
490.. rubric:: CONSTRAINTS:
491
492The following constraints apply to this configuration option:
493
494* The value of the configuration option shall be greater than or equal to zero.
495
496* The value of the configuration option shall be less than or equal to
497  `UINT32_MAX <https://en.cppreference.com/w/c/types/integer>`_.
498
499.. Generated from spec:/acfg/if/bdbuf-swapout-worker-taskp-riority
500
501.. raw:: latex
502
503    \clearpage
504
505.. index:: CONFIGURE_SWAPOUT_WORKER_TASK_PRIORITY
506
507.. _CONFIGURE_SWAPOUT_WORKER_TASK_PRIORITY:
508
509CONFIGURE_SWAPOUT_WORKER_TASK_PRIORITY
510--------------------------------------
511
512.. rubric:: CONSTANT:
513
514``CONFIGURE_SWAPOUT_WORKER_TASK_PRIORITY``
515
516.. rubric:: OPTION TYPE:
517
518This configuration option is an integer define.
519
520.. rubric:: DEFAULT VALUE:
521
522The default value is 15.
523
524.. rubric:: DESCRIPTION:
525
526The value of this configuration option defines the swapout worker task
527priority.
528
529.. rubric:: CONSTRAINTS:
530
531The value of the configuration option shall be a valid Classic API task
532priority.  The set of valid task priorities depends on the scheduler
533configuration.
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