SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
appl-config-option-type: integer
constraints:
  set:
  - 3
  - 7
  - 31
  - 63
  - 127
  - 255
copyrights:
- Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
default-value: 255
description: |
  For the following schedulers

  * ${.:/document-reference/scheduler-priority}, which is the default in uniprocessor
    configurations and can be configured through the
    ${scheduler-priority:/name} configuration option,

  * ${.:/document-reference/scheduler-smp-priority} which can be configured through the
    ${scheduler-priority-smp:/name} configuration option, and

  * ${.:/document-reference/scheduler-smp-priority-affinity} which can be configured through the
    ${scheduler-priority-affinity-smp:/name} configuration option

  this configuration option specifies the maximum numeric priority of any task
  for these schedulers and one less that the number of priority levels for
  these schedulers.  For all other schedulers provided by RTEMS, this
  configuration option has no effect.
enabled-by: true
index-entries:
- maximum priority
- number of priority levels
interface-type: appl-config-option
links:
- role: appl-config-group-member
  uid: group-schedgeneral
name: CONFIGURE_MAXIMUM_PRIORITY
notes: |
  The numerically greatest priority is the logically lowest priority in the
  system and will thus be used by the IDLE task.

  Priority zero is reserved for internal use by RTEMS and is not available to
  applications.

  Reducing the number of priorities through this configuration option reduces
  the amount of memory allocated by the schedulers listed above.  These
  schedulers use a chain control structure per priority and this structure
  consists of three pointers.  On a 32-bit architecture, the allocated memory
  is 12 bytes * (``CONFIGURE_MAXIMUM_PRIORITY`` + 1), e.g. 3072 bytes for 256
  priority levels (default), 48 bytes for 4 priority levels
  (``CONFIGURE_MAXIMUM_PRIORITY == 3``).

  The default value is 255, because RTEMS shall support 256 priority levels to
  be compliant with various standards.  These priorities range from 0 to 255.
text: ''
type: interface