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| author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2021-09-14 19:18:31 +0200 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2021-09-15 07:54:43 +0200 |
| commit | 5fdc744dcedef3a40abbc031e540a811aca6e2b1 (patch) | |
| tree | 3c7336a550d8619fdb81f08116fa70a4e0934dd4 /c-user/task/background.rst | |
| parent | c-user: Define lower and higher priority (diff) | |
| download | rtems-docs-5fdc744dcedef3a40abbc031e540a811aca6e2b1.tar.bz2 | |
c-user: Clarify task priorities
Diffstat (limited to '')
| -rw-r--r-- | c-user/task/background.rst | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/c-user/task/background.rst b/c-user/task/background.rst index a55f743..da6cabf 100644 --- a/c-user/task/background.rst +++ b/c-user/task/background.rst @@ -127,13 +127,19 @@ scheduling of a task is based on its current state and priority. .. index:: priority, task .. index:: rtems_task_priority +.. _TaskPriority: + Task Priority ------------- -A task's priority determines its importance in relation to the other tasks -executing on the same processor. RTEMS supports 255 levels of priority ranging -from 1 to 255. The data type ``rtems_task_priority`` is used to store task -priorities. +A task's :term:`priority` determines its importance in relation to the other +tasks executing on the processor set owned by a :term:`scheduler`. Normally, +RTEMS supports 256 levels of priority ranging from 0 to 255. The priority +level 0 represents a special priority reserved for the operating system. The +data type :c:type:`rtems_task_priority` is used to store task priorities. The +maximum priority level depends on the configured scheduler, see +:ref:`CONFIGURE_MAXIMUM_PRIORITY`, :ref:`ConfigurationSchedulersClustered`, and +:ref:`RTEMSAPIClassicScheduler`. Tasks of numerically smaller priority values are more important tasks than tasks of numerically larger priority values. For example, a task at priority |