On Tue, Sep 14, 2021 at 10:21 AM Sebastian Huber <sebastian.hu...@embedded-brains.de> wrote: > > --- > c-user/glossary.rst | 37 ++++++++++++++++++++++++++++++++----- > 1 file changed, 32 insertions(+), 5 deletions(-) > > diff --git a/c-user/glossary.rst b/c-user/glossary.rst > index 16a8b8d..94bf773 100644 > --- a/c-user/glossary.rst > +++ b/c-user/glossary.rst > @@ -398,6 +398,10 @@ Glossary > heterogeneous > A multiprocessor computer system composed of dissimilar processors. > > + higher priority > + A :term:`task` ``H`` has a higher :term:`priority` than a task > ``L``, if > + task ``H`` is more important than task ``L``. > + > home scheduler > The home scheduler of a :term:`task` is a :term:`scheduler` which is > an > :term:`eligible scheduler` and which is assigned to the task during > its > @@ -498,6 +502,10 @@ Glossary > A multiprocessor configuration where shared memory is not used for > communication. > > + lower priority > + A :term:`task` ``L`` has a lower :term:`priority` than a task ``H``, > if > + task ``L`` is less important than task ``H``. > + > major number > The index of a device driver in the Device Driver Table. > > @@ -664,8 +672,22 @@ Glossary > > priority > The priority is a mechanism used to represent the relative > importance of an > - element in a set of items. RTEMS uses :term:`task priorities <task > priority>` to determine > - which :term:`task` should execute. > + element in a set of items. > + > + For example, :term:`RTEMS` uses :term:`task priorities <task > priority>` to determine which > + :term:`task` should execute on a processor. In RTEMS, priorities are > + represented by non-negative integers. > + > + For the Classic :term:`API`, if a numerical priority value ``A`` is > greater > + than a numerical priority value ``B``, then ``A`` expresses a > + :term:`higher priority` than ``B``. If a numerical priority value > ``C`` is > + less than a numerical priority value ``D``, then ``C`` expresses a > + :term:`lower priority` than ``D``. > + > + For the :term:`POSIX` API, if a numerical priority value ``R`` is > less than > + a numerical priority value ``S``, then ``R`` expresses a lower > priority than > + ``S``. If a numerical priority value ``T`` is greater than a > numerical > + priority value ``U``, then ``T`` expresses a higher priority than > ``U``. >
These are backwards. Classic priorities with numerically greater values indicate lower priorities. POSIX priorities with numerically higher values express higher priorities. > priority boosting > A simple approach to extend the priority inheritance protocol for > @@ -999,13 +1021,18 @@ Glossary > and resumes execution on another processor. > > task priority > - A task priority of a :term:`task` determines its importance relative > to > - other tasks. The scheduler use task priorities to determine which > - :term:`ready task` gets a processor allocated, see :term:`scheduled > task`. The > + A task :term:`priority` of a :term:`task` determines its importance > + relative to other tasks. > + > + The scheduler use task priorities to determine which :term:`ready > task` gets > + a processor allocated, see :term:`scheduled task`. The > :term:`eligible priorities <eligible priority>` of a task define the > position of the task in a > :term:`wait queue` which uses the priority discipline. Each task > has at > least the :term:`real priority`. > > + Task priorities are used in :term:`wait queues <wait queue>` which > use the priority > + discipline to determine the dequeueing order of tasks. > + > task processor affinity > The set of processors on which a task is allowed to execute. > > -- > 2.31.1 > > _______________________________________________ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel