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doc: Minor edits needed on microkernel_fibers.rst

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General grammar edits: removed an "is is", added clarification, and
removed Latin abbreviation as per style guide reqs.

Change-Id: Ie9365dea2cdf27c107675487d4bf392711f4acb2
Signed-off-by: L.S. Cook <leonax.cook@intel.com>
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L.S. Cook 2016-02-24 07:10:33 -08:00 • committed by Gerrit Code Review
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32
doc/kernel/microkernel/microkernel_fibers.rst
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@ -6,16 +6,16 @@ Fiber Services
Concepts
********
A fiber is a lightweight, non-preemptible thread of execution that implements
a portion of an application's processing. It is is normally used when writing
device drivers and other performance critical work.
A :dfn:`fiber` is a lightweight, non-preemptible thread of execution that
implements a portion of an application's processing. Fiber-based services are
often used in device drivers and for performance-critical work.
A microkernel application can use all of the fiber capabilities that are
available to a nanokernel application; for more information see
:ref:`Nanokernel Fiber Services <nanokernel_fibers>`.
:ref:`nanokernel_fibers`.
While a fiber often uses one or more nanokernel object types to carry
out its work, it can also interact with microkernel events and semaphores
out its work, it also can interact with microkernel events and semaphores
to a limited degree. For example, a fiber can signal a task by giving a
microkernel semaphore, but it cannot take a microkernel semaphore. For more
information see :ref:`microkernel_events` and :ref:`microkernel_semaphores`.
@ -28,12 +28,20 @@ Microkernel Server Fiber
The microkernel automatically spawns a system thread, known as the
*microkernel server* fiber, which performs most operations involving
microkernel objects; see :ref:`Microkernel Server <microkernel_server>`.
microkernel objects. The nanokernel scheduler decides which fibers
get scheduled and when; it will schedule the microkernel server fiber
when there are no fibers of a higher priority.
Both the fiber's stack size and scheduling priority can be configured,
using the :option:`MICROKERNEL_SERVER_STACK_SIZE` and
:option:`MICROKERNEL_SERVER_PRIORITY` configuration options, respectively.
By default, the microkernel server fiber has priority 0 (that is,
the highest priority). However, this can be changed. If you drop its
priority, the nanokernel scheduler will give precedence to other,
higher-priority fibers, such as time-sensitive device driver or
application fibers.
By default, the microkernel server has priority 0 (i.e. highest priority).
However, this can be changed so that the nanokernel scheduler gives precedence
to other fibers, such as time-sensitive device driver or application fibers.
Both the fiber's stack size and scheduling priority can be configured
with the :option:`MICROKERNEL_SERVER_STACK_SIZE` and
:option:`MICROKERNEL_SERVER_PRIORITY` configuration options,
respectively.
See also :ref:`microkernel_server`.