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Update more information about the sporadic scheduler

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Gregory Nutt 2015-07-24 10:02:37 -06:00
parent 2d13f29afa
commit fc66e45b16
1 changed files with 7 additions and 8 deletions
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Documentation/NuttxUserGuide.html
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@ -1619,21 +1619,20 @@ int posix_spawn_file_actions_init(FAR posix_spawn_file_actions_t *file_actions);
</table> </table>
<p> <p>
By default, NuttX performs strict priority scheduling: Tasks of higher By default, NuttX performs strict priority scheduling: Tasks of higher priority have exclusive access to the CPU until they become blocked.
priority have exclusive access to the CPU until they become blocked.
At that time, the CPU is available to tasks of lower priority. At that time, the CPU is available to tasks of lower priority.
Tasks of equal priority are scheduled FIFO. Tasks of equal priority are scheduled FIFO.
</p> </p>
<p> <p>
Optionally, a Nuttx task or thread can be configured with round-robin Optionally, a Nuttx task or thread can be configured with round-robin or <i>sporadic</i> scheduler.
scheduler. This is similar to priority scheduling <i>except</i> that The round-roben is similar to priority scheduling <i>except</i> that tasks with equal priority and share CPU time via <i>time-slicing</i>.
tasks with equal priority and share CPU time via <i>time-slicing</i>.
The time-slice interval is a constant determined by the configuration The time-slice interval is a constant determined by the configuration
setting <code>CONFIG_RR_INTERVAL</code>. setting <code>CONFIG_RR_INTERVAL</code> to a positive, non-zero value.
Sporadic scheduling scheduling is more complex, varying the priority of a thread over a <i>replenishment</i> period.
Support for sporadic scheduling is enabled by the configuration option <code>CONFIG_SCHED_SPORADIC</code>.
</p> </p>
<p> <p>
The OS interfaces described in the following paragraphs provide The OS interfaces described in the following paragraphs provide a POSIX- compliant interface to the NuttX scheduler:
a POSIX- compliant interface to the NuttX scheduler:
</p> </p>
<ul> <ul>
<li><a href="#schedsetparam">2.2.1 sched_setparam</a></li> <li><a href="#schedsetparam">2.2.1 sched_setparam</a></li>