[RTEMS Project] #3819: Consider FAA AC 20-148 - Reusable Software Components in RTEMS Software Engineering manual
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Fri Nov 8 07:05:34 UTC 2019
#3819: Consider FAA AC 20-148 - Reusable Software Components in RTEMS Software
Engineering manual
------------------------------+-----------------------------
Reporter: Sebastian Huber | Owner: Sebastian Huber
Type: task | Status: assigned
Priority: normal | Milestone: 5.1
Component: doc | Version: 5
Severity: normal | Keywords:
Blocked By: | Blocking:
------------------------------+-----------------------------
Review of the Software Requirements Engineering chapter for the RTEMS
Software Engineering manual suggested that we should take the
[https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/22207
FAA AC 20-148 - Reusable Software Components] into account:
https://lists.rtems.org/pipermail/devel/2019-November/056027.html
{{{
+Resources and Performance
+-------------------------
+
+Normally, resource and performance requirements are formulated like
this:
+
+* The resource U shall need less than V storage units.
+
+* The operation Y shall complete within X time units.
+
+Such statements are difficult to make for a software product like
RTEMS which
+runs on many different target platforms in various configurations.
So, the
+performance requirements of RTEMS shall be stated in terms of
benchmarks. The
+benchmarks are run on the project-specific target platform and
configuration.
+The results obtained by the benchmark runs are reported in a human
readable
+presentation. The application designer can then use the benchmark
results to
+determine if its system performance requirements are met. The
benchmarks shall
+be executed under different environment conditions, e.g. varying
cache states
+(dirty, empty, valid) and system bus load generated by other
processors. The
+application designer shall have the ability to add additional
environment
+conditions, e.g. system bus load by DMA engines or different system
bus
+arbitration schemes.
+
+To catch resource and performance regressions via test suite runs
there shall be
+a means to specify threshold values for the measured quantities. The
threshold
+values should be provided for each validation platform. How this can
be done
+and if the threshold values are maintained by the RTEMS Project is
subject to
+discussion.
We focused on big-O and whether methods were constant time, bounded, or
O(n)
when designing. Perhaps the focus could be there. But this is a design
goal for all
of RTEMS and something we would document. Nothing to do except a general
design goal.
This section also sounds like part of what is required by a systems
integrator
when leveraging what the FAA calls a Reusable Software Component:
https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/22207
You get credit for what's common and have to fill in details for your
system.
}}}
--
Ticket URL: <http://devel.rtems.org/ticket/3819>
RTEMS Project <http://www.rtems.org/>
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