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8th International Workshop on
Software and Compilers for Embedded Systems
SCOPES 2004
Workshop Program - Presentation Abstract
| Dynamic Mapping and Ordering Tasks of Embedded Real-Time Systems on
Multiprocessor Platforms |
Peng Yang - IMEC/KU Leuven
Francky Catthoor - IMEC/KU Leuven
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| Tradeoff exploration can be found in several different areas of
embedded system design. One example is task scheduling, where different
task mapping and ordering choices for a target platform will lead to
different performance/cost tradeoffs, which can be represented in a
so-called Pareto curve. Though many scheduling algorithms have been
suggested, on-line or off-line, few have been really implemented on a
real platform, especially on an embedded multi-processor one. We have
implemented a middleware layer to handle that problem and we have
integrated a hierarchical task scheduler into it. It is compatible with
most current RTOS implementations as long as they have a well defined
API for task activation and synchronization. A simple DCT example
demonstrates that the extra overhead is acceptable low. With a real-life
test case from H.263, we demonstrate how big an impact our approach can
cause. The deadline miss rate is dramatically reduced since we map and
order the tasks at run-time. When voltage scaling is considered, we can
save 10% more energy compared to the state-of-the-art solution.
Moreover, this integration enables a novel design methodology flow,
which allows further design space exploration and optimization at run
time. |
Presentation
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