Li, Zheng:
> Thank you Prof Dick
> When you say learn that task on-line and do corresponding assignment,do you
> mean that both assignment and thus scheduling will be on-linerather than
> design time? Actually I think one-line assignment is pretty common in
> generalpurpose processor, I'm not sure whether this will be an
> importantproblem for embedded system.

It is already done by operating systems for general-purpose multiprocessors.
However, there is active research on doing it properly for thermal issues.
Developing a good solution for heterogenous multiprocessors might be a good
project. Another option would be to consider some special optimization
objective such as reliability.

> Since embedded system are
> applicationspecific, we can know the task pretty well in design time.

That is true for many embedded systems but not all embedded systems. At the
cellphone/PDA complexity level and above, if the system is not hard real-time,
it is common to use on-line assignment and scheduling.

> Besides, ifwe do the assignment and scheduling on-fly, maybe we will run
> out ofdead line or power budget. Is this the trend of future
> embeddedsystem?

Guaranteeing deadlines will be more difficult if we do on-line assignment and
scheduling. However, it can be the best solution for some systems, e.g.,
reactive or interactive systems. I think it is the trend for systems at
PDA/cellphone level and above.

-Robert Dick-
Received on Fri Aug 24 13:12:25 2007