Studying and Implementing

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Studying and Implementing Multi-processor based
Real-time Scheduling Algorithms in Linux
Musfiq Niaz Rahman musfiq_at_cs.pitt.edu
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Which Algorithms
1. Pfair Scheduling (it is my primary focus) 2.
EDF Scheduling
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The Pfair Algorithm
What is Pfair ? Under Pfair (proportionate
progress and fairness) scheduling, each task is
broken into quantum-length subtasks, each of
which must execute within a window of time slots.
These windows divide each period of a task into
potentially overlapping subintervals of
approximately equal length. By breaking tasks
into smaller executable units, it is easier to to
evenly distribute them among available processors
(for instance, we can use suitable bin-packing
algorithms to do that). Why Pfair ? 1.
Guarantees task deadlines. 2. Tasks execute at
steady progressive rates.
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Why Linux ?
1. The scheduler is currently O(1) and uses time
quantum based scheduling. 2. The kernel
efficiently handles SMP architecture. 3. There
is an existing framework to schedule RT
tasks based on their priority (fifo and
round-robit scheduling). 4. There are many
existing RT applications for Linux to test the
experimental implementation. 5. Easier to get
help, thanks to the community of kernel hackers.

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Experimental Workload
The implementation will be tested with real-time
applications that have soft deadlines. Examples
are streaming media players, VoIP softwares and
so on.
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Thank you!