Motivation Initial algorithm Adaptation Large instances Conclusion
Accelerating a local search algorithm for large instances of the - - PowerPoint PPT Presentation
Accelerating a local search algorithm for large instances of the - - PowerPoint PPT Presentation
Motivation Initial algorithm Adaptation Large instances Conclusion Accelerating a local search algorithm for large instances of the independent task scheduling problem with the GPU Frederic Pinel Johnatan Pecero Pascal Bouvry Computer
Motivation Initial algorithm Adaptation Large instances Conclusion
Outline
Motivation Initial algorithm Adaptation Large instances Conclusion
Motivation Initial algorithm Adaptation Large instances Conclusion
Motivation
- Independent tasks
- Makespan, combines several perspectives:
- User: flowtime
- Provider: load balance, energy (low machine heterogeneity)
Motivation Initial algorithm Adaptation Large instances Conclusion
Parallel CGA
Selection Recombination Mutation Replacement
Figure: Generating solution
Motivation Initial algorithm Adaptation Large instances Conclusion
Parallel CGA
- Parallel asynchronous cellular genetic algorithm
- Initialized with heuristic (Min-Min)
- Local search
Motivation Initial algorithm Adaptation Large instances Conclusion
Feedback
Pop P_mutation Iter_mutation P_crossover P_search Iter_search Load_search Threads 0.0 0.2 0.4 0.6 0.8 1.0 main effect interactions
Motivation Initial algorithm Adaptation Large instances Conclusion
Adaptation
- Simplified algorithm
- Min-Min, incremental formulation
- Increased local search, complete-state formulation
Motivation Initial algorithm Adaptation Large instances Conclusion
Results
700 800 900 1000 1100 1200 1300 Min-Min 2PH PA-CGA-1 PA-CGA-2 PACGA-3 PACGA-4 PACGA-5
Figure: Consistent, high-h. tasks, low-h. machines
Motivation Initial algorithm Adaptation Large instances Conclusion
Results
650 700 750 800 850 900 950 1000 1050 1100 1150 Min-Min 2PH PA-CGA-1 PA-CGA-2 PA-CGA-3 PA-CGA-4 PA-CGA-5
Figure: Semi-consistent, high-h. tasks, low-h. machines
Motivation Initial algorithm Adaptation Large instances Conclusion
Results
760 770 780 790 800 810 820 830 840 850 860 Min-Min 2PH PA-CGA-1 PA-CGA-2 PA-CGA-3 PA-CGA-4 PA-CGA-5
Figure: Consistent, low-h. tasks, low-h. machines
Motivation Initial algorithm Adaptation Large instances Conclusion
Results
690 700 710 720 730 740 750 760 770 Min-Min 2PH PA-CGA-1 PA-CGA-2 PA-CGA-3 PA-CGA-4 PA-CGA-5
Figure: Semi-consistent, low-h. tasks, low-h. machines
Motivation Initial algorithm Adaptation Large instances Conclusion
Min-Min on GPU
Figure: Parallel reduction in Min-Min
Motivation Initial algorithm Adaptation Large instances Conclusion
Min-Min runtime
1 10 100 1000 10000 100000 1e+06 4096x128 8192x256 16384x512 32768x1024 65536x2048 Runtime (sec) Instance size CPU 1 thread CPU 4 threads CPU 8 threads GPU
Figure: Runtime Min-Min
Motivation Initial algorithm Adaptation Large instances Conclusion
Performance
1650 1700 1750 1800 1850 1900 1950 2000 2050 512x16 4096x128 8192x256 16384x512 32768x1024 65536x2048 Makespan Instance size 32 320 3200 CGA
Figure: Makespan
Motivation Initial algorithm Adaptation Large instances Conclusion
Performance
100 200 300 400 500 600 512x16 4096x128 8192x256 16384x512 32768x1024 65536x2048 Runtime (sec) Instance size 32 320 3200 CGA - Kgen
Figure: Runtime
Motivation Initial algorithm Adaptation Large instances Conclusion
Conclusion
- Failure
- Solution → Feedback → loop
- Learning process
Motivation Initial algorithm Adaptation Large instances Conclusion
Machine learning opportunities
- Learn on problem instance
- Task profiling
- Co-scheduling
- Learn allocation rules
- Adapt (parameters, heuristics)
- Algorithm (oracle: solved instances)
Motivation Initial algorithm Adaptation Large instances Conclusion