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Energy-efficient Microkernel. 06/06. Progress. Paper Studied Energy-Efficient Mapping Technique for Virtual Cores Convex Optimization in Local Single-Threaded Parallel Mobile Computing Real-Time Dynamic Voltage Loop Scheduling for Multi-Core Embedded Systems. Scenario.
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Progress • Paper Studied • Energy-Efficient Mapping Technique for Virtual Cores • Convex Optimization in Local Single-Threaded Parallel Mobile Computing • Real-Time Dynamic Voltage Loop Scheduling for Multi-Core Embedded Systems
Scenario • Each processor has a memory queue that accommodates an arbitrary maximum number of tasks. • Tasks and processors are heterogeneous.
Cost Function • Cj: cost of the jth stream • ij : # of task in queue • ε%,j : remaining power • Al,j : availability of executing Tl in the jthstream • tθ,r,j : overhead access time of a task Tr to be accessed by Pj
Simplification • Memory queue: no limitation • Single power source • Remove stochastic availability • Discrete processing rate
Some Math • εk=Bk(pk)2, pk = pH or pL • εk,H = 4 * εk,L • Change pk from pL → pH if • αε,k(4 * εk,L- εk,L) < • “Is it always true that we should adjust Pm before Pn, m < n?”
Cutting Point • Assume that we can change the order of tasks in queue. • Can we find a cutting point? • Cutting point: there will be not benefit if we switch the processing rate from pLto pH after that task. pH pL
Two Processing Rates • Initially all N tasks use processing rate pL. • pH = 2* pL • Sorted according to task execution time. • Descending order. • Started from task 1, change the processing rate of task k from pLto pH and compute the benefit.
Next • Multiple processing rates • Consider that each task has different cost factors.