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Progress Report. 2012/12/20. Computation Offloading. Mobile devices have limited energy and computing resources. Offloading some workloads to remote servers leads to: Power-saving. Performance improving. Shorter execution time. Better results. Our Idea. - PowerPoint PPT Presentation
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Progress Report2012/12/20
Computation OffloadingMobile devices have limited
energy and computing resources.Offloading some workloads to
remote servers leads to:◦Power-saving.◦Performance improving.
Shorter execution time. Better results.
Our IdeaInstead of studying offloading
policies, we aim at the effects caused by offloading.
After offloading, a computation-intensive process becomes I/O-intensive.◦Does this phenomenon affects
scheduler?◦Does this phenomenon affects DVFS?◦Does this phenomenon affects
cache/memory?◦…etc.
ProblemService thread
◦Computation-intensive => I/O-intensive
◦Task in waiting state will not be scheduled.
Current Flow
Offloading Framework
Scheduler DVFS
DPMLoad
change
New strategyThe original idea of virtual core
is:
N cores
C-task
Remote cores
Computation Offloading
N+1 cores
New strategy(Cont.)反其道而行Close a core after offloading
N cores
C-task
Remote cores
Computation Offloading
N-1 cores
ReasonAfter offloading, the rest of the
tasks will be scheduled to N cores.◦Should have better performance.◦Does not guarantee energy saving.
All the cores are still working!
If we close a core after offloading◦Imagine that the computation-
intensive task is non-preemptive, but consume zero power.
◦Energy saving with little effect to (other tasks) performance.
New Flow
Offloading Framework
Scheduler DVFS
DPM
Comparison
Performance of other tasks
Power Consumption
No offloading -- Highest
Virtual core (N+1) Better than No offloading
Low
Proposed strategy (N-1)
Similar to No offloading
Lowest
HoweverThis is a theoretically strategy.Need to design some
experiments to verify the strategy.
Possible TopicsClose more cores
◦-1?-2?-n/2?-(n-1)?Close which core(s)
◦The one executing the offloaded task?
◦Cache relatedTheoretical problem
◦Math model