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Vinay Devadas Hakan AydinProfessor : Chen, Ya-ShuPresenter : Ho, Shu-Wei
OutlineBreak-even time(B)Next Device Usage Time(NDUT(t))Conservative Energy-Efficient Device
Scheduling(CEEDS)Device Forbidden Region(DFR)FeasibilityDynamic Power Management(DPM) through
Device Forbidden RegionsComparisonConclusion
Break-even time
: The power consumption in active state : The power consumption in sleep state : The time overhead to perform a transition from active to sleep state : The time overhead to perform a transition from sleep to active state : The energy overhead to perform a transition from active to sleep state : The energy overhead to perform a transition from sleep to active state : The break-even time of the device
iaPisPiastisatiasEisaE
iB
[ ( )]max{ , }
i i i i ii i as sa s as sa
i as sa i ia s
E E P t tB t t
P P
Next Device Usage Time(NDUT(t))PredictionCurrent time(t)Tasks in ready queueRelease time of jobs that request
Current t NDUT(t)
Task use iD
iD
( )NDUT t t B
Conservative Energy-Efficient Device Scheduling
Predicting NDUT(t)Example : = = 1000 = = 4000 = 990 , = = 495 = 20 , = = 10 T1 : (2000, 1000) ; T2 : (4000, 1000)
1 2
12
1B
2B
1ast
1sat
2ast
2sat
Conservative Energy-Efficient Device Scheduling
1000
2000
3000
4000
5000
6000
7000
Active
Active
Sleep
Sleep
1D
2D
0
1495 1505 3495 3505 5495 5505
2010 3990 6010
1T
2T
Device Forbidden Region(DFR)Rat-Monotonic scheduling(RMS).Duration
Period
Expected Energy Savings(EES) of
( )i ii ii a s
i
BEES P P
( )NDUT t t B i
i
iD
min( )i i
i i j jB T C
max{ }1 i i
i
ii j
D
TU
FeasibilityTime demand function of
Corollary :A set of periodic tasks can be feasibly
scheduledby DFR-RMS if ∀ i ∃ t 0 ≤ t ≤ Ti,
( )
( )i
i i jhp i j
tw t C C
T
max
( )
( ) ( )i
i i
FRi i j j
hp i j DULj j
t tw t w t C C
T
i
max ( )iw t t
DPM through Device Forbidden Regions
1000
4000
5000
6000
Active
Active
Sleep
Sleep
1D
2D
0
1495 2505 5495 5505
2010 6010
1T
2T3000
2000
10 990 4990
2000
7000
1FR 1FR
2FR 2FR
ComparisonAlways on (AON) --Where the devices remain in active state throughout the simulation (no dynamic power
management).
CEEDS --Adapted to RMS settings. This scheme performs device
shutdown and activation based solely on next device usage time predictions.
DER-RMS
Comparison
mod vari i i i i idevice fixed trans fixedE E E E E E
Conclusion
Compare with original CEES, no matter with DVS or without DVS, RMS-DFR can save up to 27% energy consumption , under the worst condition, it can also save 20% consumption.