1 / 31

Jiwon Hahn ECE295 Seminar December 2, 2002

I ntegrated M anagement of P ower A ware C omputing & C ommunication T echnologies. Jiwon Hahn ECE295 Seminar December 2, 2002. IMPACCT Project. People Faculty: Pai Chou, Nader Bagherzadeh Students: Jinfeng Liu, Dexin Li, Bita Gorji-Ara, Duan Tran, and Jiwon Hahn

stash
Télécharger la présentation

Jiwon Hahn ECE295 Seminar December 2, 2002

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Integrated Managementof Power Aware Computing& Communication Technologies Jiwon Hahn ECE295 Seminar December 2, 2002

  2. IMPACCT Project • People • Faculty: • Pai Chou, Nader Bagherzadeh • Students: • Jinfeng Liu, Dexin Li, Bita Gorji-Ara, Duan Tran, and Jiwon Hahn • Collaborator • NASA JPL, Rockwell Collins, ISI • Sponsors • DARPA PAC/C, Broadcom, HP

  3. Outline • What is IMPACCT? • Motivation • How it works • Tools • Experiments and Results • Conclusions and Future Works

  4. What is IMPACCT? • A CAD tool for exploring power/performance tradeoffs • A new technique that performs component, system, and mission-level integrated power management • Target applications • Mars pathfinder, ATR, UCAV,…

  5. Motivation • Embedded Systems • Computers inside devices • PDA, cellphone, camera, vehicles, robots,… • Power management • Power-Aware vs. Low-power • Mission-Aware: meet the constraints • High-level approach • Amdahl’s law: Power saving of a component must be scaled by its percentage contribution to entire system • Evaluate combined effects in the context of system • Higher abstraction level enables global optimum

  6. How it works • Hierarchical power management • System-level power scheduling • Power-aware scheduling • Mode selection • Mission-level power scheduling • Schedule Selection

  7. Scheduling & Mode Selection • Power Aware Scheduling • Schedules tasks, meeting timing and power constraints • Output: initial schedule • Static scheduling/planning [DAC'01] • Mode Selection • Selects resource modes of each task considering mode dependency • Minimize energy consumption • Output: mode schedule • Mode selection/modeling [ASPDAC’02]Winner Best Student Paper Award

  8. Schedule Selection • Goal • To generate a mission level schedule which • Adapts to variable power constraint • Considers higher-level context change overhead • Meets the global deadline • Assumptions • A mission contains one or more applications • It is static

  9. Previous Schedule Overhead Matrix Current schedule Schedule Set P … Put N schedules here! 0 1 2 … M D Schedule Selection • Problem: • Select N schedules • among M different schedules, • by deadline D, • under the maximum power curve P. • Minimize energy • considering overhead

  10. Schedule Selection(cont.) • Parameters: t,n,k,m • t: timestamp. (discrete value) 0tD • n: schedule count excluding S0 1nN • k: schedule count including S0. (for tracking the selected path) 1kD • m:current schedule 0mM

  11. n n t t =1 k m m t =2 t = D Schedule Selection(cont.) • Algorithm: 4D Dynamic Programming • Idea: • Reach the global optimum by keeping track of optimal solutions of subproblems • Optimal substructure • For some(k,m), min{E(t,n,m)} contains the optimal value. • Space • D3 for keeping optimal Energy • D4 for bookkeeping indices • Speed • O(D3) – polynomial! • Could be optimized for speed-up Bookkeeping Cubes Energy Cube

  12. Schedule Selection(cont.) • Notation • Set of schedule, S= {S0, S1, … ,SM} • Time period of each schedule: Ts[0…M] • Power level of each schedule: Ps[0…M] • Energy of each schedule: Ts x Ps = Es[0…M] • Schedule-switch overheads from Si to Sj: Po(i,j), To(i,j), Eo(i,j)

  13. Schedule Selection(cont.) • Algorithm • Initialization • If (t,n,k,m) is the first possible selection, • E(t,n,k,m) = directly calculated energy • Else • E(t,n,k,m) =  • Process • if m!=0, • E(t,n,k,m)=E(t’,n-1,k-1,m’)+Eo(m’,m)+Ps(m)Ts(m) • t = t’+To(m’,m)+Ts(m) • if m=0, • E(t,n,k,m)= E(t’,n,k-1,m’)+Eo(m’,m)+Ps(m)Ts(m)

  14. Mission-level Constraints: Power and Deadline • Mission Schedule System-level  Mission-Level • Input: • Application Model • ports, channels,… • Architecture Model • System architecture template • Component library + mode dependency model(MDM) • Constraints • Power and Timing • Output: • Mode Schedule

  15. Mission-Level2 Mission Constraints Scheduler Initial Schedule Mode Selector Overhead Calculator MS MS MS MS MS … Schedule Collector Schedule Selector 2 MissionSchedule System-level1 Sys. Arch. Template App. Model Component Library + MDM Constraints 1 1) Mode Schedule

  16.  Mission-Level Mission Power Constraint Curve • Mission Schedule: Mission Deadline System-level • Initial Schedule: • Mode Schedule:

  17. Tools • Scheduler (Jinfeng) • Mode Selector (Dexin) • Schedule Selector (Jiwon) • Etc.. • Programs and tutorial are available

  18. Tools(I): Scheduler

  19. Tools(II): Mode Selector

  20. Tools(III): Schedule Selector

  21. Experiments and Results I • Mars Rover • Comparison over 3 scenarios • Overall mission • 3 power scenarios: best, typical, worst, 10 min each • 48 steps • Power-aware schedules • Accelerated speed by tracking available power • Finished earlier before working in the worst case • 33% faster, 32.7% less energy cost

  22. Experiments and Results I(cont.)

  23. Experiments and Results II • Mars Rover • Behaviors and tasks • Moving around on Mars surface • Communicating with the Lander • Taking pictures • Performing scientific experiments • Components in the entire system • Hazard detector, Driving motor, Steer motor, Radio frequency modem (RF), Camera (CAM), Microprocessor (PPC), Micro-controller

  24. Experiments and Results II(cont.) • On/off only • Relaxed constraints • Mode change overhead • No max power constraint • Mode selection • Energy saving:From 6.9% to 49.3% average 26.5% • Meets max power

  25. 3 3-1 0-3 1 3s, 15J, 45W 5s, 10J, 50W 10s, 5J, 50W Experiments and Results III • Example of Schedule Selection • Schedule Set: 0 1 2 3 • Overhead Matrix 20s

  26. Low Power 1 1 20s • Greedy 3 3-1 20s 0-3 1 • Dynamic Programming 2 0-2 2-1 1 20s Experiments and Results III(cont.) • Exceed deadline • Energy = 149W • Nonoptimal solution • Energy = 131W • Optimal solution!

  27. Experiments and Results III(cont.)

  28. Conclusions • IMPACCT • greatly expands the range of power/performance trade-offs • effectively integrates existing power management techniques • models system-level dependencies • saves great amount of energy consumption while meeting all constraints • proposes novel hierarchical power management technique

  29. Current & Future Works • Ongoing work • Architecture Modeling(Dexin) • Mission-level Power Management(Jiwon) • Extended experiments on broadcom and itsy board(Jinfeng) • Applying to different application: SDR(Bita) • Future work • Dynamic Power Management • Mixed application schedule selection • More applications

  30. Reference • Pai H. Chou, Jinfeng Liu, Dexin Li, and Nader Bagherzadeh, “IMPACCT: Methodology and Tools for Power-Aware Embedded Systems”, Design Automation for Embedded Systems • J. Liu, P. Chou, N. Bagherzadeh, and F. Kurdahi. “Power-aware scheduling under timing constraints for mission-critical embedded systems”. In Proc. 38th Design Automation Conference, pages 840–845, June 2001 • D. Li, P. Chou, and N. Bagherzadeh. Mode selection and mode-dependency modeling for power-aware embedded systems. In Proc. 7th Asia South Pacific Design Automation Conference, pages 697–704, January 2002 • J. Hahn, P. Chou, and N. Bagherzadeh, “Tutorial: IMPACCT Tool v1.0”, University of California at Irvine, August, 2002 THANK YOU!

  31. THANK YOU!

More Related