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dc.contributor.advisor Zhong, Lin
dc.creatorXu, Chao
dc.date.accessioned 2016-01-07T22:20:53Z
dc.date.available 2016-01-07T22:20:53Z
dc.date.created 2014-12
dc.date.issued 2014-12-01
dc.date.submitted December 2014
dc.identifier.citation Xu, Chao. "Automated OS-level Device Runtime Power Management." (2014) Master’s Thesis, Rice University. https://hdl.handle.net/1911/87791.
dc.identifier.urihttps://hdl.handle.net/1911/87791
dc.description.abstract Hardware devices on a modern System-on-Chip (SoC), ranging from accelerators to IO controllers, usually account for the largest portion of the chip area. It is therefore vital for Operating Systems (OS) to disable and enable these devices at run time, so that idle devices can enter low-power state timely while meeting user’s performance expectation. This is called device runtime Power Management (PM), for which individual device drivers in commodity OSes are held responsible. Based on the observations of existing drivers and their evolution, we consider counting on drivers for device runtime PM harmful. We identify three pieces of information essential to device runtime PM, and show that all of them can be obtained without involving drivers, either by using a software inference approach atop existing ARM-based SoC, or more efficiently, by adding one register bit to each device. We thus argue for a structural change to the current Linux runtime PM framework, replacing PM code in each individual driver with one kernel module called central PM agent. We experimentally show that central PM agent is just as effective as hand-tuned driver PM code. We also present a software tool called PowerAdvisor, as a remedy to simplify driver PM efforts without overhauling the current Linux runtime PM framework. PowerAdvisor analyzes trace generated from historic executions and suggests PM calls to be inserted at certain driver source locations. Although a best-effort tool, PowerAdvisor not only reproduces hand-tuned PM code that already exists in stock drivers, but also correctly suggests PM code never known before . Overall, our experiences show that it is promising to ultimately free driver developers from manual PM.
dc.format.mimetype application/pdf
dc.language.iso eng
dc.subjectRuntime power management
SoC
OS
dc.title Automated OS-level Device Runtime Power Management
dc.contributor.committeeMember Cavallaro, Joseph R
dc.contributor.committeeMember Vardi, Moshe Y
dc.contributor.committeeMember Wallach, Dan S
dc.date.updated 2016-01-07T22:20:53Z
dc.type.genre Thesis
dc.type.material Text
thesis.degree.department Electrical and Computer Engineering
thesis.degree.discipline Engineering
thesis.degree.grantor Rice University
thesis.degree.level Masters
thesis.degree.name Master of Science
thesis.degree.major System


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