Lorch, J. and Smith, A. J. Reducing processor power consumption by improving processor time management in a single-user operating system. Proceedings of the Second ACM International Conference on Mobile Computing and Networking (MOBICOM 96), 143--154, November 1996.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....higher power savings. As an example, the standard scheduling techniques of the operating system may have to be changed in order to maximize the use of the low power processor mode. Lorch and Smith suggested modi cations at the scheduler level in order to improve the power eciency of the MacOS [36, 37]. The Macintosh systems are not able to use the supported power modes eciently for two main reasons. First, MacOS sometimes schedules processes that have no work to do (the events they are waiting for have not arrived yet) Second, the programmers often assume that their application is the ....

....architectural design of system components. Research on high level system design has focused mostly on transition strategies in order to exploit the various low power states of modern power aware components, while studies of the regular operating system policies in terms of power have been limited [36, 37, 54] (a notable exception being the power aware page placement study of the Milli Watt group at Duke University [32] Furthermore, most studies have been based on trace driven or execution driven simulations rather than actual implementations. The drawback of trace driven simulations is that they ....

Lorch, J. R., and Smith, A. J. Reducing processor power consumption by improving processor time management in a single-user operating system. In Proc. of the 2nd Annual International Conference on Mobile Computing and Networking (MobiCom'96) (Nov. 1996), pp. 143-154.

....reducing mobile hosts power requirements. The overall goal of power management is to prolong battery life by controlling the energy consumption of a mobile host s various devices. Past research has developed techniques for reductions in the energy consumption of disk [DKM94, HLS96, LKHA94] CPU [GCW95, LS96, WWDS94], and network interface devices [SK96, CPR98, NSYA97, KK98] The goal of these techniques is to reduce the energy needs of individual devices. Building on such work, this paper considers the power consumption of a mobile host s communication device in the context of the total power consumed by the ....

J. R. Lorch and A. J. Smith. Reducing processor power consumption by improving processor time management in a single-user operating system. In Second ACM International Conference on Mobile Computing and Networking (MOBICOM), 1996.

....as displays, disks and OPUs. In particular, researchers have looked at methods to turn off the display after some period of inactivity (as often implemented in BIOS or screen savers) to spin down the hard disk of the mobile host [7, 9, 16] and to slow down or stop the OPU depending on work load [8, 17, 24]. The principle underlying the techniques for controlling these components is to estimate (or guess) when the device will not be used and suspend it for those intervals. Stemm et. al [23] have identifiod the problem of excess energy con sumption by network interfaces in hand held devices, and ....

J. R. Lorch and A. J. Smith. Reducing processor power consumption by improving processor time management in a single-user operating system. In Second ACM International Conference on Mobile Computing and Networking (MOBICOM), 1996.

....until the next interrupt occurs. With a well designed operating system, this can be deduced from the current status of all processes. Thus, whenever any process is running or ready to run, the processor should not be turned off; when all processes are blocked, the processor should be turned off [34 36]. Examples of operating systems using this strategy are Windows [37, 38] and UNIX. MacOS, however, uses a different strategy, perhaps because its strategy was designed when processors did suffer side effects from turning off. It uses an inactivity threshold, as is commonly used for hard disk ....

....[41] There may be some special cases, such as generating entirely integer versus mixed integer and floating point code, where the effects are significant, but we believe that these are the exception. Another load change technique uses the third approach, performing fewer unnecessary tasks [34]. In some cases, when an application is idle, it will busy wait for an event instead of blocking. Then, the standard transition strategy will not turn off the processor even though it is not doing any useful work. One way to solve this problem is to force an application to block for a certain ....

J. Lorch and A. J. Smith, "Reducing processor power consumption by improving processor time management in a single-user operating system, " Proc. Second ACM Int'l Conf. on Mobile Computing and Networking (MOBICOM '96), Rye Brook, NY, Nov. 1996, pp. 143--154.

....of power mode scheduling is that wasted energy due to leakage can be reduced. If a device is completely turned off, no leakage energy is dissipated. Many techniques that attempt to minimize energy consumption of devices and CPUs through power management and scheduling have been considered [29, 30, 31]. Algorithms to schedule processes on CPUs in order to minimize power consumption are the focus of [29] and [30] In [31] the authors use a semi Markov decision process model to devise a shutdown policy for various portable devices. A shutdown policy that adapts to event arrival statistics is ....

....no leakage energy is dissipated. Many techniques that attempt to minimize energy consumption of devices and CPUs through power management and scheduling have been considered [29, 30, 31] Algorithms to schedule processes on CPUs in order to minimize power consumption are the focus of [29] and [30]. In [31] the authors use a semi Markov decision process model to devise a shutdown policy for various portable devices. A shutdown policy that adapts to event arrival statistics is presented here. 6.2.1 Power Modes for the Sensor Node In Section 5, we have introduced energy models for the ....

J. Lorch and A. Smith, "Reducing Processor Power Consumption by Improving Processor Time Management in a Single-User Operating System," in Proc. of MobiCom '96, 1996.

....disk requests, caching, etc. are examples of this approach. Adaptation strategies [17] aim to modify software to enable power saving use of components. Each hardware component is treated separately, given the fact that the power and performance characteristics of each component varies. In [16], the authors have explored methods for reducing the power consumption of the CPU by turning it off when it is not doing any useful work. They identify two problems with current processor time management policies. Operating systems may schedule processes even if they don t have anything to run. ....

Jacob R. Lorch and Alan Jay Smith. Reducing processor power consumption by improving processor time management in a single-user operating system. Technical Report CSD-96-914, University of California, Berkeley, September 3, 1996.

....in [21] propose potential energy improvements for each functionality, like interprocess communication, memory allocation, CPU scheduling, while Lebeck et al. in [11] proposed a memory paging technique that aims at putting as many memory components as possible in power down mode. Lorch and Smith in [12] suggested heuristic techniques to put the processor in lowpower states when identifying idle conditions. Benini et al. in [5] designed a workload monitoring tool for supporting effective dynamic power management policies. In addition, a considerable amount of work has been done in the area of ....

J. Lorch, A. J. Smith, "Reducing Processor Power Consumption by Improving Processor Time Management in a Single-User Operating System," MOBICOM, pp. 143--154, 1996.

....a communication unit include modulating the energy used by the mobile transmitter during active communication [18] All of these techniques reduce the energy consumed when the system is active. Operating system level energy management techniques include switching between low power processor modes [6,7], adaptive and controlled spin downs of hard disks [8,9,10] and control of the device display. Energy aware network protocols either reduce energyexpensive retransmission of lost messages or suspend device operation during idle periods [19] or transition between different modes of operation ....

J. R. Lorch, A. J. Smith, Reducing processor power consumption by improving processor time management in a single-user operating system, Proceedings, ACM MOBICOM, 1996.

....wireless ad hoc networks. There are several power saving approaches for published in the past literature. Most of them deal with system level techniques for reducing the power consumption of particular devices. Examples of these system device optimizations include: disk drives [46, 47] CPUs [48, 49], and network interface cards [50, 51] More recent work investigated the savings that can be exploited by scheduling at the MAC layer such that some of the communications components such as the receiver can be turned o# for extended periods of time [51, 52, 53, 54] Other techniques optimize the ....

J. Lorch and A. Smith, "Reducing processor power consumption by improving processor time management in a single-user operating system," in Proceedings of ACM International Conference on Mobile Computing and Networking (MOBICOM), Aug. 1996, vol. 2, pp. 113--123.

....as displays, disks and CPUs. In particular, researchers have looked at methods to turn off the display after some period of inactivity (as often implemented in BIOS or screen savers) to spin down the hard disk of the mobile host [12,16,22] and to slow down or stop the CPU depending on work load [15,23,30]. The principle underlying the techniques for controlling these components is to estimate (or guess) when the device will not be used and suspend it for those intervals. Stemm et al. 29] have identified the problem of excess energy consumption by network interfaces in hand held devices, and have ....

J.R. Lorch and A.J. Smith, Reducing processor power consumption by improving processor time management in a single-user operating system, in: Proceedings of the 2nd ACM International Conference on Mobile Computing and Networking (MOBICOM) (1996).

....is unclear how effectively the use of that information reduces power consumption. Lorch et al. attempt to improve the power management scheme in the MacOS, which is based on an inactivity timer, by designing a power management scheme that turns off the processor when there is no runnable process [30]. On the MacOS, this strategy is not as straightforward as it might seem since processes can be scheduled and run even when they have no useful work to do. The problem is that originally the MacOS was designed to be a single user operating system, without preemptive multitasking, where the running ....

J. R. Lorch and A. J. Smith. Reducing Processor Power Consumption by Improving Processor Time Management in a Single-User Operating System. Proceedings of the Second Annual International Conference on Mobile Computing and Networking, November 1996.

....goal of power management for mobile computers is to prolong battery life by controlling the energy consumption of the mobile host s various devices. Past research has developed techniques to reduce the energy consumption of individual devices, including disks [DKM94, HLS96, LKHA94] 1 CPUs [GCW95, LS96, WWDS94], and network interfaces [SK96, CPR98, NSYA97, KK98] All of these techniques aim to reduce the energy consumption of individual devices on the mobile host. This paper builds on such work. It differs from it, however, by not only attempting to minimize the energy consumption of each device, but ....

J. R. Lorch and A. J. Smith. Reducing processor power consumption by improving processor time management in a single-user operating system. In Second ACM International Conference on Mobile Computing and Networking (MOBICOM), 1996.

....the use of power modes being provided in emerging PADRAM class memory devices. A novel aspect of our work is the cooperative hardware OS approach to exploit PADRAM features. Previous OS level studies focusing on power management include work on scheduling for low power processor modes [31, 32, 46], spindown policies for disks and alternatives [1, 7, 8, 9, 16, 25, 30, 47] and managing wireless communication [18, 24, 42] A consortium of companies has developed a specification [20] that addresses the lower level OS device interface, providing one model for gross system wide power states and ....

J. Lorch and A. J. Smith. Reducing Processor Power Consumption by Improving Processor Time Management in a Single-User Operating System. In Proc. of the 2nd ACM International Conf. on Mobile Computing (MOBICOM96), pages 143--154, November 1996.

....uprising of satellite constellations and other new types of mobile networks. In this paper, we show how to use ideas issued from parallel processing to reduce the power consumption of a given task. In the past, some techniques have been developed to reduce on board power. Spin down techniques [12] detect periods of inactivity of the system to cut the power. These methods have to detect long enough idle periods, so that the energy cost of resuming is lower than that of keeping the system active. This method has now been largely implemented but contains some inherent limitations, as ....

J. R. Lorch and A. J. Smith. Reducing processor power consumption by improving processor time management in a single-user operating system. In Proceedings of the Second Annual International Conference on Mobile Computing and Networking (MOBICOM'96), pages 143154, November 1996.

....in 50ms and then sits idle for 50ms. Running at 1 2 the speed, it is possible to finish the job within the deadline only using 1 4 of the energy. Other work has been performed in the area of job scheduling to minimize the amount of time a processor needs to spend in the full power mode [LS96, YDS95] 3. Wireless Communications Equipment: The wireless transmitter and receiver can be a substantial power consumer of a mobile computer. Therefore what is particularly important is the amount of time a mobile computer spends using its communication equipment. Since most mobile computing ....

....equipment. A typical method for reducing the power used by a hard disk is to stop the disk s rotation while not being accessed. Recent research performed in this area has shown that the amount of idle time needed to attempt to determine an idle user is much shorter than previously thought [HLS96] When the disk is restarted it can require a very large amount of power to bring a disk s rotational speed up to thousands of RPM from a stand still. The power used for this is in proportion to the size of the disk. As user applications become large and more disk intensive, it will be important ....

Lorch, J. and Smith, A. Reducing processor power consumption by improving processor time management in a single-user operating system. In Proceedings of the Second Annual International Conference on Mobile Computing and Networking (MobiCom '96), pages 142--54. ACM SIGMOBILE/IEEE, November 10-12 1996.

....in a manner that maximizes energy efficiency. Such an approach would be most meaningful when the energy necessary for transmission represents a significantly larger portion of the net energy drawn than the portion drawn for other internal housekeeping functions. The use of various sleep modes [7, 8] is a way to minimize the energy that is drawn for internal housekeeping and suggests that the dynamic time profile of the radiated energy from a communication device may indeed represent a significant portion of the total energy drawn. As a first model for battery sources, we assume that the ....

J.R. Lorch, A.J. Smith, "Reducing processor power consumption by improving processor time management in a single-user operating system", in Proc. of the Second ACM Conference on Mobile Computing and Networking, MOBICOM'96, Nov. 1996.

....in a manner that maximizes energy efficiency. Such an approach would be most meaningful when the energy necessary for transmission represents a significantly larger portion of the net energy drawn than the portion drawn for other internal housekeeping functions. The use of various sleep modes [7] [8] is a way to minimize the energy that is drawn for internal housekeeping and suggests that the dynamic time profile of the radiated energy from a communication device may indeed represent a significant portion of the total energy drawn. As a first model for battery sources, we assume that the ....

J.R. Lorch and A.J. Smith, "Reducing Processor Power Consumption by Improving Processor Time Management in a Single-User Operating System," Proc. Second ACM Conf. Mobile Computing and Networking, MOBICOM '96, Nov. 1996.

....communication protocols, mobility often implies physical mobility, the mobility in the real world. The application domain of physical mobility includes PDA (personal digital assistants) using GPS [66] support for laptop and notebook computers [38, 53, 54, 57] and reduction in energy consumption [50, 67]. On the other hand, for those who familiar with operating system and programming languages, mobility often implies software mobility. This is the reason why Luca Cardelli proposed that the former form of 13 14 CHAPTER 1. INTRODUCTION mobility should be designated as mobile computing, while the ....

Jacob R. Lorch and Alan Jay Smith. Reducing Processor Power Consumption by Improving Processor Time Management in a Single-User Operating System. In MOBICOM'96 Proceedings of The Second Annual International Conference on Mobile Computing and Networking, pages 143--154, 1996.

....as displays, disks and CPUs. In particular, researchers have looked at methods to turn off the display after some period of inactivity (as often implemented in BIOS or screen savers) to spin down the hard disk of the mobile host [8, 10, 17] and to slow down or stop the CPU depending on work load [9, 18, 25]. The principle underlying the techniques for controlling these components is to estimate (or guess) when the device will not be used and suspend it for those intervals. Stemm et. al [24] have identified the problem of excess energy consumption by network interfaces in hand held devices, and have ....

J. R. Lorch and A. J. Smith. Reducing processor power consumption by improving processor time management in a single-user operating system. In Second ACM International Conference on Mobile Computing and Networking (MOBICOM), 1996.

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Lorch, J. and Smith, A. J. Reducing processor power consumption by improving processor time management in a single-user operating system. Proceedings of the Second ACM International Conference on Mobile Computing and Networking (MOBICOM 96), 143--154, November 1996.

No context found.

Lorch, J. and Smith, A. J. Reducing processor power consumption by improving processor time management in a single-user operating system. Proceedings of the Second ACM International Conference on Mobile Computing and Networking (MOBICOM 96), 143--154, November 1996.

.... we have demonstrated a technique for improving the processor power savings in MacOS by 53 ; this technique involves never scheduling processes to run when they are blocked, forcibly blocking processesthat appear to be busy waiting, and turning off the processor whenever all processes are blocked [5]. We hope that the results presented in this paper serve both as an indication of what power saving techniques are most promising for future study and as a tool in the analysis of such techniques. A fourth category of further study is in how to design hardware components that consume less power. ....

Lorch, J. and Smith, A. J. Reducing processor power consumption by improving processor time management in a single-user operating system. Proceedings of the Second ACM International Conference on Mobile Computing and Networking (MOBICOM 96), 143--154, November 1996.

....until the next interrupt occurs. With a welldesigned operating system, this can be deduced from the current status of all processes. Thus, whenever any process is running or ready to run, the processor should not be turned off; when all processes are blocked, the processor should be turned off [49, 72, 74]. Examples of operating systems using this strategy are Windows [15, 62] and UNIX. MacOS, however, uses a different strategy, perhaps because its strategy was designed when processors did suffer side effects from turning off. It uses an inactivity threshold, as is commonly used for hard disk power ....

....There may besome special cases, such as generating entirely integer versus mixed integer and floating point code, where the effects are significant, but we believe that these are the exception. Another load change technique uses the third approach, performing fewer unnecessarytasks [49]. In some cases, when an application is idle, it will busy wait for an event instead of blocking. Then, the standard transition strategy will not turn off the processor even though it is not doing any useful work. One way to solve this problem is to force an application to block for a certain ....

Lorch, J. andSmith, A. J. Reducingprocessorpowerconsumptionby improving processor time management in a single-user operating system. Proceedings of the Second ACM International Conference on Mobile Computing and Networking (MOBICOM 96), Rye Brook, NY, 143--154, November 1996.

No context found.

Lorch, J., and Smith, A. J. "Reducing processor power consumption by improving processor time management in a single-user operating system". In Proc. of MOBICOM 96 (November 1996).

No context found.

J. R. Lorch and A. J. Smith. Reducing processor power consumption by improving processor time management in a single-user operating system. In Second ACM International Conference on Mobile Computing and Networking (MOBICOM), 1996.

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