Abstract: A method for adapting the periodicity of polling for pending service requests, by polling system devices for pending service requests, recording whether or not there was a pending service request and, based on accumulated data, determining whether or not the system devices are idle. Based on this determination, the system may elect to enter a power conservation mode until device activity is signaled, or an adjustable period of time elapses. The adaptation mechanism may alter the periodicity of the timer interrupt, disable or enable device interrupts, and modify variables used to determine system idleness (including minimum latency and minimum idleness thresholds). In this manner, the system can conserve power while maintaining system performance and responsiveness.

Abstract: A method, system, and computer program product for reducing power and energy consumption in a server system with multiple processor cores is disclosed. The system may include an operating system for scheduling user workloads among a processor pool. The processor pool may include active licensed processor cores and inactive unlicensed processor cores. The method and computer program product may reduce power and energy consumption by including steps and sets of instructions activating spare cores and adjusting the operating frequency of processor cores, including the newly activated spare cores to provide equivalent computing resources as the original licensed cores operating at a specified clock frequency.

Abstract: A method and a computer usable medium including a program for operating disks having units, comprising: providing a first tier of at least one disk, the first tier storing at least one popular unit, providing a second tier of at least one disk, the second tier storing at least one unpopular unit, powering on at least one first tier disk, powering down the second tier, determining whether a request for a unit requires processing on the first tier or second tier, accessing the requested unit if the requested unit requires processing on the first tier, and powering on a second tier disk to copy the requested unit from the second tier disk to a first tier disk, if the requested unit is stored on the second tier.

Abstract: A mechanism is provided for minimizing system power in a data processing system. A management control unit determines whether a convergence has been reached in the data processing system. If convergence fails to be reached, the management control unit determines whether a maximum fan flag is set to indicate that a fan is operating at a maximum speed. Responsive to the maximum fan flag failing to be set, a thermal threshold of the data processing system is either increased or decreased and thereby a fan speed of the data processing system is either increased or decreased based on whether the system power of the data processing system has either increased or decreased and based on whether a temperature of the data processing system has either increased or decreased. Thus, a new thermal threshold and a new fan speed are formed. The process is then repeated until convergence has been met.

Abstract: A mechanism is provided for scheduling application tasks. A scheduler receives a task that identifies a desired frequency and a desired maximum number of competing hardware threads. The scheduler determines whether a user preference designates either maximization of performance or minimization of energy consumption. Responsive to the user preference designating the performance, the scheduler determines whether there is an idle processor core in a plurality of processor cores available. Responsive to no idle processor being available, the scheduler identifies a subset of processor cores having a smallest load coefficient. From the subset of processor cores, the scheduler determines whether there is at least one processor core that matches desired parameters of the task. Responsive to at least one processor core matching the desired parameters of the task, the scheduler assigns the task to one of the at least one processor core that matches the desired parameters.

Abstract: A mechanism is provided for scheduling application tasks. A scheduler receives a task that identifies a desired frequency and a desired maximum number of competing hardware threads. The scheduler determines whether a user preference designates either maximization of performance or minimization of energy consumption. Responsive to the user preference designating the performance, the scheduler determines whether there is an idle processor core in a plurality of processor cores available. Responsive to no idle processor being available, the scheduler identifies a subset of processor cores having a smallest load coefficient. From the subset of processor cores, the scheduler determines whether there is at least one processor core that matches desired parameters of the task. Responsive to at least one processor core matching the desired parameters of the task, the scheduler assigns the task to one of the at least one processor core that matches the desired parameters.

Abstract: A mechanism is provided for scheduling application tasks. A scheduler receives a task that identifies a desired frequency and a desired maximum number of competing hardware threads. The scheduler determines whether a user preference designates either maximization of performance or minimization of energy consumption. Responsive to the user preference designating the performance, the scheduler determines whether there is an idle processor core in a plurality of processor cores available. Responsive to no idle processor being available, the scheduler identifies a subset of processor cores having a smallest load coefficient. From the subset of processor cores, the scheduler determines whether there is at least one processor core that matches desired parameters of the task. Responsive to at least one processor core matching the desired parameters of the task, the scheduler assigns the task to one of the at least one processor core that matches the desired parameters.

Abstract: A mechanism is provided for scheduling application tasks. A scheduler receives a task that identifies a desired frequency and a desired maximum number of competing hardware threads. The scheduler determines whether a user preference designates either maximization of performance or minimization of energy consumption. Responsive to the user preference designating the performance, the scheduler determines whether there is an idle processor core in a plurality of processor cores available. Responsive to no idle processor being available, the scheduler identifies a subset of processor cores having a smallest load coefficient. From the subset of processor cores, the scheduler determines whether there is at least one processor core that matches desired parameters of the task. Responsive to at least one processor core matching the desired parameters of the task, the scheduler assigns the task to one of the at least one processor core that matches the desired parameters.

Abstract: The distribution of power dissipation within cluster systems is managed by a combination of inter-node and intra-node policies. The inter-node policy consists of subdividing the nodes within the cluster into three sets, namely the “Operational” set, the “Standby” set and the “Hibernating” set. Nodes in the Operational set continue to function and execute computation in response to user requests. Nodes in the Standby set have their processors in the low-energy standby mode and are ready to resume the computation immediately. Nodes in the Hibernating set are turned off to further conserve energy, and they need a relatively longer time to resume operation than nodes in the Standby set. The inter-node policy further distributes the computation among nodes in the Operational set such that each node in the set consumes the same amount of energy.