Abstract: An indication that a subsystem is about to enter an idle state is received, and an original fire time for a next timer interrupt is determined. An idle state for a subsystem is selected based on the original fire time; and a new fire time for the next timer interrupt is determined based on the selected idle state to reduce timer interrupt latency. A current latency in exiting an idle state is measured. The measured latency is added to a running average of latencies for the idle state. A latency value is determined based on the running average and a worst case latency to adjust an original fire time for a next timer interrupt.

Abstract: Exemplary embodiments of methods and apparatuses to manage a power of a data processing system are described. One or more constraint parameters of a system are monitored. The data processing system is forced into an idle state for a first portion of a time while allowed to operate for a second portion of the time based on the one or more constraint parameters, wherein the system is forced into the idle state in response to comparing a target idle time to an actual idle time. The target idle time of the system is determined, in one embodiment, based on the one or more constraint parameters. The actual idle time of the system may be monitored to take into account interrupts which disrupt an idle time and idle times resulting from no software instructions to execute. The system may be allowed to operate based on comparisons of the target idle time and the actual idle time.

Abstract: Exemplary embodiments of methods and apparatuses to manage a power of a data processing system are described. One or more constraint parameters of a system are monitored. The data processing system is forced into an idle state for a first portion of a time while allowed to operate for a second portion of the time based on the one or more constraint parameters, wherein the system is forced into the idle state in response to comparing a target idle time to an actual idle time. The target idle time of the system is determined, in one embodiment, based on the one or more constraint parameters. The actual idle time of the system may be monitored to take into account interrupts which disrupt an idle time and idle times resulting from no software instructions to execute. The system may be allowed to operate based on comparisons of the target idle time and the actual idle time.

Abstract: Exemplary embodiments of methods and apparatuses to manage a power of a data processing system are described. One or more constraint parameters of a system are monitored. The data processing system is forced into an idle state for a first portion of a time while allowed to operate for a second portion of the time based on the one or more constraint parameters, wherein the system is forced into the idle state in response to comparing a target idle time to an actual idle time. The target idle time of the system is determined, in one embodiment, based on the one or more constraint parameters. The actual idle time of the system may be monitored to take into account interrupts which disrupt an idle time and idle times resulting from no software instructions to execute. The system may be allowed to operate based on comparisons of the target idle time and the actual idle time.

Abstract: Exemplary embodiments of methods and apparatuses to manage a power of a data processing system are described. One or more constraint parameters of a system are monitored. The data processing system is forced into an idle state for a first portion of a time while allowed to operate for a second portion of the time based on the one or more constraint parameters, wherein the system is forced into the idle state in response to comparing a target idle time to an actual idle time. The target idle time of the system is determined, in one embodiment, based on the one or more constraint parameters. The actual idle time of the system may be monitored to take into account interrupts which disrupt an idle time and idle times resulting from no software instructions to execute. The system may be allowed to operate based on comparisons of the target idle time and the actual idle time.

Abstract: A method and system in a distributed shared-memory data processing system are disclosed having a single operating system being executed simultaneously by a plurality of processors included within a plurality of coupled processing nodes for determining a utilization of each memory location included within a shared-memory included within each of the plurality of nodes by each of the plurality of nodes. The operating system processes a designated application utilizing the plurality of nodes. During the processing, for each of the plurality of nodes, a determination is made of a quantity of times each memory location included within a shared-memory included within each of the plurality of nodes is accessed by each of the plurality of nodes.

Abstract: A data processing system having an operating system environment, an operating system kernel, and a plurality of device drivers, wherein the plurality of device drivers are programs separate from the kernel. The data processing system includes a kernel that excludes device driver functions. The device drivers in the data processing system are user level tasks or programs. A boot volume stored in a storage device in the data processing system is provided, wherein the boot volume includes: (1) a file anchor, indicating a starting point to find files associated with the boot volume; (2) a plurality of file headers associated with the file anchor, each file header including an identification of files associated with the boot volume; and (3) a plurality of block list elements, each block list element identifying a contiguous block of data in a storage device, wherein data structures comprising a file may be identified and accessed using at least one block list element.

Abstract: A power management architecture in a data processing system comprising physical devices having at least one state, each state has corresponding power value, and where a system state is defined as the set of all current states of the physical devices. Power objects and thermal objects, each corresponding to a physical device, contain information about the power requirements and thermal characteristics of each possible state for that physical device. The power and thermal objects also describe the allowed state transitions from each possible state to another state, and the power requirements and thermal characteristics of all possible state transitions. Also communicated is the current state of each physical device. Event means generate signals indicating the occurrence of an event in the system. A policy module contains rules, implementing the power management, that direct an action, the rules being a function of events and of power object information.

Abstract: A device driver system comprises a core that manages the specific functions of a plurality of I/O devices. The core includes an operating system interface that is generic to different operating systems. An operating system has a device driver interface that is unique to the operating system. A conversion program is layered between the core and the operating system for converting communications between the device driver interface of the operating system and the generic operating system interface of the core. The core includes a channel manager including a request dispatcher, request queues, a command initiator, and a plurality of state machines corresponding to state machine in the I/O devices. A transport layer interfaces between the hardware and the channel manager.

Abstract: In a DASD caching system, in which pages of sectors of data are stored by reading in a desired sector and prefetching a plurality of adjacent sectors for later access, errors in disk storage media cause error signals to be generated. Such errors are handled by storing indications of which sectors have errors and which do not, and accessing such indications in response to later requests for such sectors. Such indications are stored in each page in the cache. Further, a history is maintained of which pages and sectors therein, were placed in the cache in the past.