International Business Machines Corporation

Andrew Matthew Theurer

Mark Alan Peloquin

Steven L Pratt

Karl Milton Rister

Kevin Michael Corry

Hubertus Franke

James Xenidis

Jon K Kriegel

Benjamin Herrenschmidt

A method and a system for allowing a guest operating system (guest OS) to modify an entry in a TLB directly without an involvement of a hypervisor are disclosed. Upon receiving a guest TLB miss exception, a guest OS issues a TLBWE (TLB Write Entry) instruction to logic. The logic runs the TLBWE instruction at a supervisor mode without invoking a hypervisor. The TLB may incorporate entries in a guest page table and entries in a host page table.

Method and apparatus for managing software controlled cache of translating the physical memory access of a virtual machine between different levels of translation entities

A hypervisor receives a memory page checksum from a guest operating system, which corresponds to a page of memory utilized by the guest. Next, the hypervisor proceeds through a series of steps to detect that the memory page checksum matches a checksum value included in a checksum entry item, which includes an identifier of a different guest. In turn, the hypervisor shares the page of memory between the guest and the different guest in response to detecting that the memory page checksum matches the checksum value included the checksum entry item.

Detection of duplicate memory pages across guest operating systems on a shared host

Recording television programs for future playback by enabling the user to record a plurality of programs that have sequential units of commercial content. There is sequential sensing for commercial content units. When a commercial content unit is reached, it is removed for separate storage. A determination is made as to whether the removed commercial content unit is the same as a previous commercial content unit that has been removed. Any previous commercial unit that has been removed has been stored in a file and a pointer to the file inserted in place of the commercial in the sequential stream of the television program being recorded. Thus, if the removed commercial unit has the same content, i.e. is a repeat of a previous commercial, the inserted pointer will point to the file of the previous commercial.

Optimizing recording space in digital video recording of television programs containing commercials

A method, data processing system and computer program product enables efficient transfer of a virtual machine from a first data processing system (DPS) to a second DPS using a combination of Transmission Control Protocol (TCP) and Uniform Data Protocol (UDP). A virtual machine migration (VMM) utility identifies all memory pages of the first virtual machine. The VMM utility notifies the second DPS via TCP of the scheduled transfer of the virtual machine. The VMM utility copies and transfers the memory pages of the virtual machine to the second DPS via UDP. When all expected components of the virtual machine are not received by the second DPS and/or memory data is modified within the memory pages during the migration, the VMM utility combines the missing data and the modified data and transfers the final components of the virtual machine using TCP. Execution of the virtual machine resumes on the second DPS.

Method for efficient guest operating system (OS) migration over a network

Improving storage efficiency for a digital video recorder is provided. It is determined whether television programming is being presented on a high definition channel or a standard definition channel. The television programming is recorded using the digital video recorder in response to determining that the television programming is being presented on a standard definition channel without making any resolution changes to the television programming. It is determined whether the content of the television programming originates in high definition or standard definition. When the television programming originates in standard definition, it is determined whether a corresponding standard definition channel is available. In response to determining the corresponding channel is available, the television programming is recorded in standard definition from the corresponding channel. Otherwise, the television programming is downscaled on the high definition channel to a standard definition resolution.

Improving storage efficiency of high definition digital video recorders

Utilization management is provided. A utilization monitor is initiated to monitor a set of processes. Utilization data for an identified process of the set of processes is recorded to form recorded utilization data. It is determined whether the recorded utilization data exceeds a utilization threshold. In responsive to determining that the recorded utilization data exceeds a utilization threshold, an action is performed to manage utilization.

Utilization management

A profiler of a multithreaded process that determines whether a process is runnable but not running by determining whether a process is both waiting for the processor and also not waiting for other events such as I/O. Counters are maintained for each such process that is runnable but not running. Reports are generated summarizing data relating to any process that may be starved due to lack of processor time. Information obtained by the method and apparatus assists developers in optimizing resources in multithreaded environments.

Thread starvation profiler by utilizing a set of counters

Statistical profile data is refined by interrupting an execution of a software program in response to detecting a profiling event during the execution of the software program. An event sample associated with the profiling event is recorded in a log file. A set of markers describing and associated with the event sample is inserted into the log file.

Managing statistical profile data

A method and a system for allowing a guest operating system (guest OS) to modify an entry in a TLB directly without an involvement of a hypervisor are disclosed. Upon receiving a guest TLB miss exception, a guest OS issues a TLBWE (TLB Write Entry) instruction to logic. The logic executes the TLBWE instruction at a supervisor mode without invoking a hypervisor. The TLB may incorporate entries in a guest page table and entries in a host page table.

A server system suitable for processing transactions includes transaction processing means to process requests issued by client systems. A transaction profiler records information regarding transactions processed by the server. Profiled transactions are selected for inclusion in a cumulative database according to a selection criteria. The transaction processor may be an HTTP server, a file server, or a database server. The profiler may be enabled by the processing means just before processing a request and disabled upon completion. In one embodiment, the transaction profiler is configured to calculate a transaction response time as the difference between the time the transaction processing means enables the profiling means and the time the transaction processing means disables the profiling means. In this embodiment, the selection criteria includes a minimum transaction response time wherein only transaction profiles indicating a response time in excess of the minimum transaction time are included in the cumulative database.

Selective profiler for use with transaction processing applications

A method, system, and computer-readable medium with executable code for enhancing real-time performance of a client device connected to a java virtual machine by incorporating a java proxy server. Java routing logic of a java proxy server is used to receive a request from a client device to access a java virtual machine. The java proxy server may use the java routing logic to select a java virtual machine from among multiple accessible java virtual machines. The java proxy server selects the java virtual machine that has the greatest amount of free memory, and is not performing a garbage collection operation. Once a java virtual machine is chosen, incoming client device connections are routed to a chosen java virtual machine. Additionally, the java routing logic may instruct one or more of the multiple java virtual machines to only perform garbage collection operations when idle, and when no other java virtual machines are performing garbage collection operations.

Enhancing real-time performance for java application serving

A computer implemented method, apparatus, system, and computer usable program product for controlling preemption rates. A scheduler identifies a preemption interval in response to a plurality of processes being executed by a processor. Only a single preemption of a process occurs during the preemption interval. The scheduler preempts a currently running process only once during the preemption interval. The preemption interval is adjusted to increase performance in executing processes.

Method and apparatus to control priority preemption of tasks

Systems, methods and media for migration of a guest from one server to another are disclosed. In one embodiment, a first server, while hosting the guest, receives a signal from the second server that the migration is to occur. The first server presents the memory used by the guest as a virtual disk. The second server accesses this disk and copies its contents to the second server over the storage area network. The first server suspends operation of the guest, and after the memory of the guest is copied to the second server, the second server resumes operation of the guest.

Growing community of inventors

Austin, TX, United States of America

Andrew Matthew Theurer