Tilera Corporation

Symantec Operating Corporation

Veritas Operating Corporation

Incert Software Corporation

Google Inc.

Hewlett-Packard Company

Richard Schooler

Anant Agarwal

Vineet Soni

Robert A Gottlieb

Andrew E Ayers

Walter Lee

Christopher D Metcalf

Michael Spertus

Mathew Hostetter

David A Stuckmann

Mark B Rosenbluth

Carl Ramey

Matthew Mattina

David M Wentzlaff

Ian Rudolf Bratt

Christopher J Jackson

Bruce Edwards

Pawel Jurczyk

Liewei Bao

Chyi-Chang Miao

Patrick Robert Griffin

Kenneth M Steele

Shane Bell

John A Amann

Richard Conlin

Ben Harrison

Kevin Joyce

Christine Deignan

A solution is provided for selectively caching streaming media based on playback data associated with the streaming media. Each media stream is divided into a number of media chunks. Spatial locality and temporal locality of each media chunk is analyzed based on playback data of the media chunk and the corresponding media stream. Based on the spatial locality and temporal locality, a spatial score and temporal score are generated, respectively. Aggregation of the spatial score and temporal score produces a final score for the media chunk. The media chunks are ranked based on their final scores, where all or a number of media chunks are selected based on their rankings for being cached. The ranking of a cached media chunk decays over time, and the ranking of a cached media chunk is dynamically recalculated when another video chunk is to be cached.

Streaming media cache for media streaming service

A system comprises a plurality of computation units interconnected by an interconnection network. A method for configuring the system comprises forming subsets of instructions corresponding to different portions of a program, the subsets of instructions being related according to a control flow graph; for each of a first subset of branches in the control flow graph, scheduling a value of an associated branch condition to be broadcast to multiple computation units; for each of a second subset of branches in the control flow graph, representing each instruction dependent on an associated branch condition as a predicated instruction that includes a predicate for computing the associated branch condition; assigning each subset of instructions to one of the computation units for execution on the assigned computation unit; and converting at least some of the predicated instructions in a subset of instructions assigned to a given computation unit into unpredicated instructions that depend on a branch local to the given computation unit.

Compiling code for parallel processing architectures based on control flow

A computing system comprises one or more cores. Each core comprises a processor. In some implementations, each processor is coupled to a communication network among the cores. In some implementations, a switch in each core includes switching circuitry to forward data received over data paths from other cores to the processor and to switches of other cores, and to forward data received from the processor to switches of other cores.

Computing in parallel processing environments

The present invention relates to a method, system, and computer program product for performing a computer program analysis. The computer program includes a plurality of instructions. The method performs a static analysis of the computer program to compute the states of a stack pointer (SP), a frame pointer (FP), and a link register (LR) at one or more instructions of the program. The static analysis is preferably performed at compile time. Further, the method computes the states of the SP, the FP, and the LR at the instructions as determined by a dynamic analysis, wherein the dynamic analysis is preferably modeled (performed) during the static analysis. Furthermore, the states determined by the static analysis and the dynamic analysis are compared. If a discrepancy is found between the two states, metadata (information operators) is inserted into the program.

Method and system for stack back-tracing in computer programs

A system comprises a plurality of computation units interconnected by an interconnection network. A method for configuring the system comprises receiving subsets of instructions corresponding to different portions of a program, each subset assigned to one of the computation units; scheduling instructions in a given subset for execution on the assigned computation unit, including scheduling communication instructions that send to or receive from a different computation unit over the interconnection network; allocating registers in a given computation unit for storing values accessed by instructions in a subset assigned to the given computation unit; and scheduling instructions after allocating registers to account for spills of values stored in allocated register to memory, preserving the order of communication instructions scheduled before allocating registers.

Communication scheduling for parallel processing architectures

A system comprises a plurality of computation units interconnected by an interconnection network. A method for configuring the system comprises receiving an initial partitioning of instructions into initial subsets corresponding to different portions of a program; forming a refined partitioning of the instructions into refined subsets each including one or more of the initial subsets, including determining whether to combine a first subset and a second subset to form a third subset according to a comparison of a communication cost between the first subset and second subset and a load cost of the third subset that is based at least in part on a number of instructions issued per cycle by a computation unit; and assigning each refined subset of instructions to one of the computation units for execution on the assigned computation unit.

Distributing parallelism for parallel processing architectures

A system comprises a plurality of computation units interconnected by an interconnection network. A method for configuring the system comprises forming subsets of instructions corresponding to different portions of a program, the subsets of instructions being related according to a control flow graph; forming one or more memory analysis regions that include one or more of the subsets of instructions, where each subset of instructions is included in a single memory analysis region; analyzing each memory analysis region to partition memory objects and instructions that access the memory objects into equivalence classes such that instructions within an equivalence class only access objects in the same equivalence class; and assigning memory access instructions a given equivalence class to one of the computation units for execution on the assigned computation unit.

Memory access assignment for parallel processing architectures

A method and mechanism for diagnosing application failures. An executable application is augmented with code which generates a list of components, as well as version information, utilized by the application. Also created is data which associates application components with applications which utilize those components. The list of components, version information, and association data are stored in a database and updated each time the application is run. In response to detecting a failure of the application, a database query is generated which returns a list of components utilized by the failed application. By comparing the date that application components changed to the date the application was last successfully run, a high priority list of components which changed since the last successful run may be generated. Diagnosis of the application failure may then begin with components in the high priority list.

Application failure diagnosis

A computer method for issuing an early warning includes determining, using change and test coverage and control flow and data flow analyses of a program, locations in the program at which to insert early warning (EW) code to monitor for an event. The program is instrumented with EW code which monitors for the event, by inserting EW code at the determined locations. Upon detecting the event, EW code performs an early action warning, or issues an early action. Early warnings are issued when an EW-instrumented block is reached. Issuance of an early warning action can be conditional upon execution of the program in a particular environment, such as a production environment. Issuance of an EW can also be conditional upon executing an untested block of code that was recently modified.

Early warning mechanism for enhancing enterprise availability

Methods and systems are provided for internal monitoring of applications. A distributed management framework may comprise a plurality of applications and application servers, wherein each of the applications is configured to make function calls to standard programming functions. The function calls to the standard programming functions are intercepted. The function calls are routed to alternative implementations of the standard programming functions, and the alternative implementations are used to collect availability metrics for the plurality of applications. Manager threads may be used for internal monitoring of application execution. Applications may be modified with additional instructions to monitor program execution and automatically generate output comprising an execution history.

Internal monitoring of applications in a distributed management framework

A program execution data trace is created by instrumenting a program to record value sets during execution and an instruction trace. By simulating instructions either backward or forward from a first instruction associated with a recorded value set to a second instruction according to the instruction trace, a value set is determined for the second instruction. Backward and forward simulation can be combined to complement each other. For backward simulation, a table of simulation instructions is preferably maintained, which associates program instructions encountered in the instruction trace with simulation instructions which reverse the operation of the associated program instructions. Preferably, one or more probes is inserted into the program to save values of particular variables whose value may be difficult to determine. Preferably, the instruction trace is displayed alongside and correlated with the data trace.

Method for simulating back program execution from a traceback sequence

A program execution data trace is created by instrumenting a program to record value sets during execution and an instruction trace. By simulating instructions either backward or forward from a first instruction associated with a recorded value set to a second instruction according to the instruction trace, a value set is determined for the second instruction. Backward and forward simulation can be combined to complement each other. For backward simulation, a table of simulation instructions is preferably maintained, which associates program instructions encountered in the instruction trace with simulation instructions which reverse the operation of the of the associated program instructions. Preferably, one or more probes is inserted into the program to save values of particular variables whose value may be difficult to determine. Preferably, the instruction trace is displayed alongside and correlated with the data trace. In one embodiment, the instruction trace is displayed and a value set is determined for an instruction upon a request by the user indicating the instruction for which the value set is desired.

A computer method for issuing an early warning includes determining, using change and test coverage and control flow and data flow analyses of a program, locations in the program at which to insert early warning (EW) code to monitor for an event. The program is instrumented with EW code which monitors for the event, by inserting EW code at the determined locations. Upon detecting the event, EW code performs an early action warning, or issues an early action. Early warnings are issued when an EW-instrumented block is reached. Issuance of an early warning action can be conditional upon execution of the program in a particular environment, such as a production environment. Issuance of an EW can also be conditional upon executing an untested block of code that was recently modified. The issuing of an early warning can include sending an email, writing into a log file, sending a message to a console, where the message causes the change of a human-perceptible characteristic, placing the program into a wait state, halting the program, sending an alarm to an operator, or triggering a failover. In some embodiments, EW code can be deactivated upon certain conditions. Issuance of an early warning can also occur upon an event such as the execution of a user-inserted assert or warning statement, or before a file is opened, wherein the EW issues if a null pointer about to be passed to a system function. In some embodiments, an EW will issue if the value of an argument to some function exceeds a predetermined range. In various embodiments, the EW code is placed in a loop, and issues an EW if the loop is executed more than a predetermined number of times, or the EW code issues an EW upon the execution of user-marked code, or the EW code issues an EW when the time duration between execution of two points in the program exceeds a predetermined value, or upon the detection of an untested configuration.

A method of back-tracing execution of a computer program, where the computer program comprises a plurality of blocks, comprises instrumenting an original version of the program by adding instrumentation code to some or all of the blocks to form an instrumented program. Instrumentation can be added at the binary or source level, or at link time. The instrumentation code records execution sequence information upon execution of the corresponding instrumented block to create a trace record of the executed program. The execution sequence information for each block comprises a block identifier which identifies the corresponding block. A detailed back-trace is generated, after the program has executed, by replacing each recorded block identifier with program counters associated with each instruction in the corresponding block. The application may comprise several programs or subprograms, in which case separate regions of memory can be maintained. Each region is associated with a program or subprogram or a set of programs or subprograms and stores therein part of the trace record corresponding to the associated set of programs or subprograms. The trace records themselves may be of different types. After execution, the trace record is presented to a user, in the form of assembly code, or more preferably, in the form of source level code. In an alternative embodiment, a summary of the trace record recorded during execution of an instrumented program is presented to a user. Various types of traces can be produced, including a last instruction trace and a first instruction trace.

Growing community of inventors

Cambridge, MA, United States of America

Richard Schooler