International Business Machines Corporation

William Evan Speight

Lixin Zhang

Ramakrishnan Rajamony

Ravi Kumar Arimilli

Lakshminarayana Baba Arimilli

Jian Li

Balaram Sinharoy

Karthick Rajamani

Elmootazbellah Nabil Elnozahy

John Bruce Carter

Hazim Shafi

Wael R El-Essawy

Gheorghe Calin Cascaval

Madhusudan K Iyengar

Edward Joseph Seminaro

Ahmed Gheith

Yaoqing Gao

Juan C Rubio

Thomas W Keller, Jr

Eric Van Hansbergen

William John Starke

Chin Ngai Sze

Freeman Leigh Rawson, Iii

David S Levitan

Sani Richard Nassif

Wesley Michael Felter

Ronald Nick Kalla

Damir Anthony Jamsek

Anne Elizabeth Gattiker

Mark William Stephenson

Thomas Henry Osiecki

Ram Rangan

Xiaoxia Wu

Min-Yu Tsai

Simulating particle beam interactions includes identifying a set of n functions F, F, . . . , Fcorresponding to a plurality of different physical aspects of a particle beam, performing simulations of each Fusing a full physics model, selecting for each Fa distribution function fthat models relevant behavior and reducing computation of the full physics model for each Fby replacing Fwith a distribution function f. The computation reduction includes comparing a set of simulations wherein each freplaces its respective Fto determine if relevant behavior is accurately modeled and selecting one of for Ffor each n, for a Monte Carlo simulation based on a runtime and accuracy criteria.

Fast and accurate proton therapy dose calculations

A technique for handling predicated code in an out-of-order processor includes detecting a predicate defining instruction associated with a predicated code region. Renaming of predicated instructions, within the predicated code region, is then stalled until a predicate of the predicate defining instruction is resolved.

Techniques for predicated execution in an out-of-order processor

A system, and computer usable program product for fast remote communication and computation between processors are provided in the illustrative embodiments. A direct core to core communication unit (DCC) is configured to operate with a first processor, the first processor being a remote processor. A memory associated with the DCC receives a set of bytes, the set of bytes being sent from a second processor. An operation specified in the set of bytes is executed at the remote processor such that the operation is invoked without causing a software thread to execute.

Fast remote communication and computation between processors using store and load operations on direct core-to-core memory

A method, system, and computer usable program product for improved register allocation in a simultaneous multithreaded processor. A determination is made that a thread of an application in the data processing environment needs more physical registers than are available to allocate to the thread. The thread is configured to utilize a logical register that is mapped to a memory register. The thread is executed utilizing the physical registers and the memory registers.

Register allocation to threads

In one embodiment, a cache memory includes a cache array including a plurality of entries for caching cache lines of data, where the plurality of entries are distributed between a first region implemented in a first memory technology and a second region implemented in a second memory technology. The cache memory further includes a cache directory of the contents of the cache array and a cache controller that controls operation of the cache memory.

Non-uniform cache architecture (NUCA)

For a flexible replication with skewed mapping in a multi-core chip, a request for a cache line is received, at a receiver core in the multi-core chip from a requester core in the multi-core chip. The receiver and requester cores comprise electronic circuits. The multi-core chip comprises a set of cores including the receiver and the requester cores. A target core is identified from the request to which the request is targeted. A determination is made whether the target core includes the requester core in a neighborhood of the target core, the neighborhood including a first subset of cores mapped to the target core according to a skewed mapping. The cache line is replicated, responsive to the determining being negative, from the target core to a replication core. The cache line is provided from the replication core to the requester core.

Flexible replication with skewed mapping in multi-core chips

In a data processing system capable of concurrently executing multiple hardware threads of execution, an intermediate address translation unit in a processing unit translates an effective address for a memory access into an intermediate address. A cache memory is accessed utilizing the intermediate address. In response to a miss in cache memory, the intermediate address is translated into a real address by a real address translation unit that performs address translation for multiple hardware threads of execution. The system memory is accessed with the real address.

Address translation through an intermediate address space

A system and method are provided for performing setup operations for receiving a different amount of data while processors are performing message passing interface (MPI) tasks. Mechanisms for adjusting the balance of processing workloads of the processors are provided so as to minimize wait periods for waiting for all of the processors to call a synchronization operation. An MPI load balancing controller maintains a history that provides a profile of the tasks with regard to their calls to synchronization operations. From this information, it can be determined which processors should have their processing loads lightened and which processors are able to handle additional processing loads without significantly negatively affecting the overall operation of the parallel execution system. As a result, setup operations may be performed while processors are performing MPI tasks to prepare for receiving different sized portions of data in a subsequent computation cycle based on the history.

Performing setup operations for receiving different amounts of data while processors are performing message passing interface tasks

A mechanism is provided in a cache for providing a read and write aware cache. The mechanism partitions a large cache into a read-often region and a write-often region. The mechanism considers read/write frequency in a non-uniform cache architecture replacement policy. A frequently written cache line is placed in one of the farther banks. A frequently read cache line is placed in one of the closer banks. The size ratio between read-often and write-often regions may be static or dynamic. The boundary between the read-often region and the write-often region may be distinct or fuzzy.

Read and write aware cache with a read portion and a write portion of a tag and status array

A method for fast remote communication and computation between processors is provided in the illustrative embodiments. A direct core to core communication unit (DCC) is configured to operate with a first processor, the first processor being a remote processor. A memory associated with the DCC receives a set of bytes, the set of bytes being sent from a second processor. An operation specified in the set of bytes is executed at the remote processor such that the operation is invoked without causing a software thread to execute.

A method, a system, an apparatus, and a computer program product for allocating resources of one or more shared devices to one or more partitions of a virtualization environment within a data processing system. At least one user defined resource assignment is received for one or more devices associated with the data processing system. One or more registers, associated with the one or more partitions are dynamically set to execute the at least one resource assignment, whereby the at least one resource assignment enables a user defined quantitative measure (number and/or percentage) of devices to operate when the one or more transactions are executed via the partition. The system enables the one or more devices to execute one or more transactions at a bandwidth/capacity that is less than or equal to the user defined resource assignment and minimizes performance interference among partitions.

Method and system for performance isolation in virtualized environments

A mechanism for assigning memory to on-chip cache coherence domains assigns caches within a processing unit to coherence domains. The mechanism assigns chunks of memory to the coherence domains. The mechanism monitors applications running on cores within the processing unit to identify needs of the applications. The mechanism may then reassign memory chunks to the cache coherence domains based on the needs of the applications running in the coherence domains. When a memory controller receives the cache miss, the memory controller may look up the address in a lookup table that maps memory chunks to cache coherence domains. Snoop requests are sent to caches within the coherence domain. If a cache line is found in a cache within the coherence domain, the cache line is returned to the originating cache by the cache containing the cache line either directly or through the memory controller.

Assigning memory to on-chip coherence domains

A mechanism is provided within a 3D stacked memory organization to spread or stripe cache lines across multiple layers. In an example organization, a 128B cache line takes eight cycles on a 16B-wide bus. Each layer may provide 32B. The first layer uses the first two of the eight transfer cycles to send the first 32B. The next layer sends the next 32B using the next two cycles of the eight transfer cycles, and so forth. The mechanism provides a uniform memory access.

Latency-tolerant 3D on-chip memory organization

A method of data processing in a processor includes maintaining a usage history indicating demand usage of prefetched data retrieved into cache memory. An amount of data to prefetch by a data prefetch request is selected based upon the usage history. The data prefetch request is transmitted to a memory hierarchy to prefetch the selected amount of data into cache memory.

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Austin, TX, United States of America

William Evan Speight