University of Pittsburgh

Rami G Melhem

Jun Yang

Ziyu Zhang

Debashis Ganguly

Donald M Chiarulli

Steven P Levitan

Sangyeun Cho

A data management method wherein a working set is distributed between near and far memories includes migrating first data from the far to the near memory according to a prefetcher algorithm. The first data (a subset of the working set) is maintained in the near memory in data structures according to predetermined semantics of the prefetcher that dictate that certain of the first data is prefetched when a first function evaluates as true. The method further includes detecting that the near memory has reached capacity, and in response, adaptively migrating a portion of the first data out of the near and into the far memory according to an eviction algorithm that is based on the set of prefetcher semantics such that certain of the portion of the first data is evicted when a second function evaluates as true, wherein the second function equals the inverse of the first function.

Method and apparatus for replacing data from near to far memory over a slow interconnect for oversubscribed irregular applications

A method of managing data during execution of an application for use in a system that includes a host memory, a near memory, and a near device associated with the near memory. The application uses a working set of data that is distributed between the far memory and the near memory. The method includes counting a number of times that the near device accesses a unit of the working set of data from the far memory, determining whether the number of times exceeds a dynamically changing access counter threshold, wherein the dynamically changing access counter threshold is calculated dynamically based on a static threshold that is set for the system, and responsive to determining that the number of times exceeds the dynamically changing access counter threshold, migrating the unit of data from the far memory to the near memory.

Method and apparatus for adaptive page migration and pinning for oversubscribed irregular applications

Systems and methods are disclosed that facilitate storage and retrieval of data to/from memory with permanent faults. Permanent 'stuck at' faults, associated with individual bits, interfere with Write operations. A memory bit with the SA-0 fault does not store the value '1' while a memory bit with the SA-1 fault does not store the value &#x201c;0&#x201d;. Hence, when later retrieved by a Read operation, stored data located on one or more bits having a permanent fault may be different from the data that was originally written. Techniques are disclosed that facilitate correct retrieval of data in the presence of &#x201c;stuck at&#x201d; faults by keeping track of the positions of the bits that are stuck at a value different from the ones that are written and then, at Read time, inverting the values read from those positions.

Recursively determined invertible set approach to correct multiple stuck-at faults in rewritable memory

The present invention pertains to an optical selector switch. The optical selector switch includes an optical waveguide means, and M means for producing light that can be transmitted through the optical waveguide means with M being greater than or equal to 2. The M light producing means are optically connected to the optical waveguide means. The optical selector switch includes means for controlling when each of the M light producing means produces optical pulses to be transmitted through the optical waveguide means. Additionally, there are N optical transduces optically connected to the optical waveguide means, with N being greater than or equal to 2. Each of the N optical transducers are capable of producing an electrical signal corresponding to the combination of optical pulses received from the M light-producing means. The N optical transducers can be arranged in either a one, two or three dimensional array. Moreover, memory cells can be included to provide for a memory array.

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Pittsburgh, PA, United States of America

Rami G Melhem