Patents by Inventor Kevin C. Stelzer

Kevin C. Stelzer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7519780
    Abstract: A system and method for reducing store latency in symmetrical multiprocessor systems are provided. Bus agents are provided which monitor reflected ownership requests (Dclaims) to determine if the reflected Dclaim is its own Dclaim. If so, the bus agent determines that it is the winner of the ownership request and can immediately perform data modification using its associated local cache. If the bus agent determines that the reflected Dclaim does not match its own Dclaim, it determines that it is the loser of the ownership request and invalidates the corresponding cache line in its own local cache. The loser bus agent may then send a Read With Intent to Modify request to obtain the data from another cache and place it into its own cache for modification. These operations are performed without the need for a Kill request and without having to perform retries of a losing ownership request.
    Type: Grant
    Filed: November 3, 2006
    Date of Patent: April 14, 2009
    Assignee: International Business Machines Corporation
    Inventors: Jonathan J. DeMent, Roy M. Kim, Alvan W. Ng, Kevin C. Stelzer, Thuong Q. Truong
  • Patent number: 7516275
    Abstract: A computer implemented method and system for managing replacement of sets in a locked cache. A cache access by a program is performed, and a side of a binary tree pointed to by a base leaf is identified. A determination is made as to whether a number of accesses to the identified side of the binary tree equals a number of sets associated with the program on the identified side. The base leaf is changed to point to an opposite side of the binary tree if the number of accesses to the identified side equals the number of sets associated with the program on the identified side.
    Type: Grant
    Filed: April 25, 2006
    Date of Patent: April 7, 2009
    Assignee: International Business Machines Corporation
    Inventors: Jonathan James DeMent, Ronald P. Hall, Brian Patrick Hanley, Kevin C. Stelzer
  • Publication number: 20080109585
    Abstract: A system and method for reducing store latency in symmetrical multiprocessor systems are provided. Bus agents are provided which monitor reflected ownership requests (Dclaims) to determine if the reflected Dclaim is its own Dclaim. If so, the bus agent determines that it is the winner of the ownership request and can immediately perform data modification using its associated local cache. If the bus agent determines that the reflected Dclaim does not match its own Dclaim, it determines that it is the loser of the ownership request and invalidates the corresponding cache line in its own local cache. The loser bus agent may then send a Read With Intent to Modify request to obtain the data from another cache and place it into its own cache for modification. These operations are performed without the need for a Kill request and without having to perform retries of a losing ownership request.
    Type: Application
    Filed: November 3, 2006
    Publication date: May 8, 2008
    Inventors: Jonathan J. DeMent, Roy M. Kim, Alvan W. Ng, Kevin C. Stelzer, Thuong Q. Truong
  • Patent number: 7069390
    Abstract: The present invention provides for a plurality of partitioned ways of an associative cache. A pseudo-least recently used binary tree is provided, as is a way partition binary tree, and signals are derived from the way partition binary tree as a function of a mapped partition. Signals from the way partition binary tree and the pseudo-least recently used binary tree are combined. A cache line replacement signal is employable to select one way of a partition as a function of the pseudo-least recently used binary tree and the signals derived from the way partition binary tree.
    Type: Grant
    Filed: September 4, 2003
    Date of Patent: June 27, 2006
    Assignee: International Business Machines Corporation
    Inventors: Wen-Tzer Thomas Chen, Peichun Peter Liu, Kevin C. Stelzer