Patents by Inventor John M. Ludden

John M. Ludden 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: 10936505
    Abstract: Verification of asynchronous page fault in a simulated environment. The methods include providing a simulated environment that includes a simulated processor core, a memory, and an interrupt handler. The methods also include executing a test code in the simulated environment by: executing a non-irritator thread code comprising a plurality of load instructions that span at least two slices of the simulated processor core, executing a first irritator thread code to bias against the execution of the plurality of load instruction by one of the at least two slices of the simulated processor core, and executing a second irritator thread code to invalidate caching of page table entries during execution of the plurality of load instructions in a fast access cache memory.
    Type: Grant
    Filed: December 20, 2018
    Date of Patent: March 2, 2021
    Assignee: International Business Machines Corporation
    Inventors: John M. Ludden, David Campbell, Lance Hehenberger, Madhusudan Kadiyala, George W. Rohrbaugh, III
  • Publication number: 20200201778
    Abstract: Verification of asynchronous page fault in a simulated environment. The methods include providing a simulated environment that includes a simulated processor core, a memory, and an interrupt handler. The methods also include executing a test code in the simulated environment by: executing a non-irritator thread code comprising a plurality of load instructions that span at least two slices of the simulated processor core, executing a first irritator thread code to bias against the execution of the plurality of load instruction by one of the at least two slices of the simulated processor core, and executing a second irritator thread code to invalidate caching of page table entries during execution of the plurality of load instructions in a fast access cache memory.
    Type: Application
    Filed: December 20, 2018
    Publication date: June 25, 2020
    Inventors: John M. Ludden, David Campbell, Lance Hehenberger, Madhusudan Kadiyala, George W. Rohrbaugh, III
  • Patent number: 8479173
    Abstract: Creating one or more irritator threads on one or more processor cores in a multi-threaded multiprocessor data processing system is provided. A test generator generates non-irritator thread code for execution by a non-irritator thread and irritator thread code for execution by one or more irritator threads of the multi-threaded multiprocessor data processing system. A simulation controller instantiates the non-irritator thread to execute the non-irritator thread code and the one or more irritator threads to execute the irritator thread code. The simulation controller determines if the non-irritator thread has finished execution of the entire instruction stream of the non-irritator thread code. Responsive to the non-irritator thread finishing execution of the entire instruction stream of the non-irritator thread code, the non-irritator thread performs an operation to terminate the execution of the irritator thread code by the one or more irritator threads.
    Type: Grant
    Filed: July 9, 2008
    Date of Patent: July 2, 2013
    Assignee: International Business Machines Corporation
    Inventors: Bryan G. Hickerson, John M. Ludden
  • Patent number: 8275598
    Abstract: A computer-implemented method, system and computer program product are presented for managing an Effective-to-Real Address Table (ERAT) and a Translation Lookaside Buffer (TLB) during test verification in a simulated densely threaded Network On a Chip (NOC). The ERAT and TLB are stripped out of the computer simulation before executing a test program. When the test program experiences an inevitable ERAT-miss and/or TLB-miss, an interrupt handler walks a page table until the requisite page for re-populating the ERAT and TLB is located.
    Type: Grant
    Filed: March 2, 2009
    Date of Patent: September 25, 2012
    Assignee: International Business Machines Corporation
    Inventors: Anatoli S. Andreev, Olaf K. Hendrickson, John M. Ludden, Richard D. Peterson, Elena Tsanko
  • Publication number: 20100223505
    Abstract: A computer-implemented method, system and computer program product are presented for managing an Effective-to-Real Address Table (ERAT) and a Translation Lookaside Buffer (TLB) during test verification in a simulated densely threaded Network On a Chip (NOC). The ERAT and TLB are stripped out of the computer simulation before executing a test program. When the test program experiences an inevitable ERAT-miss and/or TLB-miss, an interrupt handler walks a page table until the requisite page for re-populating the ERAT and TLB is located.
    Type: Application
    Filed: March 2, 2009
    Publication date: September 2, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: ANATOLI S. ANDREEV, OLAF K. HENDRICKSON, JOHN M. LUDDEN, RICHARD D. PETERSON, ELENA TSANKO
  • Publication number: 20100011345
    Abstract: Creating one or more irritator threads on one or more processor cores in a multi-threaded multiprocessor data processing system is provided. A test generator generates non-irritator thread code for execution by a non-irritator thread and irritator thread code for execution by one or more irritator threads of the multi-threaded multiprocessor data processing system. A simulation controller instantiates the non-irritator thread to execute the non-irritator thread code and the one or more irritator threads to execute the irritator thread code. The simulation controller determines if the non-irritator thread has finished execution of the entire instruction stream of the non-irritator thread code. Responsive to the non-irritator thread finishing execution of the entire instruction stream of the non-irritator thread code, the non-irritator thread performs an operation to terminate the execution of the irritator thread code by the one or more irritator threads.
    Type: Application
    Filed: July 9, 2008
    Publication date: January 14, 2010
    Applicant: International Business Machines Corporation
    Inventors: Bryan G. Hickerson, John M. Ludden