Search Patents
  • Publication number: 20120203979
    Abstract: Mechanisms are provided for debugging application code using a content addressable memory. The mechanisms receive an instruction in a hardware unit of a processor of the data processing system, the instruction having a target memory address that the instruction is attempting to access. A content addressable memory (CAM) associated with the hardware unit is searched for an entry in the CAM corresponding to the target memory address. In response to an entry in the CAM corresponding to the target memory address being found, a determination is made as to whether information in the entry identifies the instruction as an instruction of interest. In response to the entry identifying the instruction as an instruction of interest, an exception is generated and sent to one of an exception handler or a debugger application. In this way, debugging of multithreaded applications may be performed in an efficient manner.
    Type: Application
    Filed: April 4, 2012
    Publication date: August 9, 2012
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Elmootazbellah N. Elnozahy, Ahmed Gheith
  • Patent number: 7437517
    Abstract: Methods, systems, and media for reducing memory latency seen by processors by providing a measure of control over on-chip memory (OCM) management to software applications, implicitly and/or explicitly, via an operating system are contemplated. Many embodiments allow part of the OCM to be managed by software applications via an application program interface (API), and part managed by hardware. Thus, the software applications can provide guidance regarding address ranges to maintain close to the processor to reduce unnecessary latencies typically encountered when dependent upon cache controller policies. Several embodiments utilize a memory internal to the processor or on a processor node so the memory block used for this technique is referred to as OCM.
    Type: Grant
    Filed: January 11, 2005
    Date of Patent: October 14, 2008
    Assignee: International Business Machines Corporation
    Inventors: Dilma Menezes da Silva, Elmootazbellah Nabil Elnozahy, Orran Yaakov Krieger, Hazim Shafi, Xiaowei Shen, Balaram Sinharoy, Robert Brett Tremaine
  • Patent number: 7934061
    Abstract: Methods, systems, and media for reducing memory latency seen by processors by providing a measure of control over on-chip memory (OCM) management to software applications, implicitly and/or explicitly, via an operating system are contemplated. Many embodiments allow part of the OCM to be managed by software applications via an application program interface (API), and part managed by hardware. Thus, the software applications can provide guidance regarding address ranges to maintain close to the processor to reduce unnecessary latencies typically encountered when dependent upon cache controller policies. Several embodiments utilize a memory internal to the processor or on a processor node so the memory block used for this technique is referred to as OCM.
    Type: Grant
    Filed: June 24, 2008
    Date of Patent: April 26, 2011
    Assignee: International Business Machines Corporation
    Inventors: Dilma Menezes da Silva, Elmootazbellah Nabil Elnozahy, Orran Yaakov Krieger, Hazim Shafi, Xiaowei Shen, Balaram Sinharoy, Robert Brett Tremaine
  • Patent number: 8417913
    Abstract: A method of assigning virtual memory to physical memory in a data processing system allocates a set of contiguous physical memory pages for a new page mapping, instructs the memory controller to move the virtual memory pages according to the new page mapping, and then allows access to the virtual memory pages using the new page mapping while the memory controller is still copying the virtual memory pages to the set of physical memory pages. The memory controller can use a mapping table which temporarily stores entries of the old and new page addresses, and releases the entries as copying for each entry is completed. The translation lookaside buffer (TLB) entries in the processor cores are updated for the new page addresses prior to completion of copying of the memory pages by the memory controller. The invention can be extended to non-uniform memory array (NUMA) systems.
    Type: Grant
    Filed: November 13, 2003
    Date of Patent: April 9, 2013
    Assignee: International Business Machines Corporation
    Inventors: Elmootazbellah Nabil Elnozahy, James Lyle Peterson, Ramakrishnan Rajamony, Hazim Shafi
  • Patent number: 6601149
    Abstract: A system for and method of monitoring memory transactions in a data processing system are disclosed. The method includes defining a set of memory transaction attributes with a monitoring system and detecting, on a data processing system connected to the monitoring system, memory transactions that match the defined set of memory transaction attributes. The number of detected memory transactions occurring during a specified duration are then displayed in a graphical format. In one embodiment, the data processing system comprises a non-uniform memory architecture (NUMA) system comprising a set of nodes. In this embodiment, the detected transactions comprise transactions passing through a switch connecting the nodes of the NUMA system. The set of memory transaction attributes may include memory transaction type information, node information, and transaction direction information.
    Type: Grant
    Filed: December 14, 1999
    Date of Patent: July 29, 2003
    Assignee: International Business Machines Corporation
    Inventors: Bishop Chapman Brock, Eli Chiprout, Elmootazbellah Nabil Elnozahy, Ramakrishnan Rajamony, Freeman Leigh Rawson, III, Ronald Lynn Rockhold