Search Patents
  • Patent number: 8397032
    Abstract: A method for recovery in a shared memory environment is provided in the illustrative embodiments. A core in a multi-core processor is designated as a user level core (ULC), which executes an instruction to modify a memory while executing an application. A second core is designated as a operating system core (OSC), which manages checkpointing of several segments of the shared memory. A set of flags is accessible to a memory controller to manage a shared memory. A flag in the set of flags corresponds to one segment in the segments of the shared memory. A message or instruction for modification of a segment is received. A cache line tracking determination is made whether a cache line used for the modification has already been used for a similar modification. If not, a part of the segment is checkpointed. The modification proceeds after checkpointing.
    Type: Grant
    Filed: March 7, 2012
    Date of Patent: March 12, 2013
    Assignee: International Business Machines Corporation
    Inventor: Elmootazbellah Nabil Elnozahy
  • Patent number: 8312224
    Abstract: A system, and computer usable program product for recovery in a shared memory environment are provided in the illustrative embodiments. A core in a multi-core processor is designated as a user level core (ULC), which executes an instruction to modify a memory while executing an application. A second core is designated as a operating system core (OSC), which manages checkpointing of several segments of the shared memory. A set of flags is accessible to a memory controller to manage a shared memory. A flag in the set of flags corresponds to one segment in the segments of the shared memory. A message or instruction for modification of a segment is received. A cache line tracking determination is made whether a cache line used for the modification has already been used for a similar modification. If not, a part of the segment is checkpointed. The modification proceeds after checkpointing.
    Type: Grant
    Filed: May 27, 2010
    Date of Patent: November 13, 2012
    Assignee: International Business Machines Corporation
    Inventor: Elmootazbellah Nabil Elnozahy
  • Publication number: 20080263284
    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: Application
    Filed: June 24, 2008
    Publication date: October 23, 2008
    Applicant: 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: 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: 6442654
    Abstract: A system and method for providing in-server caching of shared data involves a server program that defines a server cache in RAM of a server machine and stores a selected file in the server cache. If a cached file is modified through the file system interface of the operating system of the server machine, the operating system automatically issues an upcall to the server program, the upcall identifying the modified file. In response to receipt of the upcall, the server program removes the modified file from the server cache. In one embodiment, the server program responds to a client request requiring access to a requested file by obtaining the requested file from the server cache if the server cache contains that file. Otherwise, the server program calls the operating system to obtain the requested file and then adds that file to the server cache as a cached file. The server program then generates a result based on the requested file and transmits the result to the remote data processing system.
    Type: Grant
    Filed: December 10, 1999
    Date of Patent: August 27, 2002
    Assignee: International Business Machines Corporation
    Inventors: Bishop Chapman Brock, Eli Chiprout, Elmootazbellah Nabil Elnozahy, Ramakrishnan Rajamony, Freeman Leigh Rawson, III, Ronald Lynn Rockhold