Patents by Inventor David Callahan

David Callahan 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: 9477515
    Abstract: In one embodiment, the present invention includes a method for receiving control in a kernel mode via a ring transition from a user thread during execution of an unbounded transactional memory (UTM) transaction, updating a state of a transaction status register (TSR) associated with the user thread and storing the TSR with a context of the user thread, and later restoring the context during a transition from the kernel mode to the user thread. In this way, the UTM transaction may continue on resumption of the user thread. Other embodiments are described and claimed.
    Type: Grant
    Filed: August 1, 2013
    Date of Patent: October 25, 2016
    Assignee: Intel Corporation
    Inventors: Koichi Yamada, Landy Wang, Martin Taillefer, Arun Kishan, David Callahan, Jan Gray, Gad Sheaffer, Ali-Reza Adl-Tabatabai
  • Publication number: 20160216973
    Abstract: In one embodiment, the present invention includes a method for receiving control in a kernel mode via a ring transition from a user thread during execution of an unbounded transactional memory (UTM) transaction, updating a state of a transaction status register (TSR) associated with the user thread and storing the TSR with a context of the user thread, and later restoring the context during a transition from the kernel mode to the user thread. In this way, the UTM transaction may continue on resumption of the user thread. Other embodiments are described and claimed.
    Type: Application
    Filed: August 1, 2013
    Publication date: July 28, 2016
    Inventors: Koichi Yamada, GAD SHEAFFER, JAN GRAY, LANDY WANG, MARTIN TAILLEFER, ARUN KISHAN, ALI-REZA ADL-TABATABAI, DAVID CALLAHAN
  • Patent number: 9280397
    Abstract: A method and apparatus for accelerating a Software Transactional Memory (STM) system is herein described. A data object and metadata for the data object may each be associated with a filter, such as a hardware monitor or ephemerally held filter information. The filter is in a first, default state when no access, such as a read, from the data object has occurred during a pendancy of a transaction. Upon encountering a first access to the metadata, such as a first read, access barrier operations, such as logging of the metadata; setting a read monitor; or updating ephemeral filter information with an ephemeral/buffered store operation, are performed. Upon a subsequent/redundant access to the metadata, such as a second read, access barrier operations are elided to accelerate the subsequent access based on the filter being set to the second state to indicate a previous access occurred.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: March 8, 2016
    Assignee: Intel Corporation
    Inventors: Ali-Reza Adl-Tabatabai, Gad Sheaffer, Bratin Saha, Jan Gray, David Callahan, Burton Smith, Graefe Goetz
  • Patent number: 9195600
    Abstract: In one embodiment, the present invention includes a method for executing a transactional memory (TM) transaction in a first thread, buffering a block of data in a first buffer of a cache memory of a processor, and acquiring a write monitor on the block to obtain ownership of the block at an encounter time in which data at a location of the block in the first buffer is updated. Other embodiments are described and claimed.
    Type: Grant
    Filed: November 10, 2014
    Date of Patent: November 24, 2015
    Assignee: Intel Corporation
    Inventors: Ali-Reza Adl-Tabatabai, Yang Ni, Bratin Saha, Vadim Bassin, Gad Sheaffer, David Callahan, Jan Gray
  • Patent number: 9069670
    Abstract: In one embodiment, the present invention includes a method for executing a transactional memory (TM) transaction in a first thread, buffering a block of data in a first buffer of a cache memory of a processor, and acquiring a write monitor on the block to obtain ownership of the block at an encounter time in which data at a location of the block in the first buffer is updated. Other embodiments are described and claimed.
    Type: Grant
    Filed: October 23, 2012
    Date of Patent: June 30, 2015
    Assignee: Intel Corporation
    Inventors: Ali-Reza Adl-Tabatabai, Yang Ni, Bratin Saha, Vadim Bassin, Gad Sheaffer, David Callahan, Jan Gray
  • Publication number: 20150134896
    Abstract: In one embodiment, the present invention includes a method for executing a transactional memory (TM) transaction in a first thread, buffering a block of data in a first buffer of a cache memory of a processor, and acquiring a write monitor on the block to obtain ownership of the block at an encounter time in which data at a location of the block in the first buffer is updated. Other embodiments are described and claimed.
    Type: Application
    Filed: November 10, 2014
    Publication date: May 14, 2015
    Inventors: ALI-REZA ADL-TABATABAI, YANG NI, BRATIN SAHA, VADIM BASSIN, GAD SHEAFFER, DAVID CALLAHAN, JAN GRAY
  • Patent number: 8959517
    Abstract: A scheduler in a process of a computer system schedules tasks of a task group for concurrent execution by multiple execution contexts. The scheduler provides a mechanism that allows the task group to be cancelled by an arbitrary execution context or an asynchronous error state. When a task group is cancelled, the scheduler sets a cancel indicator in each execution context that is executing tasks corresponding to the cancelled task group and performs a cancellation process on each of the execution contexts where a cancel indicator is set. The scheduler also creates local aliases to allow task groups to be used without synchronization by execution contexts that are not directly bound to the task groups.
    Type: Grant
    Filed: June 10, 2009
    Date of Patent: February 17, 2015
    Assignee: Microsoft Corporation
    Inventors: William R. Messmer, David Callahan, Paul F. Ringseth, Niklas Gustafsson
  • Publication number: 20150039869
    Abstract: In one embodiment, the present invention includes a method for receiving control in a kernel mode via a ring transition from a user thread during execution of an unbounded transactional memory (UTM) transaction, updating a state of a transaction status register (TSR) associated with the user thread and storing the TSR with a context of the user thread, and later restoring the context during a transition from the kernel mode to the user thread. In this way, the UTM transaction may continue on resumption of the user thread. Other embodiments are described and claimed.
    Type: Application
    Filed: August 1, 2013
    Publication date: February 5, 2015
    Inventors: Koichi Yamada, GAD SHEAFFER, JAN GRAY, LANDY WANG, MARTIN TAILLEFER, ARUN KISHAN, ALI-REZA ADL-TABATABAI, DAVID CALLAHAN
  • Patent number: 8886894
    Abstract: In one embodiment, the present invention includes a method for executing a transactional memory (TM) transaction in a first thread, buffering a block of data in a first buffer of a cache memory of a processor, and acquiring a write monitor on the block to obtain ownership of the block at an encounter time in which data at a location of the block in the first buffer is updated. Other embodiments are described and claimed.
    Type: Grant
    Filed: October 23, 2012
    Date of Patent: November 11, 2014
    Assignee: Intel Corporation
    Inventors: Ali-Reza Adl-Tabatabai, Yang Ni, Bratin Saha, Vadim Bassin, Gad Sheaffer, David Callahan, Jan Gray
  • Patent number: 8887162
    Abstract: Local storage may be allocated for each processing resource in a process of a computer system. Each processing resource may be virtualized and may have a one-to-one or a many-to-one correspondence with with physical processors. The contents of each local storage persist across various execution contexts that are executed by a corresponding processing resource. Each local storage may be accessed without synchronization (e.g., locks) by each execution context that is executed on a corresponding processing resource. The local storages provide the ability to segment data and store and access the data without synchronization. The local storages may be used to implement lock-free techniques such as a generalized reduction where a set of values is combined through an associative operator.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: November 11, 2014
    Assignee: Microsoft Corporation
    Inventors: Paul F. Ringseth, Rick Molloy, Niklas Gustafsson, David Callahan
  • Patent number: 8856466
    Abstract: In one embodiment, the present invention includes a method for executing a transactional memory (TM) transaction in a first thread, buffering a block of data in a first buffer of a cache memory of a processor, and acquiring a write monitor on the block to obtain ownership of the block at an encounter time in which data at a location of the block in the first buffer is updated. Other embodiments are described and claimed.
    Type: Grant
    Filed: October 23, 2012
    Date of Patent: October 7, 2014
    Assignee: Intel Corporation
    Inventors: Ali-Reza Adl-Tabatabai, Yang Ni, Bratin Saha, Vadim Bassin, Gad Sheaffer, David Callahan, Jan Gray
  • Patent number: 8812796
    Abstract: Private or shared read-only memory regions. One embodiment may be practiced in a computing environment including a plurality of agents. A method includes acts for declaring one or more memory regions private to a particular agent or shared read only amongst agents by having software utilize processor level instructions to specify to hardware the private or shared read only memory address regions. The method includes an agent executing a processor level instruction to specify one or more memory regions as private to the agent or shared read-only amongst a plurality of agents. As a result of an agent executing a processor level instruction to specify one or more memory regions as private to the agent or shared read-only amongst a plurality of agents, a hardware component monitoring the one or more memory regions for conflicting accesses or prevents conflicting accesses on the one or more memory regions.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: August 19, 2014
    Assignee: Microsoft Corporation
    Inventors: Jan Gray, David Callahan, Burton Jordan Smith, Gad Sheaffer, Ali-Reza Adl-Tabatabai
  • Patent number: 8719514
    Abstract: A method and apparatus for utilizing hardware mechanisms of a transactional memory system is herein described. Various embodiments relate to software-based filtering of operations from read and write barriers and read isolation barriers during transactional execution. Other embodiments relate to software-implemented read barrier processing to accelerate strong atomicity. Other embodiments are also described and claimed.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: May 6, 2014
    Assignee: Intel Corporation
    Inventors: Ali-Reza Adl-Tabatabai, David Callahan, Jan Gray, Vinod Grover, Bratin Saha, Gad Sheaffer
  • Patent number: 8688951
    Abstract: Operating system virtual memory management for hardware transactional memory. A system includes an operating system deciding to unmap a first virtual page. As a result, the operating system removes the mapping of the first virtual page to the first physical page from the virtual memory page table. As a result, the operating system performs an action to discard transactional memory hardware state for at least the first physical page. Embodiments may further suspend hardware transactions in kernel mode. Embodiments may further perform soft page fault handling without aborting a hardware transaction, resuming the hardware transaction upon return to user mode, and even successfully committing the hardware transaction.
    Type: Grant
    Filed: July 20, 2012
    Date of Patent: April 1, 2014
    Assignee: Microsoft Corporation
    Inventors: Koichi Yamada, Gad Sheaffer, Ali-Reza Adl-Tabatabai, Landy Wang, Martin Taillefer, Arun Kishan, David Callahan, Jan Gray, Vadim Bassin
  • Patent number: 8521995
    Abstract: A method includes receiving control in a kernel mode via a ring transition from a user thread during execution of an unbounded transactional memory (UTM) transaction, updating a state of a transaction status register (TSR) associated with the user thread and storing the TSR with a context of the user thread, and later restoring the context during a transition from the kernel mode to the user thread. In this way, the UTM transaction may continue on resumption of the user thread.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: August 27, 2013
    Assignee: Intel Corporation
    Inventors: Koichi Yamada, Gad Sheaffer, Jan Gray, Landy Wang, Martin Taillefer, Arun Kishan, Ali-Reza Adl-Tabatabai, David Callahan
  • Patent number: 8489864
    Abstract: Performing non-transactional escape actions within a hardware based transactional memory system. A method includes at a hardware thread on a processor beginning a hardware based transaction for the thread. Without committing or aborting the transaction, the method further includes suspending the hardware based transaction and performing one or more operations for the thread, non-transactionally and not affected by: transaction monitoring and buffering for the transaction, an abort for the transaction, or a commit for the transaction. After performing one or more operations for the thread, non-transactionally, the method further includes resuming the transaction and performing additional operations transactionally. After performing the additional operations, the method further includes either committing or aborting the transaction.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: July 16, 2013
    Assignee: Microsoft Corporation
    Inventors: Gad Sheaffer, Jan Gray, Martin Taillefer, Ali-Reza Adl-Tabatabai, Bratin Saha, Vadim Bassin, Robert Y. Geva, David Callahan
  • Patent number: 8407728
    Abstract: A compositional model referred to as a source-target pattern for connecting processes into process networks in a general, flexible, and extensible manner is provided. The model allows common process algebra constructs to be combined with data flow networks to form process networks. Process algebraic operations may be expressed in terms of the compositional model to form data flow networks that provide fully interoperable process algebraic operations between processes.
    Type: Grant
    Filed: June 2, 2008
    Date of Patent: March 26, 2013
    Assignee: Microsoft Corporation
    Inventors: Niklas Gustafsson, David Callahan
  • Publication number: 20130046925
    Abstract: In one embodiment, the present invention includes a method for executing a transactional memory (TM) transaction in a first thread, buffering a block of data in a first buffer of a cache memory of a processor, and acquiring a write monitor on the block to obtain ownership of the block at an encounter time in which data at a location of the block in the first buffer is updated. Other embodiments are described and claimed.
    Type: Application
    Filed: October 23, 2012
    Publication date: February 21, 2013
    Inventors: Ali-Reza Adl-Tabatabai, YANG NI, BRATIN SAHA, VADIM BASSIN, GAD SHEAFFER, DAVID CALLAHAN, JAN GRAY
  • Publication number: 20130046947
    Abstract: In one embodiment, the present invention includes a method for executing a transactional memory (TM) transaction in a first thread, buffering a block of data in a first buffer of a cache memory of a processor, and acquiring a write monitor on the block to obtain ownership of the block at an encounter time in which data at a location of the block in the first buffer is updated. Other embodiments are described and claimed.
    Type: Application
    Filed: October 23, 2012
    Publication date: February 21, 2013
    Inventors: Ali-Reza Adl-Tabatabai, Yang Ni, Bratin Saha, Vadim Bassin, Gad Sheaffer, David Callahan, Jan Gray
  • Publication number: 20130046924
    Abstract: In one embodiment, the present invention includes a method for executing a transactional memory (TM) transaction in a first thread, buffering a block of data in a first buffer of a cache memory of a processor, and acquiring a write monitor on the block to obtain ownership of the block at an encounter time in which data at a location of the block in the first buffer is updated. Other embodiments are described and claimed.
    Type: Application
    Filed: October 23, 2012
    Publication date: February 21, 2013
    Inventors: Ali-Reza Adl-Tabatabai, YANG NI, BRATIN SAHA, VADIM BASSIN, GAD SHEAFFER, DAVID CALLAHAN, JAN GRAY