Patents by Inventor Gordon T. Davis

Gordon T. Davis 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: 8543767
    Abstract: A processing system includes a memory and a first core configured to process applications. The first core includes a first cache. The processing system includes a mechanism configured to capture a sequence of addresses of the application that miss the first cache in the first core and to place the sequence of addresses in a storage array; and a second core configured to process at least one software algorithm. The at least one software algorithm utilizes the sequence of addresses from the storage array to generate a sequence of prefetch addresses. The second core issues prefetch requests for the sequence of the prefetch addresses to the memory to obtain prefetched data and the prefetched data is provided to the first core if requested.
    Type: Grant
    Filed: June 4, 2012
    Date of Patent: September 24, 2013
    Assignee: International Business Machines Corporation
    Inventors: Gordon B. Bell, Gordon T. Davis, Jeffrey H. Derby, Anil Krishna, Srinivasan Ramani, Ken Vu, Steve Woolet
  • Patent number: 8386712
    Abstract: A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design for a single unified level one instruction cache in which some lines may contain traces and other lines in the same congruence class may contain blocks of instructions consistent with conventional cache lines is provided. A mechanism is described for indexing into the cache, and selecting the desired line. Control is exercised over which lines are contained within the cache. Provision is made for selection between a trace line and a conventional line when both match during a tag compare step.
    Type: Grant
    Filed: May 7, 2008
    Date of Patent: February 26, 2013
    Assignee: International Business Machines Corporation
    Inventors: Gordon T. Davis, Richard W. Doing, John D. Jabusch, M V V Anil Krishna, Brett Olsson, Eric F. Robinson, Sumedh W. Sathaye, Jeffrey R. Summers
  • Patent number: 8250348
    Abstract: In a first aspect, a first processing method is provided. The first processing method includes the steps of (1) operating a processor in a first mode based on an operand size associated with a first instruction received by the processor; and (2) dynamically switching the processor operation mode from the first mode to a second mode based on a different operand size associated with a second instruction received by the processor. Numerous other aspects are provided.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: August 21, 2012
    Assignee: International Business Machines Corporation
    Inventors: Gordon T. Davis, Jeffrey H. Derby
  • Patent number: 8135752
    Abstract: Techniques and articles of manufacture are provided comprising computer readable programs that, when executed on the computer, cause the computer to delete a leaf from a patricia tree having leaf keys and pattern search control blocks containing a prefix and either an end-of-trail leaf or a pointer to another of the pattern search control blocks, by placing each of the prefixes in a tree prefix table; searching for a key in the tree; searching for the key in the prefix table if the tree searching does not find the key in the tree; confirming that the key is deleted if the key is not found in the prefix table; deleting the key from one of the pattern search control blocks; and collapsing the patricia tree by eliminating the left most pattern search control block from the patricia tree if the patricia tree searching finds the key.
    Type: Grant
    Filed: January 8, 2009
    Date of Patent: March 13, 2012
    Assignee: International Business Machines Corporation
    Inventors: Claude Basso, Jean L. Calvignac, Gordon T. Davis, Marco Heddes, Piyush C. Patel, Steven R. Perrin, Grayson W. Randall, Sonia K. Rovner
  • Patent number: 8005869
    Abstract: Method for compressing search tree structures used in rule classification is provided. The method includes classifying packets based on filter rules, compressing a tree structure comprising multiple levels of single bit test nodes and leaf nodes, storing the compressed tree structure in a first memory structure of a storage such that the multiple levels of single bit test nodes and leaf nodes can be accessed from the first memory structure through a single memory access of the storage, collecting single bit test nodes of the tree structure that are in a lowest level of the tree structure, storing only the collected single bit test nodes within a second memory structure of the storage that is contiguous to the first memory structure, collecting leaf nodes of the tree structure, and storing only the collected leaf nodes within a third memory structure of the storage that is contiguous to second memory structure.
    Type: Grant
    Filed: March 14, 2008
    Date of Patent: August 23, 2011
    Assignee: International Business Machines Corporation
    Inventors: Everett A. Corl, Jr., Gordon T. Davis, Marco Heddes, Piyush C. Patel, Ravinder K. Sabhikhi
  • Patent number: 8005989
    Abstract: The classification system of a network device includes a cache in which a mapping between predefined characteristics of TCP/IP packets and associated actions are stored in response to the first “Frequent Flyer” packet in of a session. Selected characteristics from subsequent received packets of that session are correlated with the predefined characteristics and the stored actions are applied to the received packets if the selected characteristics and the predefined characteristics match, thus reducing the processing required for subsequent packets. The packets selected for caching may be data packets. For mismatched characteristics, the full packet search of the classification system is used to determine the action to apply to the received packet.
    Type: Grant
    Filed: August 8, 2008
    Date of Patent: August 23, 2011
    Assignee: International Business Machines Corporation
    Inventors: Everett A. Corl, Jr., Gordon T. Davis, Clark D. Jeffries, Natarajan Vaidhyanathan, Colin B. Verrilli
  • Patent number: 7996618
    Abstract: A single unified level one instruction(s) cache in which some lines may contain traces and other lines in the same congruence class may contain blocks of instruction(s) consistent with conventional cache lines. Formation of trace lines in the cache is delayed on initial operation of the system to assure quality of the trace lines stored.
    Type: Grant
    Filed: January 28, 2011
    Date of Patent: August 9, 2011
    Assignee: International Business Machines Corporation
    Inventors: Gordon T. Davis, Richard W. Doing, John D. Jabusch, M V V Anil Krishna, Brett Olsson, Eric F Robinson, Sumedh W Sathaye, Jeffrey R Summers
  • Patent number: 7984263
    Abstract: A design structure embodied in a machine readable storage medium for at least one of designing, manufacturing, and testing a design is provided. The design structure includes a page table walker. The page table walker is moved from its conventional location in the memory management unit associated with the data processor to a location in main memory i.e. the main memory controller. As a result, wherein the processing of requests for data could selectively avoid or bypass cumbersome caches associated with the data processor.
    Type: Grant
    Filed: April 25, 2008
    Date of Patent: July 19, 2011
    Assignee: International Business Machines Corporation
    Inventors: Sumedh W. Sathaye, Gordon T. Davis
  • Publication number: 20110131394
    Abstract: A single unified level one instruction(s) cache in which some lines may contain traces and other lines in the same congruence class may contain blocks of instruction(s) consistent with conventional cache lines. Formation of trace lines in the cache is delayed on initial operation of the system to assure quality of the trace lines stored.
    Type: Application
    Filed: January 28, 2011
    Publication date: June 2, 2011
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Gordon T. Davis, Richard W. Doing, John D. Jabusch, M V V Anil Krishna, Brett Olsson, Eric F. Robinson, Sumedh W. Sathaye, Jeffrey R. Summers
  • Patent number: 7944931
    Abstract: A memory subsystem includes Data Store 0 and Data Store 1. Each data store is partitioned into N buffers, N>1. An increment of memory is formed by a buffer pair, with each buffer of the buffer pair being in a different data store. Two buffer pair formats are used in forming memory increments. A first format selects a first buffer from Data Store 0 and a second buffer from Data Store 1, while a second format selects a first buffer from Data Store 1 and a second buffer from Data Store 0. A controller selects a buffer pair for storing data based upon the configuration of data in a delivery mechanism, such as switch cell.
    Type: Grant
    Filed: July 11, 2007
    Date of Patent: May 17, 2011
    Assignee: International Business Machines Corporation
    Inventors: Brian M. Bass, Gordon T. Davis, Michael S. Siegel, Michael R. Trombley
  • Patent number: 7941390
    Abstract: The present invention relates to a system for managing a plurality of multi-field classification rules. The system provides a first table that includes a plurality of entries corresponding to a plurality of rules relating to an ingress context and a second table that includes a plurality of entries corresponding to a plurality of rules relating to an egress context. The system also includes a network processor for classifying packets of information, wherein the network processor is programmed to utilize the first table and the second table to identify any rules relating to the ingress context and any one rules relating to the egress context that match a search key.
    Type: Grant
    Filed: June 20, 2008
    Date of Patent: May 10, 2011
    Assignee: International Business Machines Corporation
    Inventors: Everett A. Corl, Jr., Gordon T. Davis, Marco C. Heddes, Piyush C. Patel, Ravinder K. Sabhikhi
  • Patent number: 7937355
    Abstract: The present invention relates to a method and computer system device for applying a plurality of rules to data packets within a network computer system. A filter rule decision tree is updated by adding or deleting a rule. If deleting a filter rule then the decision tree is provided to a network data plane processor with an incremental delete of the filter rule. If adding a filter rule then either providing an incremental insertion of the filter rule to the decision tree or rebuilding the first decision tree into a second decision tree responsive to comparing a parameter to a threshold. In one embodiment the parameter and thresholds relate to depth values of the tree filter rule chained branches. In another the parameter and thresholds relate to a total count of rule additions since a building of the relevant tree.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: May 3, 2011
    Assignee: International Business Machines Corporation
    Inventors: Everett A. Corl, Jr., Gordon T. Davis, Clark D. Jeffries
  • Patent number: 7934081
    Abstract: A single unified level one instruction(s) cache in which some lines may contain traces and other lines in the same congruence class may contain blocks of instruction(s) consistent with conventional cache lines. Formation of trace lines in the cache is delayed on initial operation of the system to assure quality of the trace lines stored.
    Type: Grant
    Filed: October 5, 2006
    Date of Patent: April 26, 2011
    Assignee: International Business Machines Corporation
    Inventors: Gordon T. Davis, Richard W. Doing, John D. Jabusch, M V V Anil Krishna, Brett Olsson, Eric F. Robinson, Sumedh W. Sathaye, Jeffrey R. Summers
  • Patent number: 7929438
    Abstract: A pipeline configuration is described for use in network traffic management for the hardware scheduling of events arranged in a hierarchical linkage. The configuration reduces costs by minimizing the use of external SRAM memory devices. This results in some external memory devices being shared by different types of control blocks, such as flow queue control blocks, frame control blocks and hierarchy control blocks. Both SRAM and DRAM memory devices are used, depending on the content of the control block (Read-Modify-Write or ‘read’ only) at enqueue and dequeue, or Read-Modify-Write solely at dequeue. The scheduler utilizes time-based calendars and weighted fair queueing calendars in the egress calendar design. Control blocks that are accessed infrequently are stored in DRAM memory while those accessed frequently are stored in SRAM.
    Type: Grant
    Filed: July 18, 2008
    Date of Patent: April 19, 2011
    Assignee: International Business Machines Corporation
    Inventors: Claude Basso, Jean L. Calvignac, Chih-jen Chang, Gordon T. Davis, Fabrice J. Verplanken
  • Patent number: 7913034
    Abstract: Access arbiters are used to prioritize read and write access requests to individual memory banks in DRAM memory devices, particularly fast cycle DRAMs. This serves to optimize the memory bandwidth available for the read and the write operations by avoiding consecutive accesses to the same memory bank and by minimizing dead cycles. The arbiter first divides DRAM accesses into write accesses and read accesses. The access requests are divided into accesses per memory bank with a threshold limit imposed on the number of accesses to each memory bank. The write receive packets are rotated among the banks based on the write queue status. The status of the write queue for each memory bank may also be used for system flow control. The arbiter also typically includes the ability to determine access windows based on the status of the command queues, and to perform arbitration on each access window.
    Type: Grant
    Filed: August 1, 2007
    Date of Patent: March 22, 2011
    Assignee: International Business Machines Corporation
    Inventors: Jean L. Calvignac, Chih-jen Chang, Gordon T. Davis, Fabrice J. Verplanken
  • Patent number: 7855966
    Abstract: A codec detects congestion in a packet network and responds via a session control protocol to re-negotiate codec-type and/or parameters with the receiving codec to reduce bit rate for supporting a session. Once the connection and session are established, encoded packets start flowing between the two codecs. A control entity sends and receives network congestion control packets periodically in the session. The congestion control packets provide a “heartbeat” signal to the receiving codec. When the network is not congested, all “heartbeat” packets will be passed through the network. As network congestion increases, routers within the network discard excess packets to prevent network failure. The codecs respond to the missing packets by slowing down the bit rate or proceeding to renegotiate a lower bit rate via the session control protocol. If there are no missing packets, the codecs detect if the session is operating at the highest bit rate, and if not, re-negotiate a higher bit rate.
    Type: Grant
    Filed: February 7, 2006
    Date of Patent: December 21, 2010
    Assignee: International Business Machines Corporation
    Inventors: Youssef Abdelilah, Gordon T. Davis, Jeffrey H. Derby, Dongming Hwang, Clark D. Jeffries, Malcolm S. Ware, Hua Ye
  • Patent number: 7792873
    Abstract: A procedure is used to provide data structures that handle large numbers of active data entries and a high rate of additions and deletions of active entries. The procedure utilizes one or more of the following modifications. Timers are removed from individual session table entries and are linked via pointers. Bilateral links are established between the session table and the timer structure. Aging/timer checks are applied to the timer control block (TCB). A chain of TCBs, optionally including an excess of blocks, may be used along with packing of multiple TCBs into a single memory location. This excess of blocks permits a terminated session to continue to occupy a TCB until the timer process progresses to that block location in the chain of blocks.
    Type: Grant
    Filed: January 16, 2008
    Date of Patent: September 7, 2010
    Assignee: International Business Machines Corporation
    Inventors: Gordon T. Davis, Marco Heddes, Dongming Hwang
  • Patent number: 7752155
    Abstract: The present invention relates to a system and computer-readable medium for storing a plurality of multi-field classification rules in a computer system. Each multi-field classification rule includes a rule specification that itself includes a plurality of fields and a plurality of field definitions corresponding to the fields. The method of the present invention includes providing a virtual rule table, where the table stores a plurality of field definitions, and for each of the plurality of multi-field classification rules, compressing the rule specification by replacing at least one field definition with an associated index into the virtual rule table. The method also includes storing each of the compressed rule specifications and the virtual rule table in a shared segment of memory.
    Type: Grant
    Filed: July 29, 2008
    Date of Patent: July 6, 2010
    Assignee: International Business Machines Corporation
    Inventors: Everett A. Corl, Jr., Gordon T. Davis, Marco C. Heddes, Piyush C. Patel, Ravinder K. Sabhikhi
  • Patent number: 7702630
    Abstract: A method and apparatus are used for finding the longest prefix match in a variable length prefix search when searching a direct table within a routing table structure of a network processor. The search through the routing table structure is expedited by hashing a first segment of an internet protocol address with a virtual private network number followed by concatenating the unhashed bits of the IP address to the result of the hash operation to form an input key. Patterns are compared a bit at a time until an exact match or the best match is found. The search is conducted in a search tree that provides that the matching results will be the best possible match.
    Type: Grant
    Filed: February 14, 2006
    Date of Patent: April 20, 2010
    Assignee: International Business Machines Corporation
    Inventors: Claude Basso, Jean L. Calvignac, Gordon T. Davis, Piyush C. Patel
  • Patent number: 7644233
    Abstract: A single unified level one instruction cache in which some lines may contain traces and other lines in the same congruence class may contain blocks of instructions consistent with conventional cache lines. A mechanism is described for indexing into the cache, and selecting the desired line. Control is exercised over which lines are contained within the cache. Provision is made for selection between a trace line and a conventional line when both match during a tag compare step.
    Type: Grant
    Filed: October 4, 2006
    Date of Patent: January 5, 2010
    Assignee: International Business Machines Corporation
    Inventors: Gordon T. Davis, Richard W. Doing, John D. Jabusch, M V V Anil Krishna, Brett Olsson, Eric F. Robinson, Sumedh W. Sathaye, Jeffrey R. Summers