David Alan Hepkin from 21416 NE 81St St, Redmond, WA 98053, age 46, Phone: 4258361730

Us Patents

System And Method For Improving Performance Of Dynamic Memory Removals By Reducing File Cache Size
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US Patent:

7240177, Jul 3, 2007
Filed:

May 27, 2004
Appl. No.:

10/855847
Inventors:

David Alan Hepkin - Austin TX, US
Bret Ronald Olszewski - Austin TX, US
Assignee:

International Business Machines Corporation - Armonk NY
International Classification:

G06F 12/00
US Classification:

711173, 711159, 711129, 711133
Abstract:

A system and method for improving dynamic memory removals by reducing the file cache size prior to the dynamic memory removal operation initiating are provided. In one exemplary embodiment, the maximum amount of physical memory that can be used to cache files is reduced prior to performing a dynamic memory removal operation. Reducing the maximum amount of physical memory that can be used to cache files causes the page replacement algorithm to aggressively target file pages to bring the size of the file cache below the new maximum limit on the file cache size. This results in more file pages, rather than working storage pages, being paged-out.

Method And System For Page Initialization Using Off-Level Worker Thread
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US Patent:

7260698, Aug 21, 2007
Filed:

Oct 30, 2003
Appl. No.:

10/697867
Inventors:

David Alan Hepkin - Austin TX, US
Assignee:

International Business Machines Corporation - Armonk NY
International Classification:

G06F 12/00
US Classification:

711170, 713 1, 713100, 711202
Abstract:

A method, an apparatus, and a computer program product are presented for memory page initialization operations. After an application thread attempts to reference a memory page, an exception or fault may be generated, and a physical memory page is allocated. The application thread is put to sleep, and a page initialization request is given to a kernel off-level worker thread, after which the interrupt-level processing is concluded. During the normal course of execution for the worker thread, the worker thread recognizes the page initialization request, and the worker thread initializes the newly allocated page by zeroing the page or by copying the contents of a source page to the newly allocated page, as appropriate. The worker thread then puts the application thread into a runnable state.

System And Method For Dynamically Adjusting Read Ahead Values Based Upon Memory Usage
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US Patent:

7318142, Jan 8, 2008
Filed:

Aug 8, 2006
Appl. No.:

11/463100
Inventors:

Jos Manuel Accapadi - Austin TX, US
Andrew Dunshea - Austin TX, US
Li Li - Austin TX, US
Grover Herbert Neuman - Austin TX, US
Mysore Sathyanarayana Srinivas - Austin TX, US
David Alan Hepkin - Austin TX, US
Assignee:

International Business Machines Corporation - Armonk NY
International Classification:

G06F 12/06
US Classification:

711204, 711170, 711169, 711167, 711213
Abstract:

A system and method for dynamically altering a Virtual Memory Manager (VMM) Sequential-Access Read Ahead settings based upon current system memory conditions is provided. Normal VMM operations are performed using the Sequential-Access Read Ahead values set by the user. When low memory is detected, the system either turns off Sequential-Access Read Ahead operations or decreases the maximum page ahead (maxpgahead) value based upon whether the amount of free space is simply low or has reached a critically low level. The altered VMM Sequential-Access Read Ahead state remains in effect until enough free space is available so that normal VMM Sequential-Access Read Ahead operations can be performed (at which point the altered Sequential-Access Read Ahead values are reset to their original levels).

Page Replacement Policy For Systems Having Multiple Page Sizes
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US Patent:

7353361, Apr 1, 2008
Filed:

Jun 6, 2005
Appl. No.:

11/146476
Inventors:

David Alan Hepkin - Austin TX, US
Thomas Stanley Mathews - Austin TX, US
Assignee:

International Business Machines Corporation - Armonk NY
International Classification:

G06F 12/00
US Classification:

711203, 711206
Abstract:

In a data processing system utilizing multiple page sizes for virtual memory paging, a system, method, and article of manufacture for managing page replacement. In one embodiment, the page replacement method begins with a page frame allocation request, such as may be generated following a page fault. A page replacement procedure is invoked to select one or more pages to be replaced by the requested page(s). In a preferred embodiment, the page replacement includes a step of selecting, in accordance with a page type allocation of at least one of the multiple page sizes, a page size to be utilized for page replacement for the page frame allocation request.

Pretranslating Input/Output Buffers In Environments With Multiple Page Sizes
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US Patent:

7418572, Aug 26, 2008
Filed:

Aug 18, 2004
Appl. No.:

10/920907
Inventors:

David Alan Hepkin - Austin TX, US
Assignee:

International Business Machines Corporation - Armonk NY
International Classification:

G06F 12/10
US Classification:

711204, 710 52, 711209
Abstract:

Pretranslating input/output buffers in environments with multiple page sizes that include determining a pretranslation page size for an input/output buffer under an operating system that supports more than one memory page size, identifying pretranslation page frame numbers for the buffer in dependence upon the pretranslation page size, pretranslating the pretranslation page frame numbers to physical page numbers, and storing the physical page numbers in association with the pretranslation page size. Typical embodiments also include accessing the buffer, including translating a virtual memory address in the buffer to a physical memory address in dependence upon the physical page numbers and the pretranslation page size and accessing the physical memory of the buffer at the physical memory address.

Method And Mechanism For Efficiently Creating Large Virtual Memory Pages In A Multiple Page Size Environment
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US Patent:

7437529, Oct 14, 2008
Filed:

Jun 16, 2005
Appl. No.:

11/154159
Inventors:

Ramanjaneya Sarma Burugula - Peekskill NY, US
David Alan Hepkin - Austin TX, US
Joefon Jann - Ossining NY, US
Thomas Stanley Mathews - Austin TX, US
Assignee:

International Business Machines Corporation - Armonk NY
International Classification:

G06F 12/00
G06F 13/00
G06F 13/28
G06F 9/26
G06F 9/34
US Classification:

711171, 711170, 711173, 711203, 711206
Abstract:

A method and system for efficiently migrating in-use small pages to enable promotion of contiguous small pages into large pages in a memory environment that includes small pages pinned to real memory and/or and small pages mapped to direct memory access (DMA) within real memory. The operating system is designed with a two-phase page promotion engine/utility that enables coalescing contiguous small virtual memory pages to create large virtual memory pages by migrating in-use small memory pages including those that are pinned and/or mapped to DMA.

Method And Apparatus For Supporting Shared Library Text Replication Across A Fork System Call
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US Patent:

7469331, Dec 23, 2008
Filed:

Jul 22, 2004
Appl. No.:

10/897329
Inventors:

David Alan Hepkin - Austin TX, US
Bret Ronald Olszewski - Austin TX, US
Assignee:

International Business Machines Corporation - Armonk NY
International Classification:

G06F 9/26
US Classification:

711202, 719312
Abstract:

A fork system call by a first process is detected. A second process is created as a replication of the first process with a second affinity. If a replication of the replicated shared library is present in the second affinity domain, effective addresses of the replication of the replicated shared library are mapped using a mapping mechanism of the present invention to physical addresses in the second affinity domain.

Page Replacement Policy For Systems Having Multiple Page Sizes
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US Patent:

7484072, Jan 27, 2009
Filed:

Feb 5, 2008
Appl. No.:

12/026334
Inventors:

David Alan Hepkin - Austin TX, US
Thomas Stanley Mathews - Austin TX, US
Assignee:

International Business Machines Corporation - Armonk NY
International Classification:

G06F 12/00
US Classification:

711203, 711206
Abstract:

In a data processing system utilizing multiple page sizes for virtual memory paging, a system, method, and article of manufacture for managing page replacement. In one embodiment, the page replacement method begins with a page frame allocation request, such as may be generated following a page fault. A page replacement procedure is invoked to select one or more pages to be replaced by the requested page(s). In a preferred embodiment, the page replacement includes a step of selecting, in accordance with a page type allocation of at least one of the multiple page sizes, a page size to be utilized for page replacement for the page frame allocation request.