International Business Machines Corporation

David Arlen Elko

Jeffrey Mark Nick

David Harold Surman

Steven N Goss

Dennis J Dahlen

Michael D Swanson

Michael J Jordan

Georgette L Kurdt

Jeffrey Alan Frey

Kelly B Pushong

Audrey A Helffrich

Ronald Morton Smith, Sr

Scott M Carlson

Wendell W Wilkinson

Thomas C Shaw

Brian B Moore

Mark A Brooks

John F Isenberg, Jr

Douglas W Westcott

Jeffrey William Josten

Ruth A Allen

Richard K Errickson

Donald Crabtree

Jimmy Paul Strickland

Denise M Sevigny

Thomas M Shaw

Inderpal Singh Narang

Judith A Wierbowski

Steven Bruce Jones

Noshir R Dhondy

David E Whitney

Steven Neil Goss

Thomas Anthony Gregg

Gregory Francis Pfister

Michel H T Hack

Joseph A Williams

Li Feng Zhang

Renato John Recio

Peter Grimm Sutton

Charles Franklin Webb

Chandrasekaran Mohan

Chetan Mehta

James Zu-Chia Teng

Gottfried Andreas Goldrian

Richard Pervin King

Patrick John Sugrue

Richard Dievendorff

James H Warnes

Dermot Flaherty

Kenneth Glenn Rothwell

Stewart Laundon Palmer

Scott F Schiffer

Riaz Ahmad

Daniel H Lepore

Judith Wierbowski

Ronald Smith

Scott Carlson

Dennis Dahlen

Denise Sevigny

Noshir Dhondy

David Whitney

Michael J Branson

Dan F Greiner

Jonathan D Bradbury

Donald W Schmidt

David F Craddock

Adam J Storm

Ian David Judd

Wen-Tzer Thomas Chen, Jr

Bruce Leroy Beukema

Patrick Allen Buckland

Steven Gene Halverson

Allan Samuel Meritt

Ronen Grosman

Carol B Hernandez

John Elliott Arwe

John Joseph Campbell

Ambrose A Verdibello, Jr

Georg Ochs

Catherine Mary Moxey

William C Shepard

Kevin F Smith

Haakon Roberts

Anthony Wayne Erwin

Stewart L Palmer

Michel Henri Théodore Hack

Trevor E Carlson

William Charles Neiman

George W Wang

Chitta L Rao

Michael Burrill Phillips

Steward L Palmer

Jeffery M Mick

Lin Zhang

Jeffery M Nick

William M Sakal

Daniel Lepore

John F Isenberg

Michel Hack

Disclosed are a method of and system for providing time synchronization among first and second computer systems, where each of the computer systems includes hardware, operating system software and a layer of microcode operating between said hardware and said software. The method comprises the steps of using the microcode of the first computer system to provide a first timestamp, using the microcode of the second computer system to provide a second timestamp and a third timestamp, and using the microcode of the first computer system to provide a fourth timestamp. The method comprises the further steps of using the first, second, third and fourth timestamps to determine a timing difference between the first and second computer systems, and adjusting the timing among said first and second computer systems on the basis of said determined timing difference. Preferably, the first and second computer systems are connected together by a point-to-point link; and the first timestamp is sent from the first computer system to the second computer system, and the second and third timestamps are sent from the second computer system to the first computer system over that point-to-point link.

Method and system for time synchronization among systems using parallel sysplex links

A coupling facility is coupled to one or more other coupling facilities via one or more peer links. The coupling of the facilities enables various functions to be supported, including the duplexing of structures of the coupling facilities. Duplexing is performed on a structure basis, and thus, a coupling facility may include duplexed structures, as well as non-duplexed or simplexed structures.

Controlling the state of duplexing of coupling facility structures

In an exemplary embodiment of this disclosure, a computer-implemented method may include storing in a primary storage a plurality of list entries belonging to an ordered list. Free space in the primary storage may be monitored to determine whether a first predetermined condition related to the free space is met. In a secondary storage, a storage block of a predetermined size may be allocated for migration, when the first predetermined condition is met. A cursor may be provided pointing to a first list entry in the primary storage. One or more list entries may be selected at the cursor. The selected list entries may be migrated to the storage block while maintaining their order in the list.

Migrating and retrieving queued data in byte-addressable storage

A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Operator message commands for testing a coupling facility

A method for managing a cache structure of a coupling facility includes receiving a conditional write command from a computing system and determining whether data associated with the conditional write command is part of a working set of data of the cache structure. If the data associated with the conditional write command is part of the working set of data of the cache structure the conditional write command is processed as an unconditional write command. If the data associated with the conditional write command is not part of the working set of data of the cache structure a conditional write failure notification is transmitted to the computing system.

Conditional write processing for a cache structure of a coupling facility

Processing operator message commands

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Austin, TX, United States of America

David Arlen Elko