International Business Machines Corporation

Kenneth Bernard Rozendal

Luke Matthew Browning

Suresh Eswara Warrier

Larry Bert Brenner

A data processing system allows processes to be checkpointed and restarted. The system saves the old process and thread identifications in a process table. When an application makes a system call passing the old process and/or thread identifications as parameters, the system performs a mapping algorithm to supply the system call with the new process and/or thread identifications. When a system call returns a new identification, the system performs a remapping algorithm to return the old identifications to the calling application program. When a group of process is restarted for which the process group leader was not checkpointed, the system creates a ghost process group leader.

Method and apparatus for allowing restarted programs to use old process identification

A data processing system allows processes to be checkpointed and restarted. The system saves the old process and thread identifications in a process table. When an application makes a system cell passing the old process and/or thread identifications as parameters, the system performs a mapping algorithm to supply the system call with the new process and/or thread identifications. When a system call returns a new identification, the system performs a remapping algorithm to return the old identifications to the calling application program. When a group of process is restarted for which the process group leader was not checkpointed, the system creates a ghost process group leader.

Method and apparatus for allowing restarted programs to use old process identifications and thread identifications

A method and apparatus allow a programmer to repeatedly debug a program from the same starting point. The entire process state of the process can be saved at any time in the course of a debugging session to a disk file, called the checkpoint file. Now registers or memory may be modified, if necessary, and the program may be brought back to the same starting point where the state had been previously saved by resuming from the checkpoint file. The method and apparatus allow the state of all the programs to be saved multiple times and resumed from any one of those states. The debugging of a problem is considerably facilitated by not having to start from scratch to debug the problem as the last saved state of the program can be used to start the debugging.

Method and apparatus to debug a program from a predetermined starting point

An apparatus and method for performing workload management is provided. In particular, an apparatus and method for performing workload management using class shares and tiers is provided. In the apparatus and method, each process is associated with a particular class of workload. Each class has an associated number of shares representing the importance of the class relative to other classes. Each class, in turn, is associated with a particular tier of workload importance. Classes of processes compete with other classes of processes in their same tier for system resources based on the number of shares that they have. These shares are representative of the percentage of the system resource the process is provided relative to the other classes in the same tier. Classes in one tier compete with classes in other tiers for system resources based on the priority assigned to the tiers.

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Austin, TX, United States of America

Kenneth Bernard Rozendal