International Business Machines Corporation

Gururaj Seshagiri Rao

Balakrishna Raghavendra Iyer

Inderpal Singh Narang

Bhaskar Sinha

Hatem Mohamed Ghafir

Satya Prakash Sharma

Casper A Scalzi

Richard I Baum

Glen A Brent

Lee Hardy Wilson

Chi-Hung Chi

A method for obtaining parallel instruction execution (PIE) for frequently used programming operations, such as database record compression or expansion, cryptographic encoding/decoding, page moving, etc., for which a hardware-assist may be provided. These functions can be performed in parallel with CPU processing by a PIE processing facility (PIE-PF). The method is hardware/microcode based and uses software control in supervisory mode. The preferred embodiment is controlled by privileged subsystem software under an operating system, and does not use I/O channel oriented off-load processing. When the CPU is interrupted during an incomplete parallel operation by the PIE-PF, it is checkpointed in main storage in a manner accessible to the subsystem. The subsystem (after completing a current CPU operation, such as a database record predicate evaluation, can check for the completion of the PIE-PF operation by examining an indicator in a control block in shared storage. Furthermore, if the parallel operation has not completed, the CPU can: a) continue the PIE-PF processing in parallel with other processing in the CPU, b) halt the parallel PIE-PF asynchronous operation and have the CPU do the rest of the operation synchronously, or c) resume the parallel operation in the processor or a hardware assist if an interruption caused the PIE-PF parallel operation to be checkpointed.

Method for a CPU to utilize a parallel instruction execution processing

A coexecutor for executing functions offloaded from central processors (CPs) in a data processing system, as requested by one or more executing control programs, which include a host operating system (host OS), and subsystem programs and applications executing under the host OS. The offloaded functions are embodied in code modules. Code modules execute in the coexecutor in parallel with non-offloaded functions being executed by the CPs. Thus, the CPs do not need to execute functions which can be executed by the coexecutor. CP requests to the coexecutor specify the code modules which are accessed by the coexecutor from host shared storage under the same constraints and access limitations as the control programs. The coexecutor may emulate host dynamic address translation, and may use a provided host storage key in accessing host storage. The restricted access operating state for the coexecutor maintains data integrity. Coexecutors can be of the same architecture or of a totally different architecture from the CPs to provide an efficient processing environment for the offloaded functions. The coexecutor interfaces host software which provides the requests to the coexecutor. Offloaded modules, once accessed by the coexecutor, may be cached in coexecutor local storage for use by future requests to allow subsequent invocations to proceed without waiting to again load the same module.

Coexecution processor isolation using an isolation process or having

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Cortlandt Maner, NY, United States of America

Gururaj Seshagiri Rao