Browse Prior Art Database

Performance Enhancement for Reducing Trace Overhead

IP.com Disclosure Number: IPCOM000037281D
Original Publication Date: 1989-Dec-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Dranchak, DE: AUTHOR [+4]

Abstract

Disclosed is a performance enhancement for reducing trace overhead on Virtual Machine/Extended Architecture* (VM/XA) for applications that use the Monitor Call class 10 interface or the Monitor Call class 14 interface. The performance enhancement is realized by adding a general virtual machine interface that allows the Conversational Monitor System (CMS) and the Group Control System (GCS) to collect trace data in a buffer which, when full, is passed to the Control Program (CP) for recording. Also disclosed is a High Level Language interface that allows applications on CMS to do external tracing.

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Performance Enhancement for Reducing Trace Overhead

Disclosed is a performance enhancement for reducing trace overhead on Virtual Machine/Extended Architecture* (VM/XA) for applications that use the Monitor Call class 10 interface or the Monitor Call class 14 interface. The performance enhancement is realized by adding a general virtual machine interface that allows the Conversational Monitor System (CMS) and the Group Control System (GCS) to collect trace data in a buffer which, when full, is passed to the Control Program (CP) for recording. Also disclosed is a High Level Language interface that allows applications on CMS to do external tracing.

The High Level Language interface that allows applications to do external tracing is added through a Callable Services Library (CSL) routine in CMS. The CSL routine provides error checking at a virtual machine level and allows an application to specify a format routine for each trace record. The format routine is later used to provide more readable output when the trace data is evaluated.

When an application invokes the Monitor Call class 10 interface, the Monitor Call class 14 interface or the CSL interface to record trace data, an interrupt is reflected back to the virtual machine as opposed to sending the trace records individually to CP for recording. The interruption handler in the virtual machine is extended to recognize the interrupt and passes control to the buffer manager routine. This routine collects the trace...