Browse Prior Art Database

Instruction tracing processing and utilization with real-time reduction

IP.com Disclosure Number: IPCOM000010472D
Original Publication Date: 2002-Dec-05
Included in the Prior Art Database: 2002-Dec-05
Document File: 1 page(s) / 36K

Publishing Venue

IBM

Abstract

Real-time Instruction Tracing and Reduction of the tracing information

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 67% of the total text.

Page 1 of 1

Instruction tracing processing and utilization with real-time reduction

The current approach to instruction tracing entails the writing of trace records to a buffer and after the tracing is completed, the information is processed to produce reports. When attempting to provide trace information for applications such as Websphere*, we find that the amount of pinned buffer space required to collect all the desired information is too large. Also, under many scenarios, it is difficult to find repeatable scenarios in the sense that one can take multiple traces and piece them together. We disclose an approach to allow for this real-time

The basic problem that must be avoided is tracing the code related to the real-time processing. This can be done by doing real-time processing on a separate process that the tracing code avoids tracing. Although interrupt avoidance is best, the tracing code could also be aware of the address range of the real-time processing code and avoid tracing code that is in the specified range. The hardware process/thread related flags for tracing can be reset for the process that is performing the reduction. The interrupt handling routine needs to avoid turning on the flags for the process that is performing the reduction. The basic approach is to write the records to a trace buffer, but also have a high priority process that is not being traced, read the data from the trace buffer and process it. Once the data is read by the post processing routi...