Browse Prior Art Database

Device for Collection of Highly Detailed Statistics Concerning Usage of I/O Devices

IP.com Disclosure Number: IPCOM000045752D
Original Publication Date: 1983-Apr-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 5 page(s) / 53K

Publishing Venue

IBM

Related People

Dixon, JD: AUTHOR [+4]

Abstract

A device is described for collecting usage statistics useful in the design of a new generation of high function I/O controllers. These statistics are collected in a fine level of detail in actual customer installation operating environments without appreciable disruption or distortion of those environments. Such statistics are also useful in the fine tuning of existing data processing installations.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 29% of the total text.

Page 1 of 5

Device for Collection of Highly Detailed Statistics Concerning Usage of I/O Devices

A device is described for collecting usage statistics useful in the design of a new generation of high function I/O controllers. These statistics are collected in a fine level of detail in actual customer installation operating environments without appreciable disruption or distortion of those environments. Such statistics are also useful in the fine tuning of existing data processing installations.

In smaller data processing systems, the trend is to implement in the I/O control units certain aspects of I/O functions previously implemented in the central processor unit of the system. This distribution of functions represents a specialized and highly effective form of distributed processing. Various desirable advantages result from such functional repositioning.

One significant problem in accomplishing these objectives relates to gathering the information necessary to choose rationally among several design alternatives. Broadly speaking, the functions distributed to the I/O controller require the design of new algorithms governing the operation of the associated I/O devices. It is necessary to determine what new items of information need to be sent to the I/O device, how these items are to be manipulated and processed so that operational decisions are made effectively, and how information parameters and decision variables are to be passed to other I/O devices affected by the new I/O device functions.

In designing new I/O controllers, several candidate designs might be formulated, built in hardware and tested in actual operating environments. Alternatively, educated guesswork might be applied, seeking to decide by abstract reasoning which alternative is best and should be constructed. A more rational approach is to design test instrumentation for the purpose of collecting the necessary statistics from the operating environment. Evaluation is then undertaken using the collected statistics to provide work load input driving simulation models of each candidate for the new I/O controller design.

The favored design approach utilizes simulation of the I/O controller design alternatives. Still, the problem remains as to how best to collect the statistics necessary for the simulation approach.

In computer systems, software-based means have been considered for the gathering of statistics. Generally, a software-based approach means additional programming operating in the central processor unit (CPU). Unfortunately, there are two significant problems with this approach. First, the extra programming tends to distort timing relationships in the system by having the CPU undertake new work it would not otherwise be doing were it not for the statistics collection process. Secondly, the statistics collection software may be operationally inconvenient to use due to the burden of installing it in complex and varying operating system and application programming environm...