Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Suspension Locking in a Multilevel Multiprocessor

IP.com Disclosure Number: IPCOM000047392D
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Curran, RJ: AUTHOR [+3]

Abstract

In a multiprocessor, interprocessor competition for serial reusable system resources is controlled by locks which are set when a processor becomes the owner of a task. The ability to set the appropriate lock is a necessary condition for becoming the owner of the associated task, failure suspending the potential owner. When the lock is released by the current owner, a suspended potential owner can obtain the lock and resume processing. Where the processors are single-level processors, the return to the potential owner on lock release is simple, particularly when only two processors are incorporated into the multiprocessor.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 62% of the total text.

Page 1 of 1

Suspension Locking in a Multilevel Multiprocessor

In a multiprocessor, interprocessor competition for serial reusable system resources is controlled by locks which are set when a processor becomes the owner of a task. The ability to set the appropriate lock is a necessary condition for becoming the owner of the associated task, failure suspending the potential owner. When the lock is released by the current owner, a suspended potential owner can obtain the lock and resume processing. Where the processors are single-level processors, the return to the potential owner on lock release is simple, particularly when only two processors are incorporated into the multiprocessor. However, if the processors are multilevel processors in which independent processing of tasks is possible at a plurality of processing levels, current processing taking place at the most significant level at which a priority task exists, a processor in which a potential owner is suspended, becomes, in general, free to continue processing at some other level. Lock release becomes an interrupt signaled to that processor and at that level at which the interrupt is to be effective and enabled by recording the priority level of the potential user in the lock itself. Thus, a potential user is able to mark an owned lock although it cannot become the owner. In one arrangement of a two-processor system, the status of each lock is maintained in a RAM (random-access memory) array. When a processor requests...