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

Shared Memory RAM Disk for a Cluster with Shared Memory

IP.com Disclosure Number: IPCOM000105104D
Original Publication Date: 1993-Jun-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 68K

Publishing Venue

IBM

Related People

Gheith, AM: AUTHOR [+2]

Abstract

Disclosed is a program to create a RAM disk for a cluster of processors which have separate I/O subsystems but a global shared memory. The program creates a shared consistent disk device for the processors to use.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Shared Memory RAM Disk for a Cluster with Shared Memory

      Disclosed is a program to create a RAM disk for a cluster of
processors which have separate I/O subsystems but a global shared
memory.  The program creates a shared consistent disk device for the
processors to use.

      Computer systems composed of multiple processors offer
potential performance improvements over single processor systems.
Multiple processor computer systems can communicate using network
systems or with shared memory.  Investigated is a processor
architecture consisting of a number of processors.  Each processor
has its own local memory as well as access through a non-blocking
switch to a large amount of global shared memory.  The shared memory
is not cache consistent at the hardware level; all cache consistency
issues must be dealt with in software.  In addition, each processor
has its own private I/O bus.  Each I/O device can only be addressed
by the processor that to which it is attached.

      To improve the ability of the processors to work together to
solve common problems, it is useful to provide I/O devices that can
be accessed from all processors equally.  Such a shared I/O device
would allow processes which are working on a common problem to use
the shared I/O device for storage of common data, while still
allowing these processes to be run on any of the available
processors.

      Designed is a shared memory RAM disk to provide uniform access
to a shared disk system across the processors.

      The shared memory RAM disk is implemented by a pseudo-device
driver for the AIX* 3.2 operating system running on each processor.
When the device driver is configured, it allocates a large amount of
shared memory for the RAM disk storage.  The standard device switch
(dev switch) interface is supported by the shared memory RAM disk
device driver running on each pr...