Method for increasing the efficiency of a virtual memory system by selective compression of RAM memory contents

Claim 1

A method for managing RAM memory in a virtual memory computer system having a CPU and RAM, comprising the steps of: a) monitoring the computer system to track the extent of usage and the criticality of RAM memory regions utilized, said usage being the frequency and extent of use of the RAM regions by the CPU and said criticality being the ability of the CPU to function without immediate access to the contents of such memory regions; b) determining when system RAM is sufficiently depleted with reference to operating system and user program requirements to require augmentation; c) upon determination of sufficient depletion compressing the contents of a portion of memory according to a determined priority based upon relative usage and criticality of RAM regions available for compression to create a compressed portion in RAM memory and freeing the RAM memory previously occupied by the uncompressed contents and unoccupied by the compressed contents for other use; d) awaiting an attempt by the CPU to access data contained in said compressed portion and suspending such access; and e) decompressing a portion of the compressed RAM portion bearing the data sought to be accessed and passing the access to the decompressed RAM portion.

Claim 2

A method for managing RAM memory in a virtual memory computer system having a CPU and RAM, comprising the steps of: a) monitoring the computer system to track the extent of usage and the criticality of RAM memory regions utilized, said usage being the frequency and extent of use of the RAM regions by the CPU and said criticality being the ability of the CPU to function without immediate access to the contents of such memory regions; b) determining when system RAM is sufficiently depleted with reference to operating system and user program requirements to require augmentation; c) upon determination of sufficient depletion compressing the contents of a portion of memory according to a determined priority based upon relative usage and criticality of RAM regions available for compression to create a compressed portion in RAM memory and freeing the RAM memory previously occupied by the uncompressed contents and unoccupied by the compressed contents for other use; d) awaiting an attempt by the CPU to access data contained in said compressed portion and suspending such access; and e) decompressing a portion of the compressed RAM portion bearing the data sought to be accessed and passing the access to the decompressed RAM portion.

Claim 6

A method for the control of virtual memory resources in a computer system having a CPU, a secondary storage medium and a virtual memory control program, comprising the steps of: a) intercepting physical memory resource allocation activity by said virtual memory control program to ascertain the status of memory resources and to assign a criticality value to memory resources based upon the ability of the CPU to function without immediate access to the contents of such memory resources; b) simulating a continuing condition wherein all memory resources appear as sufficiently critical and occupied to the virtual memory control program such that active memory control by said virtual memory control program is suspended; c) determining when system memory resources are sufficiently depleted with reference to operating system and user program requirements to require augmentation; d) compressing the contents of a portion of RAM memory according to a determined priority based upon relative criticality of RAM regions available for compression and freeing the memory previously occupied by the uncompressed contents for other use; e) awaiting an attempt to access a compressed portion of RAM and suspending such access; and f) decompressing a portion of the compressed RAM portion sought to be accessed and passing the access to said decompressed RAM portion.

Claim 7

A method for the control of virtual memory resources in a computer system having a CPU, a secondary storage medium and a virtual memory control program, comprising the steps of: a) intercepting physical memory resource allocation activity by said virtual memory control program to ascertain the status of memory resources and to assign a criticality value to memory resources based upon the ability of the CPU to function without immediate access to the contents of such memory resources; b) simulating a continuing condition wherein all memory resources appear as sufficiently critical and occupied to the virtual memory control program such that active memory control by said virtual memory control program is suspended; c) determining when system memory resources are sufficiently depleted with reference to operating system and user program requirements to require augmentation; d) compressing the contents of a portion of RAM memory according to a determined priority based upon relative criticality of RAM regions available for compression and freeing the memory previously occupied by the uncompressed contents for other use; e) awaiting an attempt to access a compressed portion of RAM and suspending such access; and f) decompressing a portion of the compressed RAM portion sought to be accessed and passing the access to said decompressed RAM portion.