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Hierarchical memory page placement and handling of main memory subsystem

IP.com Disclosure Number: IPCOM000249568D
Publication Date: 2017-Mar-03
Document File: 4 page(s) / 85K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for memory pages handling in computer systems to leverage different memory characteristics for optimial performance. This is primarily in the context of active memory expansion (AME) feature, while compressing and decompressing memory pages.

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Hierarchical memory page placement and handling of main memory subsystem

Background:

Latest advancements in the computer server technology allows capability to support plurality characteristics of memory modules can be placed in the system. Operating System/Hypervisor abstracts these details under the covers and present the entire system memory as same irrespective of these plurality characteristics. Active memory expansion (AME) feature in the OS constantly compresses the least recently used pages from uncompressed memory pool and places them in the compressed memory pool. It is possible the pages in the compressed pool can get allocated from a higher performing module, while pages in the uncompressed memory pool from low performing module, when system supports heterogeneous attributes of memory.

This necessitates to exploit these plurality characteristics of memory subsytem, when AME compress and decompress memory pages.

Active Memory Expansion (AME) feature:

AME compresses the least recently used memory pages and keeps them in the compressed memory pool. Compressed pool can be conceptually a fast paging device. Operating System can dynamically adjusts the compression ratio based on the workload .

OS level Active Memory Expansion feature, which aims at expanding the available system memory by compressing and storing pages. This feature was primarily implemented as "paging device" concept, OS considers the expanded system memory in to two pools compressed/uncompressed. Least Recently use...