NOTE: This page is part of the Ubuntu Specification process. Please check the status and details in Launchpad before editing. If the spec is Approved then you should contact the Assignee, or another knowledgeable person, before making changes.


This spec aims to deploy compressed memory in Ubuntu Linux using the new patches.


It has been shown that compressed memory increases performance greatly when memory is overdrawn and decreases performance negligibly when ample memory is available. We should take advantage of this for both desktop and LiveCD performance.

Use cases

There are several.


This spec focuses on LiveCD, desktop, and server environments. Embedded environments such as OLPC should be handled case by case.


The compressed memory patches will be used to enable memory compression. These patches should be stable by Edgy+1.

The compressed memory infrastructure is patched into the kernel; but the actual compression engine is a module. This module shall be separately loaded.

It should be possible to disable auto-loading of the compression module using a kernel command line switch such as nocompress.


Data preservation and migration


Unresolved issues

Tuning of the compressed memory parameters is important. The current experimental patches allow direct tuning of the number of pages used for each of swap cache and page cache; it would be interesting to make this a percentage and let the kernel decide how to distribute it between the two.

BoF agenda and discussion



CompressedMemory (last edited 2008-08-06 16:33:05 by localhost)