Resource management in the Mungi single-address-space operating system

We present the accounting system used for backing store management in the Mungi singleaddress-space operating system. The model is designed such that all accounting can be done asynchronously to operations on storage objects, and hence without slowing down such operations. It is based on bank accounts from which rent is collected for the storage occupied by objects. Rent automatically increases as available storage runs low, forcing users to release unneeded storage. Bank accounts receive income, with a taxation system being used to prevent excessive buildup of funds on underutilised accounts. The accounting system is mostly implemented at user level, with minimal support from the kernel. As a consequence, the accounting model can be changed without modifying the Mungi kernel. Permission to make digital/hard copy of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage, the copyright notice, the title of the publication and its date appear, and notice is given that copying is by permission of the authors. To copy otherwise, to republish, to post on servers, or to redistribute to lists requires prior specific permission and/or a fee. Copyright c 1997 by Gernot Heiser, The University of New South Wales.